draft-ietf-lwig-terminology-02.txt   draft-ietf-lwig-terminology-03.txt 
LWIG Working Group C. Bormann LWIG Working Group C. Bormann
Internet-Draft Universitaet Bremen TZI Internet-Draft Universitaet Bremen TZI
Intended status: Informational M. Ersue Intended status: Informational M. Ersue
Expires: September 29, 2013 Nokia Siemens Networks Expires: October 02, 2013 Nokia Siemens Networks
March 28, 2013 A. Keranen
Ericsson
March 31, 2013
Terminology for Constrained Node Networks Terminology for Constrained Node Networks
draft-ietf-lwig-terminology-02 draft-ietf-lwig-terminology-03
Abstract Abstract
The Internet Protocol Suite is increasingly used on small devices The Internet Protocol Suite is increasingly used on small devices
with severe constraints, creating constrained node networks. This with severe constraints, creating constrained node networks. This
document provides a number of basic terms that have turned out to be document provides a number of basic terms that have turned out to be
useful in the standardization work for constrained environments. useful in the standardization work for constrained environments.
Status of This Memo Status of This Memo
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 29, 2013. This Internet-Draft will expire on October 02, 2013.
Copyright Notice Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Constrained Nodes . . . . . . . . . . . . . . . . . . . . 3 2.1. Constrained Nodes . . . . . . . . . . . . . . . . . . . . 3
2.2. Constrained Networks . . . . . . . . . . . . . . . . . . 4 2.2. Constrained Networks . . . . . . . . . . . . . . . . . . 4
2.2.1. Challenged Networks . . . . . . . . . . . . . . . . . 5 2.2.1. Challenged Networks . . . . . . . . . . . . . . . . . 5
2.3. Constrained Node Networks . . . . . . . . . . . . . . . . 5 2.3. Constrained Node Networks . . . . . . . . . . . . . . . . 5
2.3.1. LLN ("low-power lossy network") . . . . . . . . . . . 5 2.3.1. LLN ("low-power lossy network") . . . . . . . . . . . 5
2.3.2. LoWPAN, 6LoWPAN . . . . . . . . . . . . . . . . . . . 6 2.3.2. LoWPAN, 6LoWPAN . . . . . . . . . . . . . . . . . . . 6
3. Classes of Constrained Devices . . . . . . . . . . . . . . . 7 3. Classes of Constrained Devices . . . . . . . . . . . . . . . 7
4. Power Terminology . . . . . . . . . . . . . . . . . . . . . . 9 4. Power Terminology . . . . . . . . . . . . . . . . . . . . . . 9
4.1. Scaling Properties . . . . . . . . . . . . . . . . . . . 9 4.1. Scaling Properties . . . . . . . . . . . . . . . . . . . 9
4.2. Energy Limitation Classes . . . . . . . . . . . . . . . . 9 4.2. Classes of Energy Limitation . . . . . . . . . . . . . . 9
4.3. Power Usage Strategies . . . . . . . . . . . . . . . . . 10 4.3. Strategies of Using Power for Communication . . . . . . . 10
5. Security Considerations . . . . . . . . . . . . . . . . . . . 11 5. Security Considerations . . . . . . . . . . . . . . . . . . . 12
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12
8. Informative References . . . . . . . . . . . . . . . . . . . 11 8. Informative References . . . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
1. Introduction 1. Introduction
Small devices with limited CPU, memory, and power resources, so Small devices with limited CPU, memory, and power resources, so
called constrained devices (aka. sensor, smart object, or smart called constrained devices (also known as sensor, smart object, or
device) can constitute a network, becoming "constrained nodes" in smart device) can constitute a network, becoming "constrained nodes"
that network. Such a network may itself exhibit constraints, e.g. in that network. Such a network may itself exhibit constraints, e.g.
with unreliable or lossy channels, limited and unpredictable with unreliable or lossy channels, limited and unpredictable
bandwidth, and a highly dynamic topology. bandwidth, and a highly dynamic topology.
Constrained devices might be in charge of gathering information in Constrained devices might be in charge of gathering information in
diverse settings including natural ecosystems, buildings, and diverse settings including natural ecosystems, buildings, and
factories and send the information to one or more server stations. factories and sending the information to one or more server stations.
