Time domain duplex between CMTS and cable modems

摘要

A time domain duplex cable system includes a mechanism to change the communication direction of spectrum used in a cable plant including a Cable Modem Termination System (CMTS), a Fiber Node and a plurality of cable modems in communication with the CMTS via the Fiber Node. Active devices, e.g., directional amplifiers switch the communication direction of the cable plant in response to timing information received from the CMTS. To avoid collisions of downstream and upstream packets, a guard time is determined and used in connection with generating the timing information. In one embodiment, the timing information is transmitted in one or more Data Over Cable Service Interface Specifications (DOCSIS) Media Access Protocol (MAP) messages transmitted by the CMTS towards the cable modems.

主权项

1. A method comprising:
controlling, based on information received from a Cable Modem Termination System, an active directional device, which is in communication with a plurality of cable modems, to be oriented for downstream communication from the Cable Modem Termination System to the cable modems, for a first predetermined amount of time; and controlling, based on the information received from the Cable Modem Termination System, the active directional device to be oriented for upstream communication from the cable modems to the Cable Modem Termination System over a same bandwidth as the downstream communication, for a second predetermined amount of time, after the first predetermined period of time.