A Quantum Network Architecture
draft-van-meter-qirg-quantum-network-architecture-02
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| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Rodney Van Meter , Naphan Benchasattabuse , Amin Taherkhani | ||
| Last updated | 2026-11-01 | ||
| RFC stream | (None) | ||
| Intended RFC status | (None) | ||
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draft-van-meter-qirg-quantum-network-architecture-02
QIRG R. Van Meter
Internet-Draft N. Benchasattabuse
Intended status: Informational A. Taherkhani
Expires: 5 May 2027 Keio University
1 November 2026
A Quantum Network Architecture
draft-van-meter-qirg-quantum-network-architecture-02
Abstract
This quantum network architecture defines a set of planes providing
different views of the network, supporting different responsibilities
and modes of operation; a set of device, node and link types; some
network topologies, deployment scenarios and their relationship to
applications; and key design decisions as a result of corresponding
requirements.
About This Document
This note is to be removed before publishing as an RFC.
The latest revision of this draft can be found at https://moonshot-
nagayama-pj.github.io/draft-van-meter-qirg-quantum-network-
architecture/draft-van-meter-qirg-quantum-network-architecture.html.
Status information for this document may be found at
https://datatracker.ietf.org/doc/draft-van-meter-qirg-quantum-
network-architecture/.
Source for this draft and an issue tracker can be found at
https://github.com/moonshot-nagayama-pj/draft-van-meter-qirg-quantum-
network-architecture.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 5
3. Goals and Non-Goals of this Document . . . . . . . . . . . . 5
3.1. Goals . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.2. Non-Goals . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Relationship to Documents by QIRG and Other Organizations . . 6
5. Prerequisite Knowledge . . . . . . . . . . . . . . . . . . . 7
6. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 8
7. Applications of Networks . . . . . . . . . . . . . . . . . . 11
7.1. Types of Applications . . . . . . . . . . . . . . . . . . 11
7.2. Entangled States Consumption Patterns . . . . . . . . . . 11
7.2.1. The Entanglement Information Timeline . . . . . . . . 12
7.2.2. Classification of Consumption Patterns . . . . . . . 12
7.2.3. Class Selection and Resource Implications . . . . . . 13
7.2.4. Unentangled State Tolerant (B Class) Applications . . 14
7.2.5. Reactive Correction (C Class) Applications . . . . . 14
7.2.6. Deterministic (T Class) Applications . . . . . . . . 15
8. Architectural Concepts . . . . . . . . . . . . . . . . . . . 15
8.1. Quantum Devices . . . . . . . . . . . . . . . . . . . . . 15
8.2. Quantum Nodes . . . . . . . . . . . . . . . . . . . . . . 16
8.3. Quantum Links . . . . . . . . . . . . . . . . . . . . . . 16
8.4. Photonic Synchronization Domains . . . . . . . . . . . . 16
8.5. Direct and Indirect Multicomputer Architectures . . . . . 16
8.6. Detector-centric Architecture . . . . . . . . . . . . . . 17
8.7. Source-centric Architecture . . . . . . . . . . . . . . . 17
8.8. Qubit-Level v. Device-Level Access . . . . . . . . . . . 17
9. Quantum Optical Building Blocks . . . . . . . . . . . . . . . 18
9.1. Qubits . . . . . . . . . . . . . . . . . . . . . . . . . 18
9.2. Photons, Wave Packets and Optical Modes . . . . . . . . . 18
9.3. Photonic Qubits . . . . . . . . . . . . . . . . . . . . . 19
9.4. Memories . . . . . . . . . . . . . . . . . . . . . . . . 19
9.5. Photon Sources . . . . . . . . . . . . . . . . . . . . . 20
9.5.1. Unentangled Single Photons . . . . . . . . . . . . . 20
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9.5.2. Entangled Photon Pairs . . . . . . . . . . . . . . . 20
9.5.3. Memory-Emitted Photons . . . . . . . . . . . . . . . 20
9.6. Detectors . . . . . . . . . . . . . . . . . . . . . . . . 20
10. A Sketch of the System Model . . . . . . . . . . . . . . . . 21
10.1. Multicomputer . . . . . . . . . . . . . . . . . . . . . 21
10.2. Data Center Network (QDCN) . . . . . . . . . . . . . . . 25
10.3. Local-Area Network (QLAN) . . . . . . . . . . . . . . . 25
10.4. Wide-Area Network (QWAN) . . . . . . . . . . . . . . . . 25
11. Requirements and Goals for the Architecture . . . . . . . . . 25
11.1. Normative Requirements . . . . . . . . . . . . . . . . . 26
11.2. General Requirements . . . . . . . . . . . . . . . . . . 26
11.2.1. Functional Goals . . . . . . . . . . . . . . . . . . 26
11.2.2. Interface Requirements . . . . . . . . . . . . . . . 27
11.2.3. Physical Requirements . . . . . . . . . . . . . . . 27
11.2.4. Environmental Requirements . . . . . . . . . . . . . 27
11.3. Network Management Requirements . . . . . . . . . . . . 27
11.3.1. Configuration Management . . . . . . . . . . . . . . 27
11.3.2. Fault Management . . . . . . . . . . . . . . . . . . 28
11.3.3. Online Operations . . . . . . . . . . . . . . . . . 28
12. Architecture Overview . . . . . . . . . . . . . . . . . . . . 28
12.1. Deterministic Classical Control of Quantum States . . . 28
12.2. Nodes, Links and Operational Views . . . . . . . . . . . 29
12.3. Communication Service . . . . . . . . . . . . . . . . . 29
12.3.1. Bell Pairs as the Core Network Service . . . . . . . 30
12.3.2. Timing as a Critical Auxiliary Service . . . . . . . 30
12.4. Stateful Connections Along a Pre-established Path . . . 30
12.5. Four-Layer Protocol Stack . . . . . . . . . . . . . . . 31
12.6. RuleSet-based Network Layer . . . . . . . . . . . . . . 31
12.7. Five Planes, or Views, of the Network . . . . . . . . . 31
13. Architectural Planes . . . . . . . . . . . . . . . . . . . . 31
13.1. Device . . . . . . . . . . . . . . . . . . . . . . . . . 32
13.2. Quantum . . . . . . . . . . . . . . . . . . . . . . . . 32
13.3. Data . . . . . . . . . . . . . . . . . . . . . . . . . . 32
13.4. Control . . . . . . . . . . . . . . . . . . . . . . . . 33
13.5. Management . . . . . . . . . . . . . . . . . . . . . . . 33
14. Protocol Layers . . . . . . . . . . . . . . . . . . . . . . . 33
14.1. Physical Layer . . . . . . . . . . . . . . . . . . . . . 34
14.2. Link Layer . . . . . . . . . . . . . . . . . . . . . . . 35
14.3. Network Layer: RuleSets . . . . . . . . . . . . . . . . 36
14.4. Application Layer . . . . . . . . . . . . . . . . . . . 37
15. Nodes and Node Types . . . . . . . . . . . . . . . . . . . . 37
15.1. End Nodes . . . . . . . . . . . . . . . . . . . . . . . 37
15.2. Support Nodes . . . . . . . . . . . . . . . . . . . . . 39
15.3. Repeater Nodes . . . . . . . . . . . . . . . . . . . . . 40
15.4. Composite Nodes . . . . . . . . . . . . . . . . . . . . 41
16. Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
16.1. The Link Service . . . . . . . . . . . . . . . . . . . . 41
16.2. Link/Network Layer Interface . . . . . . . . . . . . . . 41
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16.3. Link Structures . . . . . . . . . . . . . . . . . . . . 42
16.3.1. Photonic Path Description . . . . . . . . . . . . . 42
16.3.2. Point-to-point . . . . . . . . . . . . . . . . . . . 43
16.3.3. Switched . . . . . . . . . . . . . . . . . . . . . . 43
16.3.4. Multidrop or Bus . . . . . . . . . . . . . . . . . . 43
16.4. Link Design Choices and Operational Settings . . . . . . 43
16.5. Installing and Bootstrapping a Link . . . . . . . . . . 44
16.6. Spontaneous Changes to Link Conditions . . . . . . . . . 45
16.7. Link and Channel Management . . . . . . . . . . . . . . 45
17. Connections . . . . . . . . . . . . . . . . . . . . . . . . . 45
18. Application Layer . . . . . . . . . . . . . . . . . . . . . . 46
18.1. APIs for Network Service ("Quantum Sockets") . . . . . . 46
19. Resource Management: Multiplexing and Routing . . . . . . . . 46
20. Classical Communication . . . . . . . . . . . . . . . . . . . 46
20.1. Device Plane . . . . . . . . . . . . . . . . . . . . . . 47
20.2. Quantum Plane . . . . . . . . . . . . . . . . . . . . . 47
20.3. Data Plane . . . . . . . . . . . . . . . . . . . . . . . 47
20.4. Control Plane . . . . . . . . . . . . . . . . . . . . . 48
20.5. Management plane: Node and link management . . . . . . . 48
20.6. Mechanisms . . . . . . . . . . . . . . . . . . . . . . . 48
21. Naming and Addressing . . . . . . . . . . . . . . . . . . . . 48
21.1. State naming and management in RuleSets . . . . . . . . 48
22. Example Networks . . . . . . . . . . . . . . . . . . . . . . 50
22.1. Fully Connected Point-to-Point . . . . . . . . . . . . . 50
22.2. Single Optical Switch . . . . . . . . . . . . . . . . . 50
22.3. Q-Fly Multicomputer . . . . . . . . . . . . . . . . . . 50
22.4. Optically Switched Fat Tree . . . . . . . . . . . . . . 51
22.5. Repeater Fat Tree . . . . . . . . . . . . . . . . . . . 52
22.6. 2-D Grid Multicomputer . . . . . . . . . . . . . . . . . 52
22.7. Ring . . . . . . . . . . . . . . . . . . . . . . . . . . 52
22.8. QLAN . . . . . . . . . . . . . . . . . . . . . . . . . . 52
23. Security Considerations . . . . . . . . . . . . . . . . . . . 53
24. References . . . . . . . . . . . . . . . . . . . . . . . . . 53
24.1. Normative References . . . . . . . . . . . . . . . . . . 53
24.2. Informative References . . . . . . . . . . . . . . . . . 53
Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 73
1. Introduction
This document introduces the key architectural decisions, classical
and quantum communication systems, and main node types for several
classes of quantum networks.
We define the verb _to architect_ as: within a set of environmental
constraints, using a set of building blocks, design a system that
satisfies a need, elegantly and economically. We use the noun
_architecture_ as: the set of blocks or subsystems, their roles and
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their interfaces and their overall arrangement, that defines the
system. This architecture defines the overall structure, and is
connected to a specific implementation as an example.
For a description of the key concepts in quantum networks and
additional references, see [RFC9340] and the book _Quantum
Communications_ [hajdusek-qcomm].
For more background and discussion of the design choices in this
architecture, see the Ph.D. dissertation of Naphan Benchasattabuse
[benchasattabuse-res-mgmt-het].
2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
3. Goals and Non-Goals of this Document
This section describes goals and non-goals for this document itself,
rather than the technical goals and requirements for a network.
3.1. Goals
* To define the principal concepts in a quantum network, principally
for quantum multicomputer interconnects but also data center and
wide-area networks where possible.
* To enumerate some of the key architectural decisions for this
architecture.
* To describe how device, link and node types are defined.
* To provide a guide to other documents.
3.2. Non-Goals
* Specification of physical links (including photonic wave packets)
* Detailed definition of application-layer protocols and software
interfaces such as sockets
* Internetworking
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4. Relationship to Documents by QIRG and Other Organizations
Other organizations, including national laboratories and standards
development organizations, are developing documents describing
quantum networks and quantum computing technology. These are mostly
_pre-standardization_ documents, not yet on any formal
standardization track. To the extent possible, this document
conforms to their terminology. However, as this document describes a
specific quantum network architecture, it does not attempt to conform
to specific design decisions made in other contexts. See an August
2025 Science Policy Forum [aboy-governance] for additional discussion
of some standardization efforts and their value.
Some of these are listed here for reference:
* ETSI
- Industry Specification Group (ISG) on Quantum Key Distribution
(QKD) (https://www.etsi.org/committee/qkd)
* IEEE Standards Association
- IEEE Standards & Projects for Quantum Technologies
(https://standards.ieee.org/initiatives/quantum-standards-
activities/)
- Standardization Roadmap on Quantum Applications (https://ieee-
sa.imeetcentral.com/p/eAAAAAAASqm9AAAAAFU6etg)
* ISO
- IEC/ISO JTC 3 Quantum technologies (https://www.iso.org/
committee/10138914.html)
* ITU-T
- ITU-T Focus Group on Quantum Information Technology for
Networks (FG-QIT4N) (https://www.itu.int/en/ITU-
T/focusgroups/qit4n/Pages/default.aspx)
- Y.3800 series (https://www.itu.int/itu-t/recommendations/
index.aspx?ser=Y) on quantum key distribution networks
* National Institute of Standards and Technology (NIST)
- Single-Photon Sources and Detectors Dictionary [nist-singles]
* Quantum Internet Research Group (QIRG) (part of IRTF)
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- [RFC9340]
- [RFC9583]
5. Prerequisite Knowledge
This document assumes basic knowledge of the underlying technology
and goals of quantum communications. The following list of topics
may help readers who are not yet familiar with the concepts.
* Linear algebra
* Quantum information basics
- Dirac ket notation
- von Neumann density matrix notation
- Superposition
- Entanglement
- Interference
- Unitary operation
- Measurement
- Decoherence
- No-cloning theorem
- Clifford group
- Basics of quantum error correction (QEC)
* Classical Internet-family networking
* Quantum networking
- Teleportation [bennett-teleportation]
- Purification [dur-purification]
- Entanglement swapping [zukowski-entanglement-swapping]
- Quantum key distribution [BB84], [E91], [BBM92]
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- "Generations" of quantum repeaters [muralidharan-generations],
[azuma-rmp]
- (Repeater graph states may be helpful, but are not used in the
current architecture [azuma-rgs],
[hilaire-rgs-optimizing-gen-time],[buterakos-graph-generation],
[hilaire-logical-bsm])
Because terms such as _fidelity_ have varying definitions, they will
be defined in this set of documents
[I-D.draft-hajdusek-qirg-timing-physics].