Constrained devices may work under severe resource constraints such Constrained devices may work under severe resource constraints such
as limited battery and computing power, little memory and as limited battery and computing power, little memory and
insufficient wireless bandwidth, and communication capabilities. insufficient wireless bandwidth, and communication capabilities.
Other entities on the network, e.g., a base station or controlling Other entities on the network, e.g., a base station or controlling
server, might have more computational and communication resources and server, might have more computational and communication resources and
can support the interaction between the constrained devices and could support the interaction between the constrained devices and
applications in more traditional networks. applications in more traditional networks.
Today diverse sizes of constrained devices with different resources Today diverse sizes of constrained devices with different resources
and capabilities are becoming connected. Mobile personal gadgets, and capabilities are becoming connected. Mobile personal gadgets,
building-automation devices, cellular phones, Machine-to-machine building-automation devices, cellular phones, Machine-to-machine
(M2M) devices, etc. benefit from interacting with other "things" in (M2M) devices, etc. benefit from interacting with other "things"
the near or somewhere in the Internet. With this, the Internet of nearby or somewhere in the Internet. With this, the Internet of
Things (IoT) becomes a reality, built up out of uniquely identifiable Things (IoT) becomes a reality, built up out of uniquely identifiable
and addressable objects (things). And over the next decade, this and addressable objects (things). And over the next decade, this
could grow to large numbers [fifty-billion] of Internet-connected could grow to large numbers [fifty-billion] of Internet-connected
constrained devices, greatly increasing the Internet's size and constrained devices, greatly increasing the Internet's size and
scope. scope.
The present document provides a number of basic terms that have The present document provides a number of basic terms that have
turned out to be useful in the standardization work for constrained turned out to be useful in the standardization work for constrained
environments. The intention is not to exhaustingly cover the field, environments. The intention is not to exhaustively cover the field,
but to make sure a few core terms are used consistently between but to make sure a few core terms are used consistently between
different groups cooperating in this space. different groups cooperating in this space.
2. Terminology 2. Terminology
The main focus of this field of work appears to be _scaling_: The main focus of this field of work appears to be _scaling_:
o Scaling up Internet technologies to a large number [fifty-billion] o Scaling up Internet technologies to a large number [fifty-billion]
of inexpensive nodes, while of inexpensive nodes, while
o scaling down the characteristics of each of these nodes and of the o scaling down the characteristics of each of these nodes and of the
networks being built out of them, to make this scaling up networks being built out of them, to make this scaling up
econmically and physically viable. econmically and physically viable.
The need for scaling down the characteristics of nodes leads to The need for scaling down the characteristics of nodes leads to
_constrained nodes_. _constrained nodes_.
2.1. Constrained Nodes 2.1. Constrained Nodes
The term "constrained node" is best defined on not meeting certain The term "constrained node" is best defined by contrasting the
widely held expectations: characteristics of a constrained node with certain widely held
expectations on more familiar Internet nodes:
Constrained Node: A node where some of the characteristics that are Constrained Node: A node where some of the characteristics that are
otherwise pretty much taken for granted for Internet nodes in 2013 otherwise pretty much taken for granted for Internet nodes in 2013
are not attainable, often due to cost constraints and/or physical are not attainable, often due to cost constraints and/or physical
constraints on characteristics such as size, weight, and available constraints on characteristics such as size, weight, and available
power. power.
While this is less than satisfying as a rigorous definition, it is While this is less than satisfying as a rigorous definition, it is
grounded in the state of the art and clearly sets apart constrained grounded in the state of the art and clearly sets apart constrained
nodes from server systems, desktop or laptop computers, powerful nodes from server systems, desktop or laptop computers, powerful
mobile devices such as smartphones etc. mobile devices such as smartphones etc. There may be many design
considerations that lead to these constraints, including cost, size,
weight, and other scaling factors.
(An alternative name, when the properties as a network node are not (An alternative name, when the properties as a network node are not
in focus, is "constrained device".) in focus, is "constrained device".)
There are multiple facets to the constraints on nodes, often applying There are multiple facets to the constraints on nodes, often applying
in combination, e.g.: in combination, e.g.:
o constraints on the maximum code complexity (ROM/Flash); o constraints on the maximum code complexity (ROM/Flash);
o constraints on the size of state and buffers (RAM); o constraints on the size of state and buffers (RAM);
o constraints on the available power. o constraints on the available power.
