MAC Protocol For Wireless Networks Research Articles

RCFD: A Novel Channel Access Scheme for Full-Duplex Wireless Networks Based on Contention in Time and Frequency Domains

In the last years, the advancements in signal processing and integrated circuits technology allowed several research groups to develop working prototypes of in–band full–duplex wireless systems. The introduction of such a revolutionary concept is promising in terms of increasing network performance, but at the same time poses several new challenges, especially at the MAC layer. Consequently, innovative channel access strategies are needed to exploit the opportunities provided by full–duplex while dealing with the increased complexity derived from its adoption. In this direction, this paper proposes RTS/CTS in the Frequency Domain (RCFD), a MAC layer scheme for full–duplex ad hoc wireless networks, based on the idea of time–frequency channel contention. According to this approach, different OFDM subcarriers are used to coordinate how nodes access the shared medium. The proposed scheme leads to efficient transmission scheduling with the result of avoiding collisions and exploiting full–duplex opportunities. The considerable performance improvements with respect to standard and state–of–the–art MAC protocols for wireless networks are highlighted through both theoretical analysis and network simulations.

A multi-state Q-learning based CSMA MAC protocol for wireless networks

Due to the shared nature of wireless channels, competition among the nodes to access media is inevitable. P-persistent carrier sense multiple access (CSMA) is a medium access control scheme widely ...

An Enhanced Power Based MAC Protocol for Wireless Networks

Power based connectivity is an ad hoc research topic. Implementing power control mechanisms enhance network life and to improve throughput, locate cost effective routes and spatial reuse. This paper uses MAC protocol to implement coordination functions and power control mechanisms through the use of fuzzy rules generated by upper network layers using two input variables like link quality and node neighborhood count with optimal power consumption level as the output variable. Experiments using fuzzy rules are compared to DSR routing and two hop power control methods. Result showed that two hop power control with fuzzy logic method yields lower route discovery time, increased cache replies, minimum simulation time and end to end delay when compared to DSR routing and two hop routing protocol.

Modelling, analysis and validation of wireless controller area network

The controller area network (CAN) is the pioneer in standardising vehicle and automation bus standards. For the wired CAN to meet the emergent pervasive wireless technology, wireless controller area network (WCAN) is introduced. WCAN is based on wireless token ring protocol (WTRP); a MAC protocol for wireless networks to reduce the number of retransmissions due to collision and the wired counterpart CAN attribute on message-based communication. CAN uses token frame method to provide channel access to the nodes in the system. This method allow all the nodes to share common broadcast channel by taken turns in transmitting upon receiving the token frame which is circulating within the network for specified amount of time. This method provides high throughput in bounded latency environment, consistent and predictable delays and better packet delivery ratio. WCAN is tested by simulation using QualNet and compared with IEEE 802.11 and is found to outperform it in ring network. The test results are validated using SAE benchmark.

WiMAC

This demo presents WiMAC, a general-purpose wireless testbed for researchers to quickly prototype a wide variety of real-time MAC protocols for wireless networks. As the interface between the link layer and the physical layer, MAC protocols are often tightly coupled with the underlying physical layer, and need to have extremely small latencies. Implementing a new MAC requires a long time. In fact, very few MACs have ever been implemented, even though dozens of new MAC protocols have been proposed. To enable quick prototyping, we employ the mechanism vs. policy separation to decompose the functionality in the MAC layer and the PHY layer. Built on the separation framework, WiMAC achieves the independence of the software from the hardware, offering a high degree of function reuse and design flexibility. Hence, our platform not only supports easy cross-layer design but also allows protocol changes on the fly. Following the 802.11-like reference design, we demonstrate that deploying a new MAC protocol is quick and simple on the proposed platform through the implementation of the CSMA/CA and CHAIN protocols.

The Study on Media Access Control Protocol for Wireless Network in Library

Wireless technology will be widely used in libraries with the development of the mobile network in the near future. This paper focuses on MAC protocol for wireless network based on ultra-wideband band (UWB) to solve the problems of real-time and reliability in the wireless transmitting. According to the particular signal characteristics such as low energy consumption and excellent location, we propose a multichannel MAC protocol (UWBIMAC) based on status-adaptive to choose the channel mechanism. Simulation results show that the protocol had the ability of stronger antijamming, improved network throughput, and provided better average delay performance than IEEE802.15.4 MAC, IEEE802.11 MAC, and other UWBIMAC protocols. This method could be used in the process of wireless transmission service in the library or other similar scenarios. To a certain extent, it solves the problem of real-time and reliable performance in the process of wireless communication.

