The increasing demands for high-data rate traffic stimulated the development of the fifth-generation (5G) mobile networks. The envisioned 5G network is expected to meet its challenge by devising means to further improve spectrum usage. Many alternatives to enhance spectrum usage are being researched, such as massive MIMO, operation in mmWave frequency, cognitive radio, and the employment of full-duplex antennas. Efficient utilization of the potential of any of these technologies faces a set of challenges related to medium access control (MAC) schemes. This work focuses on MAC schemes tailored for full-duplex antennas, since they are expected to play a major role in the foreseeable 5G networks. In this context, this paper presents a MAC layer technique to improve total transmission time when full-duplex antennas are employed. Several evaluations in different scenarios are conducted to assess the proposed MAC scheme. Numerical results show that the proposed scheme provides gains up to 156% when compared to a state-of-the-art full-duplex antenna MAC protocol. Compared to traditional half-duplex antenna MAC protocols, the proposed scheme yields gain up to 412%.
The use of directional antennas in support of ad hoc networks has been considered a promising alternative to improve spatial division multiple access and throughput. In general, directional Medium Access Control (MAC) protocols are based on IEEE 802.11 standard, which was designed for omnidirectional communication. When applied to di- rectional communication, the standard imposes a number of constraints to the directional MAC protocol. In order to harvest the benefits of directional communications, MAC pro- tocols tailored for directional antennas have to be devised. In particular, MAC protocols that are able to deal with deafness and channel reservation latency are highly desirable. This work proposes a technique that enables channel reservation and mitigates deafness using pulse/tone signals in the context of directional communications. At its heart, the proposed technique incorporates a deafness predictions scheme that helps nodes to over- come its effects. Analytical results show that the proposed technique is able to improve throughput up to 40% when compared to other prominent directional MAC protocols. Simulation results show that the proposed scheme improves fairness and throughput up to 350% and 76%, respectively.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.