Neighbor-aware multiple access protocol for 5G mMTC applications

In order to support massive Machine Type Communication (mMTC) applications in future Fifth Generation (5G) systems, a key technical challenge is to design a highly effective multiple access protocol for massive connection requests and huge traffic load from all kinds of smart devices, e.g. bike, watch, phone, ring, glasses, shoes, etc. To solve this hard problem in distributed scenarios with massive competing devices, this paper proposes and evaluates a Neighbor-Aware Multiple Access (NAMA) protocol, which is scalable and adaptive to different connectivity size and traffic load. By exploiting acknowledgement signals broadcasted from the neighboring devices with successful packet transmissions, NAMA is able to turn itself from a contention-based random access protocol to become a contention-free deterministic access protocol with particular transmission schedules for all neighboring devices after a short transition period. The performance of NAMA is fully evaluated from random state to deterministic state through extensive computer simulations under different network sizes and Contention Window (CW) settings. Compared with traditional IEEE 802.11 Distributed Coordination Function (DCF), for a crowded network with 50 devices, NAMA can greatly improve system throughput and energy efficiency by more than 110% and 210%, respectively, while reducing average access delay by 53% in the deterministic state.