A Standardized and Flexible IPv6 Architecture for Field
Area Networks
Smart Grid Last Mile Infrastructure

Rob Kopmeiners, AMI Consultant—Alliander, rob.kopmeiners@alliander.com
Phillip King, Manager, Telecommunications Development—Ausgrid Operational Technology & Innovation,
pking@ausgrid.com.au
Jeff Fry, Manager, Technology Innovation—Ausgrid, JFry@ausgrid.com.au
John Lilleyman, Chief technology Architect—BC Hydro, john.lilleyman@bchydro.com
Sol Lancashire, Telecom Architect—BC Hydro, sol.lancashire@bchydro.com
LIU Dong, CEO—BII Group, dliu@biigroup.com
Feng Ming, Network Division Technical department—China Telecom, fengm@chinatelecom.com.cn
Patrick Grossetete, Technical Marketing Engineer—Cisco, pgrosset@cisco.com
Jean-Philippe Vasseur, Cisco Fellow—Cisco, jpv@cisco.com
Matthew K Gillmore, Director of Enterprise Architecture and Standards—Consumer Energy,
mkgillmore@cmsenergy.com
Nicolas Déjean, Elster, nicolas.dejean@coronis.com
David Mohler, CTO and SVP—Duke Energy, david.mohler@duke-energy.com
Gary Stuebing, Strategic Product Development—Duke Energy, gary.stuebing@duke-energy.com
Steve Haemelinck, Enterprise Consultant—EANDIS, info@earchitect.beMichael John, Elster, Michael.John@elster.com
Bernard Tourancheau, Professor University Joseph Fourier of Grenoble—INRIA, Bernard.Tourancheau@INRIA.fr
Daniel Popa, CTO office—Itron, Daniel.Popa@itron.com
Jorjeta Jetcheva, CTO office—Itron, jorjeta.jetcheva@itron.com
Don Shaver, Texas Instruments Inc. Fellow—Texas Instruments Inc., shaver@ti.com
Cedric Chauvenet, Wattecco, c.chauvenet@watteco.com

Last update: December 9th, 2011

© 2011Page 1 of 22

This paper is intended to provide a synthetic and holistic view of open standards Internet Protocol version 6 (IPv6)
based architecture for Smart Grid Last Mile Infrastructures in support of a number of advanced Smart Grid
applications (meter readout, demand-response, telemetry, and grid monitoring and automation) and its benefit as atrue Multi-Services platform. In this paper, we show how the various building blocks of IPv6 networking
infrastructure can provide an efficient, flexible, secure, and multi-service network based on open standards.
In order to discuss transition paths for electric utilities that deal with such issues as legacy device, network andapplication integration, and the operation of hybrid network structures during transitional rollouts, a follow-up paper
will need to be developed.

1. Introduction
Last mile networks have gained considerable momentum over the past few years due to their prominent role in the
Smart Grid infrastructure. These networks—referred as Neighborhood Area Networks (NAN) in this document—
support a variety of applications including not only electricity usage measurement and management, but also
advanced applications such as Demand-Response (DR), which gives users the opportunity to optimize their energy
usage based on real-time electricity pricing information, Distribution Automation (DA), which allows distribution
monitoring and control, and automatic fault detection, isolation and management, and serves as a foundation for
future Virtual Power Plants, which comprise distributed power generation, residential energy storage (e.g., in
combination with Electric Vehicle (EV) charging), and small scale trading communities.
Field Area Networks (FAN)—the combination of NAN and communication device offering the backhaul WAN
interface(s)—have emerged as a central component of the Smart Grid network infrastructure. In fact, they canserve as backhaul networks for a variety of other electric grid control devices; multi-tenant services (gas and water
meters), and data exchanges to Home Area Network (HAN) devices, all connected through a variety of wireless or
wired line technologies. This has created the need for deploying the IP (Internet Protocol) suite of protocols,
enabling the use of open-standards that provide the reliability, scalability, security, inter-networking and flexibility
required to cope with the fast-growing number of critical applications for the electric grid that distribution power
networks need to support. IP also facilitates integration of the Neighborhood Area Networks (NAN) into end-to-end
network architecture.
One application being run over Field Area Networks is meter reading, where each meter periodically reports usage
data to a utility head-end application server. The majority of meter traffic was thus directed from the meter network
to the utility network in a Multipoint-to-Point (MP2P) fashion. With the emergence and proliferation of applications
such as Demand Response, distributed energy resource integration and Electrical Vehicle charging, it is expectedthat the traffic volume across the Field Area Networks would increase substantially and traffic patterns and bidirectional communication requirements would become significantly more complex. In particular, Field Area
Networks are expected to support a number of use cases leveraging network services:●

Communication with an individual meter. On-demand meter reading, real-time alert reporting, andshutdown of power to a single location require Point-to-Point (P2P) communication between the NMS/Headend and the electric meter and vice versa.

●

Communication among DA devices. Subsets of DA devices need to communicate with each other inorder to manage and control the operation of the electric grid in a given area, requiring the use of flexible
communication with each other, including Peer-to-Peer in some cases.

●

HAN applications. HAN applications typically require communication between home appliances and theutility head-end server through individual meters acting as application’s gateways. For example, a user may
activate Direct Load Control (DLC) capabilities, empowering the utility company to turn off or down certain
home appliances remotely (e.g. A/C, washer/dryer), when demand and/or the cost of electricity is high.

© 2011Page 2 of 22

●Electric Vehicle Charging. Users need to have access to their individual vehicle charging accountinformation while away from home in order to be able to charge their vehicles while on the road or while
visiting friends. Verifying user and account information would require communication through the meter tothe utility head-end servers from potentially a large set of nomadic vehicles being charged simultaneously
from dynamic locations.

●

Multi-Tenant Services. Combining information at the customer side and differentiating information into
several services at the other side devises for a complex Multipoint-to-Multipoint network (MP2MP). For
example, this could be a converged network connecting devices from multiple utilities as suggested by the
UK national multi-utility telecom operator DCC or Germany multi-utility communication box as specified inOpen Meter Systems.

●

Security. Strong authentication mechanisms for validating devices that connect to the Advanced Metering
Infrastructure (AMI) network as well as encryption for data privacy and network protection.

●

Network Management. As the FAN carries increasingly more traffic and is subject to stringent Service
Level Objectives (SLOs), managing network-related data becomes critical to monitoring and maintaining
network health and performance. This would require the communication of grid status and communications
statistics from the meters to the Network Management System (NMS)/Head-end in a MP2P fashion.

●

Multicast Services. Groups of meters may need to be addressed simultaneously using multicast, e.g., toenable software upgrade or parameters updates sent by a network management system (NMS) to allmeters using multicast requests, and multicast queries for meter readings of various subsets of the meters.

