Congestion dispersion in device-to-device discovery for proximity-based services

Proximity service (ProSe) enables the development of various applications that exploit proximity of the mobile devices. In ProSe, devices are expected to communicate with each other on device-to-device (D2D) links and make use of proximity information for the provision of a variety of services. An essential functionality in ProSe is the ability of a device to identify its neighbors. This process is referred to as D2D discovery. This paper investigates distributed D2D discovery based on greedy resource selection. In order to facilitate rapid and efficient distributed D2D discovery, we propose group-based peer discovery resource selection range restriction (GPSRR) scheme. GPSRR scheme disperses the devices concentrated at a certain discovery resource over multiple resources. This is done by limiting the resource selection of a device to a specified group of resources. We also propose group reselection (GR) scheme to resolve the unbalance of congestion among different groups of resources. Simulation results show that the proposed schemes can improve the speed of discovery and the number of discovered devices, especially in densely populated environments.