ZigBee/IEEE 802.15.4

1
ZigBee/IEEE 802.15.4

• Presented By AJAR

2
Origin Of Name ZigBee

• The domestic honeybee, a colonial insect, lives
  in a hive that contains a queen, a few male
  drones, and thousands of worker bees. The
  survival, success, and future of the colony is
  dependent upon continuous communication of vital
  information between every member of the colony.
  The technique that honey bees use to communicate
  new-found food sources to other members of the
  colony is referred to as the ZigBee Principle.
  Using this silent, but powerful communication
  system, whereby the bee dances in a zig-zag
  pattern, she is able to share information such as
  the location, distance, and direction of a newly
  discovered food source to her fellow colony
  members. Instinctively implementing the ZigBee
  Principle, bees around the world industriously
  sustain productive hives and foster future
  generations of colony members.

3
What is ZigBee

• ZigBee is a Ad-hoc networking technology for
  LR-WPAN
• Based On IEEE 802.15.4 standard that defines the
  PHY and Mac Layers for ZigBee.
• Intended for 2.45 Ghz , 868 Mhz and 915 Mhz Band.
  
• Low in cost ,complexity power consumption as
  compared to competing technologies.
• Intended to network inexpensive devices
• Data rates touch 250Kbps for 2.45Ghz ,40 Kbps
  915Mhz and 20Kbps for 868Mhz band.

4
ZigBee Alliance
5
Worlds Most Common Frequency Bands
6
Market Requirements-I

• Global licence free ISM band operation
• Unrestricted geographic use
• RF penetration through walls ceilings
• Automatic/semi-automatic installation
• Ability to add or remove devices
• Possible voice support

7
Market Requirements-II

• 10k-115.2kbps data throughput
• 10-75m coverage range (home/garden)
• Support for 32-255 nodes
• Support for 4 critical devices
• 4-100 co-located networks
• 0.5-2 year battery life
• Up to 5m/sec. (18kmph) permitted mobility
• Module cost 1.5-2.5 in 2004/5!

8
Home/Light Commercial spaces
9
Industrial Environment

• Warehouses, Fleet management, Factory,
  Supermarkets, Office complexes
• Gas/Water/Electric meter, HVAC
• Smoke, CO, H2O detector
• Refrigeration case or appliance
• Equipment management services Preventative
  maintenance
• Security services
• Lighting control
• Assembly line and work flow, Inventory
• Materials processing systems (heat, gas flow,
  cooling, chemical)

10
Application Sectors
CONSUMER ELECTRONICS
monitors sensors automation control
TV VCR DVD/CD remote
PC PERIPHERALS
PERSONAL HEALTH CARE
ZigBee LOW DATA-RATE RADIO DEVICES
HOME AUTOMATION
TOYS GAMES
security HVAC lighting closures
consolesportables educational
11
ZigBee Market Shares
12
ZigBee General Characteristics

• Data rates of 20 kbps and up to 250 kbps
• Star or Peer-to-Peer network topologies
• Support for Low Latency Devices
• CSMA-CA Channel Access
• Handshaking
• Low Power Usage consumption
• 3 Frequencies bands with 27 channels
• Extremely low duty-cycle (lt0.1)

13
ZigBee Statistics
14
868MHz/ 915MHz PHY
Channels 1-10
Channel 0
2 MHz
868.3 MHz
928 MHz
902 MHz
2.4 GHz PHY
Channels 11-26
5 MHz
2.4 GHz
15
Low Power Statistics

• Todays definition Low power Battery operation
  for several years
• Some figures
• 1 year is 36524 hours 8760 hours
• AAA battery capacity is about 1300mAh
• AA battery capacity is about 3100mAh
• Coin cell lithium CR2032 capacity is about 230mAh
• Note that peak current,(internal resistance) and
  leakage are also issues, but not today
• An average consumption of 10uA will last
• AAA15 years, AA 35 years and CR2032 2.6 years

