A novel random access scheme for stationary machine‐type communication devices

Abstract

The long term evolution (LTE) cellular network, primitively designed for human-to-human communications, is attracting more and more attention in machine-to-machine communication scenarios. However, when a massive number of machine-type communication (MTC) devices require access to the network simultaneously, the existing random access mechanism in LTE networks will inevitably suffer from severe congestion. In order to address this problem for stationary MTC devices, the authors propose a novel random access scheme. In the proposed scheme, an alleviating-collision based timing-advance selection (ACT A S) algorithm is designed where, aided by a special preamble placement method, the eNodeB (eNB) can estimate the number of contenders with different timing advance (T A ) indices. According to the estimated results, the eNB can choose the T A index to be contained in the random access response information. In addition, they further analyse the number of MTC devices which could successfully access the network in each random access slot. The simulation results prove the accuracy of the throughput analysis as well as the remarkable performance of the proposed random access scheme in terms of the number of required slots to serve all the devices.