초록 ▼

In a dynamic frame length slotted ALOHA system the synchronizing signals are transmitted by a base station at different frequencies (each having a period equivalent to a multiple of the time slot period). The different frequencies denote different frame lengths and the central stations detect these

In a dynamic frame length slotted ALOHA system the synchronizing signals are transmitted by a base station at different frequencies (each having a period equivalent to a multiple of the time slot period). The different frequencies denote different frame lengths and the central stations detect these frequencies and select a frame length accordingly.

대표청구항 ▼

A communication system comprising: a central station (1) having means (5,3) for transmitting synchronizing signals each defining the beginning of a time slot and means (4) for selecting the intervals between synchronising signals from different integral multiples of a time slot and for providing to

A communication system comprising: a central station (1) having means (5,3) for transmitting synchronizing signals each defining the beginning of a time slot and means (4) for selecting the intervals between synchronising signals from different integral multiples of a time slot and for providing to said transmitting means signals corresponding to said intervals; and a number of sub-stations (6,61) each having means (10,11,12) which is responsive to the timing of the synchronising signals and which is operative to transmit a message in a time slot selected from a number of time slots together forming a frame, the duration of said frame being determined by said synchronizing signals.