wdiff draft-ietf-roll-home-routing-reqs-02.txt draft-ietf-roll-home-routing-reqs-03.txt

Networking Working Group A. Brandt
Internet Draft Zensys, Inc.
Intended status: Informational G. Porcu
Expires: January 2009 Telecom Italia
July 14,
September 11, 2008

Home Automation Routing Requirement in Low Power and Lossy
Networks
draft-ietf-roll-home-routing-reqs-02
draft-ietf-roll-home-routing-reqs-03

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Abstract

This document presents home control and automation application
specific requirements for ROuting in 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 lighting control,
actuators (relay, light dimmer, heating control, sensors, leak detectors, healthcare systems valve), sensors (wall
switch, water leak, blood pressure) and advanced remote controls. controllers.
Because such devices only cover a limited radio range, multi-hop routing is
often required. The aim of this document is to specify the routing
requirements for networks comprising such constrained devices in a
home network control and automation environment.

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 RFC-2119
[RFC2119].

Table of Contents

Terminology......................................................3
1. Terminology....................................................3 Introduction..................................................5
2. Introduction...................................................3
3. Home automation applications...................................4
3.1. Turning off the house when leaving........................4
3.2. Automation Applications..................................6
2.1. Lighting Application In Action...........................6
2.2. Energy conservation Conservation and optimizing energy consumption.....5
3.3. Optimizing Energy Consumption....6
2.3. Moving a remote control around............................5
3.4. Remote Control Around...........................7
2.4. Adding a new lamp module to the system....................6
3.5. A New Module To The System........................7
2.5. Controlling battery operated window shades................6
3.6. Battery Operated Window Shades...............8
2.6. Remote video surveillance.................................6
3.7. Healthcare................................................7
3.7.1. Video Surveillance................................8
2.7. Healthcare...............................................8
2.7.1. At-home health reporting.............................7
3.7.2. Health Reporting............................9
2.7.2. At-home health monitoring............................8
3.7.3. Healthcare routing considerations....................8
3.8. Health Monitoring...........................9
2.8. Alarm systems.............................................8
3.9. Battery-powered devices...................................9
4. Systems............................................9
3. Unique requirements Routing Requirements of home automation applications............9
4.1. Home Automation Applications..10
3.1. Support of groupcast......................................9
4.2. Groupcast....................................11
3.2. Constraint-based Routing.................................10
4.3. Support of Mobility......................................10
4.4. Routing................................12
3.3. Support of Periodical Scanning...........................11
4.5. Scalability..............................................11
4.6. Mobility.....................................12
3.4. Sleeping Nodes..........................................13
3.5. Healthcare Routing......................................13
3.6. Scalability.............................................13
3.7. Convergence Time.........................................11
4.7. Manageability............................................12
5. Time........................................14
3.8. Manageability...........................................14
3.9. Stability...............................................14
4. Traffic Pattern...............................................12
6. Pattern..............................................14
5. Open issues...................................................13
7. Issues..................................................15
6. Security Considerations.......................................13
8. Considerations......................................15
7. IANA Considerations...........................................13 Considerations..........................................15
8. Acknowledgments..............................................15
9. Acknowledgments...............................................13
10. References...................................................14
10.1. References...................................................16
9.1. Normative References....................................14
10.2. References....................................16
9.2. Informative References..................................14 References..................................17
Disclaimer of Validity...........................................15

1. Validity..........................................18

Terminology

ROLL: ROuting in Routing Over Low-power and Lossy networks

ROLL device:
A ROLL network node with constrained CPU and memory
resources; potentially constrained power resources. may be classified as sensor, actuator
or controller.

Access Point: The access point is an infrastructure device that
connects the low power and lossy a ROLL network system to the
Internet, possibly via a customer premises local area
network (LAN).

LAN: Local Area Network.

PAN: Personal Area Network.
A geographically limited wireless network based on
e.g. 802.15.4 Internet or Z-Wave radio. some
backbone network.

Actuator: Network node which performs some physical action.
Dimmers and relays are examples of actuators.

If sufficiently powered, actuator nodes may
participate in routing network messages.

Channel: Radio frequency band used to transmit a modulated
signal carrying carry network packets.

Controller: Network node that controls actuators. Control
decisions may be based on sensor readings, sensor
events, scheduled actions or incoming commands from
the Internet or other backbone networks.
If sufficiently powered, controller nodes may
participate in routing network messages.