2. The Key Advantages of Internet Protocol
An end-to-end IP Smart-Grid architecture can leverage 30 years of Internet Protocol technology development [RFC6272] guaranteeing open standards and interoperability as largely demonstrated through the daily use of theInternet and its two billion end-users [Stats].
Note—Using the Internet protocol suite does not mean that an infrastructure running IP has to be an open or publicly accessible
network–indeed, many existing mission-critical but private and highly secure networks leverage the IP architecture, such as interbanking networks, military and defense networks, and public-safety and emergency-response networks, to name a few.

One of the differences between Information and Communications Technology (ICT) and the more traditional powerindustry is the lifetime of technologies. Selecting the IP layered stack for AMI infrastructure brings future proofing
through smooth evolutionary steps that do not modify the entire industrial workflow. Key benefits of IP for a
distribution system operator (DSO) are:●Open and Standards-based: Core components of the network, transport and applications layers
standardized by the Internet Engineering Task Force (IETF) while key physical, data link, and applications
protocols come from usual industrial organizations, such as, IEC, ANSI, DLMS/COSEM, SAE, IEEE,
ITU, etc.

●

Lightweight: Devices installed in the last mile of an AMI network such as smart meters, sensors, andactuators are not like PC and servers. They have limited resources in terms of power, CPU, memory, andstorage. Therefore, an embedded networking stack must work on few kilobits of RAM and a few dozen
kilobits of Flash memory. It has been demonstrated over the past years that production IP stacks perform
well in such constrained environments. (See [IP-light])© 2011Page 3 of 22

●Versatile: Last mile infrastructure in Smart Grid has to deal with two key challenges. First, one given
technology (wireless or wired) may not fit all field deployment’s criteria. Second, communication
technologies evolve at a pace faster than the expected 15 to 20 years lifetime of a smart meter. The layered
IP architecture is well equipped to cope with any type of physical and data link layers, making it future proof
as various media can be used in a deployment and, over time, without changing the whole solutionarchitecture and data flow.

●

Ubiquitous: All recent operating systems releases from general-purpose computers and servers tolightweight embedded systems (TinyOS, Contiki, etc.) have an integrated dual (IPv4 and IPv6) IP stack thatgets enhanced over time. This makes a new networking feature set easier to adapt over time.

●

Scalable: As the common protocol of the Internet, IP has been massively deployed and tested for robust
scalability. Millions of private or public IP infrastructure nodes, managed under a single entity (similarly towhat is expected for FAN deployments) have been operational for years, offering strong foundations fornewcomers not familiar with IP network management.

●

Manageable and Secure: Communication infrastructure requires appropriate management and security
capabilities for proper operations. One of the benefits of 30 years of operational IP networks is its set ofwell-understood network management and security protocols, mechanisms, and toolsets that are widely
available. Adopting IP network management also helps utility operational business application by leveraging
network-management tools to improve their services, for example when identifying power outage coveragethrough the help of the Network Management System (NMS).

●

Stable and resilient: With more than 30 years of existence, it is no longer a question that IP is a workable
solution considering its large and well-established knowledge base. More important for Field Area Networks
is how we can leverage the years of experience accumulated by critical infrastructures, such as financial
and defense networks as well as critical services such as Voice and Video that have already transitioned
from closed environments to open IP standards. It also benefits from a large ecosystem of IT professionals
that can help designing, deploying and operating the system solution.

●

End-to-end: The adoption of IP provides end-to-end and bi-directional communication capabilities between
any devices in the network. Centralized or distributed architecture for data manipulations are implemented
according to business requirements. The removal of intermediate protocol translation gateways facilitates
the introduction of new services.

3. An IPv6 Distribution Network Architecture
The networking requirements for Neighborhood Area Networks have been extensively documented: cost efficiency,
scalability (millions of nodes in a network is common), security, reliability and flexibility are absolute musts, andtechnologies based on open standards and the future proofing of 15 to 20 years lifetime are minimum expectations
from utilities. This explains why the IPv6 suite was the initial protocol of choice, although new IPv6 protocols havebeen designed to address the unique requirements of such networks, as discussed in the next chapter.
The adoption of IPv6 facilitates a successful transformation to connected energy network in the last mile. However,before describing in greater detail IPv6 networking components such as IP addressing, security, Quality of Service(QoS), and routing and network management, it is worth asking why should we use end-to-end IPv6? After all, IPv6
as any other technologies requires appropriate education to the whole workforce, from technicians to the
executives evaluating vendors, subcontractors and contractors.
One of the major steps in favor of building the momentum around using IP end-to-end in the last mile of Smart Grid
networks was to demonstrate that IP could be light enough to be used on constrained devices with limited
resources in terms of energy, memory, and processing power. Thus FANs were seen as single application, stub© 2011Page 4 of 22

networks with end nodes such as meters not running IP that could be reached through IP through protocoltranslation gateways, with each gateway being tied to a dedicated service and/or solution’s vendor.
The past two decades, with the transition of protocols such as SNA (through DLSw), Appletalk, DECnet, IPX, andX25, showed us that such gateways were viable options only during transition periods with smaller, single
application, networks. But proprietary protocol and translation gateways suffer from well-known severe issues,
12

such as high CapEx and OpEx , along with significant technical limitations , including lack of end-to-end
capabilities in terms of QoS, fast recovery consistency, single point of failures (unless implementing complex
stateful failover mechanisms), limiting factors in terms of innovation (forcing to least common denominator), lack ofscalability, vulnerability to security attacks, and more. Therefore, using IPv6 end-to-end (IP running on each andevery device in the network) will be, in many ways, a much superior approach for multi-services Field Area
Networks as shown on Figure 1.

Figure 1. Multi-Services Infrastructure for Last Mile Smart Grid Transformation (Source: Cisco)1

In the 1990's, fueled by a Gartner Group report stating that "users with SNA as their primary protocol will spend a total of 20%
more than IP users on training staff, hardware and software purchases, and administration", organizations began to migrate toInternet Protocol based networks.
Read more: http://www.articlesnatch.com/Article/Reducing-Costs-By-Migrating-From-Sna-Applications-ToIp/531425#ixzz1ZHZEmWkH
Under Creative Commons License: Attribution No Derivatives
2

See RFC 3027 as an example of protocol complications with translation gateways© 2011Page 5 of 22

