1.
Low Power
Wireless Sensor Network
Technologies and Standards
for the
Internet of Things
IOP Institute of Physics
Sensors & their Applications XVIII
Duncan Purves
Connect2 Systems
duncan@connect2.io
@purvesd
https://uk.linkedin.com/in/duncanpurves

2.
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)

3.
Diversity – Industry & Standards Bodies

4.
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)

5.
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)

6.
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
§ 6LoWPAN adaptation layer provides:
Ø IPv6 packet encapsulation
Ø IPv6 packet fragmentation and reassembly
Ø IPv6 header compression
Ø Link layer packet forwarding
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

7.
6LoWPAN Network Example
Internet
Server
Cellular
3G, LTE
PDN
Server
Border
Router
Server
Node
IPv6
IPv6 or IPv4

8.
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

9.
Connect2 Systems Deployment Example
Wireless
Sensor
Node
Wireless
Sensor
Node
Wireless
Sensor
Node
Wireless
Sensor
Node
Connect2 Systems
LWM2M Server
Monitoring Application
Sensor
Data
Wide Area Gateway
Connect2 Systems
Edge Gateway
IPv6/4 Cellular/Ethernet Interface
Wireless
Sensor
Network
Manager
LWM2M Client
Smart Objects
MQTT
Broker
Sensor
Network
Manager
Interface
Cellular/Ethernet Router
IoT App
Platform
Protocols
FTP
802.15.4e
6LoWPAN
Cellular
Public/Private Data Network
CoAP MQTT/FTP

10.
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
solutions
to
cities,
garages,
airports,
universities
and
other
private
parking
providers.

11.
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
telematics
solutions
for
railcars,
providing
GPS
tracking,
asset
status
and
condition
monitoring

12.
“Thread was designed with one goal in
mind:
To create the very best way to connect
and control products in the home”
Thread Group

13.
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

14.
Thread

15.
Thread
Thread defines how data is sent in network but not how to interpret it

16.
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/

17.
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/

18.
ZigBee
ZigBee Alliance
§ Non-­profit association established in 2002
§ Driving the development of ZigBee standards
ZigBee uses the PHY and MAC defined by 802.15.4
Markets:
§ Smart Home
§ Connected Lighting
§ Smart Meters -­ ZigBee Smart Energy
Ø UK DECC announced SMETS 2 which cites ZigBee Smart Energy 1.x
§ Retail

19.
ZigBee Stack Layers
Application Layer
Network Layer
Media Access Control Layer (MAC)
Physical Layer (PHY)
ZigBee
IEEE
802.15.4
ZigBee
Device
Objects
Application Support Sub Layer
Application Framework
Application
Object 1
Application
Object N
……….....

20.
ZigBee Pro
§ Support for larger networks comprised of thousands of devices
§ Global operation in 2.4 GHz Band (IEEE 802.15.4)
§ Frequency agile operating over 16 channels in the 2.4GHz band
§ Regional operation in the 915Mhz (Americas) and 868Mhz (Europe)
§ Optional -­ Green Power to connect energy harvesting or self-­powered devices

21.
ZigBee Application Profiles
§ ZigBee defines application-­level compatibility with application profiles
§ Allows multiple OEM vendors to create interoperable products
§ Describes how various application objects connect and work together,
such as lights and switches, thermostats and heating units
§ Application profiles can be public or private
§ Public Profiles:
Ø ZigBee Building Automation
Ø ZigBee Health Care
Ø ZigBee Home Automation
Ø ZigBee Input Device
Ø ZigBee Network Devices
Ø ZigBee Remote Control
Ø ZigBee Retail Services
Ø ZigBee Smart Energy
Ø ZigBee Telecom Services
Ø ZigBee 3D Sync

22.
ZigBee 3.0
§ Unification of the Alliance’s wireless standards into a single standard
§ Initial release of ZigBee 3.0 includes:
Ø ZigBee Home Automation,
Ø ZigBee Light Link
Ø ZigBee Building Automation
Ø ZigBee Retail Services
Ø ZigBee Health Care
Ø ZigBee Telecommunication services
§ Currently undergoing testing
§ Enables communication and interoperability among devices
§ Uses ZigBee PRO networking