Downstream: Data direction traveling from a Local Area Network
(LAN) to a Personal Area Network (PAN) device.

Upstream: Data direction traveling from a PAN

DR: Demand-Response
The mechanism of users adjusting their power
consumption in response to actual pricing of power.

DSM: Demand Side Management
Process allowing power utilities to enable and
disable loads in consumer premises. Where DR relies
on voluntary action from users, DSM may be based on
enrollment in a LAN device.

Sensor: formal program.

LAN: Local Area Network.

PAN: Personal Area Network.
A PAN device geographically limited wireless network based on
e.g. 802.15.4 or Z-Wave radio.

PDA Personal Digital Assistant. A small, handheld
computer.

PLC Power Line Communication

RAM Random Access Memory

Sensor: Network node that measures data and/or detects an
event.

2. Introduction

This document presents the home control and automation application
specific
The sensor may generate a trap message to notify a
controller or directly activate an actuator.
If sufficiently powered, sensor nodes may
participate in routing network messages.

Upstream: Data direction traveling from a PAN to a LAN
device.

1. Introduction

This document presents home control and automation application
specific requirements for Routing in Over Low power and Lossy Networks
networks (ROLL). In a modern home, a high number of wireless
devices are used for a wide set of purposes. Examples include lighting control
modules, heating control panels,
actuators (relay, light sensors, temperature sensors,
gas/water leak detectors, motion detectors, video surveillance,
healthcare systems dimmer, heating valve), sensors (wall
switch, water leak, blood pressure) and advanced remote controls. 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 such devices ROLL nodes only cover a limited radio range, multi-hop 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 implications implication on network nodes in this aspect, 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
sensor-style nodes to shut down radio and CPU resources for most
of the time. Often, the The radio uses tends to use the same power for listening
as for
transmitting. transmitting

Section 3 2 describes a few typical use cases for home automation
applications. Section 4 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.

3. A
full list of requirements documents may be found in the end of the
document.

2. Home automation applications Automation Applications

Home automation applications represent a special segment of
networked
wireless devices with its unique set of requirements.
Historically, such applications used wired networks or power line
communication (PLC), but wireless solutions have emerged; allowing
existing buildings to be upgraded more easily.

To facilitate the requirements discussion in Section 4, 3, this
section lists a few typical use cases of home automation
applications. New applications are being developed at a high pace
and this section does not mean to be exhaustive. Most home
automation applications tend to be running some kind of
command/response protocol. The command may come from several
places. For instance a

2.1. Lighting Application In Action

A lamp may be turned on, not only be by a wall switch but also from by a
movement sensor.

3.1. Turning off The wall switch module may itself be a push-
button sensor and an actuator at the house same time. This will often be
the case when leaving upgrading existing buildings as existing wiring is
not prepared for automation.

One event may cause many actuators to be activated at the same
time.
Using the direct analogy to an electronic car key, a house owner
may activate the "leaving home" function from an electronic house
key, mobile phone, etc. For the sake of visual impression, all
lights should turn off at the same time. At least, it should
appear to happen at the same time. A well-known problem in
wireless home automation is the "popcorn effect": Lamps are turned
on one at a time, at a rate so slow that it is clearly visible.
Some existing home automation solutions use a clever mix of a
"subnet groupcast" message in direct range with no acknowledgement and no forwarding
before sending acknowledged singlecast messages to each lighting device.

The controller forms the groups group and decides which nodes should
receive "turn-off" or "turn-on" requests.

3.2. a message.

2.2. Energy conservation Conservation and optimizing energy consumption

Parts of the world using Optimizing Energy Consumption

In order to save energy, air conditioning may let conditioning, central heating, window
shades go down and
turn off the AC device when leaving home. Air conditioning etc. may start be controlled by timer timers, motion sensors or
remotely via motion sensor when the owner returns home. The owner
may even activate the air conditioning via cell phone before getting
home.

Geographical areas using central internet or cell. Central heating may turn off heating when
not at home and use also be set to
a reduced temperature during night time.

The power grid may experience periods where more wind-generated
power is produced than is needed. Typically this may happen during
night hours. The washing machine and dish washer may just as well work
while power is cheap. The electric car should also charge its
batteries on cheap power.

In periods where electricity demands exceed available supply,
appliances such as air conditioning, climate control systems,
washing machines etc. can be turned off to avoid overloading the
power grid.
Wireless remote
This is known as Demand-Side Management (DSM).
Remote control of the household appliances is well-suited for this
application.

