DARA: A Delay-Aware Random Access for Slot Assignment in Long-Distance Wireless Networks

Propagation delay has an important impact on system performance in long-distance wireless networks. While there is not much attention paid to taking the advantage of the differential propagation delays. In this paper, we propose a cross-layer delay-aware random access (DARA) for applying for time slots to transmit data in long-distance wireless networks. Based on Irregular Repetition Slotted ALOHA (IRSA), DARA takes propagation delay into consideration and makes a better time slot selection strategy. Simulation results show that DARA could achieve 30% improvement at most compared to IRSA in respect to the rate of successful decoding. Meanwhile, we try to optimize the rate of successful decoding with minimal cost, but find it is hard to formulate the relationship among the number of mobile hosts M, the number of slots N and the rate of successful decoding. At last, curve-fitting is utilized to get an approximative result.