Docstoc

ZigBEE hives

Document Sample
ZigBEE hives Powered By Docstoc
					     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 !

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:30
posted:3/11/2011
language:English
pages:50