Survey on Symbiotic Radio: A Paradigm Shift in Spectrum Sharing and Coexistence

TL;DR

This survey explores symbiotic radio (SRad) as an innovative paradigm for spectrum sharing and coexistence, especially for IoT devices, highlighting its potential to enhance spectrum efficiency and enable dependent coexistence.

Contribution

It provides a comprehensive overview of SRad, including its background, role in spectrum sharing, and future research directions, which is a novel synthesis in this emerging field.

Findings

SRad enables dependent coexistence between radio systems.

It leverages passive radio systems for spectrum sharing.

SRad has potential applications in IoT connectivity and green communications.

Abstract

Sixth-generation (6G) of mobile communication aims to connect this world digitally through green communication networks that provide secure, ubiquitous, and unlimited connectivity in an attempt to improve the overall quality of life.The driving force behind the development of these networks is the rapid evolution of Internet-of-Things (IoT), which has stimulated the proliferation of wireless applications in health,education, agriculture, utilities, etc. However, these applications are accompanied by the deployment of a massive number of IoT devices that require a significant radio spectrum for wireless connectivity. IoT devices usually have low data rate requirements and limited power provision but desirably a long life.Recently, the development of passive radio systems has opened new paradigms of spectrum sharing and coexistence. These systems utilize the radio resources and infrastructure of the active radio systems to perform their functionalities. By enabling the dependent coexistence, a new technology named symbiotic radio (SRad) enables the symbiotic relationships between the different radio systems ranging from mutual benefits or competition in terms of sharing the resources, in particular for IoT devices. This survey first provides the motivation for dependent coexistence and background of spectrum sharing through coexistence along with existing literature. Then, it describes the active and passive radio systems definition and a brief overview. Afterward, the history of symbiosis and the role of SRad technology in spectrum sharing and coexistence are defined while focusing on symbiotic communication. Lastly, we discuss research challenges, future directions, and applications scenarios.