Overview of Wireless Sensor Networks

© Copyright Connect2 Systems Limited 2015

Current state of the art

commercial WSNs and their future development

Wireless Sensors Network in

Urban Living and Health Workshop

Duncan PurvesConnect2 Systems

[email protected]


The IoT landscape - One size doesn’t fit all

Source: Goldman Sachs, IoT Primer, September 3, 2014; ‘Internet of Things: Making sense of the next mega-trend’

Broad variety of wireless standards, industry bodies, technologies for different types of networks:

§  Body Area Network (BAN)

§  Body Sensor Network (BSN)

§  Medical Body Area Network (MBAN)

§  Personal Area Network (PAN)

§  Home Area Network (HAN)

§  Nearby Area Network (NAN)

§  Local Area Network (LAN)

§  Wide Area Network (WAN)

§  Global Area Network (GAN)


Diversity – Industry & Standards Bodies


Layer 1/2 Wireless Network Standards

§  IEEE 802.11 (WLAN) Ø Most wireless-capable residential devices operate at a frequency of 2.4

GHz under 802.11b and 802.11g or 5 GHz under 802.11a.

Ø  Some home networking devices operate in both radio-band signals and fall within the 802.11n or 802.11ac standards

§  IEEE 802.15 (WPAN) Ø  Working group of Institute of Electrical and Electronics Engineers (IEEE)

which specifies wireless personal area network (WPAN) standards

Ø  Includes seven task groups

Ø  802.15.1 (Bluetooth)

Ø  802.15.3 (High Rate WPAN)

Ø  802.15.4 (Low Rate WPAN)

Ø  802.15.6 (WBAN)

Ø  802.15.7 (Visible Light Communication)


Higher Layer Standards

The IEEE 802.15.4 technology is used for a variety of different higher layer standard e.g.:

§  Zigbee

§  Wireless Hart

§  MiWi

§  ISA100.11a

§  6LoWPAN Ø  IPv6 over Low power Wireless Personal Area Networks Ø  Specified by Internet Engineering Task Force (IETF)


6LoWPAN

§  Open Standard networking technology specification

§  Developed by the Internet Engineering Task Force (IETF)

§  Every node has its own IPv6 address

§  Originally conceived to support IEEE 802.15.4 low-power wireless networks in the 2.4-GHz band

§  Now being adapted and used over a variety of other networking media including:

Ø  Sub-1 GHz low-power RF Ø  Bluetooth Smart (BLE) Ø  Power Line Control (PLC) Ø  Low-power Wi-Fi

COAP, MQTT Websocket, etc.

IPv6 with 6LoWPAN

IEEE 802.15.4 MAC

IEEE 802.15.4 PHY

LoWPAN Adaption

TCP UDP

Application

Transport

Network

Data Link

Physical

6LoWPAN Stack Example


6LoWPAN Network Example

Internet

Server Cellular 3G, LTE

Server

Router

Server

Node

IPv6

IPv6 or IPv4


Commercially available WSN solution


Thermocouple

Counter

Frequency

Analog (0 – 5 V)

Analog (4 – 20 mA)

Digital (0-48vdc)

Flow

Temperature

Pressure

Level

Acceleration

Moisture

Position

Particulates

Motion

Proximity

Sound

Shock

Magnetic Field Inertial/Gyro

Touch There are thousands of sensor manufacturers and hundreds of sensor subcategories

WHAT TYPES OF SENSORS?


Linear Technologies – SmartMesh IPTM

§  Fully Redundant Wireless Mesh Routing Ø  Compliant to 6LoWPAN and 802.15.4e standards (2.4 GHz radio)

§  >99.999% Data Reliability Ø  Time-synchronised + channel hopping

§  Ultra-low power Ø  Devices sleep between scheduled communications, typically a duty cycle of < 1%

§  Automatic node joining and network formation

§  Secure Ø  End-to-end 128 bit AES encryption, message integrity checking, and device authentication

http://www.linear.com/products/smartmesh_ip


Street-based wireless sensors and parking meters collect real-time parking-space occupancy readings and payment activity

Streetline Parking Management

Streetline, Inc. is the leading provider of Smart Parking solu:ons to ci:es, garages, airports, universi:es and other private parking providers.


