A fully-distributed directional-to-directional MAC protocol for mobile ad hoc networks

Abstract

The use of directional antennae in ad hoc networks can provide high spatial reuse of spectrum and antenna gains. However, employment of directional antennae poses great challenges such as hidden terminal and deafness problems. The existing directional medium access control (DMAC) protocols usually work in a switching mode of omnidirectional listening and directional sending, which, however, introduces high hardware complexity and asymmetry-in-gain. In this paper, we propose a new fully-distributed directional-to-directional MAC protocol (FDD-MAC) for mobile ad hoc networks (MANETs) where all nodes operate in the directional-only mode. A scanning scheme over the antenna sectors is designed in which random periods are scheduled for listening and sending alternatively in each sector for link establishment. Meanwhile, the burst directional ready-to-send RTS (BDRTS) frame and angle-of-arrival (AoA) caching scheme are also exploited to improve the ef ciency. Extensive simulations are conducted to compare the performance of FDD-MAC and other MAC protocols, including link success probability, network throughput, and service delay. The results show that FDD-MAC is effective and ef cient in solving the deafness problem in MANETs, especially with high node density and traf c load.

Paradigm Shift in Routing Approaches for High Speed MANET Applications

“…Jianyu Niu et al have developed the effective medium access strategy at MAC layer, to exploit smart antenna's spatial diversity this enhances the overall capacity of the ad hoc networks [36]. Radiation patterns of adaptive array antenna (that is capable of introducing nulls towards interferer) have resulted in increased network capacity as illustrated in figure 8.…”

An Adaptive Beamforming Time with Round-Robin MAC Algorithm for Reducing Energy Consumption in MANET

“…In contexts in which directional smart antenna systems are used, the beamforming issue has to be deeply investigated. The use of DRTS and DCTS messages along with directional network allocator vector (DNAV) aims to reduce the excessive burden of collisions occurring when omnidirectional antennas are used; however, when SASs are employed, it is not sufficient to adopt these expedients [16][17][18][19]. The most common drawback in this field is represented by the fact that, in literature, there is an important lack relating to directional MAC proposals that could be synthesized by two main aspects: Primarily, most directional MAC works are designed for classical directional antennas and do not address issues involved by the use of an SAS.…”

An Adaptive Beamforming Time with Round Robin MAC Algorithm for Reducing Energy Consumption in MANET

“…In contexts in which directional Smart Antenna Systems are used, the beamforming issue have to be deeply investigated. The use of DRTS and DCTS frames in association with a Directional Network Allocator Vector (DNAV) information, helps to decrease the large amount of collisions that usually occurs when using omnidirectional antennas, but in environments in which SAS are employed it might not be enough to provide these expedients [10][11][12]. In the present paper, we propose to reduce these issues by enhancing the works proposed in [13][14] using SAS along with a Round-Robin scheduling in order to address more detailed challenges such as the queue and the time slice problem involved by the use of the Round-Robin.…”