ZigBEE hives
Shared by: nikeborome
-
Stats
- views:
- 29
- posted:
- 3/11/2011
- language:
- English
- pages:
- 50
Document Sample


Presented By : AJAR
ZigBee/IEEE 802.15.4
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.
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.
ZigBee Alliance
Worlds Most Common Frequency
Bands
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
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!
Home/Light Commercial spaces
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)
Application Sectors
monitors TV
sensors VCR
automation DVD/CD
control INDUSTRIAL & CONSUMER remote
COMMERCIAL ELECTRONICS
ZigBee
LOW DATA-RATE
RADIO DEVICES PC &
PERSONAL
HEALTH CARE PERIPHERALS
security
consoles
HVAC
portables
lighting
educational TOYS & HOME
GAMES AUTOMATION
closures
ZigBee Market Shares
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 (<0.1%)
ZigBee Statistics
BAND COVERAGE DATA RATE
CHANNELS
2.4 GHz ISM Worldwide 250 kbps
16
915 MHz ISM Americas 40 kbps
10
868 MHz Europe 20 kbps 1
868MHz/ Channel 0 Channels 1-10
2 MHz
915MHz
PHY
868.3 MHz 902 MHz 928 MHz
2.4 GHz
PHY Channels 11-26 5 MHz
2.4 GHz
Low Power Statistics
Today’s definition: Low power: Battery operation
for several years
Some figures
• 1 year is 365*24 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
• AAA:15 years, AA: 35 years and CR2032: 2.6 years
Comparison Chart
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, >65,000 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.
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) Network coordinator
Full Function node
– Active slave channel access Reduced Function node
time: 15 ms (typ)
Communications flow
Virtual links
ZigBee Layers
Typical Implementation’s
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.
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)
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
ZigBee Network Devices
Star and Peer to Peer Networks
Cluster Tree Network
Network Architecture
Types of PAN
Non-Beacon Enabled PAN
Un-slotted CSMA/CA
Beacon Enabled PAN
Slotted CSMA/CA
SuperFrame Structures
A superframe is formed by the PAN
coordinator to synchronize network
reception and transmission.
Communication Mechanisms-I
Communication Mechanisms-II
PHY/MAC Framing
Network Layer
Network Layer Framing
Beacon Frame
Data Frame
Acknowledgement Frame
MAC Command Frame
Primitives for PHY Layer
Mac Layer Primitives
Robustness of Architecture
CSMA/CA
Frame Acknowledgement
Data Verification
Security
Access control
Data Encryption
Frame Integrity
Sequential Freshness
Security Modes
Unsecured Mode
ACL Mode
Secured Mode
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
-85dbm minimum receiver
sensitivity
62.5 k symbols/sec +/-
40ppm
Adjacent channel rejection
0dbm
Alternate channel rejection
30dbm
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 time=12
symbols
Clear Channel Assessment
parameters
Energy Detection(10dbm threshold)
Link Quality Indication
• Receiver ED
• Signal to Noise ration estimation
Carrier sense
Chipset Comparisons
800/9 Standb Trans Reciev Othe
2400 Vdd Interf Encr Packag
Manuf Chip 00 y mit e r Remarks
MHz (V) . ypt e
acurer MHz (µA) (mA) (mA) Iface
AT86RF21 1.8 - 60 (3.3 48
Atmel yes no 1 14.5 SPI no no PHY
0 3.6 V) QFN
Freesc 2.0 - 32
MC13192 no yes 3 34 37 SPI no no PHY
ale 3.4 QFN
Chipco 2.1 - 7 x 7 48
CC2420 no yes ? 17.4 19.7 SPI no yes PHY
n 3.6 QLP
2.1 - 7 x 7 48
Ember EM2420 no yes 0.5 20.7 19.7 SPI no yes PHY
3.6 QLP
ZMD4410 Paral PHY + Thin 48
ZMD yes no 2.4 4 20 19 SPI no
1 lel MAC MLF
Comp
CX1540 no yes 3.0 1 56 57 SPI no no PHY + MAC 48
XS
OKI ML7065 no yes 3.0 1 56 57 SPI no no PHY + MAC 48
48
UBEC UZ2400 no yes 1.8 5 ? ? SPI no ? PHY + MAC
QFN
Thank You !
Get documents about "