M.Mallikarjuna Rao -200601212 V.Harish Vyas- 200601191 Presentation - - PowerPoint PPT Presentation

M.Mallikarjuna Rao -200601212 V.Harish Vyas- 200601191

Presentation Outline

 Introduction

 What ZigBee is?  What ZigBee does?

 The Zigbee layered Model

 The physical layer  The MAC layer

 Packet Structure

 PHY frame  Data Frame

 Applications

 Health Care  Home Automation

Wireless Communications

 Wi-Fi  Bluetooth  X-bee  UWB  Zig-Bee

What is Zigbee Technology?

 Wireless protocol for Personal Area

Networking.

 Designed for applications that require Low Cost Low to moderate data rates Low Power Consumption Moderate Range Security and reliability

What is Zigbee Technology?

 Designed for applications that require Flexible and dynamic network topologies like Star , cluster tree and mesh network

Zigbee Frequencies

 Operates in Unlicensed Bands  ISM 2.4 GHz Global Band at 250kbps  868 MHz European Band at 20kbps  915 MHz North American Band at 40kbps

Zigbee Feature Set

 Ad‐hoc self forming networks

• Star , cluster tree and mesh network

 Logical Device Types

• Coordinator, Router and End Device

 Security

• Symmetric Key with AES‐128
• Authentication and Encryption at MAC, NWK and

Application levels

• Master Keys, Network Keys and Link Keys

Star Network

Mesh Network

Cluster Network

Network devices

 Coordinator

• It is the starting point of the network.
• It allows other devices to connect to it.
• It provides binding and address-table services.
• It saves messages until they can be delivered.
• It is a “Full functional device” – FFD.
• It is powered.

Network devices

 Router

• It routes messages.
• It does not a start a network.
• It scans network to join.
• They are given a block of address to assign.
• It is a Full function device –FFD.
• Powered or battery depends on topology.

Network devices

 End device

• It does not a start a network.
• It scans network to join.
• It can be full function device or reduced function

device.

• Battery.

 Gateway

• Bridge between a ZigBee network and another

network

ZigBee Address Architecture

 Addressing

• Every device has a unique 64 bit MAC address
• Upon association, every device receives a unique

16 bit network address

• Only the 16 bit network address is used to route

packets within the network

• Devices retain their 16 bit address if they

disconnect from the network, however, if they LEAVE the network, the 16 bit address is re‐assig ned

ZigBee Address Architecture

 Node Addressing

ZigBee Address Architecture

 Endpoint Addressing

• To control lamp 1,2,3 by Switch 1
• ZigBee provides another level of sub-addressing
• An endpoint number is used to identify individual

switches and lamps.

• Endpoint Number range 1-240.

 Endpoint 0 is reserved for device management

and is used to address the descriptors in the node

Zigbee Layered Model

PHYSICAL LAYER

 It is responsible for wireless

transmission and reception of MAC frames.

 It performs the following functions  Energy detection, clear channel

assessment, channel selection, data modulation and the transmission and reception of bits onto the physical medium.

MAC LAYER

 Through this layer one can gain access

to channels present in the network.

 This layer makes it possible for several

stations connected to the same physical medium to share it.

MAC LAYER

 Security Services  Access Control  Data Encryption  Frame Integrity  Sequential Freshness

NETWORK LAYER

 Features  Network Scan  Creating/Joining a PAN  Device Discovery  Service Discovery  Binding

Data Transfer Model

 Device to Coordinator

• In a beacon‐enable network,

device finds the beacon to synchronize

• Uses slotted CSMA/CA to

transmit data

Data Transfer Model

 Device to Coordinator

 In a non beacon‐enable

network, device transmits its using unslotted CSMA/CA.

Data Transfer Model

 Coordinator to Device In a beacon‐enable network, the coordinator indicates in the beacon that the data is pending . Device periodically listens to the beacon and transmits a M AC command request using slotted CSMA/CA if necessary.

Data Transfer Model

 Coordinator to Device

In a non‐beacon‐enable network, a device transmits a MAC command request using unslotted CSMA/CA. If the coordinator has its pending data, the coordinat

• r transmits data frame using unslotted CSMA/CA.

Otherwise, coordinator transmits a data frame with zero length payload.

PHY frame structure

 PHY packet fields

• Preamble (32 bits) – synchronization
• Start of packet delimiter (8 bits) –it

is formatted as “11100101”

• PHY header (8 bits) –PSDU length
• PSDU (0 to 127 bytes) –data field

Data Frame Format

 Provides up to 104 byte data payload capacity



Data sequence numbering ensures that packets are tracked

 Frame Check Sequence (FCS) validates error-free

data

Acknowledgment Frame Format

 It provides active feedback from receiver

to sender that packet was received without error.

How Does ZigBee Compare?

Target Applications

 Wireless sensor networks  Remote monitoring  Wireless alarms and security systems  Home/building automation  Health, sport and entertainment

equipment

Health Care

Home Automation

References

 http://en.wikipedia.org/wiki/ZigBee_specification  http://www.ZigBee.org  http://www.zigbee.org/en/resources/#SlidePresent

ations

 http://www.zigbee.org/resources/documents/IWAS

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Thank You