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Versions: (draft-hong-6lo-use-cases) 00 01 02

6Lo Working Group                                              Y-G. Hong
Internet-Draft                                                      ETRI
Intended status: Informational                                  C. Gomez
Expires: January 4, 2018                                       UPC/i2cat
                                                               Y-H. Choi
                                                                    ETRI
                                                                 D-Y. Ko
                                                               SKtelecom
                                                               AR. Sangi
                                                  Individual Contributor
                                                             T. Aanstoot
                                                                Modio AB
                                                          S. Chakrabarti
                                                            July 3, 2017


  IPv6 over Constrained Node Networks (6lo) Applicability & Use cases
                      draft-ietf-6lo-use-cases-02

Abstract

   This document describes the applicability of IPv6 over constrained
   node networks (6lo) and provides practical deployment examples.  In
   addition to IEEE 802.15.4, various link layer technologies such as
   ITU-T G.9959 (Z-Wave), BLE, DECT-ULE, MS/TP, NFC, PLC (IEEE 1901),
   and IEEE 802.15.4e (6tisch) are used as examples.  The document
   targets an audience who like to understand and evaluate running end-
   to-end IPv6 over the constrained link layer networks connecting
   devices to each other or to each cloud.

Status of This Memo

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

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

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on January 4, 2018.





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Copyright Notice

   Copyright (c) 2017 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Conventions and Terminology . . . . . . . . . . . . . . . . .   4
   3.  6lo Link layer technologies and possible candidates . . . . .   4
     3.1.  ITU-T G.9959 (specified)  . . . . . . . . . . . . . . . .   4
     3.2.  Bluetooth LE (specified)  . . . . . . . . . . . . . . . .   4
     3.3.  DECT-ULE (specified)  . . . . . . . . . . . . . . . . . .   5
     3.4.  MS/TP (specified) . . . . . . . . . . . . . . . . . . . .   5
     3.5.  NFC (specified) . . . . . . . . . . . . . . . . . . . . .   6
     3.6.  PLC (specified) . . . . . . . . . . . . . . . . . . . . .   6
     3.7.  IEEE 802.15.4e (specified)  . . . . . . . . . . . . . . .   7
     3.8.  LTE MTC (example of a potential candidate)  . . . . . . .   8
     3.9.  Comparison between 6lo Link layer technologies  . . . . .   8
   4.  6lo Deployment Scenarios  . . . . . . . . . . . . . . . . . .   9
     4.1.  jupitermesh in Smart Grid using 6lo in network layer  . .   9
     4.2.  Wi-SUN usage of 6lo stacks  . . . . . . . . . . . . . . .  11
   5.  Design Space and Guidelines for 6lo Deployment  . . . . . . .  12
     5.1.  Design Space Dimensions for 6lo Deployment  . . . . . . .  12
     5.2.  Guidelines for adopting IPv6 stack (6lo/6LoWPAN)  . . . .  14
   6.  6lo Use Case Examples . . . . . . . . . . . . . . . . . . . .  16
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  16
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  17
   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  17
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  17
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  17
     10.2.  Informative References . . . . . . . . . . . . . . . . .  19
   Appendix A.  Other 6lo Use Case Examples  . . . . . . . . . . . .  21
     A.1.  Use case of ITU-T G.9959: Smart Home  . . . . . . . . . .  21
     A.2.  Use case of DECT-ULE: Smart Home  . . . . . . . . . . . .  22
     A.3.  Use case of MS/TP: Management of District Heating . . . .  22
     A.4.  Use case of NFC: Alternative Secure Transfer  . . . . . .  23
     A.5.  Use case of PLC: Smart Grid . . . . . . . . . . . . . . .  23



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     A.6.  Use case of IEEE 802.15.4e: Industrial Automation . . . .  24
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  25

1.  Introduction

   Running IPv6 on constrained node networks has different features from
   general node networks due to the characteristics of constrained node
   networks such as small packet size, short link-layer address, low
   bandwidth, network topology, low power, low cost, and large number of
   devices [RFC4919][RFC7228].  For example, some IEEE 802.15.4 link
   layers have a frame size of 127 octets and IPv6 requires the layer
   below to support an MTU of 1280 bytes, therefore an appropriate
   fragmentation and reassembly adaptation layer must be provided at the
   layer below IPv6.  Also, the limited size of IEEE 802.15.4 frame and
   low energy consumption requirements make the need for header
   compression.  The IETF 6LoPWAN (IPv6 over Low powerWPAN) working
   group published an adaptation layer for sending IPv6 packets over
   IEEE 802.15.4 [RFC4944], a compression format for IPv6 datagrams over
   IEEE 802.15.4-based networks [RFC6282], and Neighbor Discovery
   Optimization for 6LoPWAN [RFC6775].

   As IoT (Internet of Things) services become more popular, IPv6 over
   various link layer technologies such as Bluetooth Low Energy
   (Bluetooth LE), ITU-T G.9959 (Z-Wave), Digital Enhanced Cordless
   Telecommunications - Ultra Low Energy (DECT-ULE), Master-Slave/Token
   Passing (MS/TP), Near Field Communication (NFC), Power Line
   Communication (PLC), and IEEE 802.15.4e (TSCH), have been defined at
   [IETF_6lo] working group.  IPv6 stacks for constrained node networks
   use a variation of the 6LoWPAN stack applied to each particular link
   layer technology.

   In the 6LoPWAN working group, the [RFC6568], "Design and Application
   Spaces for 6LoWPANs" was published and it describes potential
   application scenarios and use cases for low-power wireless personal
   area networks.  Hence, this 6lo applicability document aims to
   provide guidance to an audience who is new to IPv6-over-lowpower
   networks concept and wants to assess if variance of 6LoWPAN stack
   [6lo] can be applied to the constrained L2 network of their interest.
   This 6lo applicability document puts together various design space
   dimensions such as deployment, network size, power source,
   connectivity, multi-hop communication, traffic pattern, security
   level, mobility, and QoS requirements etc.  And it described a few
   set of 6LoPWAN application scenarios and practical deployment as
   examples.

   This document provides the applicability and use cases of 6lo,
   considering the following aspects:




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   o  6lo applicability and use cases MAY be uniquely different from
      those of 6LoWPAN defined for IEEE 802.15.4.

   o  It SHOULD cover various IoT related wire/wireless link layer
      technologies providing practical information of such technologies.

   o  A general guideline on how the 6LoWPAN stack can be modified for a
      given L2 technology.

   o  Example use cases and practical deployment examples.

