Method and apparatus for synchronization in D2D communication network

A method for synchronization source negotiation by an independent synchronization source included in a device to device (D2D) communication network, the method comprising:

• determining, when a D2D synchronization signal and a D2D synchronization channel are received from at least one D2D synchronization source, whether to maintain a role as the independent synchronization source based on negotiation information for negotiation between synchronization sources included in the D2D synchronization channel;
• and
• operating as a relaying synchronization source when the role as the independent synchronization source is not maintained;
• wherein the negotiation information includes a time stamp indicating a period when the independent synchronization source operates as the independent synchronization source, and the determining includes:
• comparing the time stamp indicating the period when the independent synchronization source operates as the independent synchronization source, and a time stamp of at least one D2D synchronization source;
• and
• determining whether to maintain the role as the independent synchronization source based on a comparison result.