ETHERNET TRANSPORT FACILITY OVER DIGITAL SUBSCRIBER LINES

摘要

The present invention provides a facility transport system for transporting Ethernet over digital subscnber lines. The system, termed 10BaseS, is capable of transmitting 10 Mbps Ethernet over existing copper infrastructure. The system utilizes carrierless amplitude modulation/phase modulation (CAP), a version of suppressed carrier quadrature amplitude modulation (QAM). The 10BaseS transport facility can deliver symmetrical data at approximately 13 Mbps (net 10 Mbps) over the unscreened, twisted pair telephone wires originally intended for bandwidths between 300 Hz and 3.4 KHz. The system utilizes frequency division multiplexing (FDM) to separate downstream channels from upstream channels. FDM is also used to separate both the downstream and upstream channels from POTS signals. The downstream and upstream data channels are separated in frequency from bands used for POTS and ISDN, enabling service providers to overlay 10BaseS on existing services.