Readers needing additional background are referred to:
* [RFC9340]
* [RFC9583]
* Van Meter, _Quantum Networking_ [van-meter-q-net-book]
* Hajdusek and Van Meter, _Quantum Communications_ [hajdusek-qcomm]
6. Terminology
In this document, we use the abbreviations and other related
technical terms listed in the following table:
+=================+================================================+
| Term | Description |
+=================+================================================+
| BSA | Bell state analyzer, generally optical and |
| | incorporating one or more beamsplitters and |
| | either two or four single-photon detectors |
+-----------------+------------------------------------------------+
| CRQC | cryptographically relevant quantum computer |
+-----------------+------------------------------------------------+
| device | manipulates photons in some fashion; a |
| | component of a node |
+-----------------+------------------------------------------------+
| FASQ | fault-tolerant application-scale quantum |
+-----------------+------------------------------------------------+
| fidelity | measures how close a quantum state is to the |
| | state we have tried to create. Varies between |
| | 0 and 1, with unit fidelity indicating the |
| | actual state is the same as the desired state. |
| | It expresses the probability that the state |
| | will behave exactly the same as our desired |
| | state. (adapted from RFC 9340) |
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+-----------------+------------------------------------------------+
| FTQC | fault-tolerant quantum computer |
+-----------------+------------------------------------------------+
| group switch | In the Q-Fly architecture, the set of devices |
| | that connect the end nodes to the pool of |
| | BSAs, and the group to other groups |
+-----------------+------------------------------------------------+
| NISQ | near-term intermediate-scale quantum |
+-----------------+------------------------------------------------+
| node | a self-contained subsystem with a clear |
| | boundary that is visible to other such nodes |
| | as a single entity on one or more planes |
+-----------------+------------------------------------------------+
| optical mode | roughly, a place and time that a photon might |
| | be, which may be occupied by some, all or none |
| | of the amplitude of a single photon. More |
| | accurately, it is a field distribution |
| | obtained from solving Maxwell's equations |
| | given some boundary conditions. An optical |
| | mode is an eigensolution of the wave equation |
| | given the physical properties of the waveguide |
| | (dimensions, refractive index). It is a |
| | particular field distribution that can |
| | propagate through the waveguide. The state of |
| | a single photon can be expressed as a coherent |
| | superposition of such optical modes. For |
| | optics engineers, a 'mode' (or optical mode to |
| | be more precise) refers to a specific |
| | spatiotemporal distribution of electromagnetic |
| | field fluctuation. For quantum network |
| | engineers, especially those that would most |
| | likely be reading RFCs, two optical detectors |
| | are detecting different optical modes if one |
| | detector can be activated by light without |
| | activating the other. In that case, it is not |
| | wrong to say that the two detectors are |
| | detecting two independent optical modes. |
+-----------------+------------------------------------------------+
| path | the set of nodes and links that a connection |
| | passes through, including the end points |
+-----------------+------------------------------------------------+
| plane | a view of the entire network for a particular |
| (architectural) | purpose, such as management or data |
| | transmission |
+-----------------+------------------------------------------------+
| plane (optical) | a defined plane in physical space through |
| | which a photon passes; also referred to as a |
| | surface |
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+-----------------+------------------------------------------------+
| QBER | quantum bit error rate |
+-----------------+------------------------------------------------+
| QNIC | quantum network interface card; in practice, |
| | the physical interface to a link plus the set |
| | of quantum memories under the control of the |
| | network stack. |
+-----------------+------------------------------------------------+
| QPU | quantum processing unit |
+-----------------+------------------------------------------------+
| RuleSet | a set of SDN-inspired, event-driven, short, |
| | real-time or near-real time, near- |
| | determininistic programs executed at nodes |
| | along a path to build application-requested |
| | entangled states |
+-----------------+------------------------------------------------+
| SNSPD | Superconducting Nanowire Single Photon |
| | Detector |
+-----------------+------------------------------------------------+
| multiqubit | tensor product of Pauli operators acting on |
| Pauli operators | two or more qubits |
+-----------------+------------------------------------------------+
| switch point | a 2x2 junction that can be either X (cross) or |
| | = (straight) |
+-----------------+------------------------------------------------+
| switch device | a single integrated, fiber- or free space- |
| | connected (physical) component, comprising one |
| | or more switch points |
+-----------------+------------------------------------------------+
| teledata | application execution via teleporting data |
| | from node to node, then executing gates |
| | locally. May be done remotely, mediated by |
| | Bell pairs. [van-meter-dist-arith] |
+-----------------+------------------------------------------------+
| telegate | application execution via remote gates (as |
| | defined by Eisert et al. |
| | [eisert-remote-gate]). May be done remotely, |
| | mediated by Bell pairs. [van-meter-dist-arith] |
+-----------------+------------------------------------------------+
| time bin | a method of qubit encoding using photons; |
| | compare to window and time slot |
+-----------------+------------------------------------------------+
| time slot | a fully specified time and place where a |
| | photon may be detected; compare to window and |
| | time bin |
+-----------------+------------------------------------------------+
| time window | the time interval where a detector is enabled; |
| | compare to time bin and time slot |
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+-----------------+------------------------------------------------+
Table 1
7. Applications of Networks
The requirements for a network are determined by the application
workload. This section orients architectural decisions by briefly
introducing applications and the communication patterns they exhibit,
which is a key factor determining the suitability of particular
architectures.
7.1. Types of Applications
Applications fall into two large categories: inherently distributed
applications, or subdivision of monolithic applications for
distributed execution, as in supercomputing applications running on
multicomputer architectures. The inherently distributed applications
can be further categorized into cryptographic functions, distributed
computation, and distributed sensing. For a discussion of some
inherently distributed applications of quantum networks, see
[RFC9583]. This network architecture supports the applications
listed in that RFC, though not all networks will support all
applications.
7.2. Entangled States Consumption Patterns
The text in this section is adapted and extended from unpublished
text in [van-meter-opt-timing].
Distinct from the classification of quantum repeater generations by
Muralidharan et al. [muralidharan-generations], one can categorize
distributed quantum systems by how applications interface with the
network; specifically, the timing at which network interface qubits
are freed after attempting entangled state generation.
In the early days of quantum information research, Bennett et al.
recognized [bennett-mixed] that the component qubits of an entangled
state may be held at different times in different locations, termed
_time-separated Bell pairs_. Based on this principle, we can describe
the timeline of information availability between two nodes. This
model assumes entangled states are requested dynamically during
execution, rather than pre-caching entangled
states [schoute-shortcuts] for immediate consumption.
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7.2.1. The Entanglement Information Timeline
The lifecycle of an entanglement request, from initiation to full
state knowledge, follows three distinct stages:
1. *Attempt:* The entangled states are requested. For memory-based
links, this corresponds to the quantum memory emitting a photon
and transmitting it through the link.
2. *Heralded:* The entangled states are physically established, but
the specific states are unknown. The node has received
confirmations that photons arrived at the BSA and the BSM
succeeded, but the Pauli frame information is not yet available.
Without this information, an entangled state will be _fully
mixed_, with a fidelity of 0.25 for a two-qubit state.
3. *Correct:* The classical message regarding the Pauli frame
arrives. The node now knows the exact entangled state created
and can apply corrections (or software frame updates) to align
with the expected state.
7.2.2. Classification of Consumption Patterns
Based on the timeline above, we classify Bell pair consumption into
three classes [van-meter-opt-timing]. These classes are defined by
whether the application must *block execution* while waiting for
information at the _Heralded_ or _Correct_ stages. Note that the
term "blocking" here refers to the blocking versus non-blocking
execution models, similar to kernel-level I/O blocking or the event-
driven programming paradigm, and is distinct from the concept of
blocking in network switches.
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+================+============+========+===========================+
| Class | Wait for | Wait | Application Behavior |
| | Heralding? | for | |
| | | Pauli | |
| | | Frame? | |
+================+============+========+===========================+
| *Unentangled | No | No | *Non-Blocking:* The |
| State Tolerant | | | application consumes the |
| (B)* | | | qubit immediately, |
| | | | handling failures or |
| | | | corrections in post- |
| | | | processing. |
+----------------+------------+--------+---------------------------+
| *Reactive | Yes* | No | *Partially Blocking:* The |
| Correction | | | application waits only |
| (C)* | | | for confirmation of |
| | | | existence (heralding), |
| | | | then proceeds by tracking |
| | | | errors in software. |
+----------------+------------+--------+---------------------------+
| *Deterministic | Yes | Yes | *Strictly Blocking:* The |
| (T)* | | | application blocks until |
| | | | the state is fully |
| | | | verified and corrected. |
+----------------+------------+--------+---------------------------+
Table 2
_*Note for Class C: If the link is fully deterministic (guaranteeing
success), the application does not need to pause for heralding and
become non-blocking._
7.2.3. Class Selection and Resource Implications
It is important to note that these classes are determined by the
*nodes*, not the network. The application nodes assess their own
capabilities (number of buffer memories, gate and qubit error rate)
and the network's performance (fidelity, rate, success probability)
to select the appropriate operating class.
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The selection of a class significantly impacts network resource
utilization. For example, if a node possesses sufficient buffer
memory, it may elect to operate in *Class B* from the perspective of
the network interface. By moving the entangled state from the
communication qubit to storage immediately (or measuring it
immediately), the node frees up the network interface to service
other requests. This reduces the workload on the network and
increases the repetition rate, even if the application logic itself
eventually requires the data for a Class T operation.
7.2.4. Unentangled State Tolerant (B Class) Applications
The defining characteristic of B Class applications is the ability to
consume the (potential) entangled states immediately without waiting
(fully non-blocking). The application effectively takes over the
burden of validation from the network.
*Execution Flow:* The application does not stop. It measures or
stores the qubit immediately. If the entanglement attempt failed
(information received later), the data is discarded or treated as an
erasure error.
*Examples:*
* *Classical Correlation:* Applications like Quantum Key
Distribution (QKD) protocols (e.g., E91) or link fidelity
estimation. The application filters out failed attempts during
classical post-processing.
* *Fault-Tolerant Operations:* Certain remote quantum error
correction schemes, such as remote lattice surgery
[horsman-lattice-surgery], [ramette-remote], [leone-remote],
[sinclair-ft-interconnect] of the surface code. If the
probability of creating entanglement is high enough, unsuccessful
attempts can be treated as depolarizing errors, which the logical
code can tolerate without stalling the pipeline.
7.2.5. Reactive Correction (C Class) Applications
In C Class applications, the system requires confirmation that a link
exists, but does not wait for the state details. The application
proceeds by assuming a specific Bell state and managing deviations
via software tracking.
*Execution Flow:* The application pauses briefly to ensure the Bell
pair is _Heralded_. Once confirmed, it executes immediately. It does
not wait for the _Correct_ stage (Pauli frame); instead, it uses a
"Pauli Frame Tracker" to propagate the necessary corrections through
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the circuit virtually. If the network link is deterministic, the
specific wait for heralding is removed, as the node assumes success
by default.
*Examples:* Clifford circuit execution, distributed Pauli-based
computation with time-optimal scheme [litinski-gosc], and state
teleportation.
7.2.6. Deterministic (T Class) Applications
T Class applications impose the strictest timing constraints,
requiring the entangled state to idle the longest before being
consumed.
*Execution Flow:* The application *completely stalls*. It must wait
until the network provides both the confirmation of creation
(_Heralded_) and the specific state information (_Correct_).
Execution only resumes once the exact state is known or corrected.
*Examples:* Execution of circuits involving non-Clifford gates.
While non-Clifford operations _can_ theoretically be corrected post
hoc (similar to Class C), doing so often requires consuming
_additional_ entangled states to fix the error. Since consuming
extra resources is more costly than waiting, these operations default
to Class T to ensure the state is correct before proceeding.
8. Architectural Concepts
This section introduces concepts in classical and quantum computer
and network architecture that may be unfamiliar, or that have a
specific role in this network architecture.
8.1. Quantum Devices
A quantum device stores, carries, measures or computes on quantum
variables.
For the purposes of this architecture, a quantum device (often
shortened to just "device" in this specification) is under software
control; i.e. passive elements such as optical fibers or beam
splitters are not classified as quantum devices.
Control of devices is usually done with respect to some physical
characteristic of the device itself, rather than dealing with the
abstract notion of qubits. A controllable wave plate, for example,
may be adjusted in units of degrees of rotation of the plate. An
example of a software package that provides such functionality is
PnPQ [pnpq].
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8.2. Quantum Nodes
A quantum node comprises one or more quantum devices, and serves as a
single locus of control for network protocols. The classes of nodes
are described in detail in Section 15.
A _logical node_ or _composite node_ provides a single communication
and control point for the services of a particular node type, but may
comprise a set of physical devices rather than a single device, and
may be physically packaged in more than one box.
8.3. Quantum Links
A quantum link provides entanglement suitable for one of the
application classes described in Section 7. Links are described in
Section 16.
8.4. Photonic Synchronization Domains
A photonic synchronization domain (PSD) is the range of devices and
channels (fiber or free space) over which photons must be controlled
with high precision in order to effect e.g. photonic entanglement
swapping [mori-psds]. The primary concern of a PSD is getting
photons to arrive at beamsplitters "simultaneously", with sufficient
overlap in their wavepackets, as specified in
[I-D.draft-hajdusek-qirg-timing-physics].
Note that the most common operational mode uses only pairs of
photons, one from each of two nodes, not multi-photon operations; the
definition of PSD does not imply that all channels in a network must
be synchronized with each other and used in a single operation.
8.5. Direct and Indirect Multicomputer Architectures
In multicomputer architectures, a _direct_ architecture features
links that go directly from computational node to computational node.
Hypercubes, meshes and toruses are typically direct architectures.
An _indirect_ architecture interposes one or more switches between
computational nodes. Fat trees, Clos and Benes networks, and the
various -fly topologies are generally indirect [dally-towles].
The distinction is somewhat artificial in that direct architectures
sometimes incorporate a small switch (sometimes called a "router")
inside the node, in which case the choice of term depends on where
you draw the boundary of the node, and because computational nodes
can be configured to act only as routers within the network, modeling
an indirect architecture using direct hardware.
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8.6. Detector-centric Architecture
Several detectors may be packaged as a single subsystem for purposes
such as cooling, power, control and time stamping. An architecture
built around a shared pool of detectors is a _detector-centric
architecture_. This structure facilities entanglement distribution in
a quantum system interconnect, data center network or some forms of
local area network.
A detector-centric architecture is an indirect architecture if the
pool of detectors is behind a switch or network of switches. If the
detectors are arranged as Bell State Analyzers (BSAs), we can call
the architecture _BSA-centric_. This will be the common case.
8.7. Source-centric Architecture
Many of the detector-centric network topologies can be inverted, such
that the pool of detectors is replaced by a pool of entangled photon
pair sources. The network then is used to distribute entanglement,
with the photons measured, absorbed into memories, interfered with
locally generated photons, or otherwise utilized at or near the end
nodes. Such a network was proposed by Drost _et al._ [drost].
8.8. Qubit-Level v. Device-Level Access
Conventionally, entangled quantum networks are described in terms of
unitary and non-unitary actions on qubits, just as the Internet
protocols are defined in terms of bits and bytes (octets) rather than
voltages, signal times and optical signal strengths. This _qubit-
level access_ is natural and allows for technology-independent, high-
level protocol development.
However, as described above, quantum nodes are built of quantum
devices, and at times it is preferable to use the hardware's _device-
level access_. Such an access mode is inevitably hardware-dependent,
requiring special-purpose software, limiting network scalability and
code portability. Cases where device-level access is useful include:
* as a building block for higher-level protocols;
* during hardware development;
* during system installation or maintenance at a customer site;
* in link-level monitoring protocols; and
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* when a multicomputer compiler and/or distributed-computation
middleware wants to optimize the system for themselves,
incorporating higher-level operations into its own application and
using lower-level methods to access the system components on the
wire.
9. Quantum Optical Building Blocks
This section informally describes the physical building blocks and
concepts used in the physical layer of a quantum network. These
definitions will use equations defined in
[I-D.draft-hajdusek-qirg-timing-physics].
9.1. Qubits
This network architecture uses only qubits, which may have two states
identified as 0 and 1. Quantum information systems using qutrits,
qudits, qunats or continuous variable (c.v.) quantum states are
beyond the scope of the current set of specifications.
Qubits (defined in RFC 9340) must conform to a sufficient subset of
the DiVincenzo criteria [divincenzo-criteria].
9.2. Photons, Wave Packets and Optical Modes
Loosely, a photon is a quantum of light. More detailed analysis of a
photon requires understanding _wave packets_ and _optical modes_.
An optical mode is a well-defined state of a physical link, specified
by path, time window, frequency, polarization, or similar parameters,
such that the receiver can be configured to monitor the channel and
determine whether that state is occupied by at least one photon or is
empty. The mode exists regardless of whether a photon is present; a
photon is an excitation of the mode, not the mode itself.
(Perhaps a good analogy is the _constellation_ of states in a
quadrature amplitude-modulated (QAM) signal, combined with whatever
other multiplexing or signal encoding is used, such as temporal,
spatial, or wavelength. The constellation is the full state space,
and a mode is the equivalent of one of those states, which may be
empty or occupied.)
A wave packet is the non-zero amplitude of the electrical and
magnetic fields, and generally corresponds to a single excitation of
the electrical field, i.e. a single photon. The length of the wave
packet is determined by the physics of the photon emission process,
possibly modified by dispersion in the channel, and in turn
determines the minimum length of a time slot in the link design.
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In quantum networking, link capacity and state must be described in
terms of modes, not photons; photons merely occupy modes, while empty
modes correspond to vacuum states that are still physically and
operationally meaningful. In idealized models, distinct modes
correspond to orthogonal solutions of the field equations, ensuring
perfect distinguishability.
As an example, a quantum optical link may define one mode per time
slot or detection window. During each window, the receiver monitors
the mode. A detection event indicates that the mode was occupied by
at least one photon; the absence of a detection indicates that the
same mode was empty. Both outcomes correspond to distinct physical
states of the link.
9.3. Photonic Qubits
Photons are used in networks to carry qubits. There are several
possible on-the-wire photonic qubit representations, e.g.
* Polarization (e.g. horizontal v. vertical)
* Time bin (e.g. early v. late)
* Which path (e.g. passing through a particular set of lenses or
fibers)
* Energy level (wavelength)
These representations and more about the concept of an _optical mode_
are discussed in the "standard photon" and
[I-D.draft-hajdusek-qirg-timing-physics] documents, and are provided
here only for informational purposes.
9.4. Memories
The physical implementation of memories is beyond the scope of this
document. For architectural purposes, it matters only that they may
hold quantum data (qubits) that may be under the management of the
network software and protocols. They may be entangled with photons
or with other memory qubits.
Generally, the creation or entanglement of a state in memory is
imperfect, and the memory has a finite lifetime. This process of
accumulated errors is _decoherence_.
