| 摘要 |
A link provides multiplexed channels by means of a sequence of N potentially available slots 38, Fig 2, but each scan of the multiplex including only those slots active in the service of established channels, Fig 3; the slots being preceded by data bytes (deltas) which indicate how many slots are absent preceding the next following active slot, a processor at a switching node receiving such a multiplex using the absent slot data to step through microcode instructions to proceed to a next slot as many times as there are slots absent before the next active slot. By this means the processor identifies the channels corresponding to the active slots and steers incoming data to buffer stores allocated to each channel. Data transmission rate may be increased by increasing the number of bytes in each slot and, in assembling data from the buffer stores for transmission over such a multiplex, data rate may be reduced by employing a six-bit mask so that in each successive sequence of six multiplex cycles the particular slot active for a channel appears in only that one or more marked cycles. <IMAGE> |
