Patent ID: 8036145

Claim:
A wireless communication system comprising a base station and a plurality of fixed or mobile subscriber stations, the base station maintaining connections with each of the subscriber stations by performing wireless communication in units of frames, and within each frame, allocating resources for data transmissions and signalling in the wireless communication system, said frames being divided timewise into downlink subframes for transmissions from the base station to the subscriber stations, and uplink subframes for transmissions from the subscriber stations to the base station; characterized in that each frame has a plurality of downlink subframes and a plurality of uplink subframes including, in time order, a first downlink subframe, a first uplink subframe, a final downlink subframe and a final uplink subframe, and in that the subscriber stations comprise first type subscriber stations and second type subscriber stations, the base station allocating downlink resources to the first type subscriber stations only within the first downlink subframe, said wireless communication system being in the form of a TDD OFDMA wireless communication system operable in accordance with a plurality of communication standards, the first type subscriber stations being compliant with a first such standard and the second type subscriber stations being compliant with a second such standard which is a development of the first standard, wherein said first standard assumes frames of predetermined length with a single downlink subframe and a single uplink subframe, and the base station is arranged to configure the frame such that the timing of said plurality of downlink subframes and uplink subframes allows the frame to be compatible with said first standard whilst including at least one downlink subframe and uplink subframe reserved for use by the second-type subscriber stations, wherein the base station is operable to vary the number of downlink subframes and uplink subframes dynamically during operation of the wireless communication system, wherein the base station is responsive to the relative number of first type and second type subscriber stations when varying the number of downlink subframes and uplink subframes.