Performance Analysis of Connection Establishment Procedure Under Beamforming in 5G NR Networks

Abstract

High demand for reliability, low latency, seamless connectivity lead to the 5 G era. 5 G cellular networks employ a random access based preamble transmission procedure for the initial locking of User Equipment (UEs) to a base station (gNB) and uplink resource scheduling. It is of utmost importance that we evaluate the factors that aid and those that limit the random access procedure in achieving its envisaged goal. In this paper, we develop an analytical model for random access procedure for connection establishment in 5 G when beamforming is employed. The random access medium is modelled as a multi-channel slotted Aloha system. We use an equilibrium point analysis framework to derive the performance metrics namely, the rate at which UEs can lock on to a gNB and the average and variance of the time taken by a new UE to establish connection with the base station. We analyse the impact of the retransmission limit and the number of available preambles for random access on the performance of connection establishment of a UE. Our analysis brings out the importance of the choice of base station configurations with respect to the user demographics of a 5 G NR cell.