| 摘要 |
The distribution service centre (70) supplies multimedia services to a number of peripheral hubs (20) each linked to an ATM exchange (10), a narrowband network interface (17) and a variety of optical broadband network termination units (60, 65). The hub contains an ATM switch matrix (21), a narrowband multiplexer (22) and several optical line termination units (23). The 64 kbit/s stream of ATM cells is modulated with others in synchronous TDM on a carrier for transmission to the hub, where it is demodulated, buffer-stored and multiplexed together with streams from other subscribers into an aggregate stream of conventional capacity. |
