Contact-duration aware broadcast in WiFi direct enabled mobile social networks
Zhifei Mao, Yuming Jiang · 2016
We present a contact-duration aware scheduling scheme for broadcast in a WiFi Direct enabled mobile social network (MSN). Due to the half-duplex nature of WiFi Direct, at one time only one node in a WiFi Direct group can transmit. In addition, the contact duration of the nodes in the group tends to be limited due to their mobility and short transmission range. These two facts together make it non-trivial to provide fairness among this group of autonomous nodes with broadcast transmission. In this paper, we first pose an allocation problem - how long should each node get to broadcast data within the limited contact duration. We then formulate this problem as a Nash bargaining game wherein the nodes bargain for a fair share of the limited transmission time. Next, the game is proved to have a unique Nash bargaining solution (NBS). In addition, a water-filling algorithm is designed to obtain the NBS. To implement the NBS, a window based scheduling approach that allows the nodes to broadcast in a round-robin way, is further proposed. The simulation results show that the bargaining based scheme provides proportional fairness among nodes in a typical case.