| 摘要 |
Transmission in asynchronous mode for multiservice networks with a wide bit rate range means that digital data is transported in standardised ATM cells featuring a header and a payload of fixed length. For low bit rate services penalised as far as transmission efficiency is concerned on network routes, the process, whilst effecting all switching and all transmissions on cells in standardised format, multiplexes and demultiplexes microcells from different communications thus avoiding the transmission of partially filled standardised cells, and permitting standardised ATM networks to be transited without these networks recognising these microcells. The cells from various sources may comprise completely filled cells C 0 which are transmitted unchanged, cells with a single microcell C 1 or cells with more than one microcell C 2 . The last named are demultiplexed to single microcell packets according to defined rules 3 and as far possible reassembled into full packets for transmission. This process restricts the amount of empty packet structure, thus optimising transmission capacity. |
