Wireless Local Area Technology

 Garikayi Brasington Madzudzo  Edmund Nartey  Ismeil Ahamed  Jakub Gieryn  Arnaud Fogno

 Introduction  Definitions  Specifications & Technologies  Benefits of n Technology  Security (Authentication & Encryption)

 is an amendment to the IEEE wireless networking standard to improve network throughput over the two previous standards— a and g.  is a protocol developed by the international non- profit Institute of Electrical and Electronics Engineers.  The number "11" indicates the IEEE working group assigned to 802 standards, and the "n" refers to a special task group within this body, known as TGn.  is an industry standard for high-speed Wi-Fi networking

 n is designed to replace the a, b and g Wi-Fi standards for local area networking.  Offers greater speed and a larger frequency range.  is intended to improve WLAN data rates and range without requiring additional power or RF band allocation.  n will help with overall mobile connectivity in terms of distance and speed. By being able to have that improved distance and speed capability, n is going to bring wireless technology closer to actual wire speed and wire-based reliability, which is one of the biggest lacking factors of b and g

 It utilizes multiple receivers and transmitters, a technology known as MIMO (multiple-input multiple- output).  This allows parallel streams of data transmissions, or spatial multiplexing.  The n standard also incorporates orthogonal frequency-division multiplexing (OFDM).  OFDM splits signal frequencies up into several modulated channels for increased throughput.

 2.4 GHz band: A lot of devices use this, thus more likely to get interference, however better range than the 5 GHz band  5 GHz band: higher frequencies allow using smaller antennas, however they are more easily absorbed by obstacles such as walls.  Caters for both frequencies to allow for backward compatibility.

 Implements changes at physical layer (PHY) and MAC layer  PHY: 40MHz channels  MAC: frame aggregation (A-MSDU and A- MPDU)  maximum MAC frame body field size increased (can be 3839 or 7935 octets (A-MSDU size based)

 Supports Wi-Fi Protected Access Version 2 (WPA2)  n devices encrypt data in accordance with Advanced Encryption Standard (AES)  AES replaced WPA with TKIP and WEP as more secure method of encrypting wireless data  In n AES cipher relies on CCMP protocol to provide cryptographic encapsulation (see CTR with CBC-MAC, CCM mode, RFC 3610)

802.11a802.11b802.11g802.11n Standard Approved July 1999 June 2003 September 2009 Maximum Data Rate 54 Mbps11 Mbps54 Mbps200+ Mbps ModulationOFDMDSSS / OFDM DSSS / OFDM RF Band5 GHz2.4 GHz 2.4 GHz or 5 GHz Channel Width20 MHz 20 MHz or 40 MHz The table below shows the different wireless standard and technologies

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