2.  Conventions and Terminology

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

3.  6lo Link layer technologies and possible candidates

3.1.  ITU-T G.9959 (specified)

   The ITU-T G.9959 recommendation [G.9959] targets low-power Personal
   Area Networks (PANs).  G.9959 defines how a unique 32-bit HomeID
   network identifier is assigned by a network controller and how an
   8-bit NodeID host identifier is allocated to each node.  NodeIDs are
   unique within the network identified by the HomeID.  The G.9959
   HomeID represents an IPv6 subnet that is identified by one or more
   IPv6 prefixes [RFC7428].  The ITU-T G.9959 can be used for smart home
   applications.

3.2.  Bluetooth LE (specified)

   Bluetooth LE was introduced in Bluetooth 4.0, enhanced in Bluetooth
   4.1, and developed even further in successive versions.  Bluetooth
   SIG has also published Internet Protocol Support Profile (IPSP).  The
   IPSP enables discovery of IP-enabled devices and establishment of
   link-layer connection for transporting IPv6 packets.  IPv6 over
   Bluetooth LE is dependent on both Bluetooth 4.1 and IPSP 1.0 or
   newer.

   Devices such as mobile phones, notebooks, tablets and other handheld
   computing devices which will include Bluetooth 4.1 chipsets will
   probably also have the low-energy variant of Bluetooth.  Bluetooth LE
   will also be included in many different types of accessories that
   collaborate with mobile devices such as phones, tablets and notebook
   computers.  An example of a use case for a Bluetooth LE accessory is
   a heart rate monitor that sends data via the mobile phone to a server




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   on the Internet [RFC7668].  A typical usage of Bluetooth LE is
   smartphone-based interaction with constrained devices.

3.3.  DECT-ULE (specified)

   DECT ULE is a low power air interface technology that is designed to
   support both circuit switched services, such as voice communication,
   and packet mode data services at modest data rate.

   The DECT ULE protocol stack consists of the PHY layer operating at
   frequencies in the 1880 - 1920 MHz frequency band depending on the
   region and uses a symbol rate of 1.152 Mbps.  Radio bearers are
   allocated by use of FDMA/TDMA/TDD techniques.

   In its generic network topology, DECT is defined as a cellular
   network technology.  However, the most common configuration is a star
   network with a single Fixed Part (FP) defining the network with a
   number of Portable Parts (PP) attached.  The MAC layer supports
   traditional DECT as this is used for services like discovery,
   pairing, security features etc.  All these features have been reused
   from DECT.

   The DECT ULE device can switch to the ULE mode of operation,
   utilizing the new ULE MAC layer features.  The DECT ULE Data Link
   Control (DLC) provides multiplexing as well as segmentation and re-
   assembly for larger packets from layers above.  The DECT ULE layer
   also implements per-message authentication and encryption.  The DLC
   layer ensures packet integrity and preserves packet order, but
   delivery is based on best effort.

   The current DECT ULE MAC layer standard supports low bandwidth data
   broadcast.  However the usage of this broadcast service has not yet
   been standardized for higher layers [RFC8105].  DECT-ULE can be used
   for smart metering in a home.

3.4.  MS/TP (specified)

   MS/TP is a contention-free access method for the RS-485 physical
   layer, which is used extensively in building automation networks.

   An MS/TP device is typically based on a low-cost microcontroller with
   limited processing power and memory.  Together with low data rates
   and a small address space, these constraints are similar to those
   faced in 6lowpan networks and suggest some elements of that solution
   might be leveraged.  MS/TP differs significantly from 6lowpan in at
   least three aspects: a) MS/TP devices typically have a continuous
   source of power, b) all MS/TP devices on a segment can communicate
   directly so there are no hidden node or mesh routing issues, and c)



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   recent changes to MS/TP provide support for large payloads,
   eliminating the need for link-layer fragmentation and reassembly.

   MS/TP is designed to enable multidrop networks over shielded twisted
   pair wiring, although not according to standards, in lower speeds,
   normally 9600 bit/s, re-purposed telecom wiring is widely in use,
   keeping deployment cost down.  It can support a data rate of 115,200
   baud on segments up to 1000 meters in length, or segments up to 1200
   meters in length at lower baud rates.  An MS/TP link requires only a
   UART, an RS-485 transceiver with a driver that can be disabled, and a
   5ms resolution timer.  These features make MS/TP a cost-effective and
   very reliable field bus for the most numerous and least expensive
   devices in a building automation network [RFC8163].  MS/TP can be
   used for the management of district heating.

3.5.  NFC (specified)

   NFC technology enables simple and safe two-way interactions between
   electronic devices, allowing consumers to perform contactless
   transactions, access digital content, and connect electronic devices
   with a single touch.  NFC complements many popular consumer level
   wireless technologies, by utilizing the key elements in existing
   standards for contactless card technology (ISO/IEC 14443 A&B and
   JIS-X 6319-4).  NFC can be compatible with existing contactless card
   infrastructure and it enables a consumer to utilize one device across
   different systems.

   Extending the capability of contactless card technology, NFC also
   enables devices to share information at a distance that is less than
   10 cm with a maximum communication speed of 424 kbps.  Users can
   share business cards, make transactions, access information from a
   smart poster or provide credentials for access control systems with a
   simple touch.

   NFC's bidirectional communication ability is ideal for establishing
   connections with other technologies by the simplicity of touch.  In
   addition to the easy connection and quick transactions, simple data
   sharing is also available [I-D.ietf-6lo-nfc].  NFC can be used for
   secure transfer in healthcare services.

3.6.  PLC (specified)

   Unlike other dedicated communication infrastructure, the required
   medium (power conductor) is widely available indoors and outdoors.
   Moreover, wired technologies are more susceptible to cause
   interference but are more reliable than their wireless counterparts.
   PLC is a data transmission technique that utilizes power conductors
   as medium.



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   The below table shows some available open standards defining PLC.

   +-------------+-----------------+------------+-----------+----------+
   | PLC Systems | Frequency Range |    Type    | Data Rate | Distance |
   +-------------+-----------------+------------+-----------+----------+
   |   IEEE1901  |     <100MHz     | Broadband  |  200Mbps  |  1000m   |
   |             |                 |            |           |          |
   |  IEEE1901.1 |      <15MHz     |  PLC-IoT   |   10Mbps  |  2000m   |
   |             |                 |            |           |          |
   |  IEEE1901.2 |     <500kHz     | Narrowband |  200Kbps  |  3000m   |
   +-------------+-----------------+------------+-----------+----------+

               Table 1: Some Available Open Standards in PLC

   [IEEE1901] defines broadband variant of PLC but is effective within
   short range.  This standard addresses the requirements of
   applications with high data rate such as: Internet, HDTV, Audio,
   Gaming etc.  Broadband operates on OFDM (Orthogonal Frequency
   Division Multiplexing) modulation.

