There has been a rapid growth and development in the wireless network filed from the past several years. Till now the main focus of wireless networking is to provide high-speed and long range applications. There are many applications which requires low data rates, long battery life, and in expensive solution. What the market need is a standard which meets all the requirements such as secure data communication, low data rates, long battery life and inexpensive. Many solutions have been proposed to satisfy these needs but they are very expensive. A new standard called ZigBee has developed by the ZigBee Alliance which is based on the IEEE 802.15.4 standard for all wireless ...view middle of the document...
This communication dance is the "ZigBee Principle". This is what engineers are trying to emulate with this protocol. A group of separate and simple organisms are joining together to handle complex tasks.
Standards based protocol
Requires low cost
Very low current drains
It can be used globally
Reliable and self healing
Supports large number of nodes
Easy to deploy
Long battery life
ZigBee static Architechture
Fig 1: ZigBee Static Architecture
The MAC sub layer is responsible for handling single-hop reliable communications. It uses the security levels that are mentioned by the upper level layers.
The network layer is capable of sending broadcast requests, manages routing, processing received messages. Outgoing frames will makes use of adequate key based on routing, if the key is available; otherwise, it uses the network key which will be used to protect the payload
The application layer provides services to applications and ZDO. It offers key establishment. The application layer routes requests from devices to the trust center and network key renewals from the trust center to all devices. In addition to this, it maintains the security policies of the device.
ZigBee Device Types
A ZigBee network is comprised of ZigBee nodes. Zigbee nodes are nothing but zigbee devices. A zigbee node mainly consists of three parts 1) microcontroller 2) transceiver 3) antenna. It makes use of stack profiles that are implemented by software. A zigbee node supports multiple subunits, every subunit posses an application object. The application object is used to describe the function of the sub unit. A zigbee node operates in two modes 1) Full-function device (FFD) 2) Reduced-function device (RFD). When a zigbee node is operated in a full functional device mode it performs each and every task which is proposed by the ZigBee standard, IEEE 802.15.4 MAC layer. Where as a Reduced- function Device (RFD) can performs only a limited set of tasks.
Fig 2: ZigBee node architecture
A Zigbee node is widely used for various applications such as lighting control, smoke-detector, and home-security monitoring.
ZigBee coordinator: A zigbee coordinator is an FFD. It deals with overall network management. There is exactly only one coordinator is present for every network. The following are the functions that are performed by a zigbee coordinator:
A zigbee coordinator helps the network to select the channel
It initiates the network
Assigns the addresses to nodes or routers
Allows remaining devices to join or leave the network
Maintains a list of routers and neighbors
A zigbee router is a Full-Function Device (FFD).
The main function of the router is to identify the optimal route from source to destination to transfer a message.
A zigbee router is widely used in mesh and tree topologies.
Zigbee router is used in tree and mesh topologies.
A zigbee router is similar...