Internet-Draft DLEP Radio Band Extension March 2022
Rogge Expires 8 September 2022 [Page]
Intended Status:
Standards Track
H.R. Rogge
Fraunhofer FKIE

DLEP Radio Band Extension


This document defines an extension to the Dynamic Link Exchange Protocol (DLEP) to provide the frequency bands used by the radio.

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at

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This Internet-Draft will expire on 8 September 2022.

1. Introduction

The dynamic Link Exchange Protocol (DLEP) is defined in [RFC8175]. It provides the exchange of link-related control information between DLEP peers. DLEP peers are comprised of a modem and a router. DLEP defines a base set of mechanisms as well as support for possible extensions. This document defines one such extension.

1.1. Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

2. Extension Usage and Identification

The use of the Radio Band Extension SHOULD be configurable. To indicate that the Radio Band Extension is to be used, an implementation MUST include the Radio Band Extension Type Value in the Extensions Supported Data Item. The Extensions Supported Data Item is sent and processed according to [RFC8175].

The Radio Band Extension Type Value is TBD; see Section TBD.

3. Radio Band Data Item

Radio Band Data Item contains information which radio frequency resources are being used. These values are usually interface specific and static during the DLEP session.

The Radio Band Data Item can be used multiple times to represent multiple radio bands.

The Item can be used in a neighbor specific message if the radio use dedicated subcarriers to talk to neighbors.

The information in this Item gives the router an easy way to calculate the spectral efficiency of a radio link, how much bandwidth is used for the current data-rate reported by DLEP. This can be integrated into the routing metric to focus traffic on links that use the spectrum efficiently.

The Item can also be used as an interface to a cognitive radio controller on the router, analyzing the correlation of transmission disruptions with the frequency bands and could (together with the Request Link Characteristics message) be used to change the frequency of the radio in a standardized way.

The format of the Radio Band Data Item is:

0                   1                   2                   3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
| Data Item Type                | Length                        |
|                       Carrier Frequency                       |
|                       Carrier Frequency                       |
|                           Bandwidth                           |
|                           Bandwidth                           |
|     Flags     |
Figure 1
Data Item Type:
Center Frequency:
The center frequency of the band in Hz.
The bandwidth of the band in Hz.
Flags field as defined below.

The Flags field is defined as:

0 1 2 3 4 5 6 7
| Reserved  |U|D|
Figure 2
Uplink Flag, indicating the band is used for transmitting data.
Downlink Flag, indicating the band is used for receiving data.
MUST be zero. Left for future assignment.

4. Security Considerations

The extension introduces a new Data Item for DLEP. The extension does not inherently introduce any additional vulnerabilities above those documented in [RFC8175]. The approach taken to security in that document applies equally when running the extension defined in this document.

5. IANA Considerations

As described below, IANA has assigned two values per this document. Both assignments are to registries defined by [RFC8175].

5.1. Extension Type Value

IANA has assigned the following value in the "Extension Type Values" registry within the "Dynamic Link Exchange Protocol (DLEP) Parameters" registry. The new value is in the range with the "Specification Required" [RFC8126] policy:

Table 1: New Extension Type Value
Code Description
TBD Radio Band

5.2. Data Item Value

IANA has assigned the following value in the "Data Item Type Values" registry within the "Dynamic Link Exchange Protocol (DLEP) Parameters" registry. The new value is in the range with the "Specification Required" [RFC8126] policy:

Table 2: New Data Item Value
Type Code Description
TBD Radio Band

6. Normative References

Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <>.
Ratliff, S., Jury, S., Satterwhite, D., Taylor, R., and B. Berry, "Dynamic Link Exchange Protocol (DLEP)", RFC 8175, DOI 10.17487/RFC8175, , <>.

7. Informative References

Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, , <>.

Author's Address

Henning Rogge
Fraunhofer FKIE
Fraunhofer Strasse 20
53343 Wachtberg