The start/stop decision for the appliances can also be regulated
by dynamic power pricing information obtained from the electricity
utility companies. Moreover, in This method called Demand-Response (DR) works
by motivation of users via pricing, bonus points, etc. For
example, the washing machine and dish washer may just as well work
while power is cheap. The electric car should also charge its
batteries on cheap power.

In order to achieve effective electricity savings, the energy
monitoring application
running on the Wireless Sensor Network (WSN) must guarantee that the power consumption
of the ROLL devices is much lower than that of the appliance
itself.

Most of these applications appliances are mains powered and are thus ideal for
providing reliable, always-on routing resources. Battery-powered
nodes, by comparison, are constrained routing resources and may
only provide reliable routing under some circumstances.

3.3.

2.3. Moving a remote control around Remote Control Around

A remote control is a typical example of a mobile device in a home
automation network. An advanced remote control may be used for
dimming the light in the dining room while eating and later on,
turning up the music while doing the dishes in the kitchen.
Reaction must appear to be instant (within a few hundred
milliseconds) even when the remote control has moved to a new
location. The remote control may be communicating to either a
central home automation controller or directly to the lamps and
the media center.

3.4.

2.4. Adding a new lamp module to the system A New Module To The System

Small-size, low-cost modules may have no user interface except for
a single button. Thus, an automated inclusion process is needed
for controllers to find new modules. Inclusion covers the
detection of neighbors and assignment of a unique node ID.
Inclusion should be completed within a few seconds.

Distribution

If assignment of unique addresses is usually performed by a central
controller. In this case,
controller, it must be possible to route the inclusion request
from the joining node to the central controller even before the joining
node is assigned a unique address.

3.5. has been included in the network.

2.5. Controlling battery operated window shades Battery Operated Window Shades

In consumer premises, window shades are often battery-powered as
there is no access to mains power over the windows. For battery
conservation purposes, the receiver such an actuator node is sleeping most of
the time. A
home automation controller sending commands to window shades a sleeping actuator
node via ROLL devices will have no problems delivering the packet
to the nearest powered router, but the that router may have to wait for some experience a
delay until the next wake-up time before the command can be delivered to the window shades if the receiver is sleeping; e.g.
up to 250ms.

3.6.
delivered.

2.6. Remote video surveillance Video Surveillance

Remote video surveillance is a fairly classic application for Home
networking providing the ability for the end user to get a video
stream from a Web Cam reached via the Internet, which can Internet. The video stream
may be triggered by the end-user that has received after receiving an alarm from a movement
sensor (movement or smoke detector - detector) or the user simply wants to
check the home status via video.
Note that in the former case, more than likely, there will be a
form of inter-device communication: indeed, upon Upon detecting some movement
in the home, the movement sensor may send a request to the light
controller to turn-on turn on the lights, to the Web Cam to start a video
stream that would then be directed to the end user (cell phone, PDA) user's cell phone or
Personal Digital Assistant (PDA) via the Internet.
By
In contrast with to other applications, e.g. industrial sensors sensors, where
data would mainly be originated by sensor to a sink and vice
versa, this scenario implicates a direct inter-device
communication between ROLL devices.

3.7.

2.7. Healthcare

By adding communication capability to devices, patients and
elderly citizens may be able to do simple measurements at home.
Thanks to online devices, a doctor can keep an eye on the
patient's health and receive warnings if a new trend is discovered
by automated filters.

Fine-grained daily measurements presented in proper ways may allow
the doctor to establish a more precise diagnosis.

Such applications may be realized as wearable products which
frequently do a measurement and automatically deliver the result
to a data sink locally or over the Internet.

Applications falling in this category are referred to as at-home
health reporting. Whether measurements are done in a fixed
interval or if they are manually activated, they leave all
processing to the receiving data sink.

A more active category of applications may send an alarm if some
alarm condition is triggered. This category of applications is
referred to as at-home health monitoring. Measurements are
interpreted in the device and may cause reporting of an event if
an alarm is triggered.

Many implementations may overlap both categories.

3.7.1.

2.7.1. At-home health reporting Health Reporting

Applications might include:

o Temperature
o Weight
o Blood pressure
o Insulin level

Measurements may be stored for long term statistics. At the same
time, a critically high blood pressure may cause the generation of
an alarm report. Refer to 3.7.2. 2.7.2.

