Channel Access Methods for RF-Powered IoT Networks: A Survey

TL;DR

This survey reviews channel access protocols for RF-powered IoT networks, focusing on contention-based and contention-free methods involving dedicated energy sources, and discusses challenges, comparisons, and future research directions.

Contribution

It provides the first comprehensive review of RF-energy source-based channel access protocols in IoT, covering various methods and highlighting research gaps.

Findings

Analyzes protocols based on Aloha, CSMA, polling, and TDMA.

Identifies key challenges and issues in RF-powered IoT networks.

Suggests future research directions for improving channel access.

Abstract

Many Internet of Things (IoT) networks with Radio Frequency (RF) powered devices operate over a shared medium. They thus require a channel access protocol. Unlike conventional networks where devices have unlimited energy, in an RF-powered IoT network, devices must first harvest RF energy in order to transmit or/and receive data. To this end, this survey presents the {\em first} comprehensive review of prior works that employ contention-based and contention-free protocols in IoT networks with one or more {\em dedicated} energy sources. Specifically, these protocols work in conjunction with RF-energy sources to deliver energy delivery or/and data. In this respect, this survey covers protocols based on Aloha, Carrier Sense Multiple Access (CSMA), polling, and dynamic Time Division Multiple Access (TDMA). Further, it covers successive interference cancellation protocols. It highlights key issues and challenges addressed by prior works, and provides a qualitative comparison of these works. Lastly, it identifies gaps in the literature and presents a list of future research directions.