Patent ID: 6603747
Filing Date: 2003-08-05
Classification: H04B

Abstract:
A communication control method in which plural slave stations transmit data to a master station through a transmission channel of a time division multiple access system, said master station transmits data to said slave stations in a broadcast mode, said master station assigns a time slot to a time slot assignment request transmitted from each of said slave stations to said master station, and each of said slave stations performs the communication by using the time slot assigned thereto, the method comprising:an initial priority level assigning step for securing time slots for each priority level, said initial priority level assigning step being executed by said master station; a priority level assigning step for assigning, in accordance with the emergency level of a communication, a priority level to a time slot assignment request to be transmitted from each of said slave stations to said master station, said priority level assigning step being executed by each of said slave stations; a priority level judging step for judging the priority level assigned to the time slot assignment request when said master station receives the time slot assignment request to which the priority level is assigned in said priority level assigning steps, said priority level judging step being executed by said master station; a time slot assigning step for assigning to the time slot assignment request a time slot having the same priority level as the time slot assignment request when there is at least one time slot having the same priority level as the time slot assignment request, and alternatively assigning to the time slot assignment request a time slot having a priority level which is lower than the priority level of the time slot assignment request when there is no time slot having the same priority level as the time slot assignment request, and there is at least one time slot having a priority level which is lower than the priority level of the time slot assignment request, said time slot assigning step being executed by said master station; an assignment request accumulating step for accumulating time slot assignment request in a queue if there is at least one time slot assignment request accumulated in a queue for every priority level, said assignment request accumulating step being executed by said master station; and a time slot number changing step for increasing the number of time slots having a given priority level when the number of accumulated time slot assignment requests of that priority level exceeds a predetermined number, while decreasing the number of time slots having the other priorities in compensation for the increase, said time slot number increasing step being executed by said master station, wherein said time slot assignment step is executed for a new time slot assignment request if there is no past time slot assignment request which has been accumulated in a queue for every priority level, and wherein accumulation of a time slot assignment request in the queue is executed if the time slot having the same priority level as the time slot assignment request is occupied and the time slot having a priority level which is lower than the priority level of the time slot assignment request is also occupied in said time slot assignment step.