The wireless local loop

In telephony, the loop is defined as the circuit connecting a subscriber's station (e.g., telephone set) with the line terminating equipment in a central office (a switch in the telephone network). The trunks start from the central office in the loop; they break down into several smaller bundles of circuits after moving away from the central office. These circuits are eventually separated into individual drops for the residential homes. The cost of the loop tends to be dominated by the residential side. (It is typically referred to as the "expensive last km"). This statement is particularly true for rural areas. The International Telecommunications Union's (ITU) projection indicates that 150 million new telephone lines will need to be installed in developing countries by the year 2000. As a result, telecommunication operators are looking to wireless technology to replace part of the hard-wire infrastructure. Wireless local loop (WLL) technology is being considered because the radio systems can be rapidly developed, easily extended and are distance insensitive. The WLL eliminates the wires, poles and ducts essential for a wired network.