Public safety users’ priority-based energy and time-efficient device discovery scheme with contention resolution for ProSe in third generation partnership project long-term evolution-advanced systems

A device-to-device (D2D) discovery scheme is key enabler for proximity-based services in third generation partnership project long-term evolution-advanced systems for public safety (PS) and general LTE scenarios. The deployment of D2D networks results in severe co-channel interference between conventional cellular users and D2D users, and faces proximity interference management challenges because of the co-existence of multiple D2D users. We propose a time and energy-efficient contention-resolving device discovery resource allocation (TEECR-DDRA) scheme that has the capability to enhance the success ratio for discovery of D2D users by reducing collisions among users. Moreover, the proposed TEECR-DDRA scheme has the ability to prioritise PS users to meet their QoS and latency requirements. Furthermore, multi-channel slotted ALOHA with energy sensing can be used to increase the probability of successful discovery of non-PS users. This ability helps to reduce the discovery time of PS users under disaster scenarios, and also reduces the energy consumption of non-PS users by minimising the number of beacon retransmissions. System-level simulations show that the proposed TEECR-DDRA scheme performs remarkably well under D2D network. Compared with the conventional random access scheme, the proposed scheme almost doubles the discovery range and significantly improves the success ratio for discovery of D2D users.