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The entanglement of a memory qubit with a photon is a technology-
dependent process. To create fiber-compatible and optical equipment-
compatible photons, wavelength conversion via transduction may be
necessary. In 2025, transduction is a low-probability process, and
hurts fidelity as well.
9.5. Photon Sources
Photons may be emitted by _sources_ of many types [nist-singles].
Single photons may come from attenuated lasers, or be emitted by a
variety of quantum devices, such as quantum dots, or by individual
atoms.
Photons may be unentangled, entangled with other photons, or
entangled with quantum memories.
9.5.1. Unentangled Single Photons
Unentangled photons exhibit quantum properties. They can carry
information in any of the characteristics listed above, and may be
put into a superposition of multiple basis states for e.g. quantum
key distribution purposes. In this document, unentangled individual
photons are not used.
9.5.2. Entangled Photon Pairs
Pairs of photons entangled with each other can be made via a variety
of physical processes. Devices that make such pairs can be
components of nodes such as the Entangled Photon Pair Source (EPPS),
described in a separate document.
9.5.3. Memory-Emitted Photons
Photons emitted by quantum memories, such as single atoms, may remain
entangled to the memory, if the memory was in a superposition of
basis states.
9.6. Detectors
Detectors may be either _single-photon detectors_, which click when
_one or more_ photons hit the detector, or _number resolving
detectors_, which can distinguish between one, two, or more photons
hitting the detector within the same time window [nist-singles]. In
this document, detectors may be assumed to be single-photon
detectors.
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10. A Sketch of the System Model
As noted in the 2022 roadmap for quantum interconnects
[awschalom-roadmap], entangled quantum network technology can be
deployed in a variety of scenarios with different requirements and
assumptions. A full description of each of these is delegated to
other documents, but a brief description here will help to orient
discussions of design points in order to justify certain decisions.
10.1. Multicomputer
The first deployment of production-level, distant quantum
entanglement is likely to be in a _quantum multicomputer_
[rdv-thesis], based on the same principles as classical distributed-
memory supercomputers from the Caltech Cosmic Cube
[seitz-cosmic-cube] to Fugaku [wikipedia-fugaku]. Multicomputer
deployments will likely involve computational nodes, optical
switches, Bell state analyzers, and possibly entangled photon pair
sources (all defined below). Quantum repeaters with memory are less
likely to be deployed in multicomputers, though one such architecture
[choi-fat-tree] has been proposed. Because the current technology
roadmaps favor this type of deployment, where network design choices
are in conflict or unclear, multicomputer designs are given priority
over wide-area networks in this set of specifications.
A multicomputer may be a noisy, intermediate-scale quantum (NISQ)
system without quantum error correction [preskill-nisq], or may be a
fault-tolerant system. Fault-tolerant systems are variously
described as fault-tolerant quantum computers (FTQC), fault-tolerant
application-scale quantum (FASQ) systems, or cryptographically
relevant quantum computers (CRQC). FTQCs require the network to
generate many more entangled states with tight timing requirements to
allow distributed quantum error correction or the creation of fully
error-corrected entangled states for application use.
The program structural model is expected to be much like the
classical supercomputing Message Passing Interface (MPI) [mpi-5.0],
in the sense that nodes cooperate in a tightly coupled fashion,
exchanging data and controlling program execution, with each node
executing a portion of a single, large computation. One specific
implementation of Quantum MPI has, in fact, been proposed
[haener-qmpi], but here we mean this in the broader sense.
General hardware environment:
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* A multicomputer consists of a set of quantum nodes that are
connected via quantum optical channels. The system may be either
a direct (point-to-point, end node-to-end node) or an indirect
(switched) design.
* Every quantum node has a set of quantum devices and a classical
controller.
* End nodes are generally computational nodes, but measurement-only,
sensor, and specialized memory storage nodes may be included.
* End nodes are capable of running application programs as well as
executing the minimum operations to build end-to-end entangled
states.
* End nodes may be built using multi-level hardware interconnects;
when gates between physically distant qubits are mediated by first
creating shared entangled states, the creation of those entangled
states is the responsibility of the network subsystem.
* Multicomputer interconnects are closed systems, with no need for
cryptographic security mechanisms.
Many aspects of compilation and job execution are beyond the scope of
this set of specifications, but some points will affect the network
node definitions and interfaces, so it is important to present them
here to establish a basis for design decisions:
* The general purpose of a multicomputer system is to execute
application programs that exceed the capabilities of a single
quantum node. The subdivision of the application into smaller
quantum programs and the assignment of those sub-programs to nodes
in the network is beyond the scope of this specification, and may
be either automatically done by the compiler or manually done by
the programmer.
* Programs are centrally compiled and distributed to nodes. (Note
that, technically, this is different from classical MPI, where a
_command_ is sent to worker nodes, but the mapping of that command
to an executable program and versioning and distribution of
programs are outside the scope of MPI. It is, however, a
convenient assumption and common practice to ensure the same
program is executed at all worker nodes.)
* Execution is coordinated by a job controller: every node executes
the same program, but with different parameters (e.g., which
portion of the problem to work on).
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* Applications consist of both classical computation and quantum
computation; within a node, the classical portion of the program
delegates certain computational tasks to the quantum processor
(sometimes called a QPU), similar to a classical coprocessor
(https://en.wikipedia.org/wiki/Coprocessor) such as a GPU
(https://en.wikipedia.org/wiki/Graphics_processing_unit).
* Classical data related to quantum operations (principally
measurement results and event notifications that trigger further
actions) is sent peer-to-peer, not back to the centralized
controller, during execution.
* Within the runtime system, the interface between the (portion of
the) application running at each node's classical controller is
analogous to the interface between an application and the MPI
messaging system or a socket (https://en.wikipedia.org/wiki/
Network_socket) in an ordinary Internet application. This quantum
socket is an active area of research and is not defined here.
* In principle, all nodes are running the same program, distributed
to all nodes. Since the compiled application circuits are often
parameter- or input-dependent as well, separate nodes may have
separate instances of the application. This may result in a small
additional burden on the execution management system.
* In principle, the application and the communication system are
separately compiled and managed. However, in practice the RuleSet
(Section 12.6 and Section 14.3) may be compiled as part of the
application by using a library of network functions. (As with
classical parallel program runtime systems, the boundary between
the application program, supplied libraries, and the kernel itself
(if any) is implementation-dependent.)
* Compiling the network communication into the application program
eliminates the need for separate program and RuleSet distribution
protocols. However, the event messages that are part of the
architecturally defined RuleSet operation are sent and received as
usual, such that the behavior of the node is the same regardless
of such implementation choices.
* Compilation and execution may achieve application goals via
teledata, telegate or measurement of multiqubit Pauli operators
transparently; the network is unaware of this distinction.
Management of application-level variables and their movement from
node to node, if any, is the responsibility of the compiler and is
beyond the scope of this specification.
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* The resources in a multicomputer may be partitioned to run
multiple jobs [sane-jobs], but this is beyond the scope of the
current specifications.
The realities of quantum hardware result in a few important
differences from classical multicomputers:
* Multicomputer interconnects may be either optically switched or
composed entirely of point-to-point links. In switched networks,
depending on optical hardware as well as photonic qubit
representation, reconfiguring the switch or switches may be an
extremely high-latency operation.
* Application execution at end nodes proceeds in phases tied to
specific communication patterns. Even with a fixed sequence of
application-level operations, the execution time of a phase can be
variable because entanglement generation is probabilistic. Local
gates can also be probabilistic under some circumstances, but for
many node hardware types, fast local gate execution means the
impact of variable gate execution time will be small.
* In switched systems, reconfiguration of switches is centrally
coordinated between phases. Thus, while classical data moves
directly node-to-node during autonomous phase execution, advancing
from phase to phase in quantum multicomputer program execution
must be done at the direction of the job controller.
* Because execution is centrally coordinated, the network system is
not required to provide multiplexing. (This is a substantial
difference from data center networks, QLANs and QWANs.)
* The compiler may include multihop communication within a phase
using hop-by-hop teleportation without reconfiguring any switches;
this is beyond the scope of this architecture.
* Execution of the quantum portion of the node program generally
involves hard real-time actions, both unconditional and
conditioned on prior quantum measurement results. This generally
requires compilation of the quantum program to very low-level
actions to be executed by FPGAs or ASICs.
* Systems may be partially or completely emulated, decoupling
development of different subsystems. e.g., an EPPS plus a MEAS
together can emulate a COMP node that emits single photons.
* Systems may be noisy, intermediate-scale quantum (NISQ); near-
term, small-scale fault tolerant; or fault-tolerant, application-
scale quantum (FASQ).
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* Quantum error correction is above the level of these
specifications, but may involve distributed lattice surgery
[ramette-remote], [leone-remote],[sinclair-ft-interconnect].
10.2. Data Center Network (QDCN)
The hardware for quantum data center networks will be almost
identical to multicomputers; the primary differences are in the
workload, scheduling, programming model and assumptions of trust.
Distributed control and protocols for multiplexing and connection
setup may be necessary.
10.3. Local-Area Network (QLAN)
A QLAN will be deployed within a building or across a campus. It may
connect quantum computers (including but not necessarily
multicomputers) and sensors. A sensor, for example, may be connected
to a computer with substantial memory for e.g. shadow tomography,
learning from few measurements and related protocols.
A QLAN will have a less regular topology than a multicomputer or
QDCN. Distance, latency, fidelity, and success probability will all
vary on a per-link basis.
Distributed control and protocols for multiplexing and connection
setup are necessary [aparicio-spie].
10.4. Wide-Area Network (QWAN)
Wide-area networks may involve client-server or peer-to-peer
communication. One particular scenario of interest is a measurement-
only (MEAS) client end node connecting to a centralized,
supercomputer-scale quantum computer (perhaps, but not necessarily, a
multicomputer) for the purposes of executing _blind quantum
computation_ [fitzsimons-blind], [morimae-blind].
QWAN client-server communication very likely will suffer from the
"incast" problem of excessive traffic concentrating near certain
nodes [chen-incast]. Management of this problem is beyond the scope
of this document.
11. Requirements and Goals for the Architecture
This section documents the requirements for all networks adhering to
this architecture.
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11.1. Normative Requirements
* The architecture must support an open development process
[RFC6852].
* The architecture must support the creation of robust, extensible,
maintainable protocols in keeping with best current practice
[RFC9413] [RFC6250] [RFC1958] [RFC5218].
11.2. General Requirements
11.2.1. Functional Goals
The following are goals of this architecture. Note that while the
architectural decisions support all of these goals, individual
implementations may not support every item in the list, i.e. a
single-PSD implementation may not support memory-based entanglement
swapping or may be insufficient for wide-area networking.
* The architecture is defined only for qubits. Qutrits, qudits,
qunats and continuous-variable systems are out of scope of this
architecture, except where physical or link layers present such
physical variables as qubits.
* The architecture defines support for pairwise Bell pair creation
between nodes with one or more of the B, C or T timing classes in
Section 7. (The architecture does not define multipartite states
as a service of the network; applications that require them are
responsible for building them from Bell pairs.)
* The architecture is independent of physical implementation of
memories, photonic data representations, etc.
* The architecture supports deployments ranging from multicomputer
to wide area networks.
* The architecture supports multiple photonic synchronization
domains, as either point-to-point or optically switched paths.
The architecture must support some form of buffering between PSDs.
* The architecture supports entanglement swapping. (Note that
single PSD deployments may not need entanglement swapping.)
* The architecture supports methods of assessing and managing
errors, including photon loss and decoherence.
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* The architecture aims to support evolution of single-photon,
unentangled, single-purpose quantum key distribution networks
(perhaps with trusted relay nodes) to fully entangled,
multipurpose networks [wehner-roadmap].
11.2.2. Interface Requirements
* Supports one or more applications, such as the ones in [RFC9583],
with APIs consistent with the B, C, or T classes.
* The network must enable applications to match quantum states at
each end of the Bell pair by name.
11.2.3. Physical Requirements
Physical requirements such as distance, wavelength, vibration, power,
etc. will be case-dependent.
11.2.4. Environmental Requirements
Physical requirements such as distance, wavelength, vibration, power,
etc. will be case-dependent.
11.3. Network Management Requirements
Network management tasks largely revolve around installation,
maintenance and fault isolation and correction. Links and nodes may
also be enabled or disabled through automated or manual subsystems.
11.3.1. Configuration Management
The architecture must support the use of both manual and automated
network configuration tools to suit different installations and
development processes.
Configuration will include manual tasks such as physically setting up
equipment, as described in Section 16.5.
Configuration also includes setting up software: manually configuring
node devices that do not autoconfigure; selecting, turning on, and
configuring the quantum-related software services for the node; and
configuring the underlying classical control operating system.
Integration of these processes into existing or new network
management tools is beyond the scope of this document.
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11.3.2. Fault Management
Quantum networks likely will be less stable than their classical
counterparts for the foreseeable future. Hardware will require
extremely low-level, hardware-dependent monitoring and adjustment.
The architecture must:
* support isolation of hardware and software faults, and
* support monitoring and reporting of fidelity.
Integration of these processes into existing or new network
management tools is beyond the scope of this document.
11.3.3. Online Operations
Link and node monitoring tools, either automated or manual, can
enable or disable links and nodes. For example, a link that falls
below a certain fidelity or entanglement generation rate may be taken
out of service for maintenance. Such an action must notify the
routing subsystem, which in turn will relay the information via
routing protocols.
The behavior of connections passing through nodes or links whose
status changes to disabled is currently undefined.
Integration of these processes into existing or new network
management tools is beyond the scope of this document.
12. Architecture Overview
This section describes key design decisions made to achieve the goals
outlined in Section 11. Details are provided in the following
sections.
12.1. Deterministic Classical Control of Quantum States
This network architecture is entirely classically controlled. Its
task is to generate shared quantum states for applications residing
at separate nodes. While many quantum events are inherently
probabilistic, and loss of photons is also inherently probabilistic,
this architecture does not use multipartite quantum states for e.g.
routing of two-party requests. (An extension of this network
architecture may support generation of multi-partite state for
applications at a later date.)
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This control requires extensive classical communication, which is
carried over a variety of channels Section 20, according to the
requirements for various tasks
[I-D.draft-hajdusek-qirg-timing-physics].
12.2. Nodes, Links and Operational Views
As with typical networks, this architecture comprises nodes
(Section 15) and links (Section 16), which will connect two or more
nodes.
While the end-to-end goal is the delivery of qubit-based
entanglement, for a variety of purposes lower-level access to
hardware can be desirable, so nodes may present a qubit-level view
(incorporated in the data plane) or a device-level view (incorporated
in the device plane).
12.3. Communication Service
(Substantial portions of this section are adapted from Naphan
Benchasattabuse's Ph.D. thesis, which in turn is adapted from earlier
papers by Van Meter et al. [van-meter-qi-arch] and others.)
The design of a quantum network must begin with a clear definition of
its fundamental services --- what quantum states or capabilities the
network is expected to provide to end users. These decisions
determine the complexity of the protocols at the network layer and
the applications that run above it. A minimalist design treats _Bell
pairs_ as the primary network-level service. Bell pairs serve as the
smallest unit of entanglement and the foundation for nearly all
quantum communication protocols. Restricting the service to Bell
pair distribution simplifies the network's responsibilities.
However, this approach shifts complexity to the applications, which
must construct multipartite or fault-tolerant states themselves and
manage the coordination overhead that entails.
At the other end of the spectrum, networks may offer richer services
such as multipartite entangled states [ghz], [dur-w-state],
[hein-multiparty], [hein-graph-entanglement] or fault-tolerant state
teleportation. While applications can, in theory, synthesize these
states from Bell pairs, direct network-level support may offer
efficiency gains and reduce sensitivity to noise by internalizing
complex procedures like direct graph state generations or supporting
the delivery of error-correcting code encoded logical qubits.
More concretely, this architecture supports the B, C, and T
application classes described in Section 7, requiring both Bell pairs
and accompanying timestamps for some applications.
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12.3.1. Bell Pairs as the Core Network Service
In our architecture, we adopt Bell pair distribution as the core
network service, as it allows for a well-scoped, foundational
architectural framework.
Importantly, the semantics of Bell pair distribution are not merely
those of passive delivery. Even in this basic model, distributed
quantum computation occurs along the path via entanglement swapping,
possibly combined with purification at intermediate repeater nodes.
A proper service definition must account for this processing, as it
directly affects fidelity, latency, and trust assumptions in the
network.
12.3.2. Timing as a Critical Auxiliary Service
In addition to quantum state delivery, timing information is often a
critical part of the service. Applications in distributed quantum
sensing and clock synchronization [degen-sensing],
[proctor-quantum-sensing], [proctor-multiparm], [giovannetti-metro],
[gottesman-telescope], [ilo-okeke-clock] require precise knowledge of
when entanglement was established or when measurement events
occurred. Hence, high-precision timestamps may need to be bundled
into the service interface offered by the network.
