Optical network system and method for supporting upstream signals propagated according to a cable modem protocol
View Patent ↗A modification to a cable modem termination system (CMTS) can include instructing the CMTS to ignore or skip steps of its timing algorithm so that upstream cable modem signals are controlled only by the upstream protocol of the optical network system. According to another exemplary aspect, a time stamp can be added to the upstream cable modem signals so that the CTMS timing scheme can be used. This time stamp can be used in the data service hub to adjust for the delays that occur while the upstream cable modem signals are sent across the optical network. Another adjustment of the CMTS timing scheme can include using less than a total number of miniature time slots for upstream cable modem transmissions. According to another exemplary aspect, a cable modem termination system can be positioned within a laser transceiver node or a subscriber optical interface.
1. A method for supporting upstream signals propagated according to a cable modem protocol sent over an optical network comprising:
receiving the upstream signals;
monitoring a downstream time synchronization produced by the cable modem protocol;
adding a time stamp to the upstream signals with a time stamp device which is independent of the cable modem protocol and the stamp not being processed by the cable modem protocol but based on the downstream time synchronization, the time stamp compensating for propagation delays caused by digital switching in the optical network;
converting the upstream signals into the optical domain for propagation through the optical network; and
sending the upstream optical signals over the optical network to a cable modem termination system operating according to the cable modem protocol.
2. The method of claim 1 , wherein monitoring a downstream time synchronization comprises monitoring a media access control management message sent by a cable modem termination system.
3. The method of claim 1 , wherein monitoring a downstream time synchronization comprises monitoring a time message produced by a circuit that is independent of a cable modem termination system.
4. The method of claim 1 , further comprising holding the upstream signals for a predetermined time period based on the time stamp before sending the upstream signals to the cable modem termination system.
5. The method of claim 1 , further comprising converting the upstream signals from an analog format to a digital format.
6. The method of claim 1 , further comprising reducing a size of the upstream signals.
7. The method of claim 1 , wherein the cable modem protocol comprises a Data Over Cable Service Interface Specification.
8. The method of claim 5 , further comprising reducing a size of the upstream signals.
9. The method of claim 8 , wherein the cable modem protocol comprises a Data Over Cable Service Interface Specification.
10. A method for supporting upstream signals propagated according to a cable modem protocol sent over an optical network comprising:
overriding a time synchronization routine of the cable modem protocol by ignoring unique response time intervals assigned to one or more cable modem devices with a cable modem termination system;
receiving upstream cable modem signals based on an upstream protocol of the optical network that is different from the cable modem protocol; and
processing the upstream cable modem signals with the cable modem termination system.
11. The method of claim 10 , wherein overriding a time synchronization routine of the cable modem protocol further comprises overriding a time synchronization routine of cable modem protocol comprising a Data-Over-Cable Service Interface Specification (DOCSIS).
12. The method of claim 10 , further comprising managing upstream data signals originating from devices other than cable modems with the upstream protocol of the optical network.
13. The method of claim 10 , further comprising converting upstream electrical cable modem signals into an optical domain.
14. The method of claim 12 , further comprising converting optical cable modem signals back into an electrical domain for processing by the cable modem protocol termination system.
15. The method of claim 14 , further comprising managing upstream data signals originating from devices other than cable modems with the upstream protocol of the optical network.