Full-duplex medium access control protocols in wireless networks: a survey Mahdi Dibaei 1 • Ali Ghaffari 1 Ó Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract Medium Access Control (MAC) protocol plays an important role in full-duplex wireless networks. Theoretically, full- duplex communications have this ability to increase the capacity of traditional half-duplex wireless systems by up to twice. However, designing and implementing an efficient MAC protocol is a central issue in this way. Increasing throughput, collision avoidance, and fairness are common challenges in designing an efficient full-duplex MAC protocol. After giving a short introduction to the general classification of traditional MAC protocols, IEEE 802.11 MAC protocol, and the identified challenges of full-duplex communications in wireless networks, this review paper provides a comprehensive survey of current major MAC protocols for full-duplex wireless communications and classifies them in to three categories i.e. distributed wireless local area networks, centralized wireless local area networks, and other types of networks. This paper also explores and gives a comparative analysis of current full-duplex MAC protocols with stating their advantages and disadvantages as well as comparing them one with another. Keywords Medium access control (MAC) protocol Á Full-duplex MAC protocols Á Fairness Á Inter-client interference Á Self-interference cancellation 1 Introduction The past decade has seen a rapid development of mobile devices in a wide variety of aspects. Under these circum- stances, the dramatic use of wireless devices has led to an exponential increase in the volume of wireless data traffic. For instance, Cisco forecasts the global mobile data traffic will increase to 49 exabytes per month by 2021 [1]. Therefore, the development of new technologies for pro- viding higher capacity to fulfill this urgent demand is a major issue. Full-duplex communications provide the ability to transmit and receive in a single time/frequency channel and increase the capacity of wireless networks [2]. The research to date in the field of wireless communi- cations has tended to focus on half-duplex rather than full- duplex communications. Therefore, there has been little discussion about full-duplex wireless communications. Full-duplex communications potentially improve data rates and enhance the throughput of wireless networks due to the fact that they do not need time partitioning (e.g. Wi-Fi networks) or frequency partitioning (e.g. Cellular net- works). Although full-duplex communications double the capacity of a half-duplex (HD) channel theoretically, detailed simulations and analysis indicate that this gain of full-duplex does not take place in practice [2–4]. Conventional MAC protocols cannot exploit white space efficiently for full-duplex communications. In other words, for a full-duplex wireless network, an efficient full- duplex MAC protocol is an essential requirement in order to increase the throughput of the wireless channel [5]. Collision detection or avoidance, fairness, hidden node problem, inter-client interference, and capture effect are among other issues for designing an efficient full-duplex MAC protocol. Most studies in the field of wireless communications have only focused on half-duplex MAC protocols. How- ever, some significant review papers related to the full- & Ali Ghaffari A.Ghaffari@iaut.ac.ir Mahdi Dibaei dibayimahdi@yahoo.com 1 Department of Computer Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran 123 Wireless Networks https://doi.org/10.1007/s11276-019-02242-w