To avoid a high number of request messages, nodes may be
configured to autonomously do a measurement and send a report in
intervals.

3.7.2.

2.7.2. At-home health monitoring Health Monitoring

An alarm event may become active e.g. if the measured blood
pressure exceeds a threshold or if a person falls to the ground.
Alarm conditions must be reported with the highest priority and
timeliness.

Applications might include:

o Temperature
o Weight
o Blood pressure
o Insulin level
o Electrocardiogram (ECG)
o Position tracker

3.7.3. Healthcare routing considerations

From a ROLL perspective, all the above-mentioned applications may run
on battery. They may also be portable and therefore need to locate a
new neighbor router on a frequent basis.
Not being powered most of the time, the nodes should not be used as
routing nodes. However, sleeping, battery-powered nodes may be
involved in routing. Examples include cases where a person falls
during a power blackout. In that case it may be that no mains-powered
routers are available for forwarding the alarm message to a (battery-
backed) internet gateway located out of direct range.

Delivery of measurement data has a more relaxed requirement for route
discovery time compared to a remote control. On the other hand, it is
critical that a "person fell" alarm is actually delivered in the end.

3.8. Alarm systems

A home security alarm system is comprised

2.8. Alarm Systems

A home security alarm system is comprised of various devices like
vibration detectors, sensors
(vibration, fire or carbon monoxide detection system, door
or window contacts, glass-break detector, presence sensor, monoxide, door/window, glass-break,
presence, panic button, home security key. etc.).

Some smoke alarms are battery powered and at the same time mounted
in a high place. Battery-powered safety devices should only be
used for routing if no other alternatives exist to avoid draining
the battery. A smoke alarm with a drained battery does not provide
a lot of safety. Also, it may be inconvenient to exchange battery
in a smoke alarm.

Alarm system applications may have both a synchronous and an
asynchronous behavior; i.e. they may be periodically queried by a
central control application (e.g. for a periodical refreshment of
the network state), or send a message to the control application
on their own initiative basing upon the status of the environment they
monitor. initiative.

When a node (or a group of nodes) identifies a risk situation
(e.g. intrusion, smoke, fire), it sends an alarm message to the control
centre a
central controller that could autonomously forward it via Internet
or interact with the WSN other network nodes (e.g. trying try to obtain more
detailed information or
asking to ask other nodes close to the alarm event). Alarm messages
have, obviously, strict low-latency requirements.

Finally, routing via battery-powered nodes may be very slowly
reacting slow if the
nodes are sleeping most of the time (they could appear
unresponsive to the alarm detection). To ensure fast message
delivery and avoid battery drain, routing should be avoided via this
category of
sleeping devices.

3.9. Battery-powered devices

For convenience and low operational costs, power consumption of
consumer products must be kept at a very low level to achieve a long
battery lifetime. One implication of this fact is that RAM memory is
limited and it may even be powered down; leaving only a few 100 bytes
of RAM alive during the sleep phase.

The use of battery powered devices reduces installation costs and
does enable installation of devices even where main power lines are
not available. On the other hand, in order to be cost effective and
efficient, the devices have to maximize the sleep phase with a duty
cycle lower than 10%.

3. Unique requirements Routing Requirements of home automation applications Home Automation Applications

Home automation applications have a number of specific routing
requirements related to the set of home networking applications
and the perceived operation of the system.

4.1.

The relations of use cases to requirements are outlined in the
table below:

3.1. Support of Groupcast

+----------------------------------------------------------+
| Author's note: |
| The support of groupcast only has implication on the |
| addressing scheme and as such, it is outside the scope |
| of this document that focuses on routing requirements. |
| Nevertheless, it is an important parameter for the |
| definition of the ROLL layer interface towards various |
| layer two technologies for home control. |
| |
| Should a dedicated application-specific document be |
| created for such details? |
+----------------------------------------------------------+

Groupcast, in the context of home automation, is defined as the
ability to simultaneously transmit a message to a group of
recipients without prior interaction with the group members (i.e.
group setup). A use-case for groupcast is given in Section 3.1. 2.1.

Broadcast and groupcast in home automation MAY be used to deliver the
illusion that all recipients respond simultaneously. Distant
recipients out achieve
simultaneous reaction from a group of direct range may not react to the (unacknowledged)
groupcast. Acknowledged unicast delivery MUST nodes.

It SHOULD be used subsequently.