IBM Building Monitoring

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§  Low power motes at The Metropolitan Museum of Art monitoring temp, humidity

§  The wireless sensor network helps preserve the works of art


HANDBRAKE STATUS

ENGAGED

BEARING TEMPERATURE REPLACE WHEELSET

information from the edge™

IONX Freight Rail Monitoring IONX LLC is a developer and provider of ultralow power wireless

telema:cs solu:ons for railcars, providing GPS tracking, asset status and condi:on monitoring


“Thread was designed with one goal in mind:

To create the very best way to connect and control products in the home”

Thread Group


Thread Design Features

§  Specification released July 14, 2015

§  Security Architecture to make it simple and secure to add and remove products

§  Designed for very low power operation

§  Uses 6LoWPAN and carries IPv6 natively

§  Runs over standard 802.15.4 radios

§  Based on a robust mesh network with no single point of failure

§  Designed to support 250+ products per network for the home:

Ø  appliances, Ø  access control Ø  climate control Ø  energy management Ø  lighting, Ø  safety, and security


EnOcean

§  An energy harvesting wireless technology

§  Combines micro energy converters with ultra low power electronics

§  Enables wireless communications between battery less wireless sensors, switches, controllers and gateways

§  Ratified as the international standard ISO/IEC 14543-3-10

§  Wireless range up to 300 meters in the open and up to 30 meters inside buildings

§  Data packet only 14 bytes long and are transmitted at 125 kbit/s

§  RF energy is only transmitted for the 1's of the binary data, reducing the amount of power required

§  Transmission frequencies used for the devices are 902 MHz, 928.35 MHz, 868.3 MHz and 315 MHz https://www.enocean.com/en/home/


EnOcean Alliance

§  EnOcean, Texas Instruments, Omnio, Sylvania, Masco, and MK Electric formed the EnOcean Alliance in April 2008 as a non-profit, mutual benefit corporation

§  Aims to internationalise this technology, and is dedicated to creating interoperability between the products of OEM partners

§  More than 250 companies currently belong to the EnOcean Alliance https://www.enocean-alliance.org/en/home/


Wireless Wide Area Networks

Cellular Networks

§  GPRS, EDGE

§  UMTS (3G) HSPA+

§  LTE (4G) Long Term Evolution

Low-Power Wide-Area Network (LPWAN)

§  Ultra Narrow Band (UNB) from Sigfox

§  Weightless, from the Weightless SIG

§  LoRaWAN, Long Range WAN, from the LoRa Alliance

Cellular IoT

§  LTE-M LTE for M2M (1.4 MHz)

§  EC-GSM Extended Coverage GSM

§  Narrowband IoT


Sigfox

§  French M2M/IoT Network Operator and technology company

§  Uses UNB (Ultra Narrow Band) based radio technology to connect devices to global network

§  Seeking to develop an international presence with partners

§  Seeks to differentiate itself as a low cost alternative to cellular and a low power solution


Sigfox Technology

§  Uses ISM bands (license-free frequency bands)

§  Uses the most popular European ISM band on 868 MHz (as defined by ETSI and CEPT)

§  Uses ISM band 902MHz in the USA

§  Up to 140 messages per object per day

§  Payload size for each message is 12 bytes

§  Wireless throughput up to 100 bits per second

§  Long range 30-50km in rural areas

§  Range reduced to between 3 and 10km in urban areas

§  Communication with buried, underground equipment possible


Sigfox based Networks


Sigfox based Networks


Sigfox UK Partner Arqiva Coverage

§  Birmingham

§  Bristol

§  Edinburgh

§  Glasgow

§  Leeds

§  Leicester

§  Liverpool

§  London

§  Manchester

§  Sheffield


Weightless


Weightless Architectural overview

Internet

Network Manager Base station

interface

Air interface

Synchronisa:on database

Client informa:on / management system


Three Open Standards – Weightless-W, -N, -P

Weightless-W §  Designed for TV White

Space operation Ø  470MHz–790MHz Ø  150MHz of spectrum

available in US and soon UK and Singapore

§  Data rate – 1 kbits/s to 10Mbits/s

§  5km indoor range

§  128-bit encryption and authentication based on a shared secret key

Weightless-N §  Designed for license-

exempt ISM spectrum operation Ø  Available globally now in

868MHz and 915MHz bands

§  Uses ultra narrow band (UNB) technology

§  Uplink Data rate - Up to 500bits/s

§  Up to 10 km range

§  Star network architecture

§  128-bit encryption and authentication based on a shared secret key

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Weightless-P (New) §  Operates license-exempt

sub-GHz ISM/SRD bands: Ø  169/433/470/780/868/915/9

23 MHz global deployment

§  Uses narrow band modulation scheme

§  Adaptive data rate - 200bps to 100kbps

§  2km range in urban environment

§  Bi- Directional Ø  Network-originated and

device-originated traffic

§  Support for over-the-air firmware upgrade and security key negotiation or replacement

