Patent ID: 8660111

Claim:
A method for enabling a radio operating in a direct mode to track channel timing (CT) and support channel scanning, comprising: determining, by a non-leading radio operating on a communications channel, a diffusion period during which channel timing is to be propagated from a leading radio to non- leading radios operating on the communications channel; implementing a first scanning pattern during the diffusion period to scan a CT designated channel for a control timing message with a timing signal sent from the leading radio, by the non-leading radio, wherein first scanning pattern involves scanning the CT designated channel at alternate scan intervals and scanning non-priority channels, priority channels and optionally a user selected channel at scan intervals not used on the CT designated channel, wherein the control timing message includes a synchronization age field to indicate an elapsed period from when the leading radio last transmitted the control timing message, wherein the value of the synchronization age field is adjusted to reflect a delay in transmission of the control timing message; and scanning, by the non-leading radio outside of the diffusion period, the non-priority channels, the priority channels and optionally the CT designated channel or the user selected channel using a second scanning pattern that is different from first scanning pattern, wherein one or more non-leading radios use the timing signal to synchronize transmissions made on the communications channel.