23.
ZigBee IP, ZigBee 2030.5 and 920IP
ZigBee IP:
§ IPv6-­based wireless mesh networking
§ Designed to support ZigBee 2030.5 -­
formerly ZigBee Smart Energy 2
Ø IP-­based implementation of IEEE 2030.5-­2013
for energy management in Home Area
Networks (HANs)
§ Updated to include 920IP, which provides
specific support for
Ø ECHONET Lite
Ø Japanese Home Energy Management systems

24.
ZigBee, EnOcean & Thread Group
ZigBee and EnOcean Alliances collaborate1
§ Combining the benefits of EnOcean energy harvesting wireless solutions
with ZigBee 3.0 for worldwide applications
§ Define the technical specifications required to combine standardized
EnOcean Equipment Profiles (EEPs) with the ZigBee 3.0 solution
ZigBee Alliance and Thread Group collaborate2,3
§ Creating End-­to-­End IoT Product Development Solution
§ Brings ZigBee’s Applications Library to Thread Group’s IP Network Protocol
§ Roadmap for specifications, branding, and a test and certification program
1. ZigBee Press Release, Dec 2015:
http://www.zigbee.org/zigbee-­and-­enocean-­alliances-­collaborate-­to-­combine-­benefits-­of-­enocean-­energy-­harvesting-­wireless-­with-­zigbee-­3-­0/
2. . ZigBee Press Release, Apr 2015
http://www.zigbee.org/zigbee-­alliance-­press-­release-­zigbee-­alliance-­and-­thread-­group-­collaborate-­to-­aid-­development-­of-­connected-­home-­products/
3. 2. . ZigBee Press Release, Jan 2016
http://www.zigbee.org/zigbee-­alliance-­creating-­end-­to-­end-­iot-­product-­development-­solution-­that-­brings/

25.
ZigBee – Smart Street Lighting
§ Mayflower, part of SSE, have installed 250,000 nodes across UK
§ 150,000 nodes across the Hampshire County
§ Since 2010 it has reduced Hampshire’s street lighting energy
consumption by 21GW/hr per annum
Ø Equates to a reduction of 41% -­ or enough electricity to power 3,500 homes for a year
Source: Mayflower Complete Lighting Control: http://www.mayflowercontrol.com/

26.
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

27.
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

28.
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
§ European regulation governing the 868MHz band enforces a
transmission duty cycle of 1%
Ø A unique device is therefore not allowed to emit more than 1% of the time each
hour
Ø Since emission of a message can take up to ~6 seconds, this allows up to 6
messages per hour
§ Long range 30-­50km in rural areas
§ Range reduced to between 3 and 10km in urban areas
§ Communication with buried, underground equipment possible

29.
Sigfox Networks Operators
Vodafone, Huawei Trial Pre-­Standard
NB-­IoT

30.
Sigfox UK Partner Arqiva Coverage
§ Birmingham
§ Bristol
§ Edinburgh
§ Glasgow
§ Leeds
§ Leicester
§ Liverpool
§ London
§ Manchester
§ Sheffield

31.
Weightless
Weightless is both the name of a group, the Weightless Special Interest
Group (SIG), and the technology
Weightless SIG is a non-­profit global standards organisation
Delivers wireless connectivity for low power, wide area networks (LPWAN)

32.
Weightless Architectural overview
Internet
Network
Manager Base station
interface
Air interface
Synchronisation
database
Client
information
/
management
system

33.
Three Open Standards – Weightless-­W, -­N, -­P
Weightless-­W Weightless-­N Weightless-­P
Frequency Band TV White Space License-­exempt ISM
spectrum
License-­exempt sub-­GHz
ISM/SRD
470MHz–790MHz 868MHz and 915MHz 169/433/470/780/
868/915/923 MHz
Data Rate 1 Kbps to 10Mbps Up to 500 bps Adaptive data rate – 200
bps to 100 kbps
Range 5km+ 5Km+ 2Km+
Battery Life 3-­ 5 years 10 Years 3-­8 Years
Directionality 2-­way 1-­way 2-­way
Support for over-­the-­air
firmware upgrade and
security key negotiation or
replacement

34.
Nwave -­ Weightless-­N Network Deployments
§ Copenhagen & Esbjerg
Ø Smart City network
§ London
Ø Has been deployed in conjunction with the Digital Catapult