§  128-bit encryption and authentication


Nwave - Weightless-N Network Deployments

§  Copenhagen & Esbjerg Ø  Smart City network

§  London Ø Has been deployed in conjunction with the Digital Catapult


LoRaWAN & LoRa Alliance

§  LoRaWAN is a Low Power Wide Area Network (LPWAN) specification

§  Intended for wireless battery operated ‘Things’ in regional, national or global network

§  Allows low bit rate communication from and to connected objects

§  This technology is standardized by the LoRa Alliance


LoRa Alliance

§  An open, non-profit association of members

§  Founded in March 2015 (at Mobile World Congress)


LoRaWAN

Ø  Secure bi-directional communication Ø  Data rates range from 0.3 kbps to 50 kbps

Ø  Network architecture is typically laid out in a star-of-stars topology Ø  Gateways are a transparent bridge relaying messages between end-devices and a

central network server in the back-end

http://lora-alliance.org


Cellular IoT

LTE was designed in 3GPP Rel. 8 to provide affordable mobile broadband and has been developed by subsequent 3GPP releases

Three tracks are being standardized in 3GPP for Cellular IoT:

§  LTE-M an evolution of LTE optimized for IoT Ø  First released in Rel. 12 in Q4 2014 Ø  Further optimization will be included in Rel. 13 with specifications to be complete in Q1 2016

§  EC-GSM Extended Coverage GSM Ø  Evolutionary approach being standardized in GSM Edge Radio Access Network (GERAN) Rel. 13 Ø  Specifications to be complete in Q1 2016

§  NB-IoT Narrowband IoT Ø  Part of Part of 3GPP RAN Rel. 13

Ø  Proposals for the new NB-IoT standardization were agreed September, 2015 with specifications expected to be completed by Q2 2016

Ø  There were originally two competing solutions: -  Narrowband Cellular IoT (NB-CIoT) backed by Huawei Technologies, Vodafone, China Unicom -  Narrowband LTE (NB-LTE) 200 kHz narrowband evolution of LTE-M – backed by Ericsson,

Nokia, Intel


3GPP Release 12 updates for LTE-M

§  Rel. 12 looks at how to reduce complexity and accommodate LTE-M requirements and a new Category of UE (Cat 0) was introduced, thereby providing significant cost reductions:

§  Antennas Ø  There is the capability for only one receive antenna compared to two receive antennas for other

device categories

§  Lower data rate requirement (to 1 Mbs) Ø  The complexity and cost for both processing power and memory will be reduced significantly

§  Half Duplex Operation Ø  Half duplex devices are supported as an optional feature - this provides cost savings

3GPP Release 8 8 12 13

Cat 4 Cat 1 Cat 0 “Cat 1.4 MHz”

Downlink peak rate (Mbs) 150 10 1 1

Uplink Peak rate 50 5 1 1

Number of antennas 2 2 1 1

Duplex Mode Full Full Half Half

UE receive bandwidth 20 20 20 1.4

UE Transmit power (dBm) 23 23 23 20


LTE-M features planned for 3GPP Release 13

There are several features that are being proposed and prepared for the next release of the 3GPP standards in terms of LTE M2M capabilities:

§  Reduce bandwidth to 1.4 MHz for uplink and downlink

§  Reduce transmit power to 20dBm

§  Reduce support for downlink transmission modes

§  Relax the requirements that require high levels of processing

3GPP Release 8 8 12 13

Cat 4 Cat 1 Cat 0 “Cat 1.4 MHz”

Downlink peak rate (Mbs) 150 10 1 1

Uplink Peak rate 50 5 1 1

Number of antennas 2 2 1 1

Duplex Mode Full Full Half Half

UE receive bandwidth 20 20 20 1.4

UE Transmit power (dBm) 23 23 23 20


3GPP NB-IoT Features

§  Network can be deployed in very small bandwidth Ø  180 kHz RF bandwidth for both downlink and uplink

§  Improved indoor coverage (20 dB enhancement)

§  Ultra low device cost (<$5)

§  Low device power consumption (>10 year battery life)

§  Support for massive number of low throughput devices


3GPP NB-IoT Modes of Operation

NB-IoT should support 3 different modes of operation:

§  ‘Stand-alone operation’ utilizing for example the spectrum currently being used by GERAN systems as a replacement of one or more GSM carriers

§  ‘Guard band operation’ utilizing the unused resource blocks within a LTE carrier’s guard-band

§  ‘In-band operation’ utilizing resource blocks within a normal LTE carrier


Summary

One Size does Not fit All There are plenty of choices!


Connect2 Systems

§  We specialise in helping helping companies integrate: Ø  Sensors, data, networks and control systems Ø  With IoT Application Platforms and Enterprise Systems

§  We offer custom hardware and embedded software services

§  Developing a range Wireless Sensor Network products