4. The Unique Network Requirements of Constrained Networks
Devices deployed in the context of NANs are often constrained in terms of resources and often named IP Smart
Object. Smart-Object networks are also referred to as Low power and Lossy Networks (LLN) considering theirunique characteristics and requirements. By contrast with typical IP networks, in which powerful routers areinterconnected by highly stable and fast links, LLNs are usually interconnected by low-power, low-bandwidth links(wireless and wired) operating between a few kbps and a few-hundreds kbps and forming a meshed network forguaranteeing proper operations. In addition to providing limited bandwidth, it is not unusual to see on such links the
Packet Delivery Rate (PDR) oscillating between 60 percent and 90 percent, with large bursts of unpredictableerrors and even loss of connectivity at intervals. Those behaviors can be observed on both wireless (such as IEEE
802.15.4g) and Power Line Communication (PLC) (such as IEEE P1901.2) links, where packet delivery variation
may happen during the course of one day!
Another characteristic of IP smart objects is that various types of nodes could get mixed in the communication’s
infrastructure. It implies that the routing protocol needs to have the capability managing traffic paths based on
node’s capabilities—ie: powered electric meters able to forward traffic and co-existing with battery powered water
meters, or battery powered faulted circuit indicators, acting as leaves in a LLN routing domain. Node failures may
also be significantly more frequent than in traditional IP networks where nodes have as much as power theyrequire and are highly redundant (multiprocessors, supporting non-stop forwarding (NSF), In-Service Software
Upgrade (ISSU), etc).
Another necessary characteristic for LLNs is scalability. Some LLNs are made up of dozens of nodes; others
comprise millions of nodes, as is the case of AMI networks, however they are usually made up of subnets (orsmaller networks) of a few thousand nodes. This explains why specifying protocols for very large-scale,constrained, and unstable environments brings its own challenges. For example, one of the golden rules in an LLN
is to “under-react to failure,” by contrast to routing protocols such as OSPF or ISIS, where the network needs to reconverge within a few dozens of milliseconds. Meeting this challenge required a real paradigm shift, since overreaction would lead, very rapidly, to network collapse. Furthermore, control-plane overhead should be minimized,
while supporting dynamic link/node metrics, Multi-Topology Routing (MTR), and so forth.
That explains why several techniques that were developed for traditional IP networks had been redesigned
resulting in various protocols especially for Mesh routing (RPL) as discussed later in this paper. In addition,
the IETF Light-Weight Implementation Guidance WG [LWIG] is developing implementation guidelines forconstraint devices.
Last but not least is the strong requirement for deploying highly secure networks, using years of IP protocols andalgorithms, as discussed later in this paper.

5. The Technical Components of IPv6 Smart Grid Last Mile Infrastructure
Today, the Internet runs mostly over IP version 4 (IPv4), with exceptions in academic and research networks,
leading Internet Service Providers or Enterprises, and government networks (where IPv6 is increasingly being
deployed). See Figure 3 for an IPv4-IPv6 comparison. However, the Internet faces a major transition [OECD] dueto the exhaustion of address pool managed by IANA since February 2011. With little existing IPv4 networking
legacy in the areas of AMI and Distribution Automation, there is an opportunity to start deploying IPv6 as the defacto IP version from Day One. The industry has been working on IPv6 for nearly 15 years, and the adoption of
IPv6 —which provides the same IP services as IPv4 (see figure 5)—would be fully aligned with numerous
recommendations (U.S. OMB and FAR, European Commission IPv6 recommendations, Regional Internet Registry
recommendations, and IPv4 address depletion countdown) and latest 3G cellular evolution known as LTE (LongTerm Evolution).
© 2011Page 6 of 22

Moreover, all new developments in relation to IP for Smart Objects and LLNs as discussed above, make use of orare built on IPv6 technology. Therefore, the use of IPv6 for Smart Grid FANs deployment benefits from several
features, some being extensively reviewed in the next sections:●

A huge address space accommodating any expected multi-millions meter’s deployment (AMI), thousands ofsensors (DA) over the hundred thousands of secondary substations and additionally all standalone meters.
It includes additional flexibility of address configuration that helps adapting with the size of deployments aswell as the need to lower field workers tasks when installing small devices. The structure of the IPv6
address is also flexible enough to manage a large number of sub-networks that may be created by futures
services such as e-vehicle charging stations or distributed renewable energy●

IPv6 is the de facto IP version for meter communication over open RF Mesh wireless (IEEE 802.15.4g,
DECT Ultra Low Energy) and Power Line Communications infrastructures (IEEE P1901.2) using the
6LoWPAN adaptation layer that only defines IPv6 as its protocol version.

●

IPv6 is the de facto IP version for the standardized IETF Routing Protocol for Low Power and Lossy
Networks (RPL)—IETF RoLL WG—RPL is an IPv6-only protocol.

This goes without forgetting all well-known IP features set that enables design variations for the deployment ofhighly available and secured communications infrastructure tying a Network Operations Center(s) and all
Neighborhood Area Networks (NAN) through public and/or private Wide Area Networks (WAN) links such as
shown on Figure 2.

Figure 2. Example of basic Last Mile Smart Grid Infrastructure with several levels of redundancy(Source: Alliander)© 2011Page 7 of 22

The Head-end System of a basic FAN as shown in Figure 2 collects the meter readings, maintains meter
configurations and monitors network operation. It has end-to-end connections to the meter nodes, provided by wide
area networks (WANs) and neighborhood area networks (NANs). So, while the physical connections to the meter
nodes change from WAN to NAN technologies, the principle of logical end-to-end IPv6 connections is maintained.
This is achieved by introducing one or more routers at the borders of the NAN, also called IP Edge Routers thatconnect to the WAN, enabling bi-directional data streams between WAN and NAN. In case of multi-services
infrastructures, it may be expected that IP Edge Routers have to be configured as dual-stack—IPv6 and IPv4 andwill be capable of tunneling IPv6 over IPv4 or vice-versa. This may be required when connecting over its serial or
Ethernet interfaces legacy Distribution Automation devices that only run IPv4 or providing remote workforce
connectivity to an IPv4 Intranet or when using WAN infrastructure that are IPv4-only (ie: GPRS). The IP Edge
Router will have to be properly configured to accommodate scenario such as running both IPv6 and IPv4 over the
WAN or tunneling one protocol version over the other, mechanisms that have been well defined and tested by theInternet industry.
Distribution System Operators (DSOs) require redundancy as a means to improve communication reliability in the
LLNs, as well as measure against vendor lock-in and technology lock-in due to incompatibility in lifetime between
communication and metering technologies. Redundancy can be achieved at several levels through meshcapabilities in the WAN and NAN or by using multiple technologies simultaneously. Routing shall be transparent
from end to end and independent from the technology. For example, the WAN connection of the IP Edge Router isestablished by a private reliable fiber connection or by public flexible cellular communication technology like
GPRS/3G/LTE. An IP Edge Router can be co-located with a metering node or located as separated entity in a
substation while the majority of the metering nodes communicate over a meshed NAN through
6LoWPAN/IPv6/RPL over RF or PLC technologies or both. The possibility of multiple IP Edge Routers enabled bydynamic IP routing protocols is important to prevent single point of failure, typically introduced by concentrators as
used today for proprietary PLC and RF Mesh. Dynamic routing would allow for transportable NAN nodes, such as
electric vehicles, field tools, or pagers. IP Edge Routers capable of routing traffic over different NAN technologies
and cooperating with other IP Edge Routers over the backbone for global connectivity are key elements to prevent
vendor lock-in and technology lock-in, since alternative WAN and NAN communication technologies can easily be
adapted. This is in contrast with IP (non-IP) gateway connecting the NAN with the rest of the network where thefailure of one equipment handling states and protocol translation unavoidably leads to communication failure.
This allows DSOs also to optimize on capital investments (CAPEX) and operational costs (OPEX), both in time andplace. Take for example the situation with GSM/GPRS in some countries. While this mature technology is readily
available for rollout and has low cost, it might be at the end of its life cycle and a risk to deploy. However, using it
for WAN access only easily mitigates this risk and placing more advanced 3G/LTE modems in (some of) the IP
Edge Routers from the start or exchanging them gradually when coverage and prices are right.
Another concern for DSOs on optimizing costs is dispersed rollout. NAN technologies (RF or PLC Mesh) typicallyneed sufficiently dense grouping of nodes to achieve mesh capabilities (to see its neighbor). When starting a rollout
in a location, an IP Edge router has to be installed first, close enough from a first meter, ensuring the WAN
communications. Later it will serve as foundation for a larger NAN that will grow as soon as more neighbor nodes
are deployed as well.