English

IEEE 802.11 DCF is the MAC protocol currently used in wireless LANs. However, due to idle and collision times, 802.11 DCF performs poorly when it comes to channel utilization, system throughput, and channel access time. To overcome these sources of inefficiency in 802.11 DCF, we propose a distributed and dynamically adaptive MAC protocol for wireless networks, called Token-DCF with Append process and change contention window size. Main focus of our approach is on reducing idle and collision times by introducing an algorithm of token passing using Append process and change contention window size. In Append process strong data searched by DCF process and its queue length if greater than the threshold level, will focus on the minimum queue length in header list and add it with the new neighboring node by increasing system throughput and channel access time. We simulate in ns-2 to measure and compare performance of MAC protocols.

REAL TIME ANALYSIS OF WIRELESS CONTROLLER AREA NETWORK

It is widely known that Control Area Networks (CAN) are used in real-time, distributed and parallel processing which cover manufacture plants, humanoid robots, networking fields, etc., In applications where wireless conditions are encountered it is convenient to continue the exchange of CAN frames within the Wireless CAN (WCAN). The WCAN considered in this research is based on wireless token ring protocol (WTRP); a MAC protocol for wireless networks to reduce the number of retransmissions due to collision and the wired counterpart CAN attribute on message based communication. WCAN uses token frame method to provide channel access to the nodes in the system. This method allow all the nodes to share common broadcast channel by taken turns in transmitting upon receiving the token frame which is circulating within the network for specified amount of time. This method provides high throughput in bounded latency environment, consistent and predictable delays and good packet delivery ratio. The most important factor to consider when evaluating a control network is the end-to-end time delay between sensors, controllers, and actuators. The correct operation of a control system depends on the timeliness of the data coming over the network, and thus, a control network should be able to guarantee message delivery within a bounded transmission time. The proposed WCAN is modeled and simulated using QualNet, and its average end to end delay and packet delivery ratio (PDR) are calculated. The parameters boundaries of WCAN are evaluated to guarantee a maximum throughput and a minimum latency time, in the case of wireless communications, precisely WCAN.

Analysis of the Multi-Channel MAC Protocols in Wireless Networks

This paper discusses the problems that may be encountered in a multi-channel MAC protocol design. Furthermore, the normalization network throughput of multi-channel MAC is analyzed based on a Markov chain model. The simulation shows that compared to single channel 802.11, multi-channel MAC can improve the normalization network throughput. Moreover, the greater is the number of divided sub-channels, the higher is the normalization network throughput.

On Busy-Tone Based MAC Protocol for Wireless Networks with Directional Antennas

The application of directional antennas in wireless ad hoc networks offers numerous benefits, such as the extended communication range, the increased spatial reuse, the improved capacity and the suppressed interference. However, directional antennas can cause new location-dependent carrier sensing problems, such as new hidden terminal and deafness problems, which can severely degrade the network performance. Recently, a few schemes have been proposed to address these problems. However, most of these existing methods can only partially solve the hidden terminal and deafness problems. Some of them even bring significant performance overhead. In this paper, we propose a novel MAC protocol, in terms of the busy-tone based directional medium access control (BT-DMAC) protocol. In BT-DMAC, when the transmission is in progress, the sender and the receiver will turn on their omni-directional busy tones to protect the on-going transmission. Integrating with the directional network allocation vector (DNAV), the scheme can almost mitigate the hidden terminal problem and the deafness problem completely. We then propose an analytical model to investigate the throughput performance of BT-DMAC. The numerical results show that BT-DMAC outperforms other existing directional MAC schemes. We next evaluate the performance of BT-DMAC through extensive simulation experiments. The results show that our proposed BT-DMAC scheme has superior performance to other existing solutions, in terms of higher throughput.

A receiver-centric multi-channel MAC protocol for wireless networks

We consider the issues of mitigating interference and improving network capacity in wireless networks from the viewpoint of channel diversity. Multi-channel diversity allows multiple pairs to concurrently use the wireless medium, thus increasing the achievable capacity; this multi-channel diversity can then be fully utilized by enabling wireless nodes to dynamically switch their channels. However, the process of switching channels in a wireless transceiver incurs switching overhead, resulting in the degradation of the throughput performance. We propose a receiver-centric multi-channel MAC protocol (RcMAC) that allows nodes to efficiently utilize multiple channels by reducing unnecessary channel switching. Receiver-centric channel switching enables each sender node to asynchronously and independently switch channels to one where its intended receiver resides, without requiring explicit channel negotiation. Thus, the wait time at the control channel is reduced, in addition to the number of channel switchings, thereby improving channel utilization. As this scheme requires prior knowledge of which channel a node is switched to, each node cooperatively shares its channel usage information in order to recognize the channels that its neighboring nodes are using. Through extensive simulations, we show that the proposed MAC protocol significantly improves network throughput and reduces end-to-end delay compared with other multi-channel MAC protocols.