Section 3 defines a small number of interesting classes ("class-N" Section 3 defines a small number of interesting classes ("class-N"
for N=0,1,2) of constrained nodes focusing on relevant combinations for N=0,1,2) of constrained nodes focusing on relevant combinations
of the first two constraints. With respect to available power, of the first two constraints. With respect to available power,
[RFC6606] distinguishes "power-affluent" nodes (mains-powered or [RFC6606] distinguishes "power-affluent" nodes (mains-powered or
regularly recharged) from "power-constrained nodes" that draw their regularly recharged) from "power-constrained nodes" that draw their
power from primary batteries or using energy harvesting. power from primary batteries or by using energy harvesting.
The use of constrained nodes in networks often also leads to The use of constrained nodes in networks often also leads to
constraints on the networks themselves. However, there may also be constraints on the networks themselves. However, there may also be
constraints on networks that are largely independent from those of constraints on networks that are largely independent from those of
the nodes. We therefore distinguish _constrained networks_ and the nodes. We therefore distinguish _constrained networks_ and
_constrained node networks_. _constrained node networks_.
2.2. Constrained Networks 2.2. Constrained Networks
We define "constrained network" in a similar way: We define "constrained network" in a similar way:
Constrained Network: A network where some of the characteristics Constrained Network: A network where some of the characteristics
pretty much taken for granted for Internet link layers in 2013 are pretty much taken for granted for Internet link layers in 2013 are
not attainable. not attainable.
Again, there may be several reasons for this: Again, there may be several reasons for this:
o cost constraints on the network o cost constraints on the network,
o constraints of the nodes (for constrained node networks) o constraints of the nodes (for constrained node networks),
o physical constraints (e.g., power constraints, media constraints o physical constraints (e.g., power constraints, media constraints
such as underwater operation, limited spectrum for very high such as underwater operation, limited spectrum for very high
density). density, electromagnetic compatibility),
Constraints may include: o regulatory constraints, such as very limited spectrum availability
(including limits on effective radiated power and duty cycle), or
explosion safety.
o low achievable bit rate Constraints may include:
o high packet loss, packet loss (delivery rate) variability o low achievable bit rate (including limits on duty cycle),
o high packet loss, packet loss (delivery rate) variability,
o severe penalties for using larger packets (e.g., high packet loss o severe penalties for using larger packets (e.g., high packet loss
due to link layer fragmentation) due to link layer fragmentation),
o lack of (or severe constraints on) advanced services such as IP o lack of (or severe constraints on) advanced services such as IP
multicast multicast.
2.2.1. Challenged Networks 2.2.1. Challenged Networks
A constrained network is not necessarily a _challenged_ network A constrained network is not necessarily a _challenged_ network
[FALL]: [FALL]:
Challenged Network: A network that has serious trouble maintaining Challenged Network: A network that has serious trouble maintaining
what an application would today expect of the end-to-end IP model, what an application would today expect of the end-to-end IP model,
e.g., by: e.g., by:
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"Low-Power Wireless Personal Area Network" contains a hard to justify "Low-Power Wireless Personal Area Network" contains a hard to justify
"Personal" that is due to IEEE politics more than due to an "Personal" that is due to IEEE politics more than due to an
orientation of LoWPANs around a single person. Actually, LoWPANs orientation of LoWPANs around a single person. Actually, LoWPANs
have been suggested for urban monitoring, control of large buildings, have been suggested for urban monitoring, control of large buildings,
and industrial control applications, so the "Personal" can only be and industrial control applications, so the "Personal" can only be
considered a vestige. Maybe the term is best read as "Low-Power considered a vestige. Maybe the term is best read as "Low-Power
Wireless Area Networks" (LoWPANs) [WEI]. Originally focused on IEEE Wireless Area Networks" (LoWPANs) [WEI]. Originally focused on IEEE
802.15.4, "LoWPAN" (or when used for IPv6, "6LoWPAN") is now also 802.15.4, "LoWPAN" (or when used for IPv6, "6LoWPAN") is now also
being used for networks built from similarly constrained link layer being used for networks built from similarly constrained link layer
technologies [I-D.ietf-6lowpan-btle] technologies [I-D.ietf-6lowpan-btle]
[I-D.mariager-6lowpan-v6over-dect-ule]. [I-D.mariager-6lowpan-v6over-dect-ule] [I-D.brandt-6man-lowpanz].