© 2011Page 8 of 22

Figure 3. An IPv6 networking stack for Smart Grid Field Area Networks (Source: Cisco)
Figure 3 summarizes the whole proposed IPv6 end-to-end architecture for Field Area Networks and clearly shows
the power and flexibility provided by a layered architecture. First the layers are independent from each other, stillallowing cross-layer optimizations made possible by the Application Programming Interface (API) between thelayers. For example, new link types can be added without having to revisit the network-addressing scheme, or new
applications can be supported without impacting the rest of the stack. And yet another example, the routing
functionality taking place on Layer 3, enables new link layers to be added without impacting the routing
architecture. In the rest of this chapter, we describe, in greater detail, technical aspects related to the networking
stack for FAN, knowing that a plethora of existing IP protocols are re-used without requiring any change.

5.1. Diversity of Physical and Data Link Layers
As mentioned, one main difference between energy distribution networks and ICT is the pace of changes intechnologies. Every three to five years, physical and data link layers evolve offering greater bandwidth, enhanced
robustness, longer reach, lower cost, etc.—all contributing to the success of the IP architecture which allows
smooth evolution and future proofing without reconsidering the whole architecture. Such evolutions on the timescales above are familiar to anyone observing the evolution of Ethernet, Wi-Fi, or Cellular technologies, to namejust a few technologies with very high visibility.
Considering the lifetime of meters or other devices that will get deployed in the last mile, the use of the IP suite
guarantees new technologies and services being added without jeopardizing the stability of an overall deploymentthat is expected to serve a useful life of several decades. Deploying modular devices acting as “IP Edge routers” at
the NAN level allows the addition of new interfaces in addition to the support of new protocol and feature set via
software/firmware upgrades and the co-existence of different generations of meters, and physical and data link
layers while improving last-mile capabilities without greatly modifying existing infrastructures. This statement is not
only true for the last mile—toward the meters—but also on the backhaul links over wide-area networks—that
connect the Information System.
Looking at existing AMI projects around the world, it is obvious that several physical and data link layers
technologies will be selected for the last mile of Smart Grid FAN infrastructure and/or to connect the last mile to the
NMS/Head-End systems.

© 2011Page 9 of 22

Considering the backhaul connectivity of substations, there is no real difference of choice between technologies
selected by an Internet Service Provider (ISP) or by utilities; whatever the technology—Wired (Fiber, Ethernet,
xDSL, broadband PLC) or wireless (WiMax, GPRS, 3G, LTE, satellite)—they all support IP. The real challenge ofintroducing IP in the last mile of an AMI network is more related to selecting open standards for RF Mesh or
narrowband PLC (such as IEEE 802.15.4g and IEEE P1901.2) as current deployments include non-IP, closed or
proprietary solutions.
The physical and data-link layer standardization is outside the scope of the Internet Engineering Task Force(IETF). IETF only defines how IP and upper layers run on top of the MAC and PHY layers standardized by theInstitute of Electrical and Electronics Engineers (IEEE) or other standards bodies. Therefore, let’s have a quick
overview of standards-based PHY and MAC layers for IEEE 802.15.4g (and some of 15.4.e) RF Mesh andIEEE P1901.2 narrowband PLC as they are fully aligned with the IP layered architecture and very well suited to
AMI networks.
IEEE 802.15.4g–Smart Utility Networks (SUN)In an effort to promote open standards for the Smart Grid environment and to meet specific regional and national
regulations, the IEEE 802.15.4g Task Group, also known as the Smart Utility Networks (SUN) Task Group,
reviewed the IEEE 802.15.4-2006 standards and proposed amendments, principally for outdoor, low-data rate,
wireless, smart metering utility networks. Initially, IEEE 802.15.4 was designed as low-power wireless PHY and
MAC layers of choice for smart object networks by offering low power consumption with acceptable link speeds (upto 250 Kbits/s) in the 2.4GHz ISM frequency band.
IEEE 802.15.4g adds new PHY support for Smart Utility Networks (SUN) to IEEE 802.15.4-2011 that will
help develop and deploy standards-based RF-Mesh solutions around the world. In addition to the new PHY,
the amendment also defines MAC modifications (may require 15.4e add-on features) needed to support
their implementation.
The SUN PHY supports multiple data rates in bands ranging from 450MHz to 2450 MHz and working in one ofthese 3 modes:●

Orthogonal frequency division multiplexing (MR-OFDM) PHY–Provides higher data rates at higher
spectral efficiency●

Multi-rate and multi-regional offset quadrature phase-shift keying (MR-O-QPSK) PHY—Shares thecharacteristics of the IEEE 802.15.4-2006 O-QPSK PHY, making multi-mode systems more cost effective
and easier to design●

Multi-rate and multi-regional frequency shift keying (MR-FSK) PHY—Good transmit power efficiency due tothe constant envelope of the transmit signal

IEEE 802.15.4g addresses regional regulations (North America, Europe, Japan, Korea and China) by adding
support for new frequencies including sub-GHz frequency bands. The IEEE 802.15.4 radio can now operate in oneof the dedicated-use or unlicensed bands. A table summarizing the various operating frequencies can be found at
http://developer.cisco.com/web/cegd/blogroll.

