This presentation provides the various protocol used in internet of things environment. This presentation also provides brief information about Bluetooth Low Energy and Zigbee protocols and its applications.

1. Internet of Things ( IoT )
Session2 - Protocols

2. Protocols – IoT Device
• Bluetooth Low Energy
• Zigbee
• Z-Wave
• 6LowPAN
• Thread
• WiFi
• Cellular
• NFC
• SigFox
• Neul
• LoRaWAN

3. Bluetooth Low Energy
• Short Range communication technology
• Key for wearable IoT products
• Not designed for file transfer, more suitable
for small chunks of data
• Range : 50 – 150 meters
• Offer significantly reduced power
consumption
• Access internet via 6LowPAN directly

4. HCI
BLE Architecture
PHY
Link Layer
L2CAP
GATT/ATT
Profile
Application

5. BLE – Physical Layer
• 2.4 GHz Industrial Scientific Medical Band
• 40 Radio channels with 2 MHz spacing
• Channel Types
– Advertising Channel
• Device discovery, connection establishment and broadcast
transmission
• Three channels assigned with center frequencies
– Data channel
• Bi directional communication between connected devices
• Adaptive Frequency hopping to avoid face interferences and
wireless propagation issues.
• 37 data channels available for communication.

6. BLE – Link Layer
• To broadcast data, it transmits data in advertising
channel through advertising channels
• Advertiser
– Device that transmits the advertising packets
– Advertising event : Transmission takes place in intervals.
– Sequentially uses each advertising channel
• Scanner
– Device only aim at receiving data through advertising
channel
• Data communication
– Requires them to connect to each other

7. BLE – Link Layer …
Standby Initiating
Advertising
(Advertiser)
Scanning
( Scanner )
Connected
Conn Failed
Initiate
Success
Master
Success
Slave
Conn Lost
Disconnection

8. BLE – L2CAP Layer
• Optimized, simplified protocol based on classic
bluetooth
• Data services handled in best approach without
retransmission and flow control
• Multiplex the data of higher three layers protocols,
ATT, SMP and Link Layer Signaling
• Segmentation and reassembly are not used
• Upper layer protocol data fits into max L2CAP
payload size – 23 bytes.

9. BLE – ATT Layer
• Defines communication between two devices, which are
server & client
• Server contains set of attributes
• Attribute is a data structure that stores information managed
by GATT.
• Client or Server will be decided by GATT, is independent of
master & slave in link layer
• Client will access server attributes
• Server will also send two types of messages
– Notifications
– Indications
• Request / response and Indication / Confirmation follow
blocked communication

10. BLE – GATT Layer
• A framework uses ATT for device discovery
• Exchanges the characteristics from one device to
another
• Characteristics
– Set of data includes value and properties
• Data related to services and characteristics stored in
attributes.
• For ex: server with temperature sensor
– Attributes of the sensor
– Attributes of temperature measurement
– Attributes of measurement units

11. BLE – Security Layer
• Protects information exchange between two
connected devices
• Security Modes
– LE Security Mode 1
– LE Security Mode 2
• Provides security functionality at Link Layer and ATT
• Link Layer
– Supports encryption & authentication using Cipher Block
Chain Message Code ( CCM ).
– 4 Byte Message Integrity Check ( MIC )
• Encryption will be applied to PDU & MIC

12. BLE - GAP
• Highest level of BLE Stack
• Specifies
– device roles, modes
– Procedures for discovery of devices and services
• Roles
– Broadcaster, Observer, Peripheral and Central
• Broadcaster
– Only broadcast data
– Does not support connections
• Observer
– Complimentary of the Broadcaster
• Central
– In charge for initiating & managing multiple connections
• Peripheral
– Uses a Single connection with a device in central role.
• Device Support multiple roles, but only one at a given time.

13. BLE – Application Profiles
• Blood Pressure
• Proximity
• Heart Rate
• Phone Alert
• Alert Notification
• Fine Me
• Humidity
• iBeacon
• Health Thermometer
• Glucose meter
• Temperature
• Time
• Pressure

14. BLE – Performance Points
• Power Consumption
• Latency
• Maximum Pico Net Size
• Data Throughput

15. Some BLE Chips / Modules
• NXP KW4x
• TI CC254x, CC26xx
• Nordic nRF518xx
• BT832 – Bluetooth 5.0
• Microchip RN4020
• Silabs Bluetooth Smart

16. Zigbee
• Based on 802.15.4 specification
• Creates Personal Area Networks with small, low power
digital radios
• Simpler & less expensive than wireless PANs like
Bluetooth or WiFi
• Transmission distance of 10 – 100 meters
• Used in short range low range wireless data transfer
applications
• Transmits data over long distance by using mesh
networks
• Secured with Symmetric Encryption Key

17. Zigbee Network Architecture
ZC ZR
ZR
ZEDZED
ZED
ZED
External
Network

18. Zigbee Co Ordinator
• Forms root of network tree and bridge to
other networks
• One specific ZC in each network since it the
device started
• Stores information about the network
• Acts as Trust center & repository for security
keys

19. Zigbee Router ( ZR )
• Acts as a intermediate router
• Passes data from other devices
• Can also capable to running application along
with routing.

20. Zigbee End Device
• Contains limited to functionality to talk with
parent node like Co Ordinator or Router.
• Cannot relay data from other devices
• This makes the device asleep for a significant
amount of time
• Device will consume less power, thereby
giving long battery life.
• Requires least processing power & memory.

21. Zigbee Architecture
Physical Layer
Media Access Control Layer
Network Layer
Application Support Sublayer
Application
Framework
Zigbee Device
Control ( ZDO )

22. Zigbee PHY / MAC Layer
• PHY Layer
– IEEE 802.15.4 for low rate WPANs
– Frequency : 2.40 GHz
– Data rate : 250 Kbps
– Channels : 11 - 26
• Mac Layer
– Uses Carrier Sense Multiple Access / Collision
Avoidance ( CSMA / CA )
– Transmits beacons for synchronization
– Provides reliable communication

23. Zigbee Network Layer
• Supports both star and tree networks and generic
mesh networking
• Assigns 16 bit network addresses
• Provides the following functions,
– Network initialization
– Manages ZED joining or leaving the network
– Routes the network packets
– Route Discovery of one hop neighbors
– Receives and send network data packets
– Neighbor discovery

24. Application Support Sublayer
• Provides needed services for application objects (
endpoints ) and ZDO
– Binding tables
– Message forwarding between devices
– Group address and management
– Address mapping between 64 bit addresses and 16 bit network
address
– Fragmentation and reassembly
• Provides interface with network layer for data transfer like
request, confirm and response
• Provides communication for application by defining a
unified communication structure like a profile, cluster or
endpoint
• Application Support Data Entity
• Application Support Management Entity

25. Zigbee Device Object ( ZDO )
• Does the overall device management
• Initializes APS Sub layer and Network layer
• Configures the operating mode ( Co Ordinator,
Router or Device )
• Device and its application services discovery
• Handles the binding requests
• Supports security management

26. Zigbee Application
• Home Automation / Smart Home
• Smart Building automation
• PC & Peripherals
• Personal & Healthcare
• Industrial Automation
• Toys & Gaming Terminal

27. Some Zigbee Chips / Modules
• Xbee module
• NXP KW2x , MC1323x
• TI Simple Link
• Silabs EFR32xx