These slides explain Zigbee Technology. Also, explain the Wide Private Area Network(WPAN). Also, explain network topologies.

1. Today topic is: WPAN According
To ZIGBEE

2. INTRODUCTION
• Development started 1998, when many engineers
realized that WiFi and Bluetooth were going to be
unsuitable for many applications.
• The IEEE 802.15.4 standard was completed in May
2003.
• The ZigBee specifications were ratified on 14
December 2004.
• The ZigBee Alliance announced public availability of
Specification 1.0 on 13 June 2005.
• Much research is still going on with ZigBee.

3. WHAT IS ZIGBEE?
•Technological Standard Created for
Control and Sensor Networks
•Based on the IEEE 802.15.4 Standard
•Created by the ZigBee Alliance

4. ZIGBEE ALLIANCE (COMPANY)
• Organization defining global standards for reliable,
cost‐effective, low power wireless applications.
• Developing applications and network capability
utilizing the 802.15.4 packet delivery mechanism.

5. CHARACTERISTICS
• Low cost
• Low power consumption
• Low data rate
• Relatively short transmission range
• Scalability (System capacity, capability)
• Reliability
• Flexible protocol design suitable for many applications

6. IEEE 802.15.4 STANDARD AND ZIGBEE
• The IEEE 802.15.4 standard defines both the physical
and MAC layer protocols for most remote monitoring
and control, as well as sensor network applications.
ZigBee is an industry consortium with the goal of
promoting the IEEE 802.15.4 standard. ZigBee ensures
interoperability by defining higher network layers and
application interfaces.

7. ZIGBEE
• Zigbee emerging applications of Wireless Sensor
Network is wireless monitoring and control.
• ZigBee is such an application that uses low-power and
low-data-rate networked sensors. It was developed by
the ZigBee Alliance, an industry association of
semiconductor companies and network equipment
companies such as Ember, Honeywell, Mitsubishi
Electric, Motorola, Samsung, and Philips.

8. ZIGBEE JUST LIKE HONEYBEES
• The term ZigBee refers to the silent communication
between honeybees where the bee dances in a zig-zag
pattern to tell others the location, distance, and
direction of some newly found food.

9. IEEE 802.15.4 LR-WPAN (ZIGBEE)
• ZigBee technology is simpler (and less expensive) than
Bluetooth.
• The main objectives of an LR-WPAN like ZigBee are ease of
installation, reliable data transfer, short-range operation,
extremely low cost, and a reasonable battery life, while
maintaining a simple and flexible protocol.
• The raw data rate will be high enough (maximum of 250 kbit/s)
to satisfy a set of simple needs such as interactive toys, but is
also scalable down to the needs of sensor and automation
needs (20 kbit/s or below) using wireless communications.

10. ZIGBEE USAGE
• The initial target markets of ZigBee products are home control,
building control, industrial automation, personal healthcare,
consumer electronics, PC and peripherals control, etc. Key
specs of ZigBee include the following:
● Frequency bands: 868 MHz, 915 MHz, and 2.4 GHz
● Data transfer rate up to 250 Kbps
● Signal transmission range of 10 to 100 m, depending on the
sensors being
used
● AES(Advanced Encryption Standard) encryption of data
● Various ZigBee applications can work with each other
● Low power usage

11. ZIGBEE FREQUENCIES
• Operates in Unlicensed Bands
• ISM(International Safety Management) 2.4 GHz Global
Band at 250kbps
• 868 MHz European Band at 20kbps
• 915 MHz North American Band at 40kbps

12. IEEE 802.15.4 & ZIGBEE IN CONTEXT
S
PHY
868MHz / 915MHz / 2.4GHz
MAC
Network
Star / Mesh / Cluster-Tree
Security
32- / 64- / 128-bit encryption
Application
API
ZigBee
Alliance
IEEE
802.15.4
Customer
Silcon Stack App
“the software”
- Network, Security & Application layers
- Brand management
IEEE 802.15.4
- “the hardware”
- Physical & Media Access Control layers

13. SECURITY
• Encryption specified for MAC, Network and APS layers
• Encryption/Authentication mode CCM(CTR +CBC-MAC)
• CTR is a counter based encryption mode
• CBC-MAC provides data integrity
• All security is based on 128bit key and AES-128 block
encryption method

14. IEEE 802.15.4 PHYSICAL LAYER
• PHY functionalities:
• Activation and deactivation of the radio transceiver
• Energy detection within the current channel
• Link quality indication for received packets
• Clear channel assessment for CSMA-CA
• Channel frequency selection
• Data transmission and reception

15. PHY FRAME STRUCTURE
• PHY packet fields
• Preamble (32 bits) – synchronization
• Start of packet delimiter (8 bits) – shall be formatted as “11100101”
• PHY header (8 bits) –PSDU length
• PSDU (0 to 127 bytes) – data field
Start of
Packet
Delimiter
PHY Header
Sync Header
Frame
Length
(7 bit)
Preamble
PHY Payload
PHY Service
Data Unit (PSDU
Reserv
e
(1 bit
4 Octets 1 Octets 1 Octets 0-127 Bytes

16. WHAT DOES ZIGBEE DO?
• Designed for wireless controls and sensors
• Operates in Personal Area Networks (PAN’s) and
device-to-device networks
• Connectivity between small packet devices
• Control of lights, switches, thermostats, appliances,
etc.