12.4. Stateful Connections Along a Pre-established Path
Connections in both 1G and 2G networks require entanglement swapping
at the physical at logical level, respectively. Managing
entanglement swapping to avoid the leapfrog problem and misrouted
Bell pairs requires active, coordinated control of operations on
qubits at multiple nodes in the network. In this architecture, this
task is accomplished by establishing long-lived connections along a
path selected at connection setup time. Each such connection
consumes a small amount of classical memory at each repeater or
router. Corresponding quantum resource management (buffering,
multiplexing, etc.) is described below.
Two connection setup mechanisms are supported: a two-pass mechanism
suited for multi-hop communication, especially across technological
or administrative boundaries, and a direct-control mechanism, best
suited for data center-scale and locally-orchestrated communication.
Authentication, authorization and accounting (AAA) and security
concerns, including denial of service attacks, are beyond the scope
of the present architecture.
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12.5. Four-Layer Protocol Stack
The protocol stack for creating end-to-end entangled states consists
of four layers: physical, link, network, and application. The task
of dealing with errors and ensuring reliable E2E creation, often
handled in a transport layer that sits above the network layer, is
subsumed into the network layer in this architecture.
12.6. RuleSet-based Network Layer
The creation of sequences of end-to-end entangled states, roughly
equivalent to TCP, is the responsibility of RuleSets, inspired by
software-defined networking (SDN) (https://en.wikipedia.org/wiki/
Software-defined_networking) [farhadi-sdn] and Active Networks
[tennenhouse-an-arch]. A RuleSet can also be viewed as something
like a Berkeley Packet Filter (BPF) [mccanne-bpf] : it's a small
program that handled actions that the application could do, but the
application can't achieve the low, reliable latency to do it.
12.7. Five Planes, or Views, of the Network
A _plane_ is a view of the network, presented by the elements of the
network for a particular purpose. This architecture provides five
planes: device, quantum, data, control, and management, all described
in Section 13.
13. Architectural Planes
All nodes in the network will provide one or more of the following
classes of interfaces, also referred to as _planes_. A plane
provides a view of the network. Nodes that do not provide an
interface are not visible on the corresponding plane.
* *Device:* Control and monitoring of hardware devices such as
switches, wave plates, detectors, etc.
* *Quantum:* The quantum signals and in-channel, hardware-dependent,
real-time classical signals for timing and synchronization of
photon wave packets. A node with a quantum plane incorporates one
or more quantum devices. The quantum devices may be local or
remote.
* *Data:* Classical data plane for exchange of messages about in-
progress quantum communication sessions. Generally, the data
plane consists of _event notifications_ and _measurement results_
related to RuleSet-driven connections or testing sessions. A data
plane must be accompanied by a control plane.
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* *Control:* Classical control plane for establishing and managing
connections and testing sessions. Routing and multiplexing
messages are included in the control plane.
* *Management:* Network management for configuring the devices and
monitoring operation. Managing services provided by nodes,
security, addressing, etc., and monitoring health of links,
collecting statistics on traffic through the node, any alerts such
as security, etc.
13.1. Device
This view is primarily for low-level development and maintenance and
as a building block for higher-level protocols and software, as
discussed in Section 8.8. No interpretation of the classical data as
qubits or controls as qubit unitary or non-unitary operations is
provided here.
Software packages providing this level of access to the devices
include PnPQ [pnpq] and tdc_toolkit [tdc_toolkit]. Generally,
network-level access to this functionality will be via a form of RPC
or streaming data.
13.2. Quantum
The quantum signals and in-channel, hardware-dependent, real-time
classical signals for timing and synchronization of photon wave
packets. A node with a quantum plane incorporates one or more
quantum devices. The quantum devices may be local or remote.
The quantum plane functionality executes the functions described as
"Interferometric Stabilization" and "Wave Packet Overlap" and is
subject to the constraints in "Detector Timing Windows" in the Timing
Regimes document [I-D.draft-hajdusek-qirg-timing-physics].
13.3. Data
When operating in qubit mode, the Data Plane consists of classical
messages that convey events for RuleSet operation and the
communication ports and software that generate and consume such
messages.
Data plane functions may share data with management plane functions
as part of the link management process, e.g. using disti-mation
[casapao-disti-mation]. If this is done, security and privacy
concerns must be addressed.
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The control plane functionality executes the functions described as
"Pre-configured Event-driven Tasks" in the Timing Regimes document
[I-D.draft-hajdusek-qirg-timing-physics].
13.4. Control
The classical control plane is responsible for establishing and
managing connections and testing sessions. Routing and multiplexing
messages are included in the control plane.
Control plane functions may share data with management plane
functions, e.g. sharing parameter adjustment values and timings. If
this is done, security and privacy concerns must be addressed.
The control plane functionality executes the functions described as
"Measurement basis selection", "Optical switch control" and some
tasks in "Host-side Application-level Tasks" in the Timing Regimes
document [I-D.draft-hajdusek-qirg-timing-physics].
13.5. Management
While connection-specific changes to configuration, such as switching
and necessary, immediate changes to e.g. polarization and optical
delay may appear as control plane functions, slow-rate monitoring and
adjustment of parameters such as timing or polarization due to drift
in temperature, voltage or other parameters is the responsibility of
the management plane. The management plane may receive useful data
on the health and fidelity of links as a result of device plane, data
plane and control plane operations.
The management plane functionality executes the functions described
as "Background Tasks" in the Timing Regimes document
[I-D.draft-hajdusek-qirg-timing-physics].
14. Protocol Layers
This document describes a network architecture. Network designs are
often described in terms of a layered protocol stack such as the
7-layer OSI model (https://en.wikipedia.org/wiki/OSI_model), although
the Internet can be more accurately described as a three-, four-, or
five-layer model (https://en.wikipedia.org/wiki/
Internet_protocol_suite#Layering_evolution_and_representations_in_the_literature),
depending in part on whether a distinction is made between the
physical and link layers and in part on how the application layer is
subdivided.
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In a layered network architecture, each layer processes a prepended
header to complete its task. As messages move down the stack (from
application toward actual transmission), they may be subdivided into
smaller units, and additional layer-specific headers are prepended.
On receipt, headers are removed as the message moves up the stack,
and boundaries between messages may be altered.
A complete network architecture consists of much more than the layers
processing individual packets; many of the critical supporting
protocols around naming, routing, security, network management, etc.
utilize messages carried using the same protocol stack designed for
application data.
In a quantum network, this layering is less clear. Classical network
protocol layering is often presumed to include the sequential
addition of headers while preparing a packet for transmission and
processing proceeds down the protocol stack, with the process
inverted on packet reception. In quantum networks, the qubits
themselves are not processed in this stacked fashion, and the related
classical information typically involves separate messages with
separate end points as hop-by-hop entanglement is extended to end-to-
end entanglement through the actions of nodes all along the path.
Nevertheless, the notion of _layers of responsibility_ or _separation
of concerns_ is valid,with different needs at the link, network, and
application.
(More to be added here.)
+---------------------------+
| Application |
+---------------------------+
| Network (RuleSet) |
+---------------------------+
| Link |
+---------------------------+
| Physical |
+---------------------------+
Figure 1: Protocol Layers
14.1. Physical Layer
The physical layer incorporates the quantum channel itself, whether
free space or waveguide. Specifcation of the physical layer is out
of scope for this document, but the physical-layer specifications
must include:
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* signal transmission characteristics of the channel
* how nodes physically connect to the channel
* choice of photonic qubit
* wavelength
* wave packet envelope shape and duration
* timing/trial rate
* how link synchronization is achieved
* certain characteristics of detection subsystem
Additional details on how to specify a physical layer will be
presented in documents on the "standard photon" and "photon train",
which are currently being drafted.
14.2. Link Layer
The primary service provided by the link layer is heralded, named
entanglement across a quantum channel with defined endpoints
[I-D.draft-dahlberg-ll-quantum], [dahlberg-ll-arxiv],
[delle-donne-thesis], [delle-donne-os-nature]. The link layer sits
below the network layer and uses physical-layer quantum phenomena
plus classical messaging to provide its service. In this
architecture, the link service provides only bipartite entanglement.
The link layer architecture will support B, C and T class
applications, though not all links are required to support all
classes. In support of these classes, the entangled states may be
either still active and available for further use by the network
layer, or one or both of the qubits may already have been measured,
with the measurement basis and results and possibly a high-precision
timestamp recorded and reported.
See p. 36 of [delle-donne-thesis] for a description of the link
service. They refer to K-type (keep), M-type (measure) and R-type
(remote) entanglement requests.
The link layer may deliver entangled states to the network layer
either singly or as an ordered, tagged batch.
The link may operate entirely on demand, or as an always-on, free-
running service where requests from the network layer are serviced by
using recently created entanglement.
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The network layer can request states at one end where the status of
the qubit at the other end is unknown, in either heralding or Pauli
frame. This is necessary to support B class applications.
For multidrop links, the link layer must coordinate with multiplexing
and switch control as part of the control plane
[I-D.draft-zhu-qirg-qdcp].
The link may consist of several network nodes. Besides the two
endpoints, switches, BSAs, and EPPSes may be involved. Although
these support nodes are part of the network architecture, their
presence is not visible beyond the boundaries of the link or PSD.
In this architecture, fidelity is the responsibility of the network
layer; the link layer always provides raw Bell pairs of base
fidelity. Thus, fidelity is part of neither the request to nor
response from the link layer. During connection setup, information
about link fidelity is acquired from the link management and used by
the Responder to plan the connection.
Thus, link monitoring and link fidelity management are the
responsibility of the link architecture but are not part of the link
layer protocol.
* "message" format
* addressing
* multiplexing for multi-drop links
14.3. Network Layer: RuleSets
The network layer is responsible for both single- and multi-hop
purification, and for entanglement swapping. The network layer
subsumes the functions commonly divided into network and transport in
many architectures.
In this architecture, the network layer is a lightweight, restricted
(not Turing complete) distributed computation platform known as
RuleSets. RuleSets are distributed to nodes during the connection
setup process Section 17. RuleSets themselves are a form of state,
and they maintain internal state during the life of the connection.
The syntax and semantics of RuleSets are described in
[matsuo-link-boot] [matsuo-ms-thesis] [satoh-ms-thesis]
[aqua-ruleset-spec].
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14.4. Application Layer
Definition of the application layer protocols is beyond the scope of
this document.
15. Nodes and Node Types
(Substantial portions of this section are adapted from Naphan
Benchasattabuse's Ph.D. thesis, which in turn is adapted from earlier
papers by Van Meter et al. and others.)
The architecture of a quantum network is defined by its constituent
nodes and their specialized functions. In our architecture, we
classify nodes into three main groups: end nodes, for application
interaction; repeater and router nodes, for extending entanglement
and path management; and support nodes, for auxiliary operational
tasks.
The qNode specification (a document to be published) will provide
additional details on the common roles and responsibilities of all
quantum network nodes, and serves as the equivalent of the Internet
hosts requirements RFCs [RFC1122], [RFC1123]. Each node type is
further defined in a detailed specification in a separate document.
15.1. End Nodes
End nodes represent hosts that wish to execute a quantum application
such as quantum key distribution, secret sharing and blind quantum
computation [broadbent-bfk-protocol], [fitzsimons-blind]. The
technological maturity required of an end node heavily depends on the
desired application. There are four major kinds of end nodes:
*A measurement (MEAS) node* is the most basic type of quantum end
node, designed primarily for protocols that do not require quantum
state storage. Its core capability is to receive individual photons
and perform measurements on them in at least two different bases.
Lacking quantum memory, MEAS nodes are well-suited for applications
like quantum key distribution (QKD) or as simple terminals in certain
forms of secure delegated computation protocols
[morimae-blind],[fitzsimons-blind], typically interacting with the
network in a synchronous manner where measurement results directly
yield classical data.
*A sensor (SNSR) node* is a specialized end node designed to utilize
entangled states, often shared with distant parties, for high-
precision measurements of physical quantities, for clock
synchronization tasks, or for distributed sensing tasks [ge-linear],
[proctor-quantum-sensing], [degen-sensing], [giovannetti-metro],
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[proctor-multiparm]. These nodes typically feature limited quantum
memory to hold working qubits (e.g., one half of an entangled pair)
and possess specific quantum processing capabilities tailored for
sensing protocols. Such capabilities include performing joint
measurements, like Bell State Measurements (BSMs), between their
stored qubits and photons that have interacted with the environment
[huang-imaging-stars], [gottesman-telescope]. While an SNSR node's
internal processing is specialized, certain sensing applications may
also necessitate high-rate entanglement generation from the network
to achieve desired performance. For SNSR nodes, precise timing
information is almost invariably a critical component of the service
they provide or require, and their operation typically culminates in
outputting classical data that corresponds to the sensed phenomenon.
*A store (STOR) node* is a specialized end node whose primary
function is to serve as a high-fidelity quantum data repository. Its
core capabilities are the long-term storage of quantum states---often
prepared and teleported from other locations---and the ability to
teleport these states out on demand. While a STOR node does not
require a universal gate set, it must support certain gates (e.g.,
Clifford gates) for active quantum error correction to preserve the
stored quantum data. This includes using quantum error-correcting
codes to protect against decoherence, along with mitigation
strategies for correlated errors from events such as cosmic ray
strikes [martinis-correlated], [sane-phonons], [xu-dist-qec],
[vepsaelaeinen-ionizing], [wu-mitigating], [li-cosmic]. In a network
context, STOR nodes may function as data servers, enabling
asynchronous applications where valuable states are prepared and
stored for later retrieval.
*A computational (COMP) node* represents a full-fledged quantum
processing endpoint within the network. Equipped with quantum memory
and additional algorithmic qubits, it can store, manipulate, and
perform complex computations on quantum states received from the
network or generated locally. COMP nodes support a wide range of
advanced quantum network applications, including distributed quantum
algorithms, more general forms of blind quantum computation, and
potentially fault-tolerant quantum computing, often requiring
asynchronous interfaces to coordinate their local quantum workloads
with network operations [ambainis-multiparty-coin], [taherkhani-byz],
[mayers-unconditional], [christandl-anon], [broadbent-bfk-protocol],
[fitzsimons-blind], [mahadev-homomorphic], [dulek-homomorphic],
[shapourian-qdc-infra], [sutcliffe-dist-qec], [yoder-tour-de-gross],
[kim-ft-million].
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15.2. Support Nodes
*An entangled photon pair source (EPPS)* is a device dedicated to
generating pairs of entangled photons, commonly through processes
like Spontaneous Parametric Down-Conversion (SPDC). These entangled
photons are then typically distributed over quantum channels to be
captured or measured at link endpoints, forming the initial resource
for entanglement-based protocols. EPPS nodes can be deployed in
various scenarios, including terrestrial fiber links or free-space
satellite-to-ground communication [fittipaldi-sat],
[haldar-sat-dist], [khatri-spooky], [yin-1200km].
*A Bell state analyzer (BSA)* is a crucial component for performing
projective measurements on two incoming photons, ideally projecting
their combined state into one of the four Bell states. BSAs are
fundamental for realizing photonic entanglement
swapping[zukowski-entanglement-swapping], a primary process that
creates link-level entanglement, used particularly to convert memory-
photon entanglement into memory-memory entanglement between distant
quantum memories. The efficiency and complexity of a BSA depend on
the optical implementation and the specific photonic qubit encoding
used.
*A Repeater Graph State Source (RGSS)* is a specialized source that
generates multipartite entangled photonic states, specifically
tailored for all-photonic (memory-less) quantum repeater
architectures [azuma-rgs],
[hilaire-rgs-optimizing-gen-time],[buterakos-graph-generation],
[hilaire-logical-bsm]. An RGSS typically distributes segments of the
generated repeater graph state to adjacent network nodes, where
subsequent measurements on these photonic qubits are performed to
establish long-distance entanglement without relying on quantum
memories.
*An advanced Bell state analyzer (ABSA)* represents a more
sophisticated version of a BSA, particularly required in advanced
all-photonic repeater protocols based on repeater graph
states[azuma-rgs],
[hilaire-rgs-optimizing-gen-time],[buterakos-graph-generation],
[hilaire-logical-bsm]. Unlike basic BSAs, an ABSA must be capable of
performing measurements on single or multiple photons in dynamically
selectable bases. The choice of measurement basis often depends on
the outcomes of prior measurements within the network and the
specific structure of the repeater graph state being utilized,
implying more complex hardware and real-time classical control logic.
