Performance of a modified polling strategy for broadband wireless LANs in a harsh fading environment

A radio-based communication network is considered in which a single, high-speed radio channel is shared by some plurality of small portable notebooks. Such a system has the potential to provide LAN-like service within buildings, allowing the portable notebooks to access the CPU and database resources of a wired network. In this harsh indoor fading environment, a base-station approach is used. A modified polling scheme for the indoor radio LAN channel is proposed. The base station regularly polls each remote, in response to which the remote either generates a keep alive packet or a request packet, allowing the base to fetch the requested information from the wired network and scheduling a reply to that remote. The efficiency of such a scheme is studied and the expected turn-around delay as a function of network loading is obtained. For a polling cycle of 20 ms and a network containing 10 or 50 users, for example, the maximum link efficiency is 97% and 87%, respectively