Patent ID: 6967935

Claim:
A method for communicating between a base station and a mobile station through a designated channel, comprising the steps of: transmitting an access parameter message, including fields indicating a preamble duration and a slot duration, where the slot duration is a length of a multiple of a predetermined slot duration, from the base station to the mobile station, the base station previously knowing each start time point of each slot duration that is a multiple of the predetermined slot duration; transmitting a control message including fields indicating a designated channel number and a data rate from the base station to the mobile station over a common channel; receiving, in the mobile station, the control message and transmitting to the base station an access probe including a preamble having the preamble duration and a succeeding response message beginning at one of the start time points of the slot duration that is a multiple of the predetermined slot duration at the data rate through a designated channel associated with the designated channel number in the control message; and determining in the base station whether the preamble of the access probe is received, beginning at each of the start time points of the slot durations that is a multiple of the predetermined slot duration.