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*An optical switch (OSW)* is a device that can passively route
photons from input optical fibers or paths to different output paths
without performing measurements on them [koyama-24]. OSWs, which can
be based on technologies like nanomechanical systems or nanophotonic
circuits, can be integrated as components within other node types
(e.g., routers or complex end nodes) or can function as standalone
elements in the network to dynamically reconfigure optical pathways.
An OSW node contains at least one switch device, which comprises at
least once switch point.
15.3. Repeater Nodes
*A first-generation repeater (REP1)* is a network node with two
quantum interfaces, whose main task is to extend entanglement. Its
primary operations include generating link-level Bell pairs with its
neighbors, performing entanglement swapping to connect these
segments, and managing errors through heralded entanglement
purification on physical qubits along the connection path.
*A second-generation repeater (REP2)* also focuses on entanglement
swapping to bridge distances but generally requires a larger quantum
memory capacity and higher fidelity local quantum operations than a
REP1. It utilizes quantum error correction (QEC) to manage
operational errors in conjunction with heralded link-level
entanglement generation. Instead of, or in addition to, purifying
link-level physical Bell pairs, a REP2 node operates on logical
qubits, where quantum information is encoded across multiple physical
qubits to protect it from errors. This approach inherently demands
more sophisticated hardware and advanced computational capabilities
for encoding, decoding, and error correction routines during
swapping.
*A quantum router (RTR)* is a more complex and versatile node,
possessing all capabilities of a quantum repeater and typically
featuring three or more quantum network interfaces, enabling it to
make sophisticated path selection decisions in complex topologies.
Architecturally, an RTR may consist of multiple line cards and a
quantum backplane, allowing it to run a full suite of network
operation protocols. Beyond basic repeating functions like
entanglement swapping, an RTR can govern network borders potentially
interfacing between different repeater generations or technologies,
participate in generating multipartite entangled states if the
network provides such a service [meignant-dgs]
[bugalho-dist-multipartite] [fischer-dgs] [fan-dgs-dist], and may act
as a Responder in connection setups by rewriting or generating new
RuleSets for different network domains.
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15.4. Composite Nodes
A node may also aggregate the functions of more than one node, in a
form known as a _composite node_ or _composite logical node_. A
common form of composite node is a switching BSA. When multiple
devices of the same type are controlled by a single controller, they
may be presented either as a node with multiple devices or as a
composite node where each device is in turn represented as a node.
Presenting as a single node is preferred.
16. Links
16.1. The Link Service
A link provides Bell pairs across a single PSD. Each Bell pair is
named via an identifier. This service may be either real time or
batched. Generally, the physical link entanglement generation
mechanism is probabilistic but heralded. Although it is possible to
use repeated trials to present a near-deterministic service
[humphreys-deterministic-link], in this architecture we choose
instead to expose the asynchronous creation of Bell pairs with
timestamps.
(Does software control of buffer qubits appear in the architecture,
or is it purely an implementation detail?)
16.2. Link/Network Layer Interface
The link/network interface is best described as a software interface,
executed separately at each link endpoint.
The network-->link request:
* addresses of nodes
* single/fixed number/stream
* disposition: keep or measure, basis
The link-->network response:
* addresses of nodes
* length of array of entangled states
* array of entangled states
- identifier for entangled state
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- (timestamp separate from identifier? needed or not?)
- flags
o confirmed/pending confirmation
o measured/live
- if measured, basis
- if measured, result
16.3. Link Structures
16.3.1. Photonic Path Description
The optical path over which photons flow from source to detector in
the process of creating a Bell pair can be described using
terminology that names the node types in the path; the direction of
flow of photons can be inferred. This path description can be
applied to point-to-point or switched links within a single PSD.
Device type single-letter abbreviations and their corresponding node
type:
* M: memory (COMP or STOR)
* S: source (of entangled photons) (EPPS)
* I: interference (i.e., Bell state measurement) (BSA)
* D: detector (i.e. a measurement node) (MEAS)
* X: switch (OSW)
Examples of path descriptions that may commonly appear:
* DSD: detector-source-detector
* MIM: memory-interference-memory
* MSM: memory-source-memory
* MM: memory-memory
* DSISD: detector-source-inteference-source-detector
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At any point in a path except the ends, a photon may pass through one
or more switches.
In a switched architecture, for example, photons may pass through
paths such as:
* DXSXD
* MXIXM
* MXXIXM
(Question: Does this notation also need to represent frequency
conversion?)
16.3.2. Point-to-point
Point-to-point links may be either fiber-based or free space. A link
encompassing the path of one or more photons may be partially fiber
and partially free space.
The photonic path description notation will include no 'X's.
16.3.3. Switched
A system built around a pool of detectors, particularly organized as
BSAs, utilizing switched MIM links can also be characterized as a
_detector-centric architecture_.
For pseudocode for switching (routing) certain types of devices, see
Koyama et al. [koyama-24].
The photonic path description notation will include one or more 'X's.
16.3.4. Multidrop or Bus
A multidrop link, or a bus, is a shared physical channel to which
more than two stations may be attached.
16.4. Link Design Choices and Operational Settings
Beyond the top-level architecture of the link, defining placement of
subsystems (MIM, MSM, or MM links), and choice of photonic qubit
(polarization, time bin, etc.), designers make many choices that
affect performance, robustness, and interoperability. Many of these
choices will remain implicit, but others will be reported or managed
through link management software (below).
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Links depend upon other parameters of the physical channel and
equipment, including:
* entanglement generation trial rate,
* driving laser power (e.g. for SPDC-based EPPS),
* duration and spacing of photon detection windows,
* detector amplifier settings, and
* other hardware-specific parameters.
Depending on the implementation, some of these parameters can be
modified under software control, some can be monitored and reported,
and some are only available to software if manually added to a
configuration database.
Note that this task is far more complicated in a switched or
multidrop configuration than in a point-to-point configuration.
16.5. Installing and Bootstrapping a Link
During installation and/or bootstrapping of a link (and monitoring
during operation), qubit- and technology-appropriate reference frames
must be established. For example, the sender and receiver, or sender
and both receivers in the case of an EPPS-based link, must agree on
"horizontal" and "vertical" when using polarization qubits or "early"
and "late" when using time bin qubits.
A time reference may also be required for timestamping events such as
photon detection time Section 12.3.2.
For computational and cryptographic applications, these reference
frames are entirely arbitrary across a link or PSD; in fact, it only
matters that the link participants can agree on two orthogonal states
usable as a qubit, and can correctly agree upon matching of events
such as photon detection. For sensing applications (including clock
synchronization), depending on the application, these reference
frames may need to be tied to physical ground truth or a standard
reference. Whether the link reference frames are absolute or
relative should be reported in link management information.
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16.6. Spontaneous Changes to Link Conditions
During ordinary operations, the physical parameters of the channel
may change either gradually or suddenly. Gradual changes may be due
to e.g. temperature changes over a 24-hour cycle. Sudden changes may
be due to e.g. physical contact with or jostling of optical fibers or
other vibration- and position-sensitive optical equipment.
Detection of such changes is the responsibility of link management
services (below). Note that this task is far more complicated in a
switched or multidrop configuration than in a point-to-point
configuration.
Depending on operational needs and the severity of such changes,
necessary adjustments may be conducted without suspending link
operation or may require the link to be declared down long enough for
recalibration to be conducted. In extreme cases, manual intervention
may be required.
16.7. Link and Channel Management
The first task of link management is naturally configuration of the
link.
During operation, the ongoing tasks include management of fidelity,
trial rate, detection parameters, etc.
Supplies information about link fidelity and rate to other subsystems
such as routing and connection setup.
17. Connections
No task involving quantum communication ever involves a single qubit
or single entangled state. The connection provides the framework for
managing the creation of an order set of entangled states to be
consumed by applications. A connection is _stateful_ at the end
nodes. Nodes involved in the creation of end-to-end entanglement for
those end nodes will be _connection aware_, meaning that they can
identify resources and messages and carry out communication tasks
necessary for a specific connection, but may not have substantial
amounts of state that is dynamically updated on a per-action basis;
any actions for nodes in this class must be idempotent or known to
occur only once. Some or all nodes may be _fully stateful_, tracking
the disposition of specific, named quantum states.
Connections may be created using either a fully-distributed protocol
[I-D.draft-van-meter-qirg-quantum-connection-setup] or a centralized
mechanism. In either case, qNodes involved in the connection receive
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RuleSets that are created by a single controller to coordinate local
operations to build the end-to-end entangled states requested by an
application.
Connections are unaware of the shared use of resources and of other
connections. Multiplexing is the responsibility of a separate
subsystem, though connection setup should be done with awareness of
the availability of unavailability of resources at involved nodes.
18. Application Layer
18.1. APIs for Network Service ("Quantum Sockets")
The API used by classical software to interface with the quantum
depends on which class of timing dependency pattern (B, C, or T) is
to be supported.
19. Resource Management: Multiplexing and Routing
Both link usage time slots and memory can be shared among multiple
connections and therefore must be actively managed via a multiplexing
system. This task is particularly challenging in switched networks.
The discovery of the physical topology can be based on link state
protocols, such as direct adaptation of OSPF or IS-IS
[I-D.draft-kaws-qirg-advent]. These protocols use a unitless link
cost. It is known that, at least for certain physical systems,
selecting a link cost corresponding to "seconds per Bell pair of a
given fidelity" produces good correlation between low path cost and
high throughput [van-meter-sys-design], [van-meter-path-sel]. A
number of approaches have been proposed [abane-routing].
20. Classical Communication
A quantum network depends on classical communication; indeed, almost
all of the behavior is governed by, initiated by, or managed and
reported via classical messages and signals. These messages and
signals have several key roles, described in the following
subsections. See the Timing Regimes document
[I-D.draft-hajdusek-qirg-timing-physics] for an outline of the
physics driving these requirements.
Classical communication takes three major forms:
* direct physical signal
* request for an action, formulated as a remote procedure call (RPC)
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* a stream of events
20.1. Device Plane
Device plane classical communications will be via RPC or streaming
data service, as appropriate. Details are beyond the scope of this
document.
20.2. Quantum Plane
The quantum plane includes some classical signals to support tasks
described in Section 13.2. These signals are generally hard real
time, used for demarking per-qubit time bins and possibly the start
and end of longer trains of qubits or photons for switching purposes,
triggering emission of photons, etc. These signals may also be non-
coding, involved in link management rather than creation of qubits.
Not all quantum link designs will require such classical signals.
Due to the hard real time nature of communications at this level,
these signals are not carried over TCP/IP and indeed may be analog
events rather than digitized signals.
Links should be designed with soft-failure behavior such that
synchronization and full link operation can be recovered without
manual intervention after the loss of individual signal events or
short outages.
Where appropriate, the status of such classical communication should
be reported to or made available to management tools as part of link
health monitoring.
The details at this level are generally link-specific and are beyond
the scope of this architecture document.
20.3. Data Plane
Classical communication within the data plane sits above the link,
and concerns the creation of end-to-end entangled states for
established connections, as described in Section 13.3.
* connection-level control of switching of photons
* soft real-time event notification for RuleSets
Messages in the data plane are generally soft real time and assumed
to be reliable.
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20.4. Control Plane
Within the control plane, all communication is classical, supporting
the establishment of connections and management of resources as
described in Section 13.4.
* connection-level control of switching of photons
* soft real-time event notification for RuleSets
20.5. Management plane: Node and link management
Within the management plane, all communication is classical,
supporting the network monitoring and management of links and
ordinary network node management, as described in Section 13.5.
* reporting of parameters fixed by device physics
* reporting and setting of parameters selectable by node
configuration
* reporting and adjustment of slowly-changing parameters (such as
polarization drift)
* typical network node management tasks such as software updates
20.6. Mechanisms
* RPC for some tasks
- especially device-mode control
- qRPC wrapper for classical RPC mechanisms
* message broker or event broker for other tasks
- especially qubit-mode RuleSet notifications
21. Naming and Addressing
21.1. State naming and management in RuleSets
(Incorporates naming material from Naphan's thesis. Probably needs
updating to account for testbed realities.)
Managing and agreeing upon the specific qubits for joint operations
like entanglement purification or swapping among collaborating nodes
are critical responsibilities handled by RuleSets. While it is
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possible to draw inspiration from the IP architecture by employing
network-wide unique naming for qubits, RuleSets have local execution
contexts, making global naming for individual qubits unnecessary.
Instead, RuleSets use local logical names for qubits. At the lowest
level, physical qubits within a QNIC can be addressed by the local
node using a tuple like <QNICAddress,QubitIndex>. However, this
level of detail is not, and should not be, visible to the RuleSet
logic.
Within a RuleSet instance on a given node, the RuleSet mechanism
identifies a quantum resource primarily by its *tag* --- a label that
categorizes the resource into a specific pool corresponding to its
current role or stage in the protocol. To ensure an unambiguous and
absolute ordering of multiple resources that may share the same tag
(e.g., several Bell pairs awaiting purification), each resource, upon
being allocated to a tag, is automatically assigned a _sequence
number_ by the local RuleSet engine. The combination <tag,seq no.>
thus serves as a distinct and locally unique key within that RuleSet
instance for referencing a resource and associating it with relevant
metadata, such as its tracked fidelity. Actions specified within
Rules typically reference these resources based on their tag and
their relative order within that tag, for instance, by operating on
the resource with the smallest sequence number (i.e., the oldest
available in that pool). This structured internal naming is vital
for deterministic local operations and for preventing local
operational mismatches that could lead to problems like the
leapfrogging issue if not handled carefully at a higher protocol
design level.
The RuleSet execution mechanism itself, therefore, only requires and
manages this local <tag,seq no.> system for resource identification
within a single node's RuleSet instance; it does not impose any
inherent restrictions or requirements on how shared entangled states
are identified between nodes. It is recommended that a strategy be
used wherein the RuleSet creator (e.g., the Responder during
connection setup) devises RuleSets such that the <tag,seq no.> is
kept consistent across the RuleSets of all nodes involved in a
particular joint operation on that resource. The responsibility thus
lies with the RuleSet author to ensure that RuleSets are designed---
potentially using this consistent naming strategy---to correctly
manage shared resources and achieve the desired end-to-end protocol
behavior. This minimal local naming scheme provided by the RuleSet
engine, combined with judicious design of the RuleSets themselves, is
sufficient for implementing a wide range of complex quantum network
protocols while allowing creativity with minimal restrictions on
RuleSet creator parts.
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22. Example Networks
While a full taxonomy of networks is neither desirable nor possible
here, we present a few network examples using point-to-point links or
switched architectures. In this section, the topology is briefly
described, followed by analysis of the path characteristics of the
shortest path and network diameter.
22.1. Fully Connected Point-to-Point
Small networks may use nodes with multiple interfaces and provide a
direct link between each pair of nodes, making a _direct_ network.
Assuming sufficient node-internal capabilities, such a network
provides lowest loss (giving the fastest individual links) and the
highest aggregate bandwidth, and is inherently nonblocking. However,
with n-1 links per node and O(n^2) links in the network, its
scalability is poor. It will always provide the highest performance,
but not necessarily highest price/performance ratio.
If links are midpoint interference-based, an issue in design is
packaging of the BSAs and detectors.
PSD: Each link is a separate PSD.
All paths: MIM
22.2. Single Optical Switch
A number of the early quantum multicomputer proposals assumed a
single, large optical switch. Such a network is _indirect_.
PSD: Although the entire network is a single PSD, each pairing is
adjusted independently.
All paths: MXIXM
22.3. Q-Fly Multicomputer
An _indirect_ interconnect. A multi-group, BSA-centric architecture.
All nodes are part of the same PSD. The Q-Fly architecture is
described in Sakuma et al. [sakuma-q-fly].
PSD: Although the entire network is a single PSD, each pairing is
adjusted independently.
For DPFD topologies:
* Shortest paths
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- intra-group: MIXM
- inter-group (network diameter): MXXIM
* Longer paths:
- non-shortest path: MXXIXM or longer
For DPHD topologies:
* Shortest paths
- intra-group: MXIXM
- inter-group (network diameter): MXXIXM
* Longer paths:
- non-shortest path: MXXXIXM or longer
For SPHD topologies:
* Shortest paths
- intra-group: MXIXM
- inter-group (network diameter): MXXIXM
* Longer paths:
- non-shortest path: MXXXIXM or longer
22.4. Optically Switched Fat Tree
An _indirect_ interconnect. Several parameters are needed to
describe the full topology of a fat tree, which can also be called a
_k_-ary _n_-tree:
* _k_ is the switch radix
* _n_ is the tree depth
This simplest description assumes homogeneous hardware, where all
switches have the same number of ports and all links are the same
bandwidth. Leiserson's original fat tree proposed single links of
increasing bandwidth at higher levels of the tree, giving the network
its name; this approach provides no redundancy or path diversity, and
achieving higher transfer rates is impractical in some technologies,
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including quantum. Consequently, most fat tree deployments use
multiple links to several switches at higher levels of the tree, in a
configuration that is also know as a _folded Clos_ network.
