12-08-2011, 04:23 PM
ZIGBEE.doc (Size: 869.5 KB / Downloads: 91)
Abstract:
The past several years have witnessed a rapid development in the wireless network area. So far wireless networking has been focused on high-speed and long range applications. However, there are many wireless monitoring and control applications for industrial and home environments which require longer battery life, lower data rates and less complexity than those from existing standards. What the market need is a globally defined standard that meets the requirement for reliability, security, low power and low cost. For such wireless applications a new standard called ZigBee has been developed by the ZigBee Alliance based upon the IEEE 802.15.4 standard.
Apart from easy installation and easy implementation ZigBee has a wide application area such as home networking, industrial networking, Smart dust, many more, having different profiles specified for each field. The upcoming of ZigBee will revolutionize the home networking and rest of the Wireless world. ZigBee is not alone in the world of home automation and sensor networks. It faces competition from similar technologies such as Z-Wave, a technology based on the Zensys' Z-Wave open standard. This standard focuses on the same areas as ZigBee and may actually control a bigger corner of the market. However, it lacks a global standard and does not quite have the publicity that ZigBee currently holds.
1. Introduction:-
A wireless network is a flexible data communication system, which uses wireless media such as radio frequency technology to transmit and receive data over the air, minimizing the need for wired connections. Wireless networks are used to augment rather than replace wired networks and are most commonly used to provide last few stages of connectivity between a mobile user and a wired network.
Network:
Wireless networks use electromagnetic waves to communicate information from one point to another without relying on any physical connection. Radio waves are often referred to as radio carriers because they simply perform the function of delivering energy to a remote receiver. Multiple radio carriers can exist in the same space at the same time without interfering with each other if the radio waves are transmitted on . Wireless networks offer the following productivity, convenience, and cost advantages over traditional wired networks:
Mobility.
Provide mobile users with access to real-time information so that they can roam around in the network without getting disconnected from the network. This mobility supports productivity and service opportunities not possible with wired networks.
Installation speed and simplicity.
Installing a wireless system can be fast and easy and can eliminate the need to pull cable through walls and ceilings.
More Flexibility.
Wireless networks offer more flexibility and adapt easily to changes in the configuration of the network.
Reduced cost of ownership.
While the initial investment required for wireless network hardware can be higher than the cost of wired network hardware, overall installation expenses and life-cycle costs can be significantly lower in dynamic environments.
Scalability.
Wireless systems can be configured in a variety of topologies to meet the needs of specific applications and installations.
2. Introduction to Zigbee:-
ZigBee is a low-cost, low-power, wireless mesh networking standard. The low cost allows the technology to be widely deployed in wireless control and monitoring applications, the low power-usage allows longer life with smaller batteries, and the mesh networking provides high reliability and larger range. It builds on IEEE standard 802.15.4 which defines the physical and MAC layers.
Above this ZigBee defines the application and security layer specifications enabling interoperability between products from different manufacturers.
With the applications for remote wireless sensing and control growing rapidly it is estimated that the market size could reach hundreds of millions of dollars as early as 2007. This makes ZigBee a very attractive proposition, and one, which warrants the introduction of a focused standard
3. Zigbee Alliance:-
The ZigBee standard is organized under the auspices of the ZigBee Alliance. The ZigBee alliance is an organization of companies working together to define an open global standard for making low power wireless networks. The intended outcome of ZigBee alliance is to create a specification defining how to build different network topologies with data security features and interoperable application profiles. This organization has over 150 members, of which seven have taken on the status of what they term “promoter.” A big challenge for the alliance is to make the interoperability to work among different products. To solve this problem, the ZigBee Alliance has defines profiles, depending on what type of category the product belongs to.
The Alliance has specified three profiles:
Private Profile.
In this profile interoperability is not at all important. However producers cannot use the official ZigBee stamp, but can claim that ‘based on ZigBee platform’.
Published Profile
A private profile is shared among other users. Still one cannot use official ZigBee stamp, but can claim ‘based on ZigBee platform’.
Public profile.
It is the official ZigBee profile.