WIRELESS TECHNOLOGIES

WIRELESS TECHNOLOGIES Wireless communication in 1895 Guglielmo 29 Km away from the island of Wight Marconi'nin a of tugboat began with his publication [1]. lk wireless communication techniques are analog. Today wireless Many of the communication system using digital bits make contact. This continuous communication transmission or bit "Packet radio" in packets called bit groups in consists of [3]. Wireless first packet-based networks network in 1971 called ALOHANET Hawaii Developed at the University of [3]. 4 islands spread over 7 the campus computer centers Oahu'da was communicating with the computer center. The system as a hub central computer that uses a star topology network architecture has. Two computers wish to communicate had to communicate through the central hub. ALOHANET channel access and routing The first contains the protocol [3].

The basic ideas still ALOHANET'i Wired networks because of bandwidth sufficient wireless a specific time for it to reach the standard of network received [2]. In 1991, the International Electrical and Electronics Institute of Engineers (Institute of Electrical and Electronics Engineers-IEEE) under the leadership of IEEE 802.11 group was established. In 1999 this group, IEEE 802.11 standards developed [4]. This standard open area 100 for short distances such as 11 Mbps connection speed meter and communication can provide. Communication distance in terms of this standard wireless local area networks (Wireless Local Area Networks-WLAN) constitute [5]. This the center of a standard access point (Access Point-AP) and its related stations (Stations-STA) are available. In general, even if their communications using STA'lar AP may set up a network between them without design. Today growing In the light of the need, the IEEE 802.11 WLAN standard standard IEEE 802.11a, 802.11b, 802.11g, 802.11n, and These standards have been developed and as new versions of 802.11i been made more widely used [6-9].

Wider areas wireless data for communication studies, some telephone companies' DSL in 1996 and cable data systems insufficient distance therefore alternative broadband wireless communication systems development work started with [5]. 1997 for broadband Internet access in multi-channel Cleary multi-point distribution systems (Multichannel Multipoint Distribution System-MMDS) developed, 30 Mbps speed and 27 Mbps can be used practically with shared has proposed a 50 Km radius can communicate with the system [6]. In 2000, the local multi-point distribution Nordbotten Agne systems (Local Multipoint Distribution System - LMDS) developed, 38 Mbps applied, 25.6 Mbps can be used shared with the speed and radius of 5 Km systems has proposed, and these systems with a cable system comparisons made [7]. Small villages and towns has shown that this system may be better suited for. IEEE Working Group established at 16 in 2002 IEEE 802.16 standards established [8]. 802.16 than standard single point to point (Point to Multipoint - PMP) topology, the only hard and see each other antennas in the range between 10-66 GHz band communication regulates. Used bandwidth and modulation 36-135 Mbps bandwidth depending on the type of practical have [9, 10].

In 2003, not seeing each other for 2-11 GHz antennas bandwidth using the IEEE 802.16a standard been published [9]. This standard also mesh technology supports. Various error adjustments and arrangements with these two standards were merged in 2004 under the name of IEEE 802.16-2004 been published [9]. In 2005, for mobile users IEEE 802.16e, 802.16f IEEE in 2006, and 2007 In IEEE 802.16g, IEEE 802.16 standards arranged along with other standards and these standards Published with the name of IEEE 802.16-2007 [11]. Thus With each other, 2-11 GHz IEEE 802.16-2007 standard not see communication antennas, 10-66 GHz sight of the antenna communication, 2-6 GHz provides mobile users a collective communication became standard. IEEE 802.16 standard mobile maximum users data communication and movement rates respectively 30 Mbps and 30 Km / h. [11-14]. As fast train requiring a higher mobility rate for the IEEE 802.20 mobile broadband wireless access (Mobile Broadband Wireless Access-MBWA) standard for work continues. Which is currently in draft studies 250 Km / h mobile speed and 1-10 Mbps rates are planned to support the non-sharing [15, 16]. Figure 1 in particular has an infrastructure, but the main structure nodes can not reach without a vehicle for the design nodes where a hybrid wireless network structure as an example given

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