802 project is an IEEE(Institute of Electrical and Electronics Engineers) initiative which standardizes LAN (Local Area Networks) and MAN (Metropolitan Area Networks) communication protocols. And it gives a number after 802 and a dot for a specific network. Such as, Ethernet standardized as 802.3 and WiFi as 802.11 which are popular standards for wired LAN and wireless LAN respectively. Further, IEEE 802 project specifies the physical and the data link layer model in TCP/IP stack. Which is jointly network access layer in TCP/IP model. The reason behind to need a specification for physical and the link layer. That can be understood by different between Ethernet (IEEE 802.3) and WiFi (IEEE 802.11) local area networks.
|Original TCP/IP Stack|
Why do need specification for physical and the link layer?
Moreover, when communication medium changes form wired to wireless. The physical layer and data link layer need to be redesigned. For example in 802.3 at the data link layer there is no need of acknowledgement. Because, on wired link there is the probability of packet error is almost negligible. But in 802.11 there is need of acknowledgment packet. Since probability of packet error on the wireless link is very high.
|Modified TCP/IP Stack|
Another example is that Zigbee ( IEEE 802.15.4 specification) which sensor networks use. In which the data rate needs very low which is 200 kbps to 300 kbps. Because high data rate consumes high energy so 802.11 specification will not be useful for sensor networks.
Usually, one or more parameters from the lists changes the 802 projects develops new specification.
1- Communication Link
3- Data Rate
4- Transmission Range
5- Transmit Power
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Conclusion- In this article, I have tried to explain 802 projects hope it will help you.
Previously published on www.computex.online