The design of the WiMAX is ideal for challenges related with earlier versions of wired and wireless access networks. At the same time the backhaul connects the Wimax system to the network, it is not an integrated part of WiMAX system. Normally a WiMAX network consists of two parts, a Wimax Base Station (BS) and a Wimax receiver also referred as Customer Premise Equipment (Wimax CPE). (Deepak Pareek, 2006)
WiMAX Base Station (BS)
A WiMAX base station comprises of internal devices and a WiMAX tower. A WiMAX base station can normally covers the area of about 50 kilometers or 30 miles radius, but some other and environmental issues bound the limits of Wimax range to 10 km or 6 miles. Any wireless user within the coverage area would be able to access the WiMAX services (Fig: 2). The WiMAX base stations would use the media access control layer defines in the standard and would allocate uplink and downlink bandwidth to subscribers according to their requirements on real time basis. (Deepak Pareek, 2006)
WiMAX Receiver (WiMAX CPE)
A WiMAX receiver, which is also referred as Customer Premise Equipment (WiMAX CPE), may have a separate antenna or could be a stand-alone box or a PCMCIA card that inserted in a laptop or a desktop computer. Access to a WiMAX base station is similar to accessing a wireless access point (AP) in a Wi-Fi network, but the coverage is more.
So far one of the biggest restrictions to the widespread acceptance of WiMAX has been the cost of Wimax CPE (Wimax Receiver). This is not only the cost of Wimax CPE (Wimax Receiver) itself, but also that of installation. In the past, Broadband Wireless Access (BWA) have been predominantly Line Of Sight (LOS), requiring highly skilled labour and a truck role to install and provide a service to customer. The concept of a self-installed WiMAX CPE (WiMAX Receiver) has been difficult for BWA from the beginning, but with the advent of Wimax technology this issue seems to be getting resolved. (Xiaole Song, 2007)
WiMAX backhaul is actually a connection system from the Access Point (AP) back to the provider and to the connection from the provider to the network. A backhaul can set out any technology and media provided; it connects the system to the backbone. In most of the Wimax deployments circumstances, it is also possible to connect several wimax base stations with one another by use of high speed wimax backhaul microware links. This would also allow for roaming by a Wimax subscriber (Wimax Receiver) from one wimax base station coverage area to another, similar to roaming enabled by cellular phone companies. (Xiaole Song, 2007)