Multiplex space switch

The space switch has an inlet series to parallel converter (1) arranged to take sequential data from the i-th time slot of each of a plurality of synchronized inlet multiplexes and apply them simultaneously to a parallel connection (11) within one time slot period. These time slots are written into one of two signal stores (2 and 3), e.g. sequentially. A control store (4) controls the order in which data is read from the signal store and re-assembled into outlet multiplexes by a parallel to series converter (5), thereby performing space switching between the stored time slots. The signal stores alternate between reading and writing, and each has a capacity equal to the product of the number (p) of inlet multiplexes (E1, . . . Ep) multiplied by a submultiple of the number of time slots to a frame. When the submultiple is greater than 1 there is a possibility of limited time switching within a sector of successive time slots, the number of time slots in each sector being equal to the submultiple.