3. Classes of Constrained Devices 3. Classes of Constrained Devices
Despite the overwhelming variety of Internet-connected devices that Despite the overwhelming variety of Internet-connected devices that
can be envisioned, it may be worthwhile to have some succinct can be envisioned, it may be worthwhile to have some succinct
terminology for different classes of constrained devices. In this terminology for different classes of constrained devices. In this
document, the following class designations may be used as rough document, the class designations in Table 1 may be used as rough
indications of device capabilities: indications of device capabilities:
+-------------+-----------------------+-------------------------+ +-------------+-----------------------+-------------------------+
| Name | data size (e.g., RAM) | code size (e.g., Flash) | | Name | data size (e.g., RAM) | code size (e.g., Flash) |
+-------------+-----------------------+-------------------------+ +-------------+-----------------------+-------------------------+
| Class 0, C0 | << 10 KiB | << 100 KiB | | Class 0, C0 | << 10 KiB | << 100 KiB |
| | | | | | | |
| Class 1, C1 | ~ 10 KiB | ~ 100 KiB | | Class 1, C1 | ~ 10 KiB | ~ 100 KiB |
| | | | | | | |
| Class 2, C2 | ~ 50 KiB | ~ 250 KiB | | Class 2, C2 | ~ 50 KiB | ~ 250 KiB |
+-------------+-----------------------+-------------------------+ +-------------+-----------------------+-------------------------+
Table 1: Classes of Constrained Devices Table 1: Classes of Constrained Devices
As of the writing of this document, these characteristics correspond As of the writing of this document, these characteristics correspond
to distinguishable sets of commercially available chips and design to distinguishable clusters of commercially available chips and
cores for constrained devices. While it is expected that the design cores for constrained devices. While it is expected that the
boundaries of these classes will move over time, Moore's law tends to boundaries of these classes will move over time, Moore's law tends to
be less effective in the embedded space than in personal computing be less effective in the embedded space than in personal computing
devices: Gains made available by increases in transistor count and devices: Gains made available by increases in transistor count and
density are more likely to be invested in reductions of cost and density are more likely to be invested in reductions of cost and
power requirements than into continual increases in computing power. power requirements than into continual increases in computing power.
Class 0 devices are very constrained sensor-like motes. Most likely Class 0 devices are very constrained sensor-like motes. Most likely
they will not be able to communicate directly with the Internet in a they will not be able to communicate directly with the Internet in a
secure manner. Class 0 devices will participate in Internet secure manner. Class 0 devices will participate in Internet
communications with the help of larger devices acting as proxies, communications with the help of larger devices acting as proxies,
gateways or servers. Class 0 devices generally cannot be secured or gateways or servers. Class 0 devices generally cannot be secured or
managed comprehensively in the traditional sense. They will be most managed comprehensively in the traditional sense. They will most
likely preconfigured and if ever will be reconfigured rarely with a likely be preconfigured (and will be reconfigured rarely, if at all),
very small data set. For management purposes, they could answer with a very small data set. For management purposes, they could
keepalive signals and send on/off or basic health indications. answer keepalive signals and send on/off or basic health indications.
Class 1 devices cannot easily talk to other Internet nodes employing Class 1 devices cannot easily talk to other Internet nodes employing
a full protocol stack such as using HTTP, TLS and related security a full protocol stack such as using HTTP, TLS and related security
protocols and XML-based data representations. However, they have protocols and XML-based data representations. However, they have
enough power to use a protocol stack specifically designed for enough power to use a protocol stack specifically designed for
constrained nodes (e.g., CoAP over UDP) and participate in meaningful constrained nodes (e.g., CoAP over UDP) and participate in meaningful
conversations without the help of a gateway node. In particular, conversations without the help of a gateway node. In particular,
they can provide support for the security functions required on a they can provide support for the security functions required on a
large network. Therefore, they can be integrated as fully developed large network. Therefore, they can be integrated as fully developed
peers into an IP network, but they need to be parsimonious with state peers into an IP network, but they need to be parsimonious with state
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available electrical power and/or energy. While it is harder to find available electrical power and/or energy. While it is harder to find
recognizable clusters in this space, it is still useful to introduce recognizable clusters in this space, it is still useful to introduce
some common terminology. some common terminology.