35.
LoRa, LoRaWAN and the LoRa Alliance
§ LoRa® is the physical layer (OSI Layer 1) or the wireless modulation utilized to create
the long range communication link
§ LoRa® is Proprietary technology based on chirp spread spectrum modulation
Ø Patents/IP is owned and licensed by Semtech
§ LoRaWAN defines the MAC communication protocol and system architecture for the
network that the LoRa Alliance is standardizing for Low Power Wide Area Networks
(LPWAN)
Source: https://www.lora-­alliance.org/portals/0/documents/whitepapers/LoRaWAN101.pdf
Physical Layer
(PHY)

36.
LoRaWAN & LoRa Alliance
§ LoRa Alliance an open, non-­profit association of members
§ Founded in March 2015 at Mobile World Congress
§ Standardising the LoRaWAN specification
§ Intended for wireless battery operated ‘Things’ in regional, national or global network
§ Allows long range, low bit rate communication to and from connected objects

37.
LoRa Alliance
§ An open, non-­profit
association of members
§ Founded in March 2015 at
Mobile World Congress

38.
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
Source: https://www.lora-­alliance.org/portals/0/documents/whitepapers/LoRaWAN101.pdf

39.
Device Classes – Not All Nodes Are Created Equal
Source: https://www.lora-­alliance.org/portals/0/documents/whitepapers/LoRaWAN101.pdf

40.
LoRaWAN in the UK
§ Glasgow -­ covering 12km2 of the city
§ Collaborative project involving Stream Technologies, Semtech Inc, Boston Networks
and CENSIS
§ Working with Glasgow University, Strathclyde University and Glasgow Caledonian
University
http://www.scotsman.com/news/glasgow-­universities-­pioneer-­internet-­of-­things-­network-­1-­4169807

41.
The Things Network – based on LoRaWAN

42.
The Things Network Oxford & Flood Network
Source: Ben Ward, TTN Oxford and Flood Network:
http://thethingsnetwork.org/c/oxford
http://flood.network/

43.
Cellular IoT
Three tracks have been standardized in 3GPP for Cellular IoT:
§ LTE MTC Cat M1 an evolution of LTE optimized for IoT
§ EC-­GSM-­IoT Extended Coverage GSM
Ø Evolutionary approach being standardized in GSM Edge Radio Access Network (GERAN) Rel. 13
§ NB-­IoT Cat M2 Narrowband IoT
Ø Part of 3GPP RAN Rel. 13

44.
3GPP NB-­IoT Modes of Operation
NB-­IoT supports 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
Image source: https://www.ericsson.com/research-­blog/lte/narrowband-­iot-­cloud/

45.
3GPP User Equipment Category Comparison
3GPP Release 8 12 13 13
Cat 1 Cat 0 Cat M1 Cat M2
Downlink peak rate (Mbs) 10 1 1 ~ 0.2
Uplink Peak rate 5 1 1 ~ 0.2
Duplex Mode Full Half Half or Full Half
UE receive bandwidth 20 20 1.4 0.18
UE Transmit power (dBm) 23 20 or 23 20 23
Relative Modem Complexity 100% 50% 20-­ 25% 10%
Source: https://www.ericsson.com/research-­blog/internet-­of-­things/cellular-­iot-­alphabet-­soup/

46.
3GPP Cellular NB-­IoT Features
Source: http://www.telecomasia.net/pdf/Huawei/Huawei_13_NarrowBand_IoT_Wide_Range_Opportunities.pdf

47.
Cellular NB-­IoT Proof of Concept
From – “Vodafone and NB-­IoT”:
http://www.gsma.com/connectedliving/wp-­content/uploads/2015/12/Presentation-­3_Vodafone-­keynote-­v5.pdf

48.
Cellular NB-­IoT Proof of Concept
From – “Vodafone and NB-­IoT”:
http://www.gsma.com/connectedliving/wp-­content/uploads/2015/12/Presentation-­3_Vodafone-­keynote-­v5.pdf

49.
NB-­IoT -­ Vodafone Timeline
From – “Vodafone and NB-­IoT”:
http://www.gsma.com/connectedliving/wp-­content/uploads/2015/12/Presentation-­3_Vodafone-­keynote-­v5.pdf

50.
Summary
There are many competing
technologies and standards!
One Size does Not fit All
Duncan Purves
Connect2 Systems
duncan@connect2.io
@purvesd
https://uk.linkedin.com/in/duncanpurves