A facility
transport system for transporting high speed
Ethernet data over digital subscriber lines. The
system, referred to as 100BaseS, is capable of transmitting 100 Mbps
Ethernet over existing
copper infrastructure up to distances of approximately 400 meters. The
system achieves bit rates from 25 to 100 Mbps in increments of 25 Mbps with each 25 Mbps increment utilizing a separate
copper wire pair. Each pair used provides a bidirectional 25 Mbps link with four
copper wire pair connections providing 4×25 Mbps downstream channels and 4×25 Mbps upstream channels. The
system utilizes framing circuitry to adapt the 100BaseT input
data signal to up to four separate output signals. A DSL
Ethernet Port card couples the modem to each
twisted pair used. Each DSL Ethernet Port card comprises modem
transmitter and
receiver circuitry for sending and receiving 100BaseS signals onto
twisted pair wires. The system utilizes
QAM in combination with
frequency division multiplexing (FDM) to separate downstream channels from upstream channels and to separate both the downstream and the upstream channels from POTS and ISDN signals.