1. Subject Name: WIRELESS COMMUNICATION Subject Code: 10EC81 Prepared By: Shima Ramesh, Shivlila Department: Electronics and Communication Engineering Date: 06/04/2015 06/4/2015

2. UNIT 8 Introduction to wireless LAN 802.11X technologies. 06/4/2015

3. Wireless LANs/IEEE 802.11x Objectives – Discuss the basic differences between wireless LANs and wireless mobile systems. – Discuss the evolution of the IEEE 802.11 standard and its extensions – IEEE 802.11x. – Discuss IEEE 802.11 Design Issues.

4.  Introduction to IEEE 802.11x Technologies – Form the basis for the implementation of high –performance wireless computer networks – It define the over-the-air protocols necessary to support networking in a LAN environment – The WLAN Standards would be developed with the following goals: seamless roaming,messge forwrading,the greatest range of operation, and support for a large number of users. – The enhancement and extensions to the original specifications have raised the maximum data rates, added few frequencies of operation,and attempted to deal with other issues like interference from other services, security concerns,Qos and interoperability between different vendor access points(AP’s). Evolution of Wireless LANs – The evolution of microelectronics has continued to follow Moore’s Law,with an increased reductions in size and price and increased chip functionality and speed. 06/4/2015

5. The ALOHA-NET system allowed computers at seven campuses spread out over four islands to communicate with a central computer on Oahu without using expensive and sometimes unreliable telephone lines.. ALOHA-NET used a star topology between the central computer and the remote stations ALOHA NET 06/4/2015

6. Evolution of Wireless LANs IEEE 802.11b specified a data rate extensions of the initial 802.11DSSS specification to provide 11mbps in the 2.4GHz band. IEEE 802.11a specified operation at rates upto 54mbps in the newer 5GHz frequency band. It used OFDM Modulation technique. It provides for a number of “fall-back rates” when the radio channel conditions cannot support the highest possible data rate IEEE 802.11d added requirements and definitions that were necessary to permit 802.11 WLAN Equipment to operate in other countries not covered by the current standard. Another extension IEEE 802.11g specifies a data rate extension of the initial IEEE 802.11b DSSS Specification to provide data rate s upto 54 mbps – Extensions to 802.11 802.11e :The project purpose is to enhance the current 802.11 media access control(MAC) specification to to expand support for LAN applications that have quality of service requirements. 802.11f :Purpose is to develop an interfaces point protocol to allow for the multiple vendor acess point interoperability across a distribution system. 06/4/2015

7. 802.11h: To enhance the current 802.11 MAC and 802.11a PHY specifications with network management and control extensions to provide spectrum and transmit power control management in the unlicensed 5GHz band 802.11i :To enhance the 802.11 MAC security and Authentication 802.11j : To enhance the standard to add newly available 4.9 and 5.0GHz 802.11k : To enhance the scope of radio resource measurement from only internal use to allow access to the measurements to external entities 802.11ma : To update the standard by providing editorial and technical corrections 802.11n : To enhance the WLAN users experience by providing data throughput rates in excess of 100 mbps 802.11p: To enhance WLAN Technology to provide the ability to communicate to and between vechicles at speeds upto 200kph at distance upto 1000m using 5.850-5.925GHz 802.11r : To improve basics service set (BSS) Transitions 802.11s : To support WLAN mesh operations by providing the protocol for auto configuring and multihop technologies in an ESS mesh network 802.11u : To enhance the IEEE 802.11 MAC and PHY layers to provide ability to inter network to the other external networks. 802.11v : To provide wireless network management enhancements to IEEE 802.11 MAC and PHY layers to extend the work performed by IEEE 802.11k project. 06/4/2015

8. IEEE 802.11 Design Issues – Independent basic service set networks Basic service set :is the simplest and most fundamental structure of IEEE.802.11x WLAN 06/4/2015

9. IEEE 802.11 Design Issues – Integration of wired and wireless LANs The portal function is to provide logical integration between the wireless LAN Architecture and the existing wired LAN 06/4/2015