In recent years, various MAC (Medium Access Control) protocols using directional antennas have been proposed for ad hoc networks including our proposed MAC protocol called SWAMP (Smart antennas based Wider-range Access MAC Protocol). These are typically referred to as directional MAC protocols. This paper first summarizes the proposed directional MAC protocols and points out these common issues...

Existing medium access control (MAC) schemes for wireless local area networks (WLANs) have been shown to lack scalability in crowded networks and can suffer from widely varying delays rendering them unsuited to delay sensitive applications, such as voice and video communications. These deficiencies are mainly due to the use of random multiple access techniques in the MAC layer. The design of th...

Energy efficiency has been a main concern in wireless sensor networks where Medium Access Control (MAC) protocol plays an important role. However, current MAC protocols designed for energy saving have seldom considered multiple applications coexisting in WSN with variation of traffic load dynamics and different QoS requirements. In this paper, we propose an adaptive control algorithm at MAC lay...

Opportunistic usage selection of a licensed channel by a secondary user (SU) and its contention for data transmission is a challenging problem in coexisting cognitive radio network (CCRN). This is caused by the presence of many SUs from different CRNs in a shared environment, and the problem is further intensified when the user applications, with heterogeneous quality-of-service (QoS) requireme...

High throughput and fair resource sharing are two of the most important objectives in designing a medium access control (MAC) protocol. Currently, most MAC protocols including IEEE 802.11 DCF adopt a random access based approach in a distributed manner in order to coordinate the wireless channel accesses among competing stations. In this paper, we first identify that a random access–based MAC p...

Most existing WLAN access mechanisms cannot provide QoS assurances. Even those that are QoS aware can only provide relative service differentiation. Based on EY-NPMA, the HIPERLAN Medium Access Control algorithm, we propose a dynamic priority medium access scheme to provide time-bounded services. By approximating an ideal Earliest Deadline First (EDF) scheduler, the proposed scheme can offer de...

Control phase plays a critical role in the performance of time-division multiple access (TDMA)-based networks. Within cluster-based wireless sensor networks, a nimble and adaptive control phase algorithm called NACPA to control the control phase of TDMA-based medium access control (MAC) in cluster-based sensor networks is proposed. This algorithm takes advantage of the wireless sensor hardware ...

1 Abstract Home networks provide a means for interconnecting consumer products in home environments. In this paper the performance characteristics of the medium access protocol|a slotted persistent CSMA/CD protocol|of a twisted pair home network are investigated. Using a dedicated semi-Markov model throughput results are obtained by analyzing an overload situation. 2 Context and Introduction No...

In this paper we investigate the role of medium access control on the performance of network-wide real-time data broadcasting through flooding using three MAC protocols (IEEE 802.11, CPS, and MH-TRACE) in terms of QoS (packet delivery ratio, packet delay, and delay jitter) and energy dissipation. We conduct extensive simulations to evaluate the performance of network-wide broadcasting through f...

Wireless sensor networks rely on the cooperative effort of the densely deployed sensor nodes to report the detected events. As a result, sensor observations are highly correlated in the space domain. Typically, multiple sensor nodes may report the same event. Consequently, redundant information may be transmitted by the different sensor nodes, leading thus to unnecessary energy wastage. In this...