4.1. Scaling Properties 4.1. Scaling Properties
The power and/or energy available to a device may vastly differ, from The power and/or energy available to a device may vastly differ, from
kilowatts to microwatts, from essentially unlimited to hundreds of kilowatts to microwatts, from essentially unlimited to hundreds of
microjoules. microjoules.
Instead of defining classes or clusters, we propose simply stating Instead of defining classes or clusters, we propose simply stating,
one or both of the following quantities in SI units: in SI units, an approximate value for one or both of the quantities
listed in Table 2:
o Ps: Sustainable average power available for the device over the +--------+---------------------------------------------+------------+
time it is functioning (in W). | Name | Definition | SI Unit |
+--------+---------------------------------------------+------------+
| Ps | Sustainable average power available for the | W (Watt) |
| | device over the time it is functioning | |
| | | |
| Et | Total electrical energy available before | J (Joule) |
| | the energy source is exhausted | |
+--------+---------------------------------------------+------------+
o Et: Total electrical energy available before the energy source is Table 2: Quantities Relevant to Power and Energy
exhausted (in J).
The value of Et may need to be interpreted in conjunction with an The value of Et may need to be interpreted in conjunction with an
indication over which period of time the value is given; see the next indication over which period of time the value is given; see the next
subsection. subsection.
4.2. Energy Limitation Classes 4.2. Classes of Energy Limitation
As discussed above, some devices are limited in available energy as As discussed above, some devices are limited in available energy as
opposed to (or in addition to) being limited in available power. opposed to (or in addition to) being limited in available power.
Where no relevant limitations exist with respect to energy, the Where no relevant limitations exist with respect to energy, the
device is classified as E3. The energy limitation may be in total device is classified as E3. The energy limitation may be in total
energy available in the usable lifetime of the device (e.g. a device energy available in the usable lifetime of the device (e.g. a device
with a non-replaceable primary battery, which is discarded when this with a non-replaceable primary battery, which is discarded when this
battery is exhausted), classified as E2. Where the relevant battery is exhausted), classified as E2. Where the relevant
limitation is for a specific period, this is classified as E1, e.g. limitation is for a specific period, this is classified as E1, e.g.
a limited amount of energy available for the night with a solar- a limited amount of energy available for the night with a solar-
powered device, or for the period between recharges with a device powered device, or for the period between recharges with a device
that is manually connected to a charger. Finally, there may be a that is manually connected to a charger, or by a periodic (primary)
limited amount of energy available for a specific event, e.g. for a battery replacement interval. Finally, there may be a limited amount
button press in an energy harvesting light switch; this is classified of energy available for a specific event, e.g. for a button press in
as E0. Note that many E1 devices in a sense also are E2, as the an energy harvesting light switch; this is classified as E0. Note
rechargeable battery has a limited number of useful recharging that many E1 devices in a sense also are E2, as the rechargeable
cycles. battery has a limited number of useful recharging cycles.
In summary, we distinguish:
o E0: Event energy-limited In summary, we distinguish (Table 3):
o E1: Period energy-limited
o E2: Lifetime energy-limited +------+------------------------------+-----------------------------+
| Name | Type of energy limitation | Example Power Source |
+------+------------------------------+-----------------------------+
| E0 | Event energy-limited | Event-based harvesting |
| | | |
| E1 | Period energy-limited | Battery that is |
| | | periodically recharged or |
| | | replaced |
| | | |
| E2 | Lifetime energy-limited | Non-replaceable primary |
| | | battery |
| | | |
| E3 | No direct quantitative | Mains powered |
| | limitations to available | |
| | energy | |
+------+------------------------------+-----------------------------+
o E3: No direct quantitative limitations to available energy Table 3: Classes of Energy Limitation
4.3. Power Usage Strategies 4.3. Strategies of Using Power for Communication
Especially when wireless transmission media is used, the radio often Especially when wireless transmission is used, the radio often
consumes a big portion of the total energy consumed by the device. consumes a big portion of the total energy consumed by the device.