   [IEEE1901.2] defines narrowband variant of PLC with less data rate
   but significantly higher transmission range that could be used in an
   indoor or even an outdoor environment.  It is applicable to typical
   IoT applications such as: Building Automation, Renewable Energy,
   Advanced Metering, Street Lighting, Electric Vehicle, Smart Grid etc.
   Moreover, IEEE 1901.2 standard is based on the 802.15.4 MAC sub-layer
   and fully endorses the security scheme defined in 802.15.4.
   [RFC8036].  A typical use case of PLC is smart grid.

3.7.  IEEE 802.15.4e (specified)

   The Time Slotted Channel Hopping (TSCH) mode was introduced in the
   IEEE 802.15.4-2015 standard.  In a TSCH network, all nodes are
   synchronized.  Time is sliced up into timeslots.  The duration of a
   timeslot, typically 10ms, is large enough for a node to send a full-
   sized frame to its neighbor, and for that neighbor to send back an
   acknowledgment to indicate successful reception.  Timeslots are
   grouped into one of more slotframes, which repeat over time.

   All the communication in the network is orchestrated by a
   communication schedule which indicates to each node what to do in
   each of the timeslots of a slotframe: transmit, listen or sleep.  The
   communication schedule can be built so that the right amount of link-
   layer resources (the cells in the schedule) are scheduled to satisfy
   the communication needs of the applications running on the network,
   while keeping the energy consumption of the nodes very low.  Cells
   can be scheduled in a collision-free way, introducing a high level of
   determinism to the network.



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   A TSCH network exploits channel hopping: subsequent packet exchanges
   between neighbor nodes are done on a different frequency.  This means
   that, if a frame isn't received, the transmitter node will re-
   transmitt the frame on a different frequency.  The resulting "channel
   hopping" efficiently combats external interference and multi-path
   fading.

   The main benefits of IEEE 802.15.4 TSCH are:

      - ultra high reliability.  Off-the-shelf commercial products offer
      over 99.999% end-to-end reliability.

      - ultra low-power consumption.  Off-the-shelf commercial products
      offer over a decade of battery lifetime.

      - 6TiSCH at IETF defines communications of TSCH network and it
      uses 6LoWPAN stack [RFC7554].

   IEEE 802.15.4e can be used for industrial automation.

3.8.  LTE MTC (example of a potential candidate)

   LTE category defines the overall performance and capabilities of the
   UE(User Equipment).  For example, the maximum down rate of category 1
   UE and category 2 UE are 10.3 Mbit/s and 51.0 Mbit/s respectively.
   There are many categories in LTE standard. 3GPP standards defined the
   category 0 to be used for low rate IoT service in release 12.  Since
   category 1 and category 0 could be used for low rate IoT service,
   these categories are called LTE MTC (Machine Type Communication)
   [LTE_MTC].

   LTE MTC offer advantages in comparison to above category 2 and is
   appropriate to be used for low rate IoT services such as low power
   and low cost.  LTE MTC can be used for a gateway of a wireless
   bachhaul network.

3.9.  Comparison between 6lo Link layer technologies

   In above clauses, various 6lo Link layer technologies and a possible
   candidate are described.  The following table shows that dominant
   paramters of each use case corresponding to the 6lo link layer
   technology.









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+-----------+--------+--------+--------+--------+--------+--------+--------+
|           | Z-Wave |   BLE  |DECT-ULE|  MS/TP |   NFC  |   PLC  |  TSCH  |
+-----------+--------+--------+--------+--------+--------+--------+--------+
|           |  Home  |Interact|        |        | Health-|        |Industr-|
|   Usage   |  Auto- |w/ Smart|  Meter |District|  care  |  Smart |ial Aut-|
|           | mation | Phone  | Reading| Heating| Service|  Grid  | mation |
+-----------+--------+--------+--------+--------+--------+--------+--------+
|  Topology | L2-mesh|  Star  |  Star  |   Bus  |   P2P  |  Tree  |        |
|      &    |   or   |        |        |        |        |        |  Mesh  |
|   Subnet  | L3-mesh| No mesh| No mesh|  MS/TP | L2-mesh| No mesh|        |
+-----------+--------+--------+--------+--------+--------+--------+--------+
|           |        |        |        |        |        |        |        |
|  Mobility |   No   |   Low  |   No   |   No   |Moderate|   No   |   No   |
|   Reqmt   |        |        |        |        |        |        |        |
+-----------+--------+--------+--------+--------+--------+--------+--------+
|           | High + |        | High + | High + |        |  igh + | High + |
|  Security | Privacy| Parti- | Privacy| Authen.|  High  |Encrypt.| Privacy|
|   Reqmt   |required|  ally  |required|required|        |required|required|
+-----------+--------+--------+--------+--------+--------+--------+--------+
|           |        |        |        |        |        |        |        |
| Buffering |   Low  |   Low  |   Low  |   Low  |   Low  |   Low  |   Low  |
|   Reqmpt  |        |        |        |        |        |        |        |
+-----------+--------+--------+--------+--------+--------+--------+--------+
|  Latency, |        |        |        |        |        |        |        |
|    QoS    |  High  |   Low  |   Low  |  High  |  High  |   Low  |  High  |
|   Reqmt   |        |        |        |        |        |        |        |
+-----------+--------+--------+--------+--------+--------+--------+--------+
|           |        |        |        |        |        |        |        |
|    Data   |Infrequ-|Infrequ-|Infrequ-|Frequent|  Small |Infrequ-|Infrequ-|
|    Rate   |  ent   |  ent   |  ent   |        |        |  ent   |  ent   |
+-----------+--------+--------+--------+--------+--------+--------+--------+
|   RFC #   |        |        |        |        |        |        |        |
|    or     | RFC7428| RFC7668| RFC8105| RFC8163| 6lo-nfc|hou-6lo-| RFC7554|
|   Draft   |        |        |        |        |        |   plc  |        |
+-----------+--------+--------+--------+--------+--------+--------+--------+

                  Table 2: Comparison between 6lo Link layer technologies


4.  6lo Deployment Scenarios

4.1.  jupitermesh in Smart Grid using 6lo in network layer

   jupiterMesh is a multi-hop wireless mesh network specification
   designed mainly for deployment in large geographical areas.  Each
   subnet in jupiterMesh is able to cover an entire neighborhood with
   thousands of nodes consisting of IPv6-enabled routers and end-points




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   (e.g., hosts).  Automated network joining and load balancing allows a
   seamless deployment of a large number of subnets.

