Abstract
3rd generation partnership project (3GPP) has considered Device-to-Device (D2D) group communications as a technique for public safety (PS) to support communications in emergency situations. For the PS service, we propose a novel scheme for cluster based D2D group communication. The proposed scheme enables the UEs to form clusters by using broadcast-based information exchange and to mediate the medium access in the cluster or between clusters to communicate each other. Through the proposed scheme, UEs can communicate with UEs belong to the same cluster or the other cluster.