Design parameters such as desired range and the spectrum available Design parameters such as the available spectrum, the desired range,
and bitrate aimed for influence the power consumed during and the bitrate aimed for, influence the power consumed during
transmission and reception; the duration of transmission and transmission and reception; the duration of transmission and
reception (including potential reception) influence the total energy reception (including potential reception) influence the total energy
consumption. consumption.
Based on the type of the energy source (e.g., battery or mains power) Based on the type of the energy source (e.g., battery or mains power)
and how often device needs to communicate, it may use different kinds and how often device needs to communicate, it may use different kinds
of strategies for power usage and network attachment. of strategies for power usage and network attachment.
The general strategies for power usage can be described as follows: The general strategies for power usage can be described as follows:
skipping to change at page 10, line 41 skipping to change at page 11, line 12
needs, but the device can be connected to the network all the needs, but the device can be connected to the network all the
time. time.
Always-off: Under this strategy, the device sleeps such long periods Always-off: Under this strategy, the device sleeps such long periods
at a time that once it wakes up, it makes sense for it to not at a time that once it wakes up, it makes sense for it to not
pretend that it has been connected to the network during sleep: pretend that it has been connected to the network during sleep:
The device re-attaches to the network as it is woken up. The main The device re-attaches to the network as it is woken up. The main
optimization goal is to minimize the effort during such re- optimization goal is to minimize the effort during such re-
attachment process and any resulting application communications. attachment process and any resulting application communications.
If the device sleeps for long periods of time, for infrequent If the device sleeps for long periods of time, and needs to
communication the relative increase in energy expenditure during communicate infrequently, the relative increase in energy
reattachment may be acceptable. expenditure during reattachment may be acceptable.
Low-power: This strategy is most applicable to devices that need to Low-power: This strategy is most applicable to devices that need to
operate on a very small amount of power, but still need to be able operate on a very small amount of power, but still need to be able
to communicate on a relatively frequent basis. This implies that to communicate on a relatively frequent basis. This implies that
extremely low power solutions needs to be used for the hardware, extremely low power solutions needs to be used for the hardware,
chosen link layer mechanisms, and so on. Typically, given the chosen link layer mechanisms, and so on. Typically, given the
small amount of time between transmissions, despite their sleep small amount of time between transmissions, despite their sleep
state these devices retain some form of network attachment to the state these devices retain some form of network attachment to the
network. Techniques used for minimizing power usage for the network. Techniques used for minimizing power usage for the
network communications include minimizing any work from re- network communications include minimizing any work from re-
establishing communications after waking up, tuning the frequency establishing communications after waking up, tuning the frequency
of communications, and other parameters appropriately. of communications, and other parameters appropriately.
In summary, we distinguish the power usage strategies: In summary, we distinguish (Table 4):
o S0: Always-off
o S1: Low-power +------+------------+----------------------------------------------+
| Name | Strategy | Ability to communicate |
+------+------------+----------------------------------------------+
| S0 | Always-off | Re-attach when required |
| | | |
| S1 | Low-power | Appears connected, perhaps with high latency |
| | | |
| S2 | Always-on | Always connected |
+------+------------+----------------------------------------------+
o S2: Always-on Table 4: Strategies of Using Power for Communication
5. Security Considerations 5. Security Considerations
This draft introduces common terminology that does not raise any new This draft introduces common terminology that does not raise any new
security issue. security issue.
6. IANA Considerations 6. IANA Considerations
This document has no actions for IANA. This document has no actions for IANA.
7. Acknowledgements 7. Acknowledgements
Ari Keranen, Dominique Barthel, and Peter van der Stok provided Dominique Barthel and Peter van der Stok provided useful comments;
useful comments. Charles Palmer provided a full editorial review.
Peter van der Stok insisted that we should have power terminology, Peter van der Stok insisted that we should have power terminology,
hence Section 4. The text for Section 4.3 is mostly lifted from hence Section 4. The text for Section 4.3 is mostly lifted from
[I-D.arkko-lwig-cellular] and has been adapted for this document. [I-D.arkko-lwig-cellular] and has been adapted for this document.
