Patent ID: 7574224

Claim:
A method of operating a communications device for use in a communications system where beacon time slots occur on a periodic basis, a beacon signal being transmitted by a base station during each beacon time slot according to a periodic downlink timing structure, said downlink timing structure including a plurality of superslots within each beacon slot, the individual superslots within a beacon slot being identifiable through the use of a superslot index, each superslot including a plurality of symbol transmission time periods, the method comprising: receiving at least one beacon signal; processing the received beacon signal to determine a downlink timing reference point, superslots occurring within a beacon slot having a predetermined relationship to the determined downlink timing reference point; transmitting a first access probe at a time corresponding to a first timing offset relative to the start of a super slot in a beacon slot; transmitting a second access probe at a time corresponding to a second timing offset relative to the start of a super slot, said second access probe being transmitted at a point in time, which is less than the longer of i) twice the time required for a transmitted signal to travel from the communications device to the base station and ii) the duration of a superslot, from the point in time at which the first access probe was transmitted; monitoring to determine if a response to one of the transmitted access probes was received from the base station; and if it is determined that a response was received from the base station, performing a transmission timing adjustment as a function of information included in said response.