© 2011Page 10 of 22

IEEE P1901.2 Power Line Communication
Power Line Communications (PLC) system provides ability to transmit data over power lines.
Also known as a no new-wire technology, it simply reuses the electrical wire of mains-powered devices. Carrying
data over existing wires reduce significantly installation costs. In the context of AMI, PLC makes use of the mostwidely existing wired network: the electrical grid. PLC is not sensitive to the same disturbers as wireless links andcome with its own challenges:●

Time-varying channel characteristics and parameters varying with frequency, location, and the type ofequipment connected to it●

Low bandwidth, calling for optimizations at all layers of the communication’s stack●

Possible high propagation losses●

Frequency-dependent attenuation●

Changing characteristic impedance caused by cable transition and devices connected●

Noise/interference generated by devices connected or the electrical network itself

Some of these characteristics are common with wireless links characteristics such as IEEE 802.15.4. In particular,
PLC links characteristics are continually varying, and could benefit from principles developed for wireless or mobile
networks. Though, no standard was designed to address such challenges over PLC. This is why the IEEE 1901
working group started to specify such standards for PLC. While IEEE 1901 has been published covering In-Homeand Broadband PLC, there is an on-going effort by the IEEE P1901.2 Task Group to standardize the narrowband
PLC, which is used by utilities, also for the last-mile AMI infrastructure.
The expected benefits of IEEE P1901.2 standard for Narrowband PLC are:●Open PHY (OFDM-based) and MAC layers definition allows chipset vendors to develop their offering andusers to look at interoperability●

Data rate is expected to be scalable to 500 kbps, depending on the application requirements●

Covers the full low-frequency (below 500 KHz) PLC communication spectrum, while complying with regional
regulations such as CENELEC A band dedicated to utilities in Europe.

●

Expands the use-cases for IEEE P1901.2 PLC beyond AMI—Electric Vehicle (EV) to charging station,
street lighting, power plugs, solar panels/inverters, and Home Area Networking (HAN).

●

Enable Medium Voltage/Low Voltage crossing for grid to utility meter communication and helping to lower
the deployment cost with reducing the number of concentrators.

●

Assure coexistence with other existing Narrowband and Broadband Power Line (BPL) technologies with adedicated bandwidth●

Address the necessary security requirements that assure communication privacy and allow use for security
sensitive services●

MAC layer aligned with IEEE 802.15.4 MAC and leveraging the work done by IETF 6LoWPAN WG in
particular for header compression. Therefore, it enables straight IPv6 support and simplifying the learning
curve when running both IEEE 802.15.4 and PLC© 2011Page 11 of 22

The resulting IEEE P1901.2 standard can naturally fit with the IP layering architecture and make P1901.2 links partof the overall IPv6 network.
We presented a very short overview of two link layer technologies, but other technologies will undoubtedly be
developed in the coming years. The adoption of an IP architecture permits, from day one, a diversity of physicaland data link layer technologies appropriate to the density, cost and operational requirements of the FAN
deployment. Supporting IP and its layered architecture over PHY and MAC layers guarantees that the FAN
infrastructure can benefit of new link layer’s technologies when, and where, they are needed.

5.2. The 6LoWPAN Adaptation Layer
When sending IP packets over PHY and MAC layers, an adaptation layer is always defined as an open standard
generally published by the IETF. For example, RFC 2464 described how an IPv6 packet must get encapsulated
over an Ethernet frame, and is also used for IEEE 802.11 WiFi. Similarly, the IETF 6LoWPAN working groupspecified how IP packets are encapsulated over IEEE 802.15.4.
The main focus of the 6LoWPAN WG was to optimize the transmission of IPv6 packets over Low Power and Lossy
networks such as 15.4. 6LoWPAN WG led to the publication of RFCs specifying:●

Header compression (RFC 6282), which reduces the impact of sending IPv6 40-bytes headers and UDP 8bytes headers. The way an IPv6 header can get compressed is one of the elements that led to a specificIPv6-only adaptation layer.

Note: While nothing precludes running TCP over IPv6/6LoWPAN, no TCP header compression was defined as thecongestion avoidance algorithms could overreact to LLN’s packet drops and/or round-trip delay variance would
make TCP operate very slowly.
●

Fragmentation and reassembly of IPv6 packets, as the IEEE 802.15.4 127 bytes data link layer did notmatch the requirement of an IPv6 1280-byte Maximum Transmission Unit (MTU). It is worth noting thatIEEE 802.15.4g has no such short MTU limitations●

Other functions such as 6LoWPAN for Duplicate Address Detection (DAD) over broadcast link layers.

Although these features were initially developed for IEEE 802.15.4 links, they are now re-used by other link layers
as long as they adhere to the IEEE 802.15.4 MAC and addressing scheme. For example, this is the case for theIEEE P1901.2 narrowband PLC link layer and DECT Ultra Low Energy (ULE) or Bluetooth Low Energy (LE).

© 2011Page 12 of 22

5.3. IPv6 Addressing
The adoption of IPv6 in the FAN infrastructure requires an Energy Provider to consider all steps required by an
IP network design and particularly an understanding of IPv6 addressing and how internal policies may help
the operations.
Global, public, and private address space have been defined for IPv6, therefore a decision must be maderegarding which type of IPv6 addressing scheme should be used in utility networks. Global addressing means theutility must follow the Regional Internet Registries (RIR) policies (such as ARIN
https://www.arin.net/policy/nrpm.html) to register an IPv6 prefix that is large enough for the expected deployment
and its expansion over the coming years. This does not mean the address space allocated to the infrastructure
must be advertised over the Internet allowing any Internet users to reach a given device. The public prefix can beadvertised if representing the entire utility corporation–or not–and proper filtering mechanisms are in place to block
all access to the Field Area Networks and devices. On the other end, using a private address space means theprefix not be advertised over the Internet, but, in case there is a need for B2B services and connectivity, a private
address would lead to the deployment of additional networking devices known as IPv6-IPv6 NPT (Network Prefix
Translation, RFC 6296) gateways.
Once the IPv6 addressing structure (see RFC 4291, 4193) and policies are well understood and a prefix isallocated to the infrastructure, it is necessary to structure the addresses according to the number of sites and endpoints that would connect to it. This is no different to what an ISP or a large Enterprise has to perform. (See 6NET)Internal policies may be defined by the way an IPv6 address is assigned to an end-device, by using a global or
private prefix.
Three methods to set an IPv6 address on an end-point are available:●

Manual configuration–This is appropriate for Head-End and NMS servers that never change their address,
but is inappropriate to millions of end-points, such as meters, in regards to the associated operational costand complexity●

Stateless auto-configuration–A mechanism similar to Appletalk, IPX and OSI, meaning an IPv6 prefix
gets configured on a router interface (interface of any routing device such as a meter in a mesh or PLC AMI
network), which is then advertised to nodes attached to the interface. When receiving the prefix at boottime, the node can automatically set-up its IPv6 address●

Stateful auto-configuration–Through the use of DHCPv6 Individual Address Assignment, this method
requires DHCPv6 Server and Relay to be configured in the network but benefits of a strong security as the
DHCPv6 process can be coupled with AAA authentication, population of Naming Services (DNS) available
for Head-End and NMS applications.

