A general perception for WiMAX is that it delivers high speed data that is 70 Mbps 50 kilometers, but in factual situation WiMAX do some thing different. It increase Bit error rate if it operates at 50 kilometers, that’s why it important to use lower bitrates. If the range is low it helps in operating at higher bitrates.
As we know, there are majorly two types of WiMAX, fixed WiMax and Mobile WiMax, in fixed WiMAX network higher gain directional antenna is installed near the subscriber location which helps in increasing signal strengths, better data rate and throughput. However mobile networks are designed for indoors, it uses customer premises equipment (CPE) which is attached with computers and laptops or other WiMax products.
In mobile WiMax Omni directional antennas are used, which have lower-gain when compared to directional antenna; directional antennas are easy to use as they portable. 10 Mbps speed can be achieved within 10 km range if portable mobile WiMAX CPE used in line-of-sight. In contrast to this 10 Mbps speed can be delivered to only 2 km in urban areas as it is not possible to keep antenna on line-of-sight.
In current situation fixed WiMax throughputs 2Mbps at 10 km using high gain antenna. Higher gain directional antenna can be used with Mobile WiMax networks with good range and throughput but in result loose mobility.
As in all wireless or wired networks, the given bandwidth is divided among the users, it is same in WiMax also, available bandwidth is divided among the users in certain radio sector, and performance of the network can drop in case of many users in give sector. To improve the performance in this situation more radio cards are required to be installed in the base station for give sector.
Because of this varying performance of WiMax networks, lots architectures are incorporated into WiMax by independent development and within the 802.16j mobile multi-hop relay (MMR) task group.