Switch and MAC layer components are located at a headend and PHY layer
components for connecting a plurality of end-user devices are located
remotely at nodes. Using SSMII technology, MAC layer ports can
communicate with an equal number of PHY layer interface ports serially.
Thus, the MAC layer connects to the PHY layer via fiber links, a separate
link being used for each direction of traffic data flow.Information data
is encoded along with a frame sync signal and a clock signal into a
serial stream for transmission across the network. The serial stream is
decoded at the other end, and the frame sync signal is extracted to
provided timing functionality. This allows full duplex operation with the
MAC layer separated from the PHY layer at distances greater than a few
inches. Also, user device status may be monitored at the single switch
location.