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 Purves
Connect2 Systems
duncan@connect2.io

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
12
§  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 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
authentication based on a
shared secret key
26
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
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

Overview of Wireless Sensor Networks

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