Comparison of the ways to reduce energy costs in stable massive machine-type communication systems

Информационно-управляющие системы. 2023. Vol. 2. P. 39–50.

Бурков А. А.

Introduction: With the development of modern communication standards, various scenarios of the Internet of things, including massive machine-type communication, are actively considered. The main requirements for such systems are a stable operation with a potentially infinite number of devices and low energy costs. Therefore, it is an urgent task to study different ways to achieve these requirements. Purpose:To explore and compare the effectiveness of different approaches to reducing energy costsin systems with a potentially unlimited number of user devices. Results: We describe a basic system model based on an ALOHA-type algorithm for the scenario of massive machine-type communication in a channel with additive white Gaussian noise. We focus on the two ways to reduce energy consumption for the system under consideration. The first way is to use hybrid automatic repeat request methods. The second way is to use a conflict resolution algorithm with a dynamic schedule. For the basic system and the proposed methods, we carry out an analysis of the lower bounds for the signal power and costs energy-per-bit under the condition of the stable operation of the system and specified requirements for spectral efficiency. It is shown that both methods make it possible to reduce energy costs compared to the basic system. At the same time, the dynamic scheduling algorithm allows to most effectively reduce the signal power from 4.5 dB at any spectral efficiency. For energy costs per bit at spectral efficiency values less than 0.42 bit/s/Hz, hybrid automatic repeat request is most effective. However, for large values, the greatest gain comes from changing the conflict resolution algorithm. Practical relevance: The results obtained allow us to evaluate the potential of reducingenergy costsin stable systems with a large number of user devices through the use of hybrid automatic repeat request and a conflict resolution algorithm with a dynamic schedule.

Keywords: energy efficiency, Internet of Things, massive machine-type communication, hybrid automatic repeat request, random multiple access algorithms, spectral efficiency