Patent ID: 7336638

Claim:
A method for maintaining uplink synchronization in P 2 P (Peer to Peer) communication performed by user equipment (UE) in wireless communication systems, comprising: (a) negotiating with a UTRAN (Universal mobile telecommunications system Terrestrial Radio Access Network) of a wireless communication network system to determine a schedule and parameters for controlling the uplink synchronization for the user equipment, during a procedure of establishing a P 2 P direct link between the UE and another UE; (b) transmitting testing signals from the UE to the UTRAN of the network system via a customized uplink channel according to the negotiated schedule and parameters, wherein the negotiated schedule and parameters include at least (i) an interval corresponding to an intermittent and regular interval for sending testing signals from the UE to the UTRAN for executing unlink synchronization estimation and control, and (ii) a number corresponding to a number of continuous traffic bursts to be included in the testing signals and used for the unlink synchronization estimation and control; (c) receiving control information transmitted via a customized downlink channel from the UTRAN of the network system according to the negotiated schedule; and (d) maintaining uplink synchronization for the user equipment with the UTRAN during P 2 P communication of the UE with the another UE, according to the control information; wherein the customized uplink channel and downlink channel are channels between the user equipment and the UTRAN of the network system allotted to the user equipment by the UTRAN of the network system and used intermittently to control and maintain unlink synchronization of the UE with the UTRAN during the P 2 P communication of the UE with the another UE.