16
Comparison Chart
17
(No Transcript)
18
Bluetooth ZigBee Comparison fo PAN networks

• ZigBee Protocol was developed to serve very
  different applications than Bluetooth and leads
  to tremendous optimizations in power consumption.
  Some of the key protocol differentiators are
• ZigBee
• Very low duty cycle, very long primary battery
  life,
• Static and dynamic star and mesh networks,
  gt65,000 nodes, with low latency available,
• Ability to remain quiescent for long periods
  without communications,
• Direct Sequence Spread Spectrum allows devices to
  sleep without the requirement for close
  synchronization.
• Bluetooth
• Moderate duty cycle, secondary battery lasts same
  as master,
• Very high QoS and very low, guaranteed latency,
• Quasi-static star network up to seven clients
  with ability to participate in more than one
  network,
• Frequency Hopping Spread Spectrum is extremely
  difficult to create extended networks without
  large synchronization cost.

19
Basic Network Charachteristics

• 65,536 network (client) nodes
• Optimized for timing-critical applications
• Network join time
• 30 ms (typ)
• Sleeping slave changing to active 15 ms (typ)
• Active slave channel access time 15 ms (typ)

20
ZigBee Layers
21
Typical Implementations
22
What are the RAM/ROM requirements for the FFD and
RFD MAC ?

• ZigBee requires a small amount of system
  resources substantially simplifying the process
  of designing wireless communications into
  products while reducing time to market and
  product cost. While still in the definition
  phase, the estimated MAC size is as follows
• RFD 12KB to 16KB
• FFD 16KB to 20KB.

23
Device Addressing

• All devices have IEEE addresses
• Short addresses can be allocated
• Addressing modes
• Network device identifier (star)
• Source/destination identifier (peer-peer)
• Source/destination cluster tree device
  identifier (cluster tree)

24
IEEE 802.15.4 Device Definitions

• Full function device (FFD)
• Any topology
• Network coordinator capable
• Talks to any other device
• Reduced function device (RFD)
• Limited to star topology
• Cannot become a network coordinator
• Talks only to a network coordinator
• Very simple implementation

25
ZigBee Network Devices
26
Star and Peer to Peer Networks
27
Cluster Tree Network
28
Network Architecture
29
Types of PAN

• Non-Beacon Enabled PAN
• Un-slotted CSMA/CA
• Beacon Enabled PAN
• Slotted CSMA/CA

30
SuperFrame Structures

• A superframe is formed by the PAN coordinator to
  synchronize network reception and transmission.

31
Communication Mechanisms-I
32
Communication Mechanisms-II
33
PHY/MAC Framing
34
Network Layer
35
Network Layer Framing
36
Beacon Frame
37
Data Frame
38
Acknowledgement Frame
39
MAC Command Frame
40
Primitives for PHY Layer
41
Mac Layer Primitives
42
Robustness of Architecture

• CSMA/CA
• Frame Acknowledgement
• Data Verification

43
Security

• Access control
• Data Encryption
• Frame Integrity
• Sequential Freshness

44
Security Modes

• Unsecured Mode
• ACL Mode
• Secured Mode

45
PHY Layer Modulation and Spreading

• 2.45 Ghz Band Characteristics
• 16-ary quasi-orthogonal modulation technique (4
  information bits are used to select one out of
  16 PN sequences. )
• Concatenated PN sequences transmitted using
  O-QPSK
• Bit to Symbol mapping
• Symbol to chip mapping (32 chip)
• Half-sine wave pulse shaping
• In-Phase (I) carrier even chips
• Quadrature Phase (Q) carrier odd chips

46

• -85dbm minimum receiver sensitivity
• 62.5 k symbols/sec /-40ppm
• Adjacent channel rejection 0dbm
• Alternate channel rejection 30dbm

47
PHY Layer Modulation and Spreading

• 868 and 915Mhz bands
• DSSS with BPSK
• Differential Encoding
• Bit to Chip Mapping (15 chip)
• BPSK Modulation
• Pulse Shaping
• Symbol rate 20ksymbols/sec
• Receiver sensitivity -94dbm
• Turn-around time12 symbols

48
Clear Channel Assessment parameters

• Energy Detection(10dbm threshold)
• Link Quality Indication
• Receiver ED
• Signal to Noise ration estimation
• Carrier sense

49
Chipset Comparisons
50

• Thank You !