Patent ID: 6744697
Filing Date: 2004-06-01
Classification: H04J,H04N

Abstract:
A method of synchronizing the local clock in a cable modem (CM) to a remote clock at a cable modem termination system (CMTS), based on said CM's receipt of SYNC packets sent at intervals by said CMTS, each of said SYNC packets having an embedded time value, the method comprising:a) hardware scanning for the arrival of a new MPEG frame, until said new MPEG frame arrives; b) processing to determine if said new MPEG frame contains one of said SYNC packets; c) if one of said SYNC packets is not found in said new MPEG frame, returning to said hardware scanning operation; d) if one of said SYNC packets is found in said new MPEG frame, then i. evaluating the time skew between said SYNC time value and said receipt of said SYNC packet found in said new MPEG frame; ii. adjusting the local clock based on said time skew; and iii. after said adjusting operation, returning to said hardware scanning operation.