Concept Design of QoS Oriented MAC for 5G Spectrum Access Systems in 3.5 GHz

The federal communications commission (FCC) has addressed a three-tiered spectrum access system (SAS) in the so-called innovation band (3.5 GHz) which includes priority access licenses (PAL) an unlicensed spectrum access as general authorized access (GAA). Hence, the issue of finding a scheme that achieves an optimal spectrum access with quality-of-service (QoS) requirements among the citizens broadband radio service devices (CBSDs) and their nodes in term of maximizing the throughput is addressed. In this paper we present the design and results of a hybrid medium access control (HMAC) scheme for SAS based on a grouping approach using the distributed IEEE 802.11 enhanced distributed coordination function (EDCF) and the point coordination function (PCF) in respect to maximize the system throughput of the GAA users in an unlicensed spectrum. The system improvement shows how the HMAC scheme can be used in a minimum intrusive way to enhance the system throughput compared with the EDCF and PCF (SoA) scheme, especially in the case of overlapping basic service sets (BSS). Moreover, the suggested scheme is able to handle a large number of QoS accessing nodes which opens a new perspective for high connection density in a SAS context and beyond 5G.