The support to possible to address a group of unicast, groupcast and broadcast also has an
implication on receivers known by
the addressing scheme and are outside sender even if the scope of
this document receivers do not know that focuses on they have been
grouped by the routing requirements aspects.

It MUST sender.

3.2. Constraint-based Routing

For convenience and low operational costs, power consumption of
consumer products must be kept at a very low level to possible to address achieve a
long battery lifetime. One implication of this fact is that Random
Access Memory (RAM) is limited and it may even be powered down;
leaving only a group few 100 bytes of receivers known by RAM alive during the
sender sleep phase.

The use of battery powered devices reduces installation costs and
does enable installation of devices even if the receivers do where main power lines
are not know that they available. On the other hand, in order to be cost
effective and efficient, the devices have been grouped
by to maximize the sender.

4.2. Constraint-based Routing sleep
phase with a duty cycle lower than 1%.

Some devices only wake up in response to an event, e.g. a push
button.

Simple battery-powered nodes such as movement sensors on garage
doors and rain meters sensors may not be able to assist in routing.
Depending on the node type, the node never listens at all, listens
rarely or makes contact on demand to a pre-configured target node.
Attempting to communicate to such nodes may at best require long
time before getting a response.

Other battery-powered nodes may have the capability to participate
in routing. The routing protocol should either share the load between
nodes to preserve battery or only SHOULD route via mains-powered
nodes if possible.

The most reliable routing resource may be a battery-backed,
mains-powered smoke alarm.

The routing protocol MUST support constraint-based routing taking
into account node properties (CPU, memory, level of energy, sleep
intervals, safety/convenience of changing battery).

4.3.

3.3. Support of Mobility

In a home environment, although the majority of devices are fixed
devices, there is still a variety of mobile devices: for example a
multi-purpose remote control is likely to move. Another example of
mobile devices is wearable healthcare devices.

While healthcare devices delivering measurement results can
tolerate route discovery times measured in seconds, a remote
control appears unresponsive if using more than 0.5 seconds to
e.g. pause the music.

While, in theory, all battery-powered devices and mains-powered plug-
in
plug-in modules may be moved, the predominant case is that the
sending node has moved while the rest of the network has not
changed.

The routing protocol MUST provide mobility with convergence time
below 0.5 second if only the sender has moved.

A non-responsive node can either be caused by 1) a failure in the
node, 2) a failed link on the path to the node or 3) a moved node.
In the first two cases, the node can be expected to reappear at
roughly the same location in the network, whereas it can return
anywhere in the network in the latter case.

3.4. Sleeping Nodes

Sleeping nodes may appear to be non-responsive. The search strategy in the routing
protocol will behave differently depending MUST take into account the delivery time to a sleeping
target node.

The wake-up interval of a sleeping node MUST be less than one
second.

3.5. Healthcare Routing

Because most health care applications may run on battery, this expectation. The
leads to specific requirements for the routing protocol SHOULD make use protocol. Most
health care applications may also be portable and therefore need
to locate a new neighbor router on a frequent basis.
Not being powered most of the fact that if time, the nodes should not being able be used
as routing nodes. However, battery-powered nodes may be involved
in routing. Examples include cases where a person falls during a
power blackout. In that case it may be that no mains-powered
routers are available for forwarding the alarm message to a
(battery-backed) internet gateway located out of direct range.

Delivery of measurement data has a more relaxed requirement for
route discovery time compared to deliver a packet, remote control. On the other
hand, it is most likely that the sending node moved;
rather than a failure occurred in critical that node or in a link on the path
towards it.

4.4. Support of Periodical Scanning

The routing protocol MUST support the recognition of neighbors and
periodical scanning. This process SHOULD preserve energy capacity as
much as possible.

(Derived from use case 3.8. Alarm Systems)

4.5. "person fell" alarm is actually
delivered.

3.6. Scalability

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.

Thus, the

The routing protocol MUST support 250 devices in a subnet.
The routing protocol SHOULD support 2500 devices in a subnet.

4.6. the network.

3.7. Convergence Time

A wireless home automation Personal Area Network (PAN) network is subject to various
instability
instabilities due to signal strength variation, moving persons and
the like. Furthermore, as the number of devices increases, the
probability of a node failure also increases.

Measured from the transmission of a packet, the following
convergence time requirements apply.

The routing protocol MUST converge within 0.5 second if no nodes
have moved.