The list above is the minimum set of tasks to be performed, but as already indicated; you must also establish
internal policies and operational design rules. This is particularly true when considering security and managementtasks such as registering IPv6 addresses and names in DNS (Domain Name System) and in NMS (network
management station(s) or setting-up filtering and firewalling across the infrastructure.

© 2011Page 13 of 22

5.4. Routing
Proprietary systems originally developed for application-specific sensor networks usually neglect the architectural
aspect of a scalable networking architecture. In most of these systems, it is not rare to find non-layered
architecture, despite the lack of flexibility and scalability, with a layer violation. Routing is no exception.
Where should routing take place?
Several closed systems place the routing function at the data link layer (Layer 2). The consequence is that the
network is limiting itself to a single data link layer technology. It therefore becomes impossible to mix or add datalink layers technologies, which is a fundamental requirement of Field Area Networks (as previously discussed,
mixing low-power RF, PLC, or even Cellular is a use-case requirement). In Layer 2 routing networks, the support ofmultiple types of links, would require to superpose two routing protocols (both at the IP layer and the link layer—
this is for example the case when the NAN becomes a multi-service network, a transit network to other networks(e.g gas, water or home), etc), which is an architecture that has proven to be extremely complex, expensive anddifficult to manage even in a non-constrained classic network (IP over ATM (PNNI) is one of the notorious
examples). Needless to say that adding this level of complexity to AMI networks hurts the requirements for
scalability, ease of operations and future proofing.
Therefore, performing routing at the network layer, as fundamentally adopted in the layered IP architecture is anappropriate choice. To that end, the IETF formed in 2008 the Routing over Low Power and Lossy Networks
Working Group (RoLL WG) chartered to specify an IPv6 Routing protocol for constrained large-scale networks
such as FAN [RPL-AMI]. Tasked with designing a routing solution for IP smart-objects, the RoLL WG initially
specified four standard documents, spelling out in detail the technical routing Use-Case requirements for urban
networks, including Smart Grid, industrial, and home and building automation networks. A protocol survey made to
determine whether an existing routing protocol (OSPF, OLSRv2, TBRPF, RIP, AODV, DSDV, DYMO[Low], andDSR) could be used for IP smart objects, given the characteristics and requirements of these networks (includingtable scalability, loss response, cost control, support of cost routing for links and nodes) led to the consensus that a
new routing protocol had to be specified. Being re-chartered, and after almost two years of intensive work done by
a number of industry routing experts, RoLL WG published a new distance-vector routing protocol, called IPv6
Routing Protocol for Low Power and Lossy Networks, or RPL ([RPL]).

© 2011Page 14 of 22

Figure 4. RPL—basic network RPL initialization steps (Source: Cisco)
RPL provides support for a large number of technologies and features (as documented in [RPL-WP]) that matches
all services requirements reviewed in the introduction. One of the key characteristics of RPL is that the protocol ishighly flexible and dynamic; it has fundamentally been designed to operate in harsh environments with low-speed
links potentially experiencing high error rates, while generating very low control plane traffic. RPL offers number ofadvanced features, such as trickle timers limiting the chattiness of control plane, dynamic link (Hop count,
Throughput, Latency, Link / path Reliability, Link Colors) and node (Node state/attribute, node power levels) routing
metrics for constraint-based routing useful for combined AMI and DA deployment, multi-topology routing, and loop
detection or ability to avoid oscillations in case of transient failures (local repair mode and Global repair mode)
Today, RPL is an approved international standard with various implementations, extensive simulations and testing
being carried out. This led several alliances such as Zigbee/IP (and more explicitly as part of Smart Energy Profile(SEP) 2.0), ZWave, and others to adopt routing at the network layer, and particularly RPL, into their evolution to the
IP architecture. While offering a fairly sophisticated set of functionalities, RPL has been tailored to fit in few
kilobytes of memory footprint and should become the IPv6 routing protocol of choice for Field Area Networks as
documented in the applicability statement [RPL-AMI]. In combination with more traditional IP routing technics, suchas route redistribution, load balancing through multiple IP edge routers, dynamic re-routing in case of hardware or
WAN failures, RPL deployment has all capabilities required by large and scalable FAN infrastructure. It worth
stressing the fact that the use of multiple routing protocols all operating at the IP layer is not an issue in contrast
with the co-existence of multiple routing protocols at different layers (link layer and IP), as pointed out at the
beginning of this section.

© 2011Page 15 of 22

Note—IPv6 communications as defined by SEP 2.0 for Home Area Networks (HAN) communications requires
additional discussion in term of addressing, routing and security policies that are outside the scope of thisdocument. For example, a smart meter may get an IPv6 prefix belonging to the Utility on its NAN interface as well
as a private IPv6 prefix locally managed or a public one assigned by a broadband ISP to its HAN SEP 2.0
interface. Traffic flows between interfaces has to be strictly controlled. The new IETF HomeNet WG [In-Home] may
provide guidelines in future.

5.5. Quality of Service (QoS)
Over the past years, several Industries have leveraged the scalable IETF Differentiated Services (DiffServ)architecture for IP Quality of Services (QoS) when integrating critical classes of traffic over their IP networks.
Therefore, the mix of traffic—metering, distribution automation, remote workforce management, etc.—flowing overthe last mile of the Smart Grid network can be controlled and prioritized accordingly to defined Service Level
Agreement (SLA) policies in terms of delays, jitter, packet loss, and scheduling, etc. This implies considering thevariety of QoS mechanisms and their adaptation to the constrained AMI environment, for example:●

Compression–Control of packet size sent over low-bandwidth links helps to scale the AMI infrastructure.
As discussed in the 6LoWPAN section, this adaptation layer deals with IP and UDP headers. In addition,other compression and optimization techniques such as those discussed in the Network Management
section can be applied to other layers, validating once again the benefits of the IPv6 layered architecture.

●

Traffic marking–When packets get transmitted, they can be marked (colored) by the end-node application
or by a router performing packet inspection by setting-up the specific fields on the IPv6 header (traffic-classfield) used to specify their CoS (Class of Service). This allows appropriate prioritization of the packets
through other forwarding nodes.

●

Scheduling and congestion avoidance techniques–To give priority to traffic according to their CoS. For
example, when a device in a RF or PLC mesh network implements several queues enabling real-time traffic
from Distribution Automation sensors to pass through an interface with high priority.

●

Call Admission Control (CAC) techniques–To reserve bandwidth for high-priority traffic, for example onan edge router connecting the last mile to the Head-end system through low-speed cellular networks.

●

Multiple RPL DAG–As discussed in the RPL section, the routing metrics could get leverage to build
different DAG differentiating the routing path for a certain class of traffic. For more details on RPL, pleaserefer to [RPL-WP]

While the QoS model is not fundamentally different between IPv4 and IPv6 version, the appropriate definition ofDifferentiated Services Code Points (DSCP) will help fine-tuning the last-mile infrastructure traffic.