   The main application domains targeted by jupiterMesh are smart grid
   and smart cities.  This includes, but is not limited to the following
   applications:

   o  Automated meter reading

   o  Distribution Automation (DA)

   o  Demand-side management (DSM)

   o  Demand-side response (DSR)

   o  Power outage reporting

   o  Street light monitoring and control

   o  Transformer load management

   o  EV charging coordination

   o  Energy theft

   o  Parking space locator

   jupiterMesh specification is based on the following technologies:

   o  The PHY layer is based on IEEE 802.15.4 SUN specification [IEEE
      802.15.4-2015], supporting multiple operating modes for deployment
      in different regulatory domains and deployment scenarios in terms
      of density and bandwidth requirements. jupiterMesh supports bit
      rates from 50 kbps to 800 kbps, frame size up to 2048 bytes, up to
      11 different RF bands and 3 modulation types (i.e., FSK, OQPSK and
      OFDM).

   o  The MAC layer is based on IEEE 802.15.4 TSCH specification [IEEE
      802.15.4-2015].  With frequency hopping capability, TSCH MAC
      supports scheduling of dedicated timeslot enabling bandwidth
      management and QOS.

   o  The security layer consists of a certificate-based (i.e.  X.509)
      network access authentication using EAP-TLS, with IEEE
      802.15.9-based KMP (Key Management Protocol) transport, and PANA
      and link layer encryption using AES-128 CCM as specified in IEEE
      802.15.4-2015 [IEEE 802.15.4-2015].




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   o  Address assignment and network configuration are specified using
      DHCPv6 [RFC3315].  Neighbor Discovery (ND) [RFC6775] and stateless
      address auto-configuration (SLAAC) are not supported.

   o  The network layer consists of IPv6, ICPMv6 and 6lo/6LoPWAN header
      compression [RFC6282].  Multicast is supported using MPL.  Two
      domains are supported, a delay sensitive MPL domain for low
      latency applications (e.g.  DSM, DSR) and a delay insensitive one
      for less stringent applications (e.g.  OTA file transfers).

   o  The routing layer uses RPL [RFC6550] in non-storing mode with the
      MRHOF objective function based on the ETX metric.

4.2.  Wi-SUN usage of 6lo stacks

   Wireless Smart Ubiquitous Network (Wi-SUN) is a technology based on
   the IEEE 802.15.4g standard.  Wi-SUN networks support star and mesh
   topologies, as well as hybrid star/mesh deployments, but are
   typically laid out in a mesh topology where each node relays data for
   the network to provide network connectivity.  Wi-SUN networks are
   deployed on both powered and battery-operated devices.

   The main application domains targeted by Wi-SUN are smart utility and
   smart city networks.  This includes, but is not limited to the
   following applications:

   o  Advanced Metering

   o  Infrastructure (AMI)

   o  Distribution Automation

   o  Home Energy Management

   o  Infrastructure Management

   o  Intelligent Transportation Systems

   o  Smart Street Lighting

   o  Agriculture

   o  Structural health (bridges, buildings etc)

   o  Monitoring and Asset Management

   o  Smart Thermostats, Air Conditioning and Heat Controls




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   o  Energy Usage Information Displays

   The Wi-SUN Alliance Field Area Network (FAN) covers primarily outdoor
   networks, and its specification is oriented towards meeting the more
   rigorous challenges of these environments.  Examples include from
   meter to outdoor access point/router for AMI and DR, or between
   switches for DA.  However, nothing in the profile restricts it to
   outdoor use.  It has the following features;

   o  Open standards based on IEEE802, IETF, TIA, ETSI

   o  Architecture is an IPv6 frequency hopping wireless mesh network
      with enterprise level security

   o  Simple infrastructure which is low cost, low complexity

   o  Enhanced network robustness, reliability, and resilience to
      interference, due to high redundancy and frequency hopping

   o  Enhaced scalability, long range, and energy friendliness

   o  Supports multiple global license-exempt sub GHz bands

   o  Multi-vendor interoperability

   o  Very low power modes in development permitting long term battery
      operation of network nodes

   In the Wi-SUN FAN specification, adaptation layer based on 6lo and
   IPv6 network layer are described.  So, IPv6 protocol suite including
   TCP/UDP, 6lo Adaptation, Header Compression, DHCPv6 for IP address
   management, Routing using RPL, ICMPv6, and Unicast/Multicast
   forwarding is utilized.

5.  Design Space and Guidelines for 6lo Deployment

5.1.  Design Space Dimensions for 6lo Deployment

   The [RFC6568] lists the dimensions used to describe the design space
   of wireless sensor networks in the context of the 6LoWPAN working
   group.  The design space is already limited by the unique
   characteristics of a LoWPAN (e.g., low power, short range, low bit
   rate).  In [RFC6568], the following design space dimensions are
   described; Deployment, Network size, Power source, Connectivity,
   Multi-hop communication, Traffic pattern, Mobility, Quality of
   Service (QoS).  However, in this document, the following design space
   dimensions are considered:




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   o  Deployment/Bootstrapping: 6lo nodes can be connected randomly, or
      in an organized manner.  The bootstrapping has different
      characteristics for each link layer technology.

   o  Topology: Topology of 6lo networks may inherently follow the
      characteristics of each link layer technology.  Point-to-point,
      star, tree or mesh topologies can be configured, depending on the
      link layer technology considered.

   o  L2-Mesh or L3-Mesh: L2-mesh and L3-mesh may inherently follow the
      characteristics of each link layer technology.  Some link layer
      technologies may support L2-mesh and some may not support.

   o  Multi-link subnet, single subnet: The selection of multi-link
      subnet and single subnet depends on connectivity and the number of
      6lo nodes.

   o  Data rate: Originally, the link layer technologies of 6lo have low
      rate of data transmission.  But, by adjusting the MTU, it can
      deliver higher data rate.

   o  Buffering requirements: Some 6lo use case may require more data
      rate than the link layer technology support.  In this case, a
      buffering mechanism to manage the data is required.

   o  Security and Privacy Requirements: Some 6lo use case can involve
      transferring some important and personal data between 6lo nodes.
      In this case, high-level security support is required.

   o  Mobility across 6lo networks and subnets: The movement of 6lo
      nodes is dependent on the 6lo use case.  If the 6lo nodes can move
      or moved around, it requires a mobility management mechanism.

   o  Time synchronization requirements: The requirement of time
      synchronization of the upper layer service is dependent on the 6lo
      use case.  For some 6lo use case related to health service, the
      measured data must be recorded with exact time and must be
      transferred with time synchronization.

   o  Reliability and QoS: Some 6lo use case requires high reliability,
      for example real-time service or health-related services.

   o  Traffic patterns: 6lo use cases may involve various traffic
      patterns.  For example, some 6lo use case may require short data
      length and random transmission.  Some 6lo use case may require
      continuous data and periodic data transmission.





