Patent ID: 6260193
Filing Date: 2001-07-10
Classification: H04N

Abstract:
A method for synchronizing a decoder in a communication network to allow upstream transmission of a message from said decoder to a headend of said communication network in a time slot, wherein said decoder is adapted to receive a television signal via said communication network, comprising the steps of:providing a network sync signal having a network sync reference point at said headend;providing a delay value at said headend such that a start time of said time slot follows said network sync reference point by said delay value;determining a first horizontal scan line of said television signal at said headend that corresponds to said network sync reference point;using said delay value and said first horizontal scan line to determine a particular horizontal scan line of said television signal at said headend that corresponds to said start time;encoding identifying data which identifies said particular horizontal scan line; andinserting said identifying data into a blanking interval of said television signal.