PSD: Although the entire network is a single PSD, each pairing is
adjusted independently.
22.5. Repeater Fat Tree
The repeater fat tree is described in [choi-fat-tree].
PSD: Each link is a separate PSD.
22.6. 2-D Grid Multicomputer
A _direct_ interconnect. A 2-D grid of nodes, where nodes with
memory and certain computational capabilities (canonically COMP
nodes) have up to four interfaces connecting to neighboring nodes.
Each node must act as a memory buffer and repeater to enable
communication between non-neighboring nodes.
PSD: Each link is a separate PSD.
22.7. Ring
A _direct_ interconnect. All nodes in a ring have exactly two
neighbors. Each node must act as a memory buffer and repeater to
enable communication between non-neighboring nodes.
A ring is described in [ciobanu-multi-ring] (something from Simon's
group).
PSD: Each link is a separate PSD.
22.8. QLAN
A quantum local area network will have:
* irregular topology, possibly of heterogeneous link types
* distributed multiplexing
* distributed routing
PSD: If the QLAN does not include optical switches, but uses
repeaters, each link is a separate PSD. If the QLAN includes optical
switches, the PSDs may have irregular boundaries.
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23. Security Considerations
Quantum multicomputer systems are assumed to be constructed as
isolated, centrally controlled systems with no need for
confidentiality, integrity, and availability (the "CIA triad")
assurance via cryptographic methods.
Security considerations for other network types are an open topic of
study and as such are not yet ready for specification and
standardization [satoh-attacking].
Similarly, the relationship to AAA (authentication, authorization and
accounting) is an open topic for research.
24. References
24.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
24.2. Informative References
[abane-routing]
Abane, A., Cubeddu, M., Mai, V., and A. Battou,
"Entanglement Routing in Quantum Networks: A Comprehensive
Survey", Institute of Electrical and Electronics Engineers
(IEEE), IEEE Transactions on Quantum Engineering vol. 6,
pp. 1-39, DOI 10.1109/tqe.2025.3541123, 2025,
<https://doi.org/10.1109/tqe.2025.3541123>.
[aboy-governance]
Aboy, M., Gasser, U., Cohen, I., and M. Kop, "Quantum
technology governance: A standards-first approach",
American Association for the Advancement of Science
(AAAS), Science vol. 389, no. 6760, pp. 575-578,
DOI 10.1126/science.adw0018, August 2025,
<https://doi.org/10.1126/science.adw0018>.
[ambainis-multiparty-coin]
Ambainis, A., Buhrman, H., Dodis, Y., and H. Rohrig,
"Multiparty quantum coin flipping", IEEE, Proceedings.
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19th IEEE Annual Conference on Computational Complexity,
2004. pp. 250-259, DOI 10.1109/ccc.2004.1313848, November
2004, <https://doi.org/10.1109/ccc.2004.1313848>.
[aparicio-spie]
Aparicio, L. and R. Van Meter, "Multiplexing schemes for
quantum repeater networks", SPIE, SPIE Proceedings vol.
8163, pp. 816308, DOI 10.1117/12.893272, September 2011,
<https://doi.org/10.1117/12.893272>.
[aqua-ruleset-spec]
AQUA, "RuleSetSpec", 2023,
<https://github.com/sfc-aqua/RuleSetSpec/>.
[awschalom-roadmap]
, Awschalom, D., Bernien, H., Brown, R., Clerk, A.,
Chitambar, E., Dibos, A., Dionne, J., Eriksson, M.,
Fefferman, B., Fuchs, G., Gambetta, J., Goldschmidt, E.,
Guha, S., Heremans, F., Irwin, K., Jayich, A., Jiang, L.,
Karsch, J., Kasevich, M., Kolkowitz, S., Kwiat, P., Ladd,
T., Lowell, J., Maslov, D., Mason, N., Matsuura, A.,
McDermott, R., van Meter, R., Miller, A., Orcutt, J.,
Saffman, M., Schleier-Smith, M., Singh, M., Smith, P.,
Suchara, M., Toudeh-Fallah, F., Turlington, M., Woods, B.,
and T. Zhong, "A Roadmap for Quantum Interconnects",
Office of Scientific and Technical Information (OSTI),
DOI 10.2172/1900586, July 2022,
<https://doi.org/10.2172/1900586>.
[azuma-rgs]
Azuma, K., Tamaki, K., and H. Lo, "All-photonic quantum
repeaters", Springer Science and Business Media LLC,
Nature Communications vol. 6, no. 1,
DOI 10.1038/ncomms7787, April 2015,
<https://doi.org/10.1038/ncomms7787>.
[azuma-rmp]
Azuma, K., Economou, S., Elkouss, D., Hilaire, P., Jiang,
L., Lo, H., and I. Tzitrin, "Quantum repeaters: From
quantum networks to the quantum internet", American
Physical Society (APS), Reviews of Modern Physics vol. 95,
no. 4, DOI 10.1103/revmodphys.95.045006, December 2023,
<https://doi.org/10.1103/revmodphys.95.045006>.
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[BB84] Bennett, C. and G. Brassard, "Quantum cryptography: Public
key distribution and coin tossing", Elsevier BV,
Theoretical Computer Science vol. 560, pp. 7-11,
DOI 10.1016/j.tcs.2014.05.025, December 2014,
<https://doi.org/10.1016/j.tcs.2014.05.025>.
[BBM92] Bennett, C., Brassard, G., and N. Mermin, "Quantum
cryptography without Bell’s theorem", American Physical
Society (APS), Physical Review Letters vol. 68, no. 5, pp.
557-559, DOI 10.1103/physrevlett.68.557, February 1992,
<https://doi.org/10.1103/physrevlett.68.557>.
[benchasattabuse-res-mgmt-het]
Benchasattabuse, N., "Resource Management in Heterogeneous
Quantum Repeater Networks", Ph.D. Dissertation, Keio
University, 2025,
<https://aqua.sfc.wide.ad.jp/publications/whit3z-thesis-
local-compiled.pdf>.
[bennett-mixed]
Bennett, C., DiVincenzo, D., Smolin, J., and W. Wootters,
"Mixed-state entanglement and quantum error correction",
American Physical Society (APS), Physical Review A vol.
54, no. 5, pp. 3824-3851, DOI 10.1103/physreva.54.3824,
November 1996, <https://doi.org/10.1103/physreva.54.3824>.
[bennett-teleportation]
Bennett, C., Brassard, G., Crépeau, C., Jozsa, R., Peres,
A., and W. Wootters, "Teleporting an unknown quantum state
via dual classical and Einstein-Podolsky-Rosen channels",
American Physical Society (APS), Physical Review
Letters vol. 70, no. 13, pp. 1895-1899,
DOI 10.1103/physrevlett.70.1895, March 1993,
<https://doi.org/10.1103/physrevlett.70.1895>.
[broadbent-bfk-protocol]
Broadbent, A., Fitzsimons, J., and E. Kashefi, "Universal
Blind Quantum Computation", IEEE, 2009 50th Annual IEEE
Symposium on Foundations of Computer Science pp. 517-526,
DOI 10.1109/focs.2009.36, October 2009,
<https://doi.org/10.1109/focs.2009.36>.
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[bugalho-dist-multipartite]
Bugalho, L., Coutinho, B., Monteiro, F., and Y. Omar,
"Distributing Multipartite Entanglement over Noisy Quantum
Networks", Verein zur Forderung des Open Access
Publizierens in den Quantenwissenschaften, Quantum vol. 7,
pp. 920, DOI 10.22331/q-2023-02-09-920, February 2023,
<https://doi.org/10.22331/q-2023-02-09-920>.
[buterakos-graph-generation]
Buterakos, D., Barnes, E., and S. Economou, "Deterministic
Generation of All-Photonic Quantum Repeaters from Solid-
State Emitters", American Physical Society (APS), Physical
Review X vol. 7, no. 4, DOI 10.1103/physrevx.7.041023,
October 2017, <https://doi.org/10.1103/physrevx.7.041023>.
[casapao-disti-mation]
Casapao, J., Maity, A., Benchasattabuse, N., Hajdušek, M.,
Van Meter, R., and D. Elkouss, "Disti-Mator, an
entanglement distillation-based state estimator", Springer
Science and Business Media LLC, Communications
Physics vol. 8, no. 1, DOI 10.1038/s42005-025-02352-2,
November 2025,
<https://doi.org/10.1038/s42005-025-02352-2>.
[chen-incast]
Chen, Y., Griffith, R., Liu, J., Katz, R., and A. Joseph,
"Understanding TCP incast throughput collapse in
datacenter networks", ACM, Proceedings of the 1st ACM
workshop on Research on enterprise networking pp. 73-82,
DOI 10.1145/1592681.1592693, August 2009,
<https://doi.org/10.1145/1592681.1592693>.
[choi-fat-tree]
Choi, H., Davis, M., Iñesta, Á., and D. Englund, "Scalable
Quantum Networks: Congestion-Free Hierarchical
Entanglement Routing with Error Correction", arXiv,
DOI 10.48550/ARXIV.2306.09216, 2023,
<https://doi.org/10.48550/ARXIV.2306.09216>.
[christandl-anon]
Christandl, M. and S. Wehner, "Quantum Anonymous
Transmissions", Springer Berlin Heidelberg, Lecture Notes
in Computer Science pp. 217-235, DOI 10.1007/11593447_12,
ISBN ["9783540306849", "9783540322672"], 2005,
<https://doi.org/10.1007/11593447_12>.
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[ciobanu-multi-ring]
Ciobanu, B., Calafeteanu, T., Popa, A., Tătăroiu, R., and
P. Popescu, "Optimal entanglement distribution within a
multi-ring topology", Springer Science and Business Media
LLC, Scientific Reports vol. 15, no. 1,
DOI 10.1038/s41598-025-00391-x, May 2025,
<https://doi.org/10.1038/s41598-025-00391-x>.
[dahlberg-ll-arxiv]
Dahlberg, A., Skrzypczyk, M., Coopmans, T., Wubben, L.,
Rozpędek, F., Pompili, M., Stolk, A., Pawełczak, P.,
Knegjens, R., Filho, J., Hanson, R., and S. Wehner, "A
Link Layer Protocol for Quantum Networks", arXiv, arXiv,
DOI 10.48550/ARXIV.1903.09778, 2019,
<https://doi.org/10.48550/ARXIV.1903.09778>.
[dally-towles]
Dally, W. J. and B. P. Towles, "Principles and Practices
of Interconnection Networks", ISBN 978-0-08-049780-8,
2004.
[degen-sensing]
Degen, C., Reinhard, F., and P. Cappellaro, "Quantum
sensing", American Physical Society (APS), Reviews of
Modern Physics vol. 89, no. 3,
DOI 10.1103/revmodphys.89.035002, July 2017,
<https://doi.org/10.1103/revmodphys.89.035002>.
[delle-donne-os-arxiv]
Donne, C., Iuliano, M., van der Vecht, B., Ferreira, G.,
Jirovská, H., van der Steenhoven, T., Dahlberg, A.,
Skrzypczyk, M., Fioretto, D., Teller, M., Filippov, P.,
Montblanch, A., Fischer, J., van Ommen, B., Demetriou, N.,
Leichtle, D., Music, L., Ollivier, H., Raa, I., Kozlowski,
W., Taminiau, T., Pawełczak, P., Northup, T., Hanson, R.,
and S. Wehner, "Design and demonstration of an operating
system for executing applications on quantum network
nodes", arXiv, DOI 10.48550/ARXIV.2407.18306, 2024,
<https://doi.org/10.48550/ARXIV.2407.18306>.
[delle-donne-os-nature]
Delle Donne, C., Iuliano, M., van der Vecht, B., Ferreira,
G., Jirovská, H., van der Steenhoven, T., Dahlberg, A.,
Skrzypczyk, M., Fioretto, D., Teller, M., Filippov, P.,
Montblanch, A., Fischer, J., van Ommen, H., Demetriou, N.,
Leichtle, D., Music, L., Ollivier, H., te Raa, I.,
Kozlowski, W., Taminiau, T., Pawełczak, P., Northup, T.,
Hanson, R., and S. Wehner, "An operating system for
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executing applications on quantum network nodes", Springer
Science and Business Media LLC, Nature vol. 639, no. 8054,
pp. 321-328, DOI 10.1038/s41586-025-08704-w, March 2025,
<https://doi.org/10.1038/s41586-025-08704-w>.
[delle-donne-thesis]
Delle Donne, C., "Software Abstractions for Programmable
Quantum Network Nodes", Ph.D. Dissertation, Technical
University Delft, 2023,
<https://pure.tudelft.nl/ws/portalfiles/portal/153555360/
dissertation_cdelledonne.pdf>.
[divincenzo-criteria]
DiVincenzo, D. and IBM, "The Physical Implementation of
Quantum Computation", arXiv, arXiv, DOI
10.48550/ARXIV.QUANT-PH/0002077, 2000,
<https://doi.org/10.48550/ARXIV.QUANT-PH/0002077>.
[drost] Drost, R., Moore, T., and M. Brodsky, "Switching Networks
for Pairwise-Entanglement Distribution", Optica Publishing
Group, Journal of Optical Communications and
Networking vol. 8, no. 5, pp. 331,
DOI 10.1364/jocn.8.000331, April 2016,
<https://doi.org/10.1364/jocn.8.000331>.
[dulek-homomorphic]
Dulek, Y., Schaffner, C., and F. Speelman, "", Theory of
Computing Exchange, Theory of Computing vol. 14, no. 1,
pp. 1-45, DOI 10.4086/toc.2018.v014a007, 2018,
<https://doi.org/10.4086/toc.2018.v014a007>.
[dur-purification]
Dür, W. and H. Briegel, "Entanglement purification and
quantum error correction", IOP Publishing, Reports on
Progress in Physics vol. 70, no. 8, pp. 1381-1424,
DOI 10.1088/0034-4885/70/8/r03, July 2007,
<https://doi.org/10.1088/0034-4885/70/8/r03>.
[dur-w-state]
Dür, W., Vidal, G., and J. Cirac, "Three qubits can be
entangled in two inequivalent ways", American Physical
Society (APS), Physical Review A vol. 62, no. 6,
DOI 10.1103/physreva.62.062314, November 2000,
<https://doi.org/10.1103/physreva.62.062314>.
Van Meter, et al. Expires 5 May 2027 [Page 58]
Internet-Draft QNA November 2026
[E91] Ekert, A., "Quantum cryptography based on Bell’s theorem",
American Physical Society (APS), Physical Review
Letters vol. 67, no. 6, pp. 661-663,
DOI 10.1103/physrevlett.67.661, August 1991,
<https://doi.org/10.1103/physrevlett.67.661>.
[eisert-remote-gate]
Eisert, J., Jacobs, K., Papadopoulos, P., and M. Plenio,
"Optimal local implementation of nonlocal quantum gates",
American Physical Society (APS), Physical Review A vol.
62, no. 5, DOI 10.1103/physreva.62.052317, October 2000,
<https://doi.org/10.1103/physreva.62.052317>.
[fan-dgs-dist]
Fan, X., Zhan, C., Gupta, H., and C. Ramakrishnan,
"Optimized Distribution of Entanglement Graph States in
Quantum Networks", Institute of Electrical and Electronics
Engineers (IEEE), IEEE Transactions on Quantum
Engineering vol. 6, pp. 1-17,
DOI 10.1109/tqe.2025.3552006, 2025,
<https://doi.org/10.1109/tqe.2025.3552006>.
[farhadi-sdn]
Farhady, H., Lee, H., and A. Nakao, "Software-Defined
Networking: A survey", Elsevier BV, Computer Networks vol.
81, pp. 79-95, DOI 10.1016/j.comnet.2015.02.014, April
2015, <https://doi.org/10.1016/j.comnet.2015.02.014>.
[fischer-dgs]
Fischer, A. and D. Towsley, "Distributing Graph States
Across Quantum Networks", IEEE, 2021 IEEE International
Conference on Quantum Computing and Engineering (QCE) pp.
324-333, DOI 10.1109/qce52317.2021.00049, October 2021,
<https://doi.org/10.1109/qce52317.2021.00049>.