17. LIGHTS AND SWITCHES

18. HOW ZIGBEE WORKS
• States of operation
• Active
• Sleep
• Devices
• Full Function Devices (FFD’s)
• Reduced Function Devices (RFD’s)
• Modes of operation
• Beacon
• Non-beacon

19. HOW ZIGBEE WORKS
•Topology
•Star
•Cluster Tree
•Mesh
•Network coordinator, routers, end devices

20. LR-WPAN DEVICE TYPES
Two different device types can participate in an LR-WPAN
network:
• Full-function devices (FFD) can operate in three modes serving
as a personal area network (PAN) coordinator, a coordinator, or
a device.
• Reduced-function devices (RFD) are intended for applications
that are extremely simple.
An FFD can talk to RFDs or other FFDs, while an RFD can talk
only to an FFD.

21. NETWORK TOPOLOGIES (1)
• Two or more devices communicating on the same physical
channel constitute a WPAN. The WPAN network must include at
least one FFD that operates as the PAN coordinator.
• The PAN coordinator initiates, terminates, or routes
communication around the network. The PAN coordinator is the
primary controller of the PAN.
• The WPAN may operate in either of two topologies: the star
topology or the peer-to-peer topology.

22. NETWORK TOPOLOGIES (2)
Star topology In a star network, after an FFD is
activated for the first time, it may
establish its own network and become
the PAN coordinator.
The PAN coordinator can allow other
devices to join its network.
PAN coordinator (always FFD) FFD RFD

23. NETWORK TOPOLOGIES (3)
In a peer-to-peer network, each FFD
is capable of communicating with any
other FFD within its radio sphere of
influence. One FFD will be nominated
as the PAN coordinator.
Peer-to-peer topology
A peer-to-peer network can be ad hoc, self-
organizing and self-healing, and can combine
devices using a mesh networking topology.

24. ZIGBEE PHY AND MAC PARAMETERS
Topology
RF band
RF channels
Spreading
Chip rate
Modulation
Access method
Ad hoc (central PAN coordinator)
2.4 GHz ISM frequency band
16 channels with 5 MHz spacing
DSSS (32 chips / 4 bits)
2 Mchip/s
Offset QPSK
CSMA/CA (or slotted CSMA/CA)

25. SPREADING AND MODULATION
• Four consecutive bits are mapped into a data symbol. Each
symbol is mapped into a 32-chip pseudorandom sequence. The
even-indexed and odd-indexed chips of the chip sequence
representing each data symbol are modulated onto the carrier
using Offset-QPSK in the following way:
C0 C2 C4 C6 C8 C10 C12 ...
...
C1 C3 C5 C6 C9 C11 C13 ...
...
I-phase
Q-phase

26. BEACON FRAMES
• The LR-WPAN standard allows the optional use of a superframe
structure. The format of the superframe is defined by the
coordinator. The superframe is bounded by network beacons,
sent by the coordinator, and is divided into 16 equally sized
slots. The beacon frame is transmitted in the first slot of each
superframe. If a coordinator does not wish to use a superframe
structure, it may turn off the beacon transmissions. The
beacons are used to synchronize the attached devices, to
identify the PAN, and to describe the superframe structure.

27. CSMA/CA OPERATION (1)
• Nonbeacon-enabled networks use an unslotted CSMA-CA
channel access mechanism. Each time a device wishes to
transmit data frames or MAC commands, it shall wait for a
random period. If the channel is found to be idle, following the
random backoff, the device shall transmit its data. If the
channel is found to be busy, following the random backoff, the
device shall wait for another random period before trying to
access the channel again.
• Acknowledgment frames shall be sent without using a CSMA-
CA mechanism.

28. CSMA/CA OPERATION (2)
• Beacon-enabled networks use a slotted CSMA-CA channel
access mechanism, where the backoff slots are aligned with the
start of the beacon transmission.
• Each time a device wishes to transmit data frames, it shall wait
for a random number of backoff slots. If the channel is busy,
following this random backoff, the device shall wait for another
random number of backoff slots before trying to access the
channel again. If the channel is idle, the device can begin
transmitting on the next available backoff slot boundary.

29. ZIGBEE PRODUCTS
• Development Kits
• Sensors
• Transceivers
• Modules

30. CURRENT ZIGBEE USES
•Environmental Monitoring
•Agricultural Monitoring
•Home Automation Still on Horizon

31. PRODUCT APPLICATIONS
• Road map products-tracking
• Consumer electronics
• PC
• Personal and healthcare
• Commercial and residential control

32. ZIGBEE’S FUTURE