Standard 802.11 a, the new radio band used for wireless local area networks and broadband wireless

Standard 802.11 a, the new radio band used for wireless local area networks and broadband wireless networks to increase up to 54 Mbps. This remarkable birite increase in bandwidth modulation technique called OFDM is owed.
Standard 802.11 a, the new radio band used for wireless local area networks and broadband wireless networks to increase up to 54 Mbps. This remarkable increase in bandwidth modulation technique called OFDM is owed. The IEEE 802.11 a standard data rates are: 6, 9, 12, 18, 24, 36, 48, 54 Mbps based on the standard, supports speeds of 6, 12, 24 Mbps is required. Some experts wireless LANs, IEEE 802.11 a standard IEEE 802.11Tlqy the next generation, and even some products such as chips, Atheros network Vkarthay PCMCIA / Cardbus Card Access Inc. product IEEE 802.11 birite a standard has been implemented. Undoubtedly the wide bandwidth and fast data rate limitations as well. The increased bandwidth in IEEE 802.11 a standard has made its operating range compared with IEEE 802.11 / b decreases. In addition to increased overheads of protocol processing, interference, and correction of errors, the actual bandwidth is far less than the nominal bandwidth of this standard. In many applications, feasibility and installation of additional equipment is required which in turn increases the cost of the wireless network infrastructure. Because the operating range of the standard operating range than in standard IEEE 802.11 b and therefore birite the access birite points or base stations will need to increase infrastructure spending to follow. The standard of a particular frequency band, known as the UNII uses. This frequency band is divided into three contiguous frequency as follows:
One of the misconceptions is the belief that the 802.11 standards 802.11 a 802.11 b before the operation is located. In fact, 802.11 b second generation wireless standards (after 802.11) and 802.11 a third generation of this standard is set. Standard 802.11 a claim many wireless equipment vendors because it does not replace the physical layer 802.11 b used in any other major differences. The throughput birite (data rate) is different in each interval.
In Figure 4-1, the three operational birite areas UNII and also authorized the FCC radio emission is observed. They provide a work area of 12 frequency channels. UNII- 1 band for indoor applications, indoor and outdoor applications UNII- 2 band, and the band UNII- 3 for outdoor applications and are used to bridge the network. These areas are usable frequency in Japan. This standard is currently not available in Qarharvpa. birite HyperLAN 2Bray wireless networks used in Europe, which uses the same frequency band 802.11 a. One of the interesting points is defined in the standard 802.11 a bridge network applications in indoor birite and outdoor applications. In fact, the standard rules for bridges and through a bridge of communication between network applications provide indoor and outdoor. In general one can be divided into three major features and benefits 802.11 a summarized below. increase in bandwidth compared birite to standard birite 802.11 b (standard 802.11 a maximum bandwidth of 54 Mbps) is. The use of the frequency spectrum alone (band 5 GHz) using a 12-channel frequency Ghyrpvsha (three in each of the 4 channels Ghyrpvsha birite Mhdvdhfrkansy there) birite 802.11 a standard bandwidth and bandwidth of 11 Mbps, compared with 802.11 b Hdakr provides 54 Mbps bandwidth. The most significant factor in increasing the bandwidth of the standard birite techniques using advanced modulation, OFDM is called. OFDM technique technology (IT) is evolved and matured in wireless birite applications. This technology has considerable resistance against radio interference and multi-path effect takes less than a phenomenon. OFDM under multi-carrier modulation or modulation Chndahngy known discrete. This modulation technique in addition to wireless networks and digital television (in Europe, Japan, and Australia) as well as the technology used in ADSL lines. Andrew McCormick Andrew McCormik birite of Edinburgh University of Technology has collected some interesting interactive display that is visible in the address http://www.ee.ed.ac.uk/~acmc/OFDMTut.html. QAM and OFDM technique of digital signal processing and data signals are multiplexed with precise frequencies. These frequencies are chosen to provide orthogonality property and thus, despite overlapping frequency of each individual carrier frequencies are obvious and need to protect the band frequencies for the interval not. For more information birite on this technique, you can refer to the following address: http://wireless.per.nl/telelearn/ofdm with the increased bandwidth of the standard, used also diminish distance. In fact, almost double the frequency band 5 GHz frequency band ISM (2.4 GHz), which is used in Astandard802.11 b. The effective range of standard and varies according to different birite manufacturers of wireless chips can be straightforward, but as a rule at one-third of the standard frequency range 2.4 GHz (802.11 b) the assessment. Now the