Angle-Based Interference-Aware Routing Algorithm for Multicast over Wireless D2D Networks

Wireless device-to-device(D2D)communications sharing thespectrum of cellular networks is important for improving spec-trum efficiency.Furthermore,introducing multicast and multi-hop communications to D2D networks can expand D2D ser-vice functions.In this paper,we propose an angle-based inter-ference-aware routing algorithm for D2D multicast communica-tions.This algorithm reuses the uplink cellular spectrum.Ourproposed algorithm aims to reduce the outage probability andminimize the average hop count over all multicast destina-tions(i.e.,multicast receivers),while limiting interference tocellular users to a tolerable level.In particular,our algorithmintegrates two design principles for hop-by-hop route selec-tion.First,we minimize the distance ratio of the candidate-to-destination link to the candidate-to-base-station link,suchthat the selected route advances closer to a subset of multi-cast receivers.Second,we design the angle-threshold basedmerging strategy to divide multicast receivers into subsetswith geographically close destinations.By applying the twoprinciples for selection of each hop and further deriving anadaptive power-allocation strategy,the message can be moreefficiently delivered to destinations with fewer branches whenconstructing the multicast tree.This means fewer duplicateddata transmissions.Analyses and simulations are presented toshow the impact of system parameters on the routing perfor-mances.Simulation results also demonstrate the superiority ofour algorithm over baseline schemes in terms of outage proba-bility and average hop count.