Patent ID: 6959013
Filing Date: 2005-10-25
Classification: H04J,H04W,Y02D

Abstract:
1. A transmitter for transmitting an intermittent sequence of messages to maintain synchronization between the transmitter and at least one receiver, comprising: control means arranged to provide messages for transmission, each of said messages forming part of said sequence of messages and comprising control information for effecting synchronization, including timing information, wherein said timing information is dependent upon when the transmission of a following message in the sequence occurs; and transmission means, responsive to said control means, for transmitting each of said messages, wherein said sequence of messages comprises a sequence of groups of messages each of said groups of messages comprising a plurality of messages in series, wherein said following message is a message in a following group, wherein said following group is the next group, and wherein said control means is arranged to vary the time between the transmission of a pair of successive groups of messages by an amount such that there is coincidence between the time of transmission of a message in the following group of the pair and the expected time of transmission, in the absence of a variation, of a message in the following group.