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   o  Security Bootstrapping: Without the external operations, 6lo nodes
      must have the security bootstrapping mechanism.

   o  Power use strategy: to enable certain use cases, there may be
      requirements on the class of energy availability and the strategy
      followed for using power for communication [RFC7228].  Each link
      layer technology defines a particular power use strategy which may
      be tuned [I-D.ietf-lwig-energy-efficient].  Readers are expected
      to be familiar with [RFC7228] terminology.

   o  Update firmware requirements: Most 6lo use cases will need a
      mechanism for updating firmware.  In these cases support for over
      the air updates are required, probably in a broadcast mode when
      bandwith is low and the number of identical devices is high.

5.2.  Guidelines for adopting IPv6 stack (6lo/6LoWPAN)

   The following guideline targets candidates for new constrained L2
   technologies that consider running modified 6LoWPAN stack.  The
   modification of 6LoWPAN stack should be based on the following:

   o  Addressing Model: Addressing model determines whether the device
      is capable of forming IPv6 Link-local and global addresses and
      what is the best way to derive the IPv6 addresses for the
      constrained L2 devices.  Whether the device is capable of forming
      IPv6 Link-local and global addresses, L2-address-derived IPv6
      addresses are specified in [RFC4944], but there exist implications
      for privacy.  For global usage, a unique IPv6 address must be
      derived using an assigned prefix and a unique interface ID.
      [RFC8065] provides such guidelines.  For MAC derived IPv6 address,
      please refer to [RFC8163] for IPv6 address mapping examples.
      Broadcast and multicast support are dependent on the L2 networks.
      Most lowpower L2 implementations map multicast to broadcast
      networks.  So care must be taken in the design when to use
      broadcast and try to stick to unicast messaging whenever possible.

   o  MTU Considerations: The deployment SHOULD consider their need for
      maximum transmission unit of a packet (MTU) over the link layer
      and should consider if fragmentation and reassembly of packets are
      needed at the 6LoWPAN layer.  For example, if the link-layer
      supports fragmentation and reassembly of packets, then 6LoWPAN
      layer may skip supporting fragmentation/reassembly.  In fact, for
      most efficiency, choosing a low-power link-layer that can carry
      unfragmented application packets would be optimum for packet
      transmission if the deployment can afford it.  Please refer to 6lo
      RFCs [RFC7668], [RFC8163], [RFC8105] for example guidance.





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   o  Mesh or L3-Routing: 6LoWPAN specifications do provide mechanisms
      to support for mesh routing at L2.  [RFC6550] defines L3 routing
      for low power lossy networks using directed graphs. 6LoWPAN is
      routing protocol agnostic and other L2 or L3 routing protocols can
      be run using a 6LoWPAN stack.

   o  Address Assignment: 6LoWPAN requires that IPv6 Neighbor Discovery
      for low power networks [RFC6775] be used for autoconfiguration of
      stateless IPv6 address assignment.  Considering the energy
      sensitive networks [RFC6775] makes optimization from classical
      IPv6 ND [RFC4861] protocol.  It is the responsibility of the
      deployment to ensure unique global IPv6 addresses for the Internet
      connectivity.  For local-only connectivity IPv6 ULA may be used.
      [RFC6775] specifies the 6LoWPAN border router(6LBR) which is
      responsible for prefix assignment to the 6lo/6LoWPAN network. 6LBR
      can be connected to the Internet or Enterprise network via its one
      of the interfaces.  Please refer to [RFC7668] and [RFC8105] for
      examples of address assignment considerations.  In addition,
      privacy considerations [RFC8065] must be consulted for
      applicability.  In certain scenarios, the deployment may not
      support autoconfiguration of IPv6 addressing due to regulatory and
      business reasons and may choose to offer a separate address
      assignment service.

   o  Header Compression: IPv6 header compression [RFC6282] is a vital
      part of IPv6 over low power communication.  Examples of header
      compression for different link-layers specifications are found in
      [RFC7668], [RFC8163], [RFC8105].  A generic header compression
      technique is specified in [RFC7400].

   o  Security and Encryption: Though 6LoWPAN basic specifications do
      not address security at network layer, the assumption is that L2
      security must be present.  In addition, application level security
      is highly desirable.  The working groups [ace] and [core] should
      be consulted for application and transport level security. 6lo
      working group is working on address authentication [6lo-ap-nd] and
      secure bootstrapping is also being discussed at IETF.  However,
      there may be different levels of security available in a
      deployment through other standards such as hardware level security
      or certificates for initial booting process.  Encryption is quite
      important if the implementation can afford it.

   o  Additional processing: [RFC8066] defines guidelines for ESC
      dispatch octets use in the 6LoWPAN header.  An implementation may
      take advantage of ESC header to offer a deployment specific
      processing of 6LoWPAN packets.





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6.  6lo Use Case Examples

   As IPv6 stacks for constrained node networks use a variation of the
   6LoWPAN stack applied to each particular link layer technology,
   various 6lo use cases can be provided.  In this clause, one 6lo use
   case example of Bluetooth LE (Smartphone-Based Interaction with
   Constrained Devices) is described.  Other 6lo use case examples are
   described in Appendix.

   The key feature behind the current high Bluetooth LE momentum is its
   support in a large majority of smartphones in the market.  Bluetooth
   LE can be used to allow the interaction between the smartphone and
   surrounding sensors or actuators.  Furthermore, Bluetooth LE is also
   the main radio interface currently available in wearables.  Since a
   smartphone typically has several radio interfaces that provide
   Internet access, such as Wi-Fi or 4G, the smartphone can act as a
   gateway for nearby devices such as sensors, actuators or wearables.
   Bluetooth LE may be used in several domains, including healthcare,
   sports/wellness and home automation.

   Example: Use of Bluetooth LE-based Body Area Network for fitness

   A person wears a smartwatch for fitness purposes.  The smartwatch has
   several sensors (e.g. heart rate, accelerometer, gyrometer, GPS,
   temperature, etc.), a display, and a Bluetooth LE radio interface.
   The smartwatch can show fitness-related statistics on its display.
   However, when a paired smartphone is in the range of the smartwatch,
   the latter can report almost real-time measurements of its sensors to
   the smartphone, which can forward the data to a cloud service on the
   Internet.  In addition, the smartwatch can receive notifications
   (e.g. alarm signals) from the cloud service via the smartphone.  On
   the other hand, the smartphone may locally generate messages for the
   smartwatch, such as e-mail reception or calendar notifications.