The routing protocol MUST converge within 2 seconds if the
destination node of the packet has moved.

4.7.

In both cases, "converge" means "the originator node has received
a response from the destination node".

3.8. Manageability

The ability of the home network to support auto-configuration is
of the utmost importance. Indeed, most end users will not have the
expertise and the skills to perform advanced configuration and
troubleshooting. Thus the routing protocol designed for home PAN
automation networks MUST provide a set of features including zero-configuration zero-
configuration of the routing protocol for a new node to be added
to the network. From ROLL a routing perspective, zero-configuration
means that a node can obtain an address and join the network on
its own, without human intervention.

3.9. Stability

The routing protocol MUST support the ability to isolate a
misbehaving node thus preserving the correct operation of the
overall network.

4. Traffic Pattern

Depending on the design philosophy of the home network, wall
switches may be configured to directly control individual lamps or
alternatively, all wall switches send control commands to a
central lighting control computer which again sends out control
commands to relevant devices.

In a distributed system, the traffic tends to be any-to-many. multipoint-to-
multipoint. In a centralized system, it is a mix of any-to-one multipoint-to-
point and one-to-many. point-to-multipoint.

Wall switches only generate traffic when activated, which
typically happens from a one to tens of times per hour.

Remote controls have a similar transmit pattern to wall switches,
but are activated more frequently.

Temperature/air pressure/rain sensors send frames when queried by
the user or can be preconfigured to send measurements at fixed
intervals (typically minutes). Motion sensors typically send a
frame when motion is first detected and another frame when an idle
period with no movement has elapsed. The highest transmission
frequency depends on the idle period used in the sensor.
Sometimes, a timer will trigger a frame transmission when an
extended period without status change has elapsed.

All frames sent in the above examples are quite short, typically
less than 5 bytes of payload. Lost frames and interference from
other transmitters may lead to retransmissions. In all cases,
acknowledgment frames with a size of a few bytes are used.

5. Open issues Issues

Other items to be addressed in further revisions of this document
include:

o Load Balancing (Symmetrical and Asymmetrical)
o Groupcast definition in a separate document? (TBD)
o Use case: Home Control Installer Scenario
o Security

6. Security Considerations

Encryption can be employed to provide confidentiality, integrity and
authentication of the messages carried on the wireless links. Adding
these capabilities to the

Implementing security mechanisms in ROLL network devices will may
degrade energy efficiency and increase cost, so a trade-off must be made for each specific
application.

Door locks, alarm sensors and medication dosage equipment are
examples where strong encryption and authentication are needed. cost.

The
command to unlock a door must be authenticated, as must the
communication between an alarm sensor and the central alarm
controller. Furthermore, traffic analysis of the alarm system
communication must not reveal if the alarm is activated.

Light dimmers, window shades, motion sensors, weight sensors etc. may
not need encryption. routing protocol chosen for ROLL MUST allow for low-power,
low-cost network devices with limited security needs.

Protection against unintentional inclusion in neighboring networks
must
MUST be provided. Providing confidentiality, integrity and
authentication against malicious opponents is optional.

7. IANA Considerations

This document includes no request to IANA.

8. Acknowledgments

J. P. Vasseur, Jonathan Hui, Eunsook "Eunah" Kim, Mischa Dohler
and Massimo Maggiorotti are gratefully acknowledged for their
contributions to this document.

This document was prepared using 2-Word-v2.0.template.dot.

10.

9. References

10.1.

As an exception, this internet draft contains references to other
internet drafts. The reason is that the referenced internet drafts
are developed in parallel to this document.

When promoted to an RFC, the references MUST be updated to RFCs as
well or removed from the references section.

9.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.

10.2.

draft-ietf-roll-indus-routing-reqs-01.txt

draft-ietf-roll-urban-routing-reqs-01.txt

draft-martocci-roll-commercial-routing-reqs-00.txt

draft-ietf-roll-protocols-survey-00.txt

9.2. Informative References

Author's Addresses

Anders Brandt
Zensys, Inc.
Emdrupvej 26
Copenhagen, DK-2100
Denmark

Email: abr@zen-sys.com

Jakob Buron
Zensys, Inc.
Emdrupvej 26
Copenhagen, DK-2100
Denmark

Email: jbu@zen-sys.com

Giorgio Porcu
Telecom Italia
Piazza degli Affari, 2
20123 Milan
Italy

Email: giorgio.porcu@guest.telecomitalia.it

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