5.6. Security
Coupling data communications capabilities with the power transmission, distribution, and consumption
infrastructures increases the efficiency of the power grid, but also creates a long list of operational challenges—
Security tops that list. Thus, security represents a key challenge for enabling a successful rollout of Smart
Grids and AMIs. It needs to be addressed in a holistic, end-to-end fashion, leveraging the concept of “Security
by Design”.
In the past it was sometimes claimed that the use of open standards and protocols may itself represent a security
issue, but this is overcome by the largest possible community effort, knowledge database and solutions available
for monitoring, analyzing and fixing flaws and threats—something a proprietary system could never achieve.

© 2011Page 16 of 22

Said otherwise, a private network, IP-based architecture based on open standards has the best understood andremedied set of threat models and attack types that have taken place and have been remedied against, on the
open Internet. This is the strongest negation of the now deprecated concept of “security by obscurity” that argues
that the use of non-standard networking protocols increases security and which is unanimously rejected by the
network security expert community. Security per se is not a new topic to utilities as they are already operating andmaintaining large-scale data communication networks. Using IP as a common technology in the core of Smart
Grids and AMIs will help to ensure security knowledge is available within the involved organizations.
It is important to note that IPv6 security has at least the same strengths as IPv4, but both IPv4 and IPv6 arecertainly not worse than proprietary networking protocols. We recommend people focusing on FAN security toreview documents such as NISTIR 7628, Guidelines for Smart Grid Cyber Security or UCAIUG, AMI System
Security Requirements. In Europe, Smart Grid Information Security requirements are currently under definitionby the standardization organizations, several guidelines and requirements have been issued or are under
definition by the Member States. All are asking for open standards. With Security being a multi-layer challenge, it isimportant to review some additional features that provide nodes authentication and data integrity and privacy on a
FAN deployment.
Strong authentication of nodes can be achieved by leveraging a set of open standards mechanisms. For example,
after a node discovered a RF or PLC Mesh network leveraging IEEE 802.15e enhanced Beacon frames, it can get
properly authenticated through IEEE 802.1x, PKI, certificate and AAA/Radius mechanisms before beginning tocommunicate using a Link-local IPv6 address. From there, the node can join its RPL domain before getting a global
IPv6 address through DHCPv6 as well as other information (DNS server, NMS, etc).
Data integrity and privacy leverages the encryption mechanisms available at various layers of the communication
stack. For example, an IPv6 node on a last mile subnet has options to encrypt data at layer 2 (AES-128 on IEEE
802.15.4g or IEEE P1901.2), layer 3 (IPsec), layer 4 (DTLS) or per application at layer 7, ie: encryption of ANSI
C12.22 or DLMS/COSEM for the metering traffic. While multiple levels of encryption may be implemented on aconstraint node, the processing resources (processor speed and memory, energy consumption) requirements mustbe evaluated in regards of the additional hardware cost this could generate. With multiple options available it canbe assured that nodes can be integrated into existing security architectures, relying on Link, Transport and/or
Application Layer encryption. Furthermore, this will ease the integration and enhancement of existing Application
Layer protocols (i.e. ANSI C12.22 or DLMS/COSEM) where certain security functions could convert at a lower
layer, e.g. by providing a secured end-to-end path, and where other functionalities (i.e. message integrity / proof oforigin) can remain at the Application Layer.
The choice of a given layer for data encryption and devices performing the encryption also impact the network
services, performances and scalability of a deployment. For example, when software upgrade, demand/responseor dynamic pricing should use Multicasting, the choice of encrypting data at transport layer (L4 DTLS) precludes
leveraging the replication capabilities of IP Multicast routers on the infrastructure.
Whatever the encryption layer selected on the NAN devices, an IP Edge router can also perform layer 3 encryption(IPsec) for all traffic forwarded over the backhaul links. Therefore, hardware cost and resources may limit to layer 2
authentication and encryption and potentially encryption at layer 3 or 7 on constrained devices while layer 3
encryption on the IP Edge router takes care of all traffic sent over the WAN without loosing network
services capabilities.
Combined with more traditional security features such as digital signatures for firmware images or data objects on
devices (ie. for meter reads or critical commands), traffic filtering, firewalling and intrusion prevention on the IP
Edge routers, the last mile of a Smart Grid deployment can get strong security reinforcement whatever the
traffic patterns.
© 2011Page 17 of 22

With IP offering the possibility of end-to-end communication down to the last mile, also, in case this is required,
end-to-end encryption can be established in an efficient manner. Moreover, Application Layer protocol translation
would not be required within the communication network. Multiple protocols do not have to be maintained, thiswould represent a clear advantage for the efficiency and security of the network.
In addition, IP, as well known technology, offers already available, tested, certified software stacks, implementing
proven security algorithms and Computer Security Incident Response Teams (CSIRTs) and Computer Emergency
Response Team (CERT)). Thus, the Security of Smart Grids and AMIs can directly benefit from security findings
within the Internet Community, now and in the future.

5.7. Network Management for Smart Meters
Today, use cases solution, such as AMI or DA handles most, if not all, services at the application layer. By
adopting IPv6 for the last mile (and therefore enabling bi-directional IP end-to-end communications) there is theopportunity of leveraging well-known services from the open-standards IP architecture, decreasing complexity, andenabling required services of Smart Grid applications which could stay focused on utility data and application
requirements, helping on achieving modularity and scalability and dealing with security at all levels. However, to beable to leverage all services, we acknowledge that some features would not only require proper configuration on
the last mile, but may also need an evolution of the Information System which is due in any case as IPv6 adoption
for the last mile requires changes on the head-end system and Meter Data Management System (MDMS) to deal
with IPv6 address of meters. For example, the use of DNS may allow devices to automatically register their names
and the services they offer which can simplify add/move/change operations on the last mile infrastructure.
When focusing on the particular use case of AMI, with millions of end-points with constrained resources and lowbandwidth built subnets, it is important to stress that gathering network statistics for network management can beachieved through a pull model (for example, SNMP), as well as a push model (for example, CoAP or IPfix). The
push model represents a key feature to scale network management to millions of nodes that have scarce CPU
resources. Therefore, although not restricted to IPv6, the overview of network services as shown in figure-5 is an
opportunity to introduce a new protocol called Constrained Application Protocol (CoAP) designed by the IETF
Constrained Restful Environments (CoRE) working group. CoAP is a new lightweight application protocol for
constrained devices such as those deployed in IPv6/6LoWPAN FAN infrastructures. Although CoAP can be used
end-to-end, the architecture also supports proxies performing a mapping function between CoAP and HTTP Rest
API, independent of the application. CoAP supports various modes of caching and traffic flow (UDP binding with
optional reliability supporting unicast and multicast requests, Asynchronous message exchanges, etc), which canbe useful in AMI. Although CoAP is not yet fully mature and widely deployed as a protocol, its progress is
significant with about a dozen companies having implemented CoAP with several successful interoperability tests.
It will definitively be a key protocol of an IPv6-based FAN deployment.
To summarize, the adoption of IP based networking for all Smart Grid services allows all devices involved in thedelivery of these services to be managed through a single network view. All devices and the relationships between
them at the IP level can be defined in the network management application and the impact of a failure ofcommunication to any given device can be instantly evaluated and displayed.

