LINE ASSIGNMENT CONTROL SYSTEM

PURPOSE:To considerably improve a line use efficiency with a circuit constitution equivalent to the conventional constitution by rearranging calls in the busy state of a slave station, which uses a carrier having no idle time slots, on another carrier having idle time slots. CONSTITUTION:If a new call originates from a slave station but there are no idle time slots on a carrier 2, calls of a slave station 3 using three time slots one smaller than four idle time slots of a carrier 3 whose number of idle time slots is largest are rearranged on idle time slots of the carrier 3 in the next period frame as shown in a figure (b) to generate idle time slots on the carrier 2. The call originating from the slave station 5 is assigned to one of idle time slots generated on the carrier 2 as shown in a figure (c). Thus, the call loss is prevented to improve the line use efficiency even if a call originates from the slave station using the carrier which has no idle time slots.