M2M Massive Access in LTE: RACH Performance Evaluation in a Smart City Scenario

TL;DR

This paper enhances an LTE network simulator to better evaluate RACH performance under massive simultaneous access typical in IoT and Smart City scenarios, revealing potential issues with current procedures.

Contribution

It introduces a detailed patch for the ns-3 LTE module to improve simulation accuracy of RACH performance during massive access attempts.

Findings

Improved simulation accuracy of LTE RACH in ns-3

Identification of issues in LTE RACH under massive access

Comparison showing differences between default and patched simulations

Abstract

Several studies assert that the random access procedure of the Long Term Evolution (LTE) cellular standard may not be effective whenever a massive number of simultaneous connection attempts are performed by terminals, as may happen in a typical Internet of Things or Smart City scenario. Nevertheless, simulation studies in real deployment scenarios are missing because many system-level simulators do not implement the LTE random access procedure in detail. In this paper, we propose a patch for the LTE module of ns-3, one of the most prominent open-source network simulators, to improve the accuracy of the routine that simulates the LTE Random Access Channel (RACH). The patched version of the random access procedure is compared with the default one and the issues arising from massive simultaneous access from mobile terminals in LTE are assessed via a simulation campaign.