[fittipaldi-sat]
Fittipaldi, P., Teramoto, K., Benchasattabuse, N.,
Hajdušek, M., Van Meter, R., and F. Grosshans,
"Entanglement Swapping in Orbit: a Satellite Quantum Link
Case Study", IEEE, 2024 IEEE International Conference on
Quantum Computing and Engineering (QCE) pp. 1924-1930,
DOI 10.1109/qce60285.2024.00222, September 2024,
<https://doi.org/10.1109/qce60285.2024.00222>.
[fitzsimons-blind]
Fitzsimons, J., "Private quantum computation: an
introduction to blind quantum computing and related
protocols", Springer Science and Business Media LLC, npj
Van Meter, et al. Expires 5 May 2027 [Page 59]
Internet-Draft QNA November 2026
Quantum Information vol. 3, no. 1,
DOI 10.1038/s41534-017-0025-3, June 2017,
<https://doi.org/10.1038/s41534-017-0025-3>.
[ge-linear]
Ge, W., Jacobs, K., Eldredge, Z., Gorshkov, A., and M.
Foss-Feig, "Distributed Quantum Metrology with Linear
Networks and Separable Inputs", American Physical Society
(APS), Physical Review Letters vol. 121, no. 4,
DOI 10.1103/physrevlett.121.043604, July 2018,
<https://doi.org/10.1103/physrevlett.121.043604>.
[ghz] Greenberger, D., Horne, M., and A. Zeilinger, "Going
Beyond Bell's Theorem", arXiv, arXiv,
DOI 10.48550/ARXIV.0712.0921, 2007,
<https://doi.org/10.48550/ARXIV.0712.0921>.
[giovannetti-metro]
Giovannetti, V., Lloyd, S., and L. Maccone, "Advances in
quantum metrology", Springer Science and Business Media
LLC, Nature Photonics vol. 5, no. 4, pp. 222-229,
DOI 10.1038/nphoton.2011.35, March 2011,
<https://doi.org/10.1038/nphoton.2011.35>.
[gottesman-telescope]
Gottesman, D., Jennewein, T., and S. Croke, "Longer-
Baseline Telescopes Using Quantum Repeaters", American
Physical Society (APS), Physical Review Letters vol. 109,
no. 7, DOI 10.1103/physrevlett.109.070503, August 2012,
<https://doi.org/10.1103/physrevlett.109.070503>.
[haener-qmpi]
Häner, T., Steiger, D., Hoefler, T., and M. Troyer,
"Distributed quantum computing with QMPI", ACM,
Proceedings of the International Conference for High
Performance Computing, Networking, Storage and
Analysis pp. 1-13, DOI 10.1145/3458817.3476172, November
2021, <https://doi.org/10.1145/3458817.3476172>.
[hajdusek-qcomm]
Hajdušek, M. and R. Van Meter, "Quantum Communications",
arXiv, DOI 10.48550/ARXIV.2311.02367, 2023,
<https://doi.org/10.48550/ARXIV.2311.02367>.
[haldar-sat-dist]
Haldar, S., Agullo, I., Brady, A., Lamas-Linares, A.,
Proctor, W., and J. Troupe, "Towards global time
distribution via satellite-based sources of entangled
Van Meter, et al. Expires 5 May 2027 [Page 60]
Internet-Draft QNA November 2026
photons", American Physical Society (APS), Physical Review
A vol. 107, no. 2, DOI 10.1103/physreva.107.022615,
February 2023,
<https://doi.org/10.1103/physreva.107.022615>.
[hein-graph-entanglement]
Hein, M., Dür, W., Eisert, J., Raussendorf, R., Van den
Nest, M., and H. Briegel, "Entanglement in graph states
and its applications", IOS Press, Proceedings of the
International School of Physics “Enrico Fermi” vol. 162,
pp. 115–218, DOI 10.3254/978-1-61499-018-5-115, 2006,
<https://doi.org/10.3254/978-1-61499-018-5-115>.
[hein-multiparty]
Hein, M., Eisert, J., and H. Briegel, "Multiparty
entanglement in graph states", American Physical Society
(APS), Physical Review A vol. 69, no. 6,
DOI 10.1103/physreva.69.062311, June 2004,
<https://doi.org/10.1103/physreva.69.062311>.
[hilaire-logical-bsm]
Hilaire, P., Barnes, E., Economou, S., and F. Grosshans,
"Error-correcting entanglement swapping using a practical
logical photon encoding", American Physical Society (APS),
Physical Review A vol. 104, no. 5,
DOI 10.1103/physreva.104.052623, November 2021,
<https://doi.org/10.1103/physreva.104.052623>.
[hilaire-rgs-optimizing-gen-time]
Hilaire, P., Barnes, E., and S. Economou, "Resource
requirements for efficient quantum communication using
all-photonic graph states generated from a few matter
qubits", Verein zur Forderung des Open Access Publizierens
in den Quantenwissenschaften, Quantum vol. 5, pp. 397,
DOI 10.22331/q-2021-02-15-397, February 2021,
<https://doi.org/10.22331/q-2021-02-15-397>.
[horsman-lattice-surgery]
Horsman, D., Fowler, A., Devitt, S., and R. Meter,
"Surface code quantum computing by lattice surgery", IOP
Publishing, New Journal of Physics vol. 14, no. 12, pp.
123011, DOI 10.1088/1367-2630/14/12/123011, December 2012,
<https://doi.org/10.1088/1367-2630/14/12/123011>.
Van Meter, et al. Expires 5 May 2027 [Page 61]
Internet-Draft QNA November 2026
[huang-imaging-stars]
Huang, Z., Brennen, G., and Y. Ouyang, "Imaging Stars with
Quantum Error Correction", American Physical Society
(APS), Physical Review Letters vol. 129, no. 21,
DOI 10.1103/physrevlett.129.210502, November 2022,
<https://doi.org/10.1103/physrevlett.129.210502>.
[humphreys-deterministic-link]
Humphreys, P., Kalb, N., Morits, J., Schouten, R.,
Vermeulen, R., Twitchen, D., Markham, M., and R. Hanson,
"Deterministic delivery of remote entanglement on a
quantum network", Springer Science and Business Media LLC,
Nature vol. 558, no. 7709, pp. 268-273,
DOI 10.1038/s41586-018-0200-5, June 2018,
<https://doi.org/10.1038/s41586-018-0200-5>.
[I-D.draft-dahlberg-ll-quantum]
Dahlberg, A., Skrzypczyk, M., and S. Wehner, "The Link
Layer service in a Quantum Internet", Work in Progress,
Internet-Draft, draft-dahlberg-ll-quantum-03, 10 October
2019, <https://datatracker.ietf.org/doc/html/draft-
dahlberg-ll-quantum-03>.
[I-D.draft-hajdusek-qirg-timing-physics]
Hajdusek, M. and R. Van Meter, "Timing Regimes in Quantum
Networks and their Physical Underpinnings", Work in
Progress, Internet-Draft, draft-hajdusek-qirg-timing-
physics-01, 18 March 2026,
<https://datatracker.ietf.org/doc/html/draft-hajdusek-
qirg-timing-physics-01>.
[I-D.draft-kaws-qirg-advent]
Kompella, K., Aelmans, M., Wehner, S., Sirbu, C., and A.
Dahlberg, "Advertising Entanglement Capabilities in
Quantum Networks", Work in Progress, Internet-Draft,
draft-kaws-qirg-advent-03, 27 March 2019,
<https://datatracker.ietf.org/doc/html/draft-kaws-qirg-
advent-03>.
[I-D.draft-van-meter-qirg-quantum-connection-setup]
Van Meter, R. and T. Matsuo, "Connection Setup in a
Quantum Network", Work in Progress, Internet-Draft, draft-
van-meter-qirg-quantum-connection-setup-01, 11 September
2019, <https://datatracker.ietf.org/doc/html/draft-van-
meter-qirg-quantum-connection-setup-01>.
Van Meter, et al. Expires 5 May 2027 [Page 62]
Internet-Draft QNA November 2026
[I-D.draft-zhu-qirg-qdcp]
Zhu, A., Zhang, Y., Broberg, R. M., Feng, L., and J. M.
Smith, "Quantum Datagram Control Protocol (QDCP) for IP
Optical Environments", Work in Progress, Internet-Draft,
draft-zhu-qirg-qdcp-01, 1 April 2026,
<https://datatracker.ietf.org/doc/html/draft-zhu-qirg-
qdcp-01>.
[ilo-okeke-clock]
Ilo-Okeke, E., Tessler, L., Dowling, J., and T. Byrnes,
"Remote quantum clock synchronization without synchronized
clocks", Springer Science and Business Media LLC, npj
Quantum Information vol. 4, no. 1,
DOI 10.1038/s41534-018-0090-2, August 2018,
<https://doi.org/10.1038/s41534-018-0090-2>.
[khatri-spooky]
Khatri, S., Brady, A., Desporte, R., Bart, M., and J.
Dowling, "Spooky action at a global distance: analysis of
space-based entanglement distribution for the quantum
internet", Springer Science and Business Media LLC, npj
Quantum Information vol. 7, no. 1,
DOI 10.1038/s41534-020-00327-5, January 2021,
<https://doi.org/10.1038/s41534-020-00327-5>.
[kim-ft-million]
Kim, J., Min, D., Cho, J., Jeong, H., Byun, I., Choi, J.,
Hong, J., and J. Kim, "A Fault-Tolerant Million Qubit-
Scale Distributed Quantum Computer", ACM, Proceedings of
the 29th ACM International Conference on Architectural
Support for Programming Languages and Operating Systems,
Volume 2 pp. 1-19, DOI 10.1145/3620665.3640388, April
2024, <https://doi.org/10.1145/3620665.3640388>.
[koyama-24]
Koyama, M., Yun, C., Taherkhani, A., Benchasattabuse, N.,
Sane, B., Hajdušek, M., Nagayama, S., and R. Meter,
"Optimal Switching Networks for Paired-Egress Bell State
Analyzer Pools", IEEE, 2024 IEEE International Conference
on Quantum Computing and Engineering (QCE) pp. 1897-1907,
DOI 10.1109/qce60285.2024.00219, September 2024,
<https://doi.org/10.1109/qce60285.2024.00219>.
[leone-remote]
Leone, H., Le, T., Srikara, S., and S. Devitt, "Resource
overheads and attainable rates for trapped-ion lattice
surgery", arXiv, DOI 10.48550/ARXIV.2406.18764, 2024,
<https://doi.org/10.48550/ARXIV.2406.18764>.
Van Meter, et al. Expires 5 May 2027 [Page 63]
Internet-Draft QNA November 2026
[li-cosmic]
Li, X., Wang, J., Jiang, Y., Xue, G., Cai, X., Zhou, J.,
Gong, M., Liu, Z., Zheng, S., Ma, D., Chen, M., Sun, W.,
Yang, S., Yan, F., Jin, Y., Zhao, S., Ding, X., and H. Yu,
"Cosmic-ray-induced correlated errors in superconducting
qubit array", Springer Science and Business Media LLC,
Nature Communications vol. 16, no. 1,
DOI 10.1038/s41467-025-59778-z, May 2025,
<https://doi.org/10.1038/s41467-025-59778-z>.
[litinski-gosc]
Litinski, D., "A Game of Surface Codes: Large-Scale
Quantum Computing with Lattice Surgery", Verein zur
Forderung des Open Access Publizierens in den
Quantenwissenschaften, Quantum vol. 3, pp. 128,
DOI 10.22331/q-2019-03-05-128, March 2019,
<https://doi.org/10.22331/q-2019-03-05-128>.
[mahadev-homomorphic]
Mahadev, U., "Classical Homomorphic Encryption for Quantum
Circuits", Society for Industrial & Applied Mathematics
(SIAM), SIAM Journal on Computing vol. 52, no. 6, pp.
FOCS18-189-FOCS18-215, DOI 10.1137/18m1231055, December
2020, <https://doi.org/10.1137/18m1231055>.
[martinis-correlated]
Martinis, J., "Saving superconducting quantum processors
from decay and correlated errors generated by gamma and
cosmic rays", Springer Science and Business Media LLC, npj
Quantum Information vol. 7, no. 1,
DOI 10.1038/s41534-021-00431-0, June 2021,
<https://doi.org/10.1038/s41534-021-00431-0>.
[matsuo-link-boot]
Matsuo, T., Durand, C., and R. Van Meter, "Quantum link
bootstrapping using a RuleSet-based communication
protocol", American Physical Society (APS), Physical
Review A vol. 100, no. 5, DOI 10.1103/physreva.100.052320,
November 2019,
<https://doi.org/10.1103/physreva.100.052320>.
[matsuo-ms-thesis]
Matsuo, T., "Simulation of a Dynamic, RuleSet-based
Quantum Network", arXiv, arXiv,
DOI 10.48550/ARXIV.1908.10758, 2019,
<https://doi.org/10.48550/ARXIV.1908.10758>.
Van Meter, et al. Expires 5 May 2027 [Page 64]
Internet-Draft QNA November 2026
[mayers-unconditional]
Mayers, D., "Unconditional security in Quantum
Cryptography", arXiv, arXiv, DOI 10.48550/ARXIV.QUANT-
PH/9802025, 1998,
<https://doi.org/10.48550/ARXIV.QUANT-PH/9802025>.
[mccanne-bpf]
McCanne, S. and V. Jacobson, "The BSD packet filter: a new
architecture for user-level packet capture", USENIX'93:
Proceedings of the USENIX Winter 1993 Conference
Proceedings on USENIX Winter 1993 Conference Proceedings,
25 January 1993.
[meignant-dgs]
Meignant, C., Markham, D., and F. Grosshans, "Distributing
graph states over arbitrary quantum networks", American
Physical Society (APS), Physical Review A vol. 100, no. 5,
DOI 10.1103/physreva.100.052333, November 2019,
<https://doi.org/10.1103/physreva.100.052333>.
[mori-psds]
Mori, Y., Sasaki, T., Ikuta, R., Teramoto, K., Ohno, H.,
Hajdušek, M., Van Meter, R., and S. Nagayama, "Scalable
Timing Coordination of Bell State Analyzers in Quantum
Networks", IEEE, 2024 IEEE International Conference on
Quantum Computing and Engineering (QCE) pp. 1890-1896,
DOI 10.1109/qce60285.2024.00218, September 2024,
<https://doi.org/10.1109/qce60285.2024.00218>.
[morimae-blind]
Morimae, T. and K. Fujii, "Blind quantum computation
protocol in which Alice only makes measurements", American
Physical Society (APS), Physical Review A vol. 87, no. 5,
DOI 10.1103/physreva.87.050301, May 2013,
<https://doi.org/10.1103/physreva.87.050301>.
[mpi-5.0] Message_Passing_Interface_Forum, "MPI A Message-Passing
Interface Standard Version 5.0", June 2025,
<https://www.mpi-forum.org/docs/mpi-5.0/mpi50-report.pdf>.
[muralidharan-generations]
Muralidharan, S., Li, L., Kim, J., Lütkenhaus, N., Lukin,
M., and L. Jiang, "Optimal architectures for long distance
quantum communication", Springer Science and Business
Media LLC, Scientific Reports vol. 6, no. 1,
DOI 10.1038/srep20463, February 2016,
<https://doi.org/10.1038/srep20463>.
Van Meter, et al. Expires 5 May 2027 [Page 65]
Internet-Draft QNA November 2026
[nist-singles]
Bienfang, J., Gerrits, T., Kuo, P., Migdall, A., Polyakov,
S., and O. Slattery, "Single-photon Sources and Detectors
Dictionary", National Institute of Standards and
Technology, DOI 10.6028/nist.ir.8486r1, August 2025,
<https://doi.org/10.6028/nist.ir.8486r1>.
[pnpq] Taherkhani, A., Todd, A., Matsumiya, L., and T. Shen,
"PnPQ", Zenodo, DOI 10.5281/ZENODO.16886214, October 2026,
<https://doi.org/10.5281/ZENODO.16886214>.
[preskill-nisq]
Preskill, J., "Quantum Computing in the NISQ era and
beyond", Verein zur Forderung des Open Access Publizierens
in den Quantenwissenschaften, Quantum vol. 2, pp. 79,
DOI 10.22331/q-2018-08-06-79, August 2018,
<https://doi.org/10.22331/q-2018-08-06-79>.
[proctor-multiparm]
Proctor, T., Knott, P., and J. Dunningham, "Multiparameter
Estimation in Networked Quantum Sensors", American
Physical Society (APS), Physical Review Letters vol. 120,
no. 8, DOI 10.1103/physrevlett.120.080501, February 2018,
<https://doi.org/10.1103/physrevlett.120.080501>.
[proctor-quantum-sensing]
Proctor, T., Knott, P., and J. Dunningham, "Networked
quantum sensing", arXiv, DOI 10.48550/ARXIV.1702.04271,
2017, <https://doi.org/10.48550/ARXIV.1702.04271>.
