Abstract: A method of communicating different size items of information between terminals via channels of a time-division-multiplexed parallel bus (1) operating with a predetermined frame period (F) divided into a predetermined number of time slots. Each terminal transmits the whole of each of first size items in a respective separate first time slot and transmits the whole of each of second size items larger than the first size items each in a respective group of consecutive second time slots (M, M+1) in each frame. Preferably, the first time slots (N) are uniformly spaced apart so as to occur at a frequency which is multiple of the frame frequency. Preferably, the second size items are transmitted in two or more groups (M, M+1) of consecutive second time slots within each frame, said two or more groups being uniformly spaced apart.

Abstract: A packet transmission system comprising a network of one or more nodes (1) each comprising a number of inputs connected via packet switching means to a number of outputs each of which has storage means (11) associated with it in which to store a queue of packets to be outputted; characterized in that each node (1) is provided with timer means (14) to measure the time each packet spends in a queue of said storage means (11); and stamping means (12) to add to a time stamp field (TS) of each packet before it is outputted from the node, the time the packet has spent in a queue as measured by the timer means (14).