   The functionality supported by the smartwatch may be complemented by
   other devices such as other on-body sensors, wireless headsets or
   head-mounted displays.  All such devices may connect to the
   smartphone creating a star topology network whereby the smartphone is
   the central component.

7.  IANA Considerations

   There are no IANA considerations related to this document.








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8.  Security Considerations

   Security considerations are not directly applicable to this document.
   The use cases will use the security requirements described in the
   protocol specifications.

9.  Acknowledgements

   Carles Gomez has been funded in part by the Spanish Government
   (Ministerio de Educacion, Cultura y Deporte) through the Jose
   Castillejo grant CAS15/00336.  His contribution to this work has been
   carried out in part during his stay as a visiting scholar at the
   Computer Laboratory of the University of Cambridge.

   Thomas Watteyne, Pascal Thubert, Xavier Vilajosana, Daniel Migault,
   and Jianqiang HOU have provided valuable feedback for this draft.

   Das Subir and Michel Veillette have provided valuable information of
   jupiterMesh and Paul Duffy has provided valuable information of Wi-
   SUN for this draft.

10.  References

10.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC4919]  Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6
              over Low-Power Wireless Personal Area Networks (6LoWPANs):
              Overview, Assumptions, Problem Statement, and Goals",
              RFC 4919, DOI 10.17487/RFC4919, August 2007,
              <http://www.rfc-editor.org/info/rfc4919>.

   [RFC4944]  Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler,
              "Transmission of IPv6 Packets over IEEE 802.15.4
              Networks", RFC 4944, DOI 10.17487/RFC4944, September 2007,
              <http://www.rfc-editor.org/info/rfc4944>.

   [RFC5826]  Brandt, A., Buron, J., and G. Porcu, "Home Automation
              Routing Requirements in Low-Power and Lossy Networks",
              RFC 5826, DOI 10.17487/RFC5826, April 2010,
              <http://www.rfc-editor.org/info/rfc5826>.






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   [RFC6282]  Hui, J., Ed. and P. Thubert, "Compression Format for IPv6
              Datagrams over IEEE 802.15.4-Based Networks", RFC 6282,
              DOI 10.17487/RFC6282, September 2011,
              <http://www.rfc-editor.org/info/rfc6282>.

   [RFC6550]  Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J.,
              Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur,
              JP., and R. Alexander, "RPL: IPv6 Routing Protocol for
              Low-Power and Lossy Networks", RFC 6550,
              DOI 10.17487/RFC6550, March 2012,
              <http://www.rfc-editor.org/info/rfc6550>.

   [RFC6568]  Kim, E., Kaspar, D., and JP. Vasseur, "Design and
              Application Spaces for IPv6 over Low-Power Wireless
              Personal Area Networks (6LoWPANs)", RFC 6568,
              DOI 10.17487/RFC6568, April 2012,
              <http://www.rfc-editor.org/info/rfc6568>.

   [RFC6775]  Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C.
              Bormann, "Neighbor Discovery Optimization for IPv6 over
              Low-Power Wireless Personal Area Networks (6LoWPANs)",
              RFC 6775, DOI 10.17487/RFC6775, November 2012,
              <http://www.rfc-editor.org/info/rfc6775>.

   [RFC7228]  Bormann, C., Ersue, M., and A. Keranen, "Terminology for
              Constrained-Node Networks", RFC 7228,
              DOI 10.17487/RFC7228, May 2014,
              <http://www.rfc-editor.org/info/rfc7228>.

   [RFC7400]  Bormann, C., "6LoWPAN-GHC: Generic Header Compression for
              IPv6 over Low-Power Wireless Personal Area Networks
              (6LoWPANs)", RFC 7400, DOI 10.17487/RFC7400, November
              2014, <http://www.rfc-editor.org/info/rfc7400>.

   [RFC7428]  Brandt, A. and J. Buron, "Transmission of IPv6 Packets
              over ITU-T G.9959 Networks", RFC 7428,
              DOI 10.17487/RFC7428, February 2015,
              <http://www.rfc-editor.org/info/rfc7428>.

   [RFC7554]  Watteyne, T., Ed., Palattella, M., and L. Grieco, "Using
              IEEE 802.15.4e Time-Slotted Channel Hopping (TSCH) in the
              Internet of Things (IoT): Problem Statement", RFC 7554,
              DOI 10.17487/RFC7554, May 2015,
              <http://www.rfc-editor.org/info/rfc7554>.







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   [RFC7668]  Nieminen, J., Savolainen, T., Isomaki, M., Patil, B.,
              Shelby, Z., and C. Gomez, "IPv6 over BLUETOOTH(R) Low
              Energy", RFC 7668, DOI 10.17487/RFC7668, October 2015,
              <http://www.rfc-editor.org/info/rfc7668>.

   [RFC8036]  Cam-Winget, N., Ed., Hui, J., and D. Popa, "Applicability
              Statement for the Routing Protocol for Low-Power and Lossy
              Networks (RPL) in Advanced Metering Infrastructure (AMI)
              Networks", RFC 8036, DOI 10.17487/RFC8036, January 2017,
              <http://www.rfc-editor.org/info/rfc8036>.

   [RFC8065]  Thaler, D., "Privacy Considerations for IPv6 Adaptation-
              Layer Mechanisms", RFC 8065, DOI 10.17487/RFC8065,
              February 2017, <http://www.rfc-editor.org/info/rfc8065>.

   [RFC8066]  Chakrabarti, S., Montenegro, G., Droms, R., and J.
              Woodyatt, "IPv6 over Low-Power Wireless Personal Area
              Network (6LoWPAN) ESC Dispatch Code Points and
              Guidelines", RFC 8066, DOI 10.17487/RFC8066, February
              2017, <http://www.rfc-editor.org/info/rfc8066>.

   [RFC8105]  Mariager, P., Petersen, J., Ed., Shelby, Z., Van de Logt,
              M., and D. Barthel, "Transmission of IPv6 Packets over
              Digital Enhanced Cordless Telecommunications (DECT) Ultra
              Low Energy (ULE)", RFC 8105, DOI 10.17487/RFC8105, May
              2017, <http://www.rfc-editor.org/info/rfc8105>.

   [RFC8163]  Lynn, K., Ed., Martocci, J., Neilson, C., and S.
              Donaldson, "Transmission of IPv6 over Master-Slave/Token-
              Passing (MS/TP) Networks", RFC 8163, DOI 10.17487/RFC8163,
              May 2017, <http://www.rfc-editor.org/info/rfc8163>.

10.2.  Informative References

   [RFC3315]  Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins,
              C., and M. Carney, "Dynamic Host Configuration Protocol
              for IPv6 (DHCPv6)", RFC 3315, DOI 10.17487/RFC3315, July
              2003, <http://www.rfc-editor.org/info/rfc3315>.