[ramette-remote]
Ramette, J., Sinclair, J., Breuckmann, N., and V. Vuletić,
"Fault-tolerant connection of error-corrected qubits with
noisy links", Springer Science and Business Media LLC, npj
Quantum Information vol. 10, no. 1,
DOI 10.1038/s41534-024-00855-4, June 2024,
<https://doi.org/10.1038/s41534-024-00855-4>.
[rdv-thesis]
Van Meter III, R. D., "Architecture of a Quantum
Multicomputer Optimized for Shor's Factoring Algorithm",
Ph.D. Dissertation, Keio University, 2006,
<https://arxiv.org/abs/quant-ph/0607065>.
[RFC1122] Braden, R., Ed., "Requirements for Internet Hosts -
Communication Layers", STD 3, RFC 1122,
DOI 10.17487/RFC1122, October 1989,
<https://www.rfc-editor.org/rfc/rfc1122>.
Van Meter, et al. Expires 5 May 2027 [Page 66]
Internet-Draft QNA November 2026
[RFC1123] Braden, R., Ed., "Requirements for Internet Hosts -
Application and Support", STD 3, RFC 1123,
DOI 10.17487/RFC1123, October 1989,
<https://www.rfc-editor.org/rfc/rfc1123>.
[RFC1958] Carpenter, B., Ed., "Architectural Principles of the
Internet", RFC 1958, DOI 10.17487/RFC1958, June 1996,
<https://www.rfc-editor.org/rfc/rfc1958>.
[RFC5218] Thaler, D. and B. Aboba, "What Makes for a Successful
Protocol?", RFC 5218, DOI 10.17487/RFC5218, July 2008,
<https://www.rfc-editor.org/rfc/rfc5218>.
[RFC6250] Thaler, D., "Evolution of the IP Model", RFC 6250,
DOI 10.17487/RFC6250, May 2011,
<https://www.rfc-editor.org/rfc/rfc6250>.
[RFC6852] Housley, R., Mills, S., Jaffe, J., Aboba, B., and L.
St.Amour, "Affirmation of the Modern Paradigm for
Standards", RFC 6852, DOI 10.17487/RFC6852, January 2013,
<https://www.rfc-editor.org/rfc/rfc6852>.
[RFC9340] Kozlowski, W., Wehner, S., Van Meter, R., Rijsman, B.,
Cacciapuoti, A. S., Caleffi, M., and S. Nagayama,
"Architectural Principles for a Quantum Internet",
RFC 9340, DOI 10.17487/RFC9340, March 2023,
<https://www.rfc-editor.org/rfc/rfc9340>.
[RFC9413] Thomson, M. and D. Schinazi, "Maintaining Robust
Protocols", RFC 9413, DOI 10.17487/RFC9413, June 2023,
<https://www.rfc-editor.org/rfc/rfc9413>.
[RFC9583] Wang, C., Rahman, A., Li, R., Aelmans, M., and K.
Chakraborty, "Application Scenarios for the Quantum
Internet", RFC 9583, DOI 10.17487/RFC9583, June 2024,
<https://www.rfc-editor.org/rfc/rfc9583>.
[sakuma-q-fly]
Sakuma, D., Tsuno, T., Shimizu, H., Kurosawa, Y.,
Friedrich, M., Teramoto, K., Taherkhani, A., Todd, A.,
Ueno, Y., Hajdušek, M., Ikuta, R., Van Meter, R., Sasaki,
T., and S. Nagayama, "Q-Fly: An Optical Interconnect for
Modular Quantum Computers", arXiv,
DOI 10.48550/ARXIV.2412.09299, 2024,
<https://doi.org/10.48550/ARXIV.2412.09299>.
Van Meter, et al. Expires 5 May 2027 [Page 67]
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[sane-jobs]
Sane, B., Hajdušek, M., and R. Van Meter, "Optimizing
Resource Allocation in a Distributed Quantum Computing
Cloud: A Game-Theoretic Approach", arXiv,
DOI 10.48550/ARXIV.2504.18298, 2025,
<https://doi.org/10.48550/ARXIV.2504.18298>.
[sane-phonons]
Sane, B., Meter, R., and M. Hajdusek, "Fight or Flight:
Cosmic Ray-Induced Phonons and the Quantum Surface
Code<sup>*</sup>", IEEE, 2023 IEEE International
Conference on Quantum Computing and Engineering (QCE) pp.
1378-1388, DOI 10.1109/qce57702.2023.00156, September
2023, <https://doi.org/10.1109/qce57702.2023.00156>.
[satoh-attacking]
Satoh, T., Nagayama, S., Suzuki, S., Matsuo, T., Hajdusek,
M., and R. Meter, "Attacking the Quantum Internet",
Institute of Electrical and Electronics Engineers (IEEE),
IEEE Transactions on Quantum Engineering vol. 2, pp. 1-17,
DOI 10.1109/tqe.2021.3094983, 2021,
<https://doi.org/10.1109/tqe.2021.3094983>.
[satoh-ms-thesis]
Satoh, R., "RuLa A Programming Language for RuleSet-based
Quantum Repeaters", M.S. Thesis, Keio University, 2023,
<https://aqua.sfc.wide.ad.jp/publications/
cocori_mthesis.pdf>.
[schoute-shortcuts]
Schoute, E., Mancinska, L., Islam, T., Kerenidis, I., and
S. Wehner, "Shortcuts to quantum network routing", arXiv,
DOI 10.48550/ARXIV.1610.05238, 2016,
<https://doi.org/10.48550/ARXIV.1610.05238>.
[seitz-cosmic-cube]
Seitz, C., "The cosmic cube", Association for Computing
Machinery (ACM), Communications of the ACM vol. 28, no. 1,
pp. 22-33, DOI 10.1145/2465.2467, January 1985,
<https://doi.org/10.1145/2465.2467>.
[shapourian-qdc-infra]
Shapourian, H., Kaur, E., Sewell, T., Zhao, J., Kilzer,
M., Kompella, R., and R. Nejabati, "Quantum Data Center
Infrastructures: A Scalable Architectural Design
Perspective", arXiv, DOI 10.48550/ARXIV.2501.05598, 2025,
<https://doi.org/10.48550/ARXIV.2501.05598>.
Van Meter, et al. Expires 5 May 2027 [Page 68]
Internet-Draft QNA November 2026
[sinclair-ft-interconnect]
Sinclair, J., Ramette, J., Grinkemeyer, B., Bluvstein, D.,
Lukin, M., and V. Vuletić, "Fault-tolerant optical
interconnects for neutral-atom arrays", arXiv,
DOI 10.48550/ARXIV.2408.08955, 2024,
<https://doi.org/10.48550/ARXIV.2408.08955>.
[sutcliffe-dist-qec]
Sutcliffe, E., Jonnadula, B., Le Gall, C., Moylett, A.,
and C. Westoby, "Distributed Quantum Error Correction
Based on Hyperbolic Floquet Codes", IEEE, 2025 IEEE
International Conference on Quantum Computing and
Engineering (QCE) pp. 649-657,
DOI 10.1109/qce65121.2025.00076, August 2025,
<https://doi.org/10.1109/qce65121.2025.00076>.
[taherkhani-byz]
Taherkhani, M., Navi, K., and R. Meter, "Resource-aware
system architecture model for implementation of quantum
aided Byzantine agreement on quantum repeater networks",
IOP Publishing, Quantum Science and Technology vol. 3, no.
1, pp. 014011, DOI 10.1088/2058-9565/aa9bb1, December
2017, <https://doi.org/10.1088/2058-9565/aa9bb1>.
[tdc_toolkit]
Todd, A. and K. Teramoto, "tdc_toolkit", Zenodo,
DOI 10.5281/ZENODO.16932740, June 2026,
<https://doi.org/10.5281/ZENODO.16932740>.
[tennenhouse-an-arch]
Tennenhouse, D. and D. Wetherall, "Towards an active
network architecture", Association for Computing Machinery
(ACM), ACM SIGCOMM Computer Communication Review vol. 26,
no. 2, pp. 5-17, DOI 10.1145/231699.231701, April 1996,
<https://doi.org/10.1145/231699.231701>.
[van-meter-dist-arith]
Meter, R., Munro, W., Nemoto, K., and K. Itoh, "Arithmetic
on a distributed-memory quantum multicomputer",
Association for Computing Machinery (ACM), ACM Journal on
Emerging Technologies in Computing Systems vol. 3, no. 4,
pp. 1-23, DOI 10.1145/1324177.1324179, January 2008,
<https://doi.org/10.1145/1324177.1324179>.
Van Meter, et al. Expires 5 May 2027 [Page 69]
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[van-meter-opt-timing]
Van Meter, R., Satoh, T., Nagayama, S., Matsuo, T., and S.
Suzuki, "Optimizing Timing of High-Success-Probability
Quantum Repeaters", arXiv, DOI 10.48550/ARXIV.1701.04586,
2017, <https://doi.org/10.48550/ARXIV.1701.04586>.
[van-meter-path-sel]
Van Meter, R., Satoh, T., Ladd, T., Munro, W., and K.
Nemoto, "Path selection for quantum repeater networks",
Springer Science and Business Media LLC, Networking
Science vol. 3, no. 1-4, pp. 82-95,
DOI 10.1007/s13119-013-0026-2, December 2013,
<https://doi.org/10.1007/s13119-013-0026-2>.
[van-meter-q-net-book]
Van Meter, R., "Quantum Networking", Wiley,
DOI 10.1002/9781118648919, ISBN ["9781848215375",
"9781118648919"], April 2014,
<https://doi.org/10.1002/9781118648919>.
[van-meter-qi-arch]
Van Meter, R., Satoh, R., Benchasattabuse, N., Teramoto,
K., Matsuo, T., Hajdusek, M., Satoh, T., Nagayama, S., and
S. Suzuki, "A Quantum Internet Architecture", IEEE, 2022
IEEE International Conference on Quantum Computing and
Engineering (QCE) pp. 341-352,
DOI 10.1109/qce53715.2022.00055, September 2022,
<https://doi.org/10.1109/qce53715.2022.00055>.
[van-meter-sys-design]
Van Meter, R., Ladd, T., Munro, W., and K. Nemoto, "System
Design for a Long-Line Quantum Repeater", Institute of
Electrical and Electronics Engineers (IEEE), IEEE/ACM
Transactions on Networking vol. 17, no. 3, pp. 1002-1013,
DOI 10.1109/tnet.2008.927260, June 2009,
<https://doi.org/10.1109/tnet.2008.927260>.
[vepsaelaeinen-ionizing]
Vepsäläinen, A., Karamlou, A., Orrell, J., Dogra, A.,
Loer, B., Vasconcelos, F., Kim, D., Melville, A.,
Niedzielski, B., Yoder, J., Gustavsson, S., Formaggio, J.,
VanDevender, B., and W. Oliver, "Impact of ionizing
radiation on superconducting qubit coherence", Springer
Science and Business Media LLC, Nature vol. 584, no. 7822,
pp. 551-556, DOI 10.1038/s41586-020-2619-8, August 2020,
<https://doi.org/10.1038/s41586-020-2619-8>.
Van Meter, et al. Expires 5 May 2027 [Page 70]
Internet-Draft QNA November 2026
[wehner-roadmap]
Wehner, S., Elkouss, D., and R. Hanson, "Quantum internet:
A vision for the road ahead", American Association for the
Advancement of Science (AAAS), Science vol. 362, no. 6412,
DOI 10.1126/science.aam9288, October 2018,
<https://doi.org/10.1126/science.aam9288>.
[wikipedia-fugaku]
Wikipedia_contributors, "Fugaku (supercomputer)",
September 2026, <https://en.wikipedia.org/w/
index.php?title=Fugaku_(supercomputer)&oldid=1373731812>.
[wu-mitigating]
Wu, X., Joshi, Y., Yan, H., Andersson, G., Anferov, A.,
Conner, C., Karimi, B., King, A., Li, S., Malc, H.,
Miller, J., Mishra, H., Qiao, H., Ryu, M., Xing, S., Shi,
J., and A. Cleland, "Mitigating cosmic-ray-like correlated
events with a modular quantum processor", American
Physical Society (APS), Physical Review Applied vol. 24,
no. 4, DOI 10.1103/4ctq-r6w6, October 2025,
<https://doi.org/10.1103/4ctq-r6w6>.
[xu-dist-qec]
Xu, Q., Seif, A., Yan, H., Mannucci, N., Sane, B., Van
Meter, R., Cleland, A., and L. Jiang, "Distributed Quantum
Error Correction for Chip-Level Catastrophic Errors",
American Physical Society (APS), Physical Review
Letters vol. 129, no. 24,
DOI 10.1103/physrevlett.129.240502, December 2022,
<https://doi.org/10.1103/physrevlett.129.240502>.
[yin-1200km]
Yin, J., Cao, Y., Li, Y., Liao, S., Zhang, L., Ren, J.,
Cai, W., Liu, W., Li, B., Dai, H., Li, G., Lu, Q., Gong,
Y., Xu, Y., Li, S., Li, F., Yin, Y., Jiang, Z., Li, M.,
Jia, J., Ren, G., He, D., Zhou, Y., Zhang, X., Wang, N.,
Chang, X., Zhu, Z., Liu, N., Chen, Y., Lu, C., Shu, R.,
Peng, C., Wang, J., and J. Pan, "Satellite-based
entanglement distribution over 1200 kilometers", American
Association for the Advancement of Science (AAAS),
Science vol. 356, no. 6343, pp. 1140-1144,
DOI 10.1126/science.aan3211, June 2017,
<https://doi.org/10.1126/science.aan3211>.
Van Meter, et al. Expires 5 May 2027 [Page 71]
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[yoder-tour-de-gross]
Yoder, T., Schoute, E., Rall, P., Pritchett, E., Gambetta,
J., Cross, A., Carroll, M., and M. Beverland, "Tour de
gross: A modular quantum computer based on bivariate
bicycle codes", arXiv, DOI 10.48550/ARXIV.2506.03094,
2025, <https://doi.org/10.48550/ARXIV.2506.03094>.
[yu-two-level]
Yu, S., Perego, E., Phillips, J., Cheah, Y., Umesh, P.,
Gao, G., Liu, J., Kissel, E., Bregar, M., Sun, K., Wu, Q.,
Valivarthi, R., Saglamyurek, E., Wu, W., Spiropulu, M.,
Häffner, H., and I. Monga, "A Two-Level Control Framework
for Quantum Networks", IEEE, 2025 IEEE International
Conference on Quantum Computing and Engineering (QCE) pp.
1302-1311, DOI 10.1109/qce65121.2025.00145, August 2025,
<https://doi.org/10.1109/qce65121.2025.00145>.
[zukowski-entanglement-swapping]
Kaszlikowski, D., Kwek, L., Chen, J., Żukowski, M., and C.
Oh, "Clauser-Horne inequality for three-state systems",
American Physical Society (APS), Physical Review A vol.
65, no. 3, DOI 10.1103/physreva.65.032118, February 2002,
<https://doi.org/10.1103/physreva.65.032118>.
Contributors
Michal Hajdusek
Keio University
5322 Endo, Fujisawa, Kanagawa
252-0882
Japan
Michal was involved in document development and technical discussions
from the beginning.
Andrew Todd
Keio University
5322 Endo, Fujisawa, Kanagawa
252-0882
Japan
Andrew leads the software team implementing much of the network, and
provides feedback on system structure.
Van Meter, et al. Expires 5 May 2027 [Page 72]
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Monet Tokuyama Friedrich
Keio University
5322 Endo, Fujisawa, Kanagawa
252-0882
Japan
Contributed presentations and clarity; reviewed this document;
authoring related specifications.
Shota Nagayama
Keio University
5322 Endo, Fujisawa, Kanagawa
252-0882
Japan
Contributed presentations and clarity; reviewed this document and
related documents; technical and managerial leadership.
Akihito Soeda
National Institute for Informatics
2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo
101-8430
Japan
Technical and managerial discussions.
Authors' Addresses
Rodney Van Meter
Keio University
5322 Endo, Fujisawa, Kanagawa
252-0882
Japan
Email: rdv@sfc.wide.ad.jp
Naphan Benchasattabuse
Keio University
5322 Endo, Fujisawa, Kanagawa
252-0882
Japan
Email: whit3z@sfc.wide.ad.jp
Van Meter, et al. Expires 5 May 2027 [Page 73]
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Amin Taherkhani
Keio University
5322 Endo, Fujisawa, Kanagawa
252-0882
Japan
Email: amin@sfc.wide.ad.jp
Van Meter, et al. Expires 5 May 2027 [Page 74]