US 10,560,908 B2
System and method for device-to-device synchronization
Philippe Sartori, Plainfield, IL (US); Deping Liu, Schaumburg, IL (US); Brian Classon, Palatine, IL (US); and Qiang Li, Beijing (CN)
Assigned to Futurewei Technologies, Inc., Plano, TX (US)
Filed by Futurewei Technologies, Inc., Plano, TX (US)
Filed on Oct. 31, 2014, as Appl. No. 14/530,269.
Claims priority of provisional application 61/898,194, filed on Oct. 31, 2013.
Prior Publication US 2015/0117375 A1, Apr. 30, 2015
Int. Cl. H04W 72/04 (2009.01); H04W 56/00 (2009.01)
CPC H04W 56/001 (2013.01) 28 Claims
OG exemplary drawing
 
1. A method, comprising:
sending, by a base station, a radio resource control (RRC) signal to a first user equipment (UE), the RRC signal instructing the first UE to transmit a first device-to-device synchronization signal (D2DSS) over a synchronization communication resource when the first UE is in a radio resource control connected (RRC_CONNECTED) state with the base station;
receiving, by the base station, a request to become a synchronization source from a second UE after sending the RRC signal to the first UE; and
determining that the second UE does not satisfy at least one criterion for becoming the synchronization source, and based thereon sending a denial message to the second UE.