   [RFC4861]  Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
              "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
              DOI 10.17487/RFC4861, September 2007,
              <http://www.rfc-editor.org/info/rfc4861>.








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   [I-D.ietf-6lo-nfc]
              Choi, Y., Hong, Y., Youn, J., Kim, D., and J. Choi,
              "Transmission of IPv6 Packets over Near Field
              Communication", draft-ietf-6lo-nfc-07 (work in progress),
              June 2017.

   [I-D.ietf-lwig-energy-efficient]
              Gomez, C., Kovatsch, M., Tian, H., and Z. Cao, "Energy-
              Efficient Features of Internet of Things Protocols",
              draft-ietf-lwig-energy-efficient-07 (work in progress),
              March 2017.

   [I-D.ietf-roll-aodv-rpl]
              Anamalamudi, S., Zhang, M., Sangi, A., Perkins, C., and S.
              Anand, "Asymmetric AODV-P2P-RPL in Low-Power and Lossy
              Networks (LLNs)", draft-ietf-roll-aodv-rpl-01 (work in
              progress), March 2017.

   [I-D.ietf-6tisch-6top-sf0]
              Dujovne, D., Grieco, L., Palattella, M., and N. Accettura,
              "6TiSCH 6top Scheduling Function Zero (SF0)", draft-ietf-
              6tisch-6top-sf0-04 (work in progress), April 2017.

   [I-D.satish-6tisch-6top-sf1]
              Anamalamudi, S., Zhang, M., Sangi, A., Perkins, C., and S.
              Anand, "Scheduling Function One (SF1) for hop-by-hop
              Scheduling in 6tisch Networks", draft-satish-6tisch-6top-
              sf1-03 (work in progress), February 2017.

   [IETF_6lo]
              "IETF IPv6 over Networks of Resource-constrained Nodes
              (6lo) working group",
              <https://datatracker.ietf.org/wg/6lo/charter/>.

   [G.9959]   "International Telecommunication Union, "Short range
              narrow-band digital radiocommunication transceivers - PHY
              and MAC layer specifications", ITU-T Recommendation",
              January 2015.

   [LTE_MTC]  "3GPP TS 36.306 V13.0.0, 3rd Generation Partnership
              Project; Technical Specification Group Radio Access
              Network; Evolved Universal Terrestrial Radio Access
              (E-UTRA); User Equipment (UE) radio access capabilities
              (Release 13)", December 2015.







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   [IEEE1901]
              "IEEE Standard, IEEE Std. 1901-2010 - IEEE Standard for
              Broadband over Power Line Networks: Medium Access Control
              and Physical Layer Specifications", 2010,
              <https://standards.ieee.org/findstds/
              standard/1901-2010.html>.

   [IEEE1901.1]
              "IEEE Standard (work-in-progress), IEEE-SA Standards
              Board", <http://sites.ieee.org/sagroups-1901-1/>.

   [IEEE1901.2]
              "IEEE Standard, IEEE Std. 1901.2-2013 - IEEE Standard for
              Low-Frequency (less than 500 kHz) Narrowband Power Line
              Communications for Smart Grid Applications", 2013,
              <https://standards.ieee.org/findstds/
              standard/1901.2-2013.html>.

Appendix A.  Other 6lo Use Case Examples

A.1.  Use case of ITU-T G.9959: Smart Home

   Z-Wave is one of the main technologies that may be used to enable
   smart home applications.  Born as a proprietary technology, Z-Wave
   was specifically designed for this particular use case.  Recently,
   the Z-Wave radio interface (physical and MAC layers) has been
   standardized as the ITU-T G.9959 specification.

   Example: Use of ITU-T G.9959 for Home Automation

   Variety of home devices (e.g. light dimmers/switches, plugs,
   thermostats, blinds/curtains and remote controls) are augmented with
   ITU-T G.9959 interfaces.  A user may turn on/off or may control home
   appliances by pressing a wall switch or by pressing a button in a
   remote control.  Scenes may be programmed, so that after a given
   event, the home devices adopt a specific configuration.  Sensors may
   also periodically send measurements of several parameters (e.g. gas
   presence, light, temperature, humidity, etc.) which are collected at
   a sink device, or may generate commands for actuators (e.g. a smoke
   sensor may send an alarm message to a safety system).

   The devices involved in the described scenario are nodes of a network
   that follows the mesh topology, which is suitable for path diversity
   to face indoor multipath propagation issues.  The multihop paradigm
   allows end-to-end connectivity when direct range communication is not
   possible.  Security support is required, specially for safety-related
   communication.  When a user interaction (e.g. a button press)
   triggers a message that encapsulates a command, if the message is



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   lost, the user may have to perform further interactions to achieve
   the desired effect (e.g. a light is turned off).  A reaction to a
   user interaction will be perceived by the user as immediate as long
   as the reaction takes place within 0.5 seconds [RFC5826].

A.2.  Use case of DECT-ULE: Smart Home

   DECT is a technology widely used for wireless telephone
   communications in residential scenarios.  Since DECT-ULE is a low-
   power variant of DECT, DECT-ULE can be used to connect constrained
   devices such as sensors and actuators to a Fixed Part, a device that
   typically acts as a base station for wireless telephones.  Therefore,
   DECT-ULE is specially suitable for the connected home space in
   application areas such as home automation, smart metering, safety,
   healthcare, etc.

   Example: Use of DECT-ULE for Smart Metering

   The smart electricity meter of a home is equipped with a DECT-ULE
   transceiver.  This device is in the coverage range of the Fixed Part
   of the home.  The Fixed Part can act as a router connected to the
   Internet.  This way, the smart meter can transmit electricity
   consumption readings through the DECT-ULE link with the Fixed Part,
   and the latter can forward such readings to the utility company using
   Wide Area Network (WAN) links.  The meter can also receive queries
   from the utility company or from an advanced energy control system
   controlled by the user, which may also be connected to the Fixed Part
   via DECT-ULE.

A.3.  Use case of MS/TP: Management of District Heating

   The key feature of MS/TP is it's ability to run on the same cabling
   as BACnet and some use of ModBus, the defacto standard for low
   bandwith industry communication.  Specially Modbus has been around
   since the 1980 and is still the standard for talking to fans, heat
   pumps, water purifying equipment and everything else delivering
   electricity, clean water and ventilation.

