Technical Summary
This document presents home control and automation application
specific requirements for Routing Over Low power and Lossy
networks (ROLL). In a modern home, a high number of wireless
devices are used for a wide set of purposes. Examples include
actuators (relay, light dimmer, heating valve), sensors (wall
switch, water leak, blood pressure) and advanced controllers.
Basic home control modules such as wall switches and plug-in
modules may be turned into an advanced home automation solution
via the use of an IP-enabled application responding to events
generated by wall switches, motion sensors, light sensors, rain
sensors, and so on.
Network nodes may be sensors and actuators at the same time. An
example is a wall switch for replacement in existing buildings.
The push buttons may generate events for a controller node or for
activating other actuator nodes. At the same time, a built-in
relay may act as actuator for a controller or other remote
sensors.
Because ROLL nodes only cover a limited radio range, routing is
often required. These devices are usually highly constrained in
term of resources such as battery and memory and operate in
unstable environments. Persons moving around in a house, opening
or closing a door or starting a microwave oven affect the
reception of weak radio signals. Reflection and absorption may
cause a reliable radio link to turn unreliable for a period of
time and then being reusable again, thus the term "lossy".
Unlike other categories of PANs, the connected home area is very
much consumer-oriented. The implication on network nodes is that
devices are very cost sensitive, which leads to resource-
constrained environments having slow CPUs and small memory
footprints. At the same time, nodes have to be physically small
which puts a limit to the physical size of the battery; and thus,
the battery capacity. As a result, it is common for low-power
sensor-style nodes to shut down radio and CPU resources for most
of the time. The radio tends to use the same power for listening
as for transmitting
Section 2 describes a few typical use cases for home automation
applications. Section 3 discusses the routing requirements for
networks comprising such constrained devices in a home network
environment. These requirements may be overlapping requirements
derived from other application-specific routing requirements. A
full list of requirements documents may be found in the end of the
document.
Working Group Summary
No controversy.
Document Quality
The I-D is informational and specifies routing requirements
Personnel
JP Vasseur (jpv@cisco.com) is the Document Shepherd.
Adrian Farrel (adrian.farrel@huawei.com) is the Responsible AD.
RFC Editor Note
Section 1
ADD new paragraph before the paragraph beginning "Section 2 describes a
few..."
Although this document focuses its text on radio-based wireless
networks, home automation networks may also operate using a variety
of links, such as IEEE 802.15.4, Bluetooth, Low Power WiFi, wired or
other low power PLC (Powerline Communication) links. Many such low
power link technologies share similar characteristics with low power
wireless and this document should be regarded as applying equally to
all such links.
---
Section 3.3
OLD
Looking at the number of wall switches, power outlets, sensors of
various nature, video equipment and so on in a modern house, it
seems quite realistic that hundreds of low power devices may form
a home automation network in a fully populated "smart" home.
Moving towards professional building automation, the number of
such devices may be in the order of several thousands.
The routing protocol MUST support 250 devices in the network.
NEW
Looking at the number of wall switches, power outlets, sensors of
various nature, video equipment and so on in a modern house, it
seems quite realistic that hundreds of devices may form a home
automation network in a fully populated "smart" home, and a large
proportion of those may be low power devices. Moving towards
professional building automation, the number of such devices may be
in the order of several thousands.
The routing protocol needs to be able to support a basic home
deployment and so MUST be able to support at least 250 devices in the
network. Furthermore, the protocol SHOULD be extensible to support
more sophisticated and future deployments with a larger number of
devices.
---
Section 3.4
OLD
The routing protocol MUST converge within 0.5 second if no nodes
have moved.
NEW
The routing protocol MUST converge within 0.5 second if no nodes
have moved (see Section 3.2 for motivation).
---
Section 3.4
OLD
The routing protocol MUST converge within 4 seconds if nodes have
moved.
NEW
The routing protocol MUST converge within 4 seconds if nodes have
moved to re-establish connectivity within a time that a human
operator would find tolerable as, for example, when moving a
remote control unit.
---
Section 4
OLD
Remote controls have a similar transmit pattern to wall switches,
but are activated more frequently.
NEW
Remote controls have a similar transmit pattern to wall switches,
but may be activated more frequently in some deployments.
---
Section 4
DELETE
As mentioned in the introduction, all messages are carried in IPv6
packets; typically as UDP but ICMP echo and other types may also
appear.
In order to save bandwidth, the transport layer will typically be
using header compression [I-D.Hui-HeaderCompression].
---