Modeling and Analysis of Irregular Repetition Slotted ALOHA in Multi-Cell Scenarios

Irregular repetition slotted ALOHA (IRSA) has received growing attention to alleviate random access collisions in next-generation (5G) networks. The performance of irregular repetition slotted ALOHA (IRSA) in single-cell scenarios has been analyzed extensively. However, the performance of IRSA in multi-cell scenarios remains unexplored due to stochastic base station and user distributions, irregular repetition rates and complex inter-cell interference. Motivated by this, we propose an analytical framework of the performance of IRSA in large cellular networks which takes into account user location distributions, uplink power control, fading, and inter-cell interference. Moreover, an optimization problem aimed at finding the optimal repetition degree profile to support the highest system load is proposed. We show that the optimal average repetition rate in multi-cell scenarios differs from that in single-cell scenarios.