PluralisMAC: a generic multi-MAC framework for heterogeneous, multiservice wireless networks, applied to smart containers

Developing energy-efficient MAC protocols for lightweight wireless systems has been a challenging task for decades because of the specific requirements of various applications and the varying environments in which wireless systems are deployed. Many MAC protocols for wireless networks have been proposed, often custom-made for a specific application. It is clear that one MAC does not fit all the requirements. So, how should a MAC layer deal with an application that has several modes (each with different requirements) or with the deployment of another application during the lifetime of the system? Especially in a mobile wireless system, like Smart Monitoring of Containers, we cannot know in advance the application state (empty container versus stuffed container). Dynamic switching between different energy-efficient MAC strategies is needed. Our architecture, called PluralisMAC, contains a generic multi-MAC framework and a generic neighbour monitoring and filtering framework. To validate the real-world feasibility of our architecture, we have implemented it in TinyOS and have done experiments on the TMote Sky nodes in the w-iLab.t testbed. Experimental results show that dynamic switching between MAC strategies is possible with minimal receive chain overhead, while meeting the various application requirements (reliability and low-energy consumption).

MAC layer jamming mitigation using a game augmented by intervention

MAC layer jamming is a common attack on wireless networks, which is easy to launch by the attacker and which is very effective in disrupting the service provided by the network. Most of the current MAC protocols for wireless networks, for example, IEEE 802.11, do not provide sufficient protection against MAC layer jamming attacks. In this paper, we first use a non-cooperative game model to characterize the interactions among a group of self-interested regular users and a malicious user. It can be shown that the Nash equilibrium of this game is either inefficient or unfair for the regular users. We introduce a policer (an intervention user) who uses an intervention function to transform the original non-cooperative game into a new non-cooperative game augmented by the intervention function, in which the users will adjust to play a Nash equilibrium of the augmented game. By properly designing the intervention function, we show that the intervention user can effectively mitigate the jamming attacks from the malicious user, and at the same time let the regular users choose more efficient transmission strategies. It is proved that any feasible point in the rate region can be achieved as a Nash equilibrium of the augmented game by appropriately designing the intervention.

MAC Layer Jamming Mitigation Using a Game Augmented by Intervention

MAC layer jamming is a common attack on wireless networks, which is easy to launch by the attacker and which is very effective in disrupting the service provided by the network. Most of the current MAC protocols for wireless networks, for example, IEEE 802.11, do not provide sufficient protection against MAC layer jamming attacks. In this paper, we first use a non-cooperative game model to characterize the interactions among a group of self-interested regular users and a malicious user. It can be shown that the Nash equilibrium of this game is either inefficient or unfair for the regular users. We introduce a policer (an intervention user) who uses an intervention function to transform the original non-cooperative game into a new non-cooperative game augmented by the intervention function, in which the users will adjust to play a Nash equilibrium of the augmented game. By properly designing the intervention function, we show that the intervention user can effectively mitigate the jamming attacks from the malicious user, and at the same time let the regular users choose more efficient transmission strategies. It is proved that any feasible point in the rate region can be achieved as a Nash equilibrium of the augmented game by appropriately designing the intervention.

Phoenix: making cooperation more efficient through network coding in wireless networks

This paper introduces a novel MAC protocol for wireless networks, called Phoenix, that employs ideas from network coding to enhance decode and forward cooperation. A relay is allowed to code data of its own together with a corrupted packet during a retransmission at no additional cost in bandwidth. Therefore, while in conventional cooperative protocols a node becomes a relay only to assist other terminals, with our proposal a cooperator can also serve its own traffic. We evaluate Phoenix's performance by means of a theoretical model and extensive simulation campaigns. We show that Phoenix is especially beneficial in multihop settings and interesting gains over benchmark protocols can be achieved.

Evaluation of WiseMAC and extensions on wireless sensor nodes

In the past five years, many energy-efficient medium access protocols for all kinds of wireless networks (WSNs