dccn ppt
TRANSCRIPT
Presentation on ZigBee by
BEE-4BCh Ahsan AliFasih ur RehmanTashfain Yousuf
WAGGLE DANCE
ZigBee
INTRODUCTION
Zigbee is an emerging worldwide standard for Wireless Personal Area Networks (WPAN).
Defined rate of 250 kbit/s on 2.4 Ghz frequency, best suited for a single signal transmission from a sensor or input device.
Network based on IEEE 802.15.4 standard. low cost, low power, wireless mesh network
standard. Applications include wireless light switches,
electrical meters with in-home-displays, traffic management systems, and other consumer and industrial equipment.
WHY WE NEED ZIGBEE!
There are many standards that address mid to high data rates for voice, PC LANs, video,
etc. However, up till now there hasn’t been a wireless network standard that meets
the unique needs of sensors and control devices.
USES
Home automation Wireless sensor networks Industrial control Embedded sensing Medical data collection Smoke and intruder warning Building automation
ZIGBEE DIVICES
Zigbee devices are of three types:1) ZigBee coordinator (ZC) The main device, the coordinator forms the network
tree and is a bridge to other networks. There is exactly one ZigBee coordinator in each network it stores information about the network, including acting as the Trust Center & repository for security keys.
2) ZigBee Router (ZR) As well as running an application function, a router can
act as an intermediate router, passing on data from other devices.
3)ZigBee End Device (ZED) Contains just enough functionality to talk to the parent
node (either the coordinator or a router); it cannot relay data from other devices.
HOW ZIGBEE WORKS It works in the unlicensed 2.4 GHz (worldwide), 915 MHz
(Americas and Australia) and 868 MHz (Europe) ISM bands. Sixteen channels are allocated in the 2.4 GHz band, with
each channel requiring 5 MHz of bandwidth. It is built on a single chip which reduces its cost and power
consumption. It has few analog stages and uses digital circuits wherever
possible. The radios use direct-sequence spread spectrum coding,
which is managed by the digital stream into the modulator. Binary phase-shift keying (BPSK) is used in the 868 and 915 MHz bands, and offset quadrature phase-shift keying (OQPSK) that transmits two bits per symbol is used in the 2.4 GHz band.
The current ZigBee protocols support beacon and non-beacon enabled networks.
DATA RATE
Frequency Data Rate Indoor Outdoor
2.4Ghz 250kb/s 10 to 20m 1500m
915Mhz 40kb/s - 1000m
868Mhz 20kb/s - 800m
LAYERED ARCHITECTURE OF ZIGBEE TECHNOLOGY.
ZIGBEE NETWORK &SECURITY ARCHITECTURE
Network Setup Searches for a Radio Channel. Automatically assigns PAN(Personal Area
Networks) ID.
ZIGBEE NETWORK &SECURITY ARCHITECTURE ZigBee uses 128-bit keys to implement its security
mechanisms. Initial master key must be obtained through a secure
medium (transport or pre-installation), as the security of the whole network depends on it.
A secure network will designate one special device which other devices trust for the distribution of security keys: the trust center.
The MAC sub layer is capable of single-hop reliable communications.
The network layer manages routing, processing received messages and being capable of broadcasting requests.
The application layer offers key establishment and transport services to both ZDO and applications.
ADVANTAGES OF ZIGBEE
Low power consumption. They are more ecological saving megawatts
at its full deployment. Low cost (device, installation, maintenance). High density of nodes per network(using IEEE
802.15.4 PHY and MAC).
SIMULATION OF ZIGBEE NETWORKS
NS2, OPNET, and NetSim can be used using C++.
Simulation on Opnet