   Example: Use of MS/TP for management of district heating

   The mechanical room in the cellar of an apartment building gets
   district heating and electricity from the utility providers.  The
   room has a Supervisory Control And Data Acquisition (SCADA) computer
   talking to a centralized server and command center somewhere else
   over IP, on the other hand it is controlling the heating, fans and
   distribution panel over a 2-wire RS-485 based protocol to make sure
   the logic controller for district heating keeps a constant
   temperature at the tapwater, the logic controller for heat produktion



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   keeps the right radiator temperature depending on the weather and the
   fans have a correct speed and are switched off in case district
   heating fails to prevent cooling out the building and give certain
   commands in case smoke is detected.  Speed is not important, in this
   usecase, 19,200 bit/s capable equipment is sold as high speed
   communication capable.  Reliability is important, this not working
   will easily give millions of dollars of damage.  Normally the setup
   is that the SCADA device asks a question to a specific controlling
   device, gets an answer from the controlling device, asks a new
   question to some other device.

A.4.  Use case of NFC: Alternative Secure Transfer

   According to applications, various secured data can be handled and
   transferred.  Depending on security level of the data, methods for
   transfer can be alternatively selected.

   Example: Use of NFC for Secure Transfer in Healthcare Services with
   Tele-Assistance

   A senior citizen who lives alone wears one to several wearable 6lo
   devices to measure heartbeat, pulse rate, etc.  The 6lo devices are
   densely installed at home for movement detection.  An LoWPAN Border
   Router (LBR) at home will send the sensed information to a connected
   healthcare center.  Portable base stations with LCDs may be used to
   check the data at home, as well.  Data is gathered in both periodic
   and event-driven fashion.  In this application, event-driven data can
   be very time-critical.  In addition, privacy also becomes a serious
   issue in this case, as the sensed data is very personal.

   While the senior citizen is provided audio and video healthcare
   services by a tele-assistance based on LTE connections, the senior
   citizen can alternatively use NFC connections to transfer the
   personal sensed data to the tele-assistance.  At this moment, hidden
   hackers can overhear the data based on the LTE connection, but they
   cannot gather the personal data over the NFC connection.

A.5.  Use case of PLC: Smart Grid

   Smart grid concept is based on numerous operational and energy
   measuring sub-systems of an electric grid.  It comprises of multiple
   administrative levels/segments to provide connectivity among these
   numerous components.  Last mile connectivity is established over LV
   segment, whereas connectivity over electricity distribution takes
   place in HV segment.

   Although other wired and wireless technologies are also used in Smart
   Grid (Advance Metering Infrastructure - AMI, Demand Response - DR,



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   Home Energy Management System - HEMS, Wide Area Situational Awareness
   - WASA etc), PLC enjoys the advantage of existing (power conductor)
   medium and better reliable data communication.  PLC is a promising
   wired communication technology in that the electrical power lines are
   already there and the deployment cost can be comparable to wireless
   technologies.  The 6lo related scenarios lie in the low voltage PLC
   networks with most applications in the area of Advanced Metering
   Infrastructure, Vehicle-to-Grid communications, in-home energy
   management and smart street lighting.

   Example: Use of PLC for Advanced Metering Infrastructure

   Household electricity meters transmit time-based data of electric
   power consumption through PLC.  Data concentrators receive all the
   meter data in their corresponding living districts and send them to
   the Meter Data Management System (MDMS) through WAN network (e.g.
   Medium-Voltage PLC, Ethernet or GPRS) for storage and analysis.  Two-
   way communications are enabled which means smart meters can do
   actions like notification of electricity charges according to the
   commands from the utility company.

   With the existing power line infrastructure as communication medium,
   cost on building up the PLC network is naturally saved, and more
   importantly, labor operational costs can be minimized from a long-
   term perspective.  Furthermore, this AMI application speeds up
   electricity charge, reduces losses by restraining power theft and
   helps to manage the health of the grid based on line loss analysis.

   Example: Use of PLC (IEEE1901.1) for WASA in Smart Grid

   Many sub-systems of Smart Grid require low data rate and narrowband
   variant (IEEE1901.2) of PLC fulfils such requirements.  Recently,
   more complex scenarios are emerging that require higher data rates.

   WASA sub-system is an appropriate example that collects large amount
   of information about the current state of the grid over wide area
   from electric substations as well as power transmission lines.  The
   collected feedback is used for monitoring, controlling and protecting
   all the sub-systems.

A.6.  Use case of IEEE 802.15.4e: Industrial Automation

   Typical scenario of Industrial Automation where sensor and actuators
   are connected through the time-slotted radio access (IEEE 802.15.4e).
   For that, there will be a point-to-point control signal exchange in
   between sensors and actuators to trigger the critical control
   information.  In such scenarios, point-to-point traffic flows are




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   significant to exchange the controlled information in between sensors
   and actuators within the constrained networks.

   Example: Use of IEEE 802.15.4e for P2P communication in closed-loop
   application

   AODV-RPL [I-D.ietf-roll-aodv-rpl] is proposed as a standard P2P
   routing protocol to provide the hop-by-hop data transmission in
   closed-loop constrained networks.  Scheduling Functions i.e. SF0
   [I-D.ietf-6tisch-6top-sf0] and SF1 [I-D.satish-6tisch-6top-sf1] is
   proposed to provide distributed neighbor-to-neighbor and end-to-end
   resource reservations, respectively for traffic flows in
   deterministic networks (6TiSCH).

   The potential scenarios that can make use of the end-to-end resource
   reservations can be in health-care and industrial applications.
   AODV-RPL and SF0/SF1 are the significant routing and resource
   reservation protocols for closed-loop applications in constrained
   networks.

Authors' Addresses

   Yong-Geun Hong
   ETRI
   161 Gajeong-Dong Yuseung-Gu
   Daejeon  305-700
   Korea

   Phone: +82 42 860 6557
   Email: yghong@etri.re.kr


   Carles Gomez
   Universitat Politecnica de Catalunya/Fundacio i2cat
   C/Esteve Terradas, 7
   Castelldefels  08860
   Spain

   Email: carlesgo@entel.upc.edu












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   Younghwan Choi
   ETRI
   218 Gajeongno, Yuseong
   Daejeon  305-700
   Korea

   Phone: +82 42 860 1429
   Email: yhc@etri.re.kr


   Deoknyong Ko
   SKtelecom
   9-1 Byundang-gu Sunae-dong, Seongnam-si
   Gyeonggi-do  13595
   Korea

   Phone: +82 10 3356 8052
   Email: engineer@sk.com


   Abdur Rashid Sangi
   Individual Contributor

   Email: sangi_bahrian@yahoo.com


   Take Aanstoot
   Modio AB
   S:t Larsgatan 15, 582 24
   Linkoping
   Sweden

   Email: take@modio.se


   Samita Chakrabarti
   San Jose, CA
   USA

   Email: samitac.ietf@gmail.com











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