© 2011Page 18 of 22

Figure 5. Leveraging IPv6 Network Services (IPv6 specific features) (Source: Cisco)

6. Conclusion
The IP protocol suites have been deployed in a number of private and public networks (Internet) during the past
three decades interconnecting billions of IP devices. The architecture has proven to be highly flexible (thusprotecting investments) in many ways: new link types have been adapted, new routing and transport protocols
have been specified and deployed; the number of supported applications has exceeded all expectations by anorder of magnitude! Once again, this is not just because all of these protocols were well designed but due to thelayered nature of the architecture, which provides a very high degree of flexibility.
Field Area Networks are a key component of Smart Grid infrastructures and the number of applications that these
networks support keeps growing at a fast pace. Their networking requirements are no different: flexibility, reliability,
QoS, security, manageability and scalability, which are absolute requirements that explain why IPv6 was evaluatedas the most appropriate networking architecture for Field Area Networks. Additionally, FAN imposed constraints:
links are not only low-speed (which is no different than in the early days of the Internet), but lossy and unstablewith a large number of constrained devices, and they must provide high reliability without requiring heavy andcostly management.
The vast majority of the IP protocols and technologies could be re-used “as-is” (addressing, address provisioning,
QoS, transport, reliability, etc.) and several new IPv6 protocols have been specified to meet the uniquerequirements of the Last Mile in Smart Grid networks (RPL, 6LoWPAN, and CoAP) in addition to several lowpower, low-speed links such as IEEE 802.15.4 or IEEE P1901.2.
We are at the beginning of an exciting journey that will extend the use of IPv6 to billions of devices of a new typesuch as meters and sensors deployed in Field Area Networks. The IPv6 protocols supporting these networks havebeen specified and standardized and a number of large-scale IPv6 networks are being deployed, once again
showing the impressive ability of meeting new networking requirements.

© 2011Page 19 of 22

To summarize, the IP adoption for the last mile enables:●

Media diversity: Physical and data link technology evolution, driven by innovation in communication
technology at its own pace, independently from the Information System (driven by its own innovation paceand decoupled from the above)●

Future proofing: Adoption of new standards when available and required. No major architecture change inthe sense of any necessary “cut-over day” but instead an evolutionary and piecemeal evolutionary path●

Industry transformation: Ease the infrastructure convergence for multi-services such as metering,
Distribution Automation, workforce communications, etc.

●

Cost control: Localized or global CAPEX and OPEX optimization●

Reliability: from ruggedized hardware to dynamic routing and multiple routers connecting a NAN, a FAN
infrastructure can be designed for high-availability.

●

Management: open standards based tools can contribute to improve the operations and customer support.

●

Security: Strong security through IP solutions, also leveraging associated industry processes and IT
professional ecosystem●

Interoperability between IP devices in a multi-service network sharing a common physical infrastructurewith no need for complex and hard to manage multiprotocol gateways.

© 2011Page 20 of 22

Glossary●

6LoWPAN: IPv6 over Low power Wireless Personal Area Networks●

AMI: Advanced Metering Infrastructure●

ANSI: American National Standards Institute●

CERT: Computer Emergency Response Team●

CoAP: Constrained Applications●

CoRE: Constrained Restful Environments●

COSEM: COmpanion Specification for Energy Metering●

CSIRT: Computer Security Incident Response Teams●

DA: Distribution Automation●

DAG: Directed Acyclic Graph●DLMS: Device Language Message specification●

DR: Demand/Response●

DTLS: Datagram Transport Layer Security●

EV: Electrical Vehicle●

FAN: Field Area Network●

HAN: Home Area Network●

IEC: International Electrotechnical Commission●

IEEE: Institute of Electrical and Electronics Engineers●

IETF: Internet Engineering Task Force●

IPv6: Internet Protocol version 6●

LLN: Low-power and Lossy Networks●

LTE: Long Term Evolution●

NAN: Neighborhood Area Network●

NERC CIP: North American Electric Reliability Corporation—Critical Infrastructure Protection●

OFDM: Orthogonal frequency-division multiplexing●

PAN: Personal Area Network●

PLC: Power Line Communication●

QoS: Quality of Service●

RFC: Request For Comment●

RIR: Regional Internet Registry●

RPL: IPv6 Routing Protocol for Low Power and Lossy Networks●

UCAIUG: Utility Communications Architecture International Users Group●

WAN: Wide Area Network© 2011Page 21 of 22

References[6LoWPAN] IPv6 over Low-Power Wireless Personal Area Networks (6LoWPANs)
http://datatracker.ietf.org/wg/6lowpan/[IEEE 1888] IEEE Standard for Ubiquitous Green Community Control Network Protocol (UGCCNet)
http://standards.ieee.org/findstds/standard/1888-2011.html[In-Home] IETF HomeNet WG http://datatracker.ietf.org/wg/homenet/charter/[IP-Light] “Internet Protocol for Smart Objects (IPSO) Alliance”
http://ipso-alliance.org/wp-content/uploads/why_ip.pdf[IP-Smart-Objects] Interconnecting Smart Objects with IP, JP Vasseur and Adam Dunkels, Morgann Kauman,
July 2010.
[LP-Links] “A survey of several low power Link layers for IP Smart Objects ”—
http://ipso-alliance.org/wp-content/uploads/low_power_link_layer.pdf[LWIG] IETF Light-Weight Implementation Guidance WG http://datatracker.ietf.org/wg/lwig/charter/[OECD] “Economic Considerations in the Management of IPv4 and in the Deployment of IPv6”, June 2008
http://www.oecd.org/sti/ict/ipv6[RFC 6272] Internet Protocols for the Smart Grid ftp://ftp.ietf.org/rfc/rfc6272.txt[RPL] “RPL: IPv6 Routing Protocol for Low power and Lossy Networks”—
http://datatracker.ietf.org/doc/draft-ietf-roll-rpl/[RPL-AMI] Applicability Statement for the Routing Protocol for Low Power and Lossy Networks (RPL) in AMI
Networks http://datatracker.ietf.org/doc/draft-ietf-roll-applicability-ami/[RPL-WP] “RPL: The IP routing protocol designed for low power and lossy networks ”—
http://ipso-alliance.org/wp-content/uploads/RPL.pdf[Stats] Worldwide Internet statistics—http://www.internetworldstats.com/stats.htm© 2011Page 22 of 22