8. Informative References 8. Informative References
[FALL] Fall, K., "A Delay-Tolerant Network Architecture for [FALL] Fall, K., "A Delay-Tolerant Network Architecture for
Challenged Internets", SIGCOMM 2003, 2003. Challenged Internets", SIGCOMM 2003, 2003.
[I-D.arkko-lwig-cellular] [I-D.arkko-lwig-cellular]
Arkko, J., Eriksson, A., and A. Keraenen, "Building Power- Arkko, J., Eriksson, A., and A. Keraenen, "Building Power-
Efficient CoAP Devices for Cellular Networks", draft- Efficient CoAP Devices for Cellular Networks", draft-
arkko-lwig-cellular-00 (work in progress), February 2013. arkko-lwig-cellular-00 (work in progress), February 2013.
[I-D.brandt-6man-lowpanz]
Brandt, A. and J. Buron, "Transmission of IPv6 packets
over ITU-T G.9959 Networks", draft-brandt-6man-lowpanz-00
(work in progress), February 2013.
[I-D.clausen-lln-rpl-experiences] [I-D.clausen-lln-rpl-experiences]
Clausen, T., Verdiere, A., Yi, J., Herberg, U., and Y. Clausen, T., Verdiere, A., Yi, J., Herberg, U., and Y.
Igarashi, "Observations of RPL: IPv6 Routing Protocol for Igarashi, "Observations of RPL: IPv6 Routing Protocol for
Low power and Lossy Networks", draft-clausen-lln-rpl- Low power and Lossy Networks", draft-clausen-lln-rpl-
experiences-06 (work in progress), February 2013. experiences-06 (work in progress), February 2013.
[I-D.hui-vasseur-roll-rpl-deployment] [I-D.hui-vasseur-roll-rpl-deployment]
Vasseur, J., Hui, J., Dasgupta, S., and G. Yoon, "RPL Vasseur, J., Hui, J., Dasgupta, S., and G. Yoon, "RPL
deployment experience in large scale networks", draft-hui- deployment experience in large scale networks", draft-hui-
vasseur-roll-rpl-deployment-01 (work in progress), July vasseur-roll-rpl-deployment-01 (work in progress), July
skipping to change at page 12, line 47 skipping to change at page 13, line 39
[RFC6606] Kim, E., Kaspar, D., Gomez, C., and C. Bormann, "Problem [RFC6606] Kim, E., Kaspar, D., Gomez, C., and C. Bormann, "Problem
Statement and Requirements for IPv6 over Low-Power Statement and Requirements for IPv6 over Low-Power
Wireless Personal Area Network (6LoWPAN) Routing", RFC Wireless Personal Area Network (6LoWPAN) Routing", RFC
6606, May 2012. 6606, May 2012.
[WEI] Shelby, Z. and C. Bormann, "6LoWPAN: the Wireless Embedded [WEI] Shelby, Z. and C. Bormann, "6LoWPAN: the Wireless Embedded
Internet", ISBN 9780470747995, 2009. Internet", ISBN 9780470747995, 2009.
[fifty-billion] [fifty-billion]
Ericsson, -., "More Than 50 Billion Connected Devices", Ericsson, "More Than 50 Billion Connected Devices",
Ericsson White Paper 284 23-3149 Uen, February 2011, Ericsson White Paper 284 23-3149 Uen, February 2011,
<http://www.ericsson.com/res/docs/whitepapers/ <http://www.ericsson.com/res/docs/whitepapers/
wp-50-billions.pdf>. wp-50-billions.pdf>.
Authors' Addresses Authors' Addresses
Carsten Bormann Carsten Bormann
Universitaet Bremen TZI Universitaet Bremen TZI
Postfach 330440 Postfach 330440
Bremen D-28359 D-28359 Bremen
Germany Germany
Phone: +49-421-218-63921 Phone: +49-421-218-63921
Email: cabo@tzi.org Email: cabo@tzi.org
Mehmet Ersue Mehmet Ersue
Nokia Siemens Networks Nokia Siemens Networks
St.-Martinstrasse 76
81541 Munich
Germany
Phone: +49 172 8432301
Email: mehmet.ersue@nsn.com Email: mehmet.ersue@nsn.com
Ari Keranen
Ericsson
Hirsalantie 11
02420 Jorvas
Finland
Email: ari.keranen@ericsson.com
 End of changes. 49 change blocks. 
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