This is my seminar called "IEEE 802.11n",which i presented in my college as part of my M.Sc. Computer Science course.

1. IEEE 802.11n NITHINKUMAR C.N B.P.C. College , Piravom

2. Introduction IEEE initiated the IEEE 802.11 project in 1990. In 1997, IEEE first approved the interoperability standard for WLANs. In 1999 , IEEE ratified two amendments to the IEEE 802.11 standard-IEEE 802.11a and 802.11b. In 2003 , IEEE released the IEEE 802.11g amendment. In 2006 , the first IEEE 802.11n draft was introduced.

6. Radio

7. channel

8. DSP

9. DSP

10. Radio

11. Bits

12. Radio

13. Bits

14. Radio

15. Radio

16. TX

17. RX

18. Compare to traditional Single Input Single Output Radio (with optional receive diversity)channel Bits DSP DSP Radio Radio Bits TX RX What is MIMO? Multiple Input Multiple Output (MIMO) Transmit and Receive with multiple radios simultaneously in same spectrum

20. IEEE 802.11a-1999 IEEE 802.11a-1999 or 802.11a is an amendment to the IEEE 802.11 specification that added a higher data rate of up to 54 Mbps using the 5 GHz band. It uses a 52-subcarrier orthogonal frequency-division multiplexing (OFDM) with a maximum raw data rate of 54 Mbps , which yields realistic net achievable throughput in the mid-20 Mbps.

21. IEEE 802.11g-2003 IEEE 802.11g-2003 or 802.11g is an amendment to the IEEE 802.11specification that extended throughput to up to 54 Mbps using the same 2.4 GHz band as 802.11b. 802.11g hardware is fully backwards compatible with 802.11b hardware. The modulation scheme used in 802.11g is orthogonal frequency-division multiplexing.

22. IEEE 802.11k-2008 IEEE 802.11k-2008 is an amendment to IEEE 802.11-2007 standard for radio resource management. It defines and exposes radio and network information to facilitate the management and maintenance of a mobile Wireless LAN. It provides information to discover the best available access point.

23. IEEE 802.11r-2008 IEEE 802.11r-2008 or fast BSS transition (FT) is an amendment to the IEEE 802.11 standard to permit continuous connectivity aboard wireless devices in motion, with fast and secure handoffs from one base station to another managed in a seamless manner. IEEE 802.11r specifies fast Basic Service Set(BSS) transitions between access points by redefining the security key negotiation protocol.

24. IEEE 802.11y-2008 IEEE 802.11y-2008 is an amendment to the IEEE 802.11-2007 standard that enables high powered Wi-Fi equipment to operate on a co-primary basis in the 3650 to 3700 MHz band in the United States. It adds three new concepts to 802.11-2007 Standard: Contention Based Protocol (CBP) - enhancements have been made to the carrier sensing and energy detection mechanisms of 802.11 in order to meet the FCC's requirements for a contention based protocol.

25. Extended channel switch announcement(ECSA)- provides a mechanism for an access point to notify the stations connected to it of its intention to change channels or to change channel bandwidth. Dependent station enablement(DSE)- is the mechanism by which an operator extends and retracts permission to license exempt devices (referred to as dependent STAs in .11y) to use licensed radio spectrum.

26. IEEE 802.11w-2009 IEEE 802.11w-2009 is an approved amendment to the IEEE 802.11 standard to increase the security of its management frames. IEEE 802.11w is the Protected Management Frames standard for the IEEE 802.11 family of standards.

27. Modulation and Coding Schemes The 802.11n standard defines Modulation and Coding Scheme (MCS) – a simple integer assigned to every permutation of modulation , coding rate, guard interval , channel width, and number of spatial streams. Modulation and coding rate determines how data is sent over the air. Guard Interval is the time between transmitted symbols. Unequal Modulation refers to using a different modulation type and coding rate on each spatial stream.

28. Frame Aggregation The main medium access control (MAC) feature that provides a performance improvement is aggregation. Two types of aggregation are defined: 1.MAC Service Data Unit Aggregation (A-MSDU) 2.MAC Protocol Data Unit Aggregation (A-MPDU)

29. Backward Compatibility 802.11n systems are fully backward compatible with 802.11a/b/g. The 802.11 standard defines three different modes of operation that describe backward compatibility of 802.11n networks. These are: 1.High Thoughput , Greenfield Mode 2.High Thoughput , Mixed Mode 3.Legacy Mode

30. 802.11n Deployment Challenges Infrastructure Upgrades RF Planning & Site Surveying WLAN Security Troubleshooting and Tuning 1.WLAN analyzers must be able to capture and decode 802.11n traffic. 2.Spectrum analyzers must recognize the spectral usage patterns associated with 802.11n APs – including Greenfield mode.

31. 3.Connection diagnostic tools will require the ability to connect to 802.11n APs using any supported MCS value. 4. WLAN analyzers must help 802.11n users overcome their potentially inability to achieve high throughput, due to presence of legacy devices, implementation of protection mechanisms, etc. 5.WLAN analyzers must help administrators understand the real-world overhead incurred when supporting legacy devices.

32. 6.WIPS alerts and reports must be extended to analyze 802.11n PHY and MAC extensions and their impact on WLAN operation and performance. 7. Integration between WIPS and WLAN management systems can help administrators better understand the long-term impact of real-time dynamic channel adjustments caused by 802.11n APs and controllers.

33. Applications VoIP Streaming Music Gaming Network Attached Storage(NAS)

34. Conclusion 802.11n will substantially increase the performance and ubiquitous wireless access of laptops , desktops , smart phones and entertainment devices over the next several years. 802.11n will first appear in client devices and begin to be pervasively deployed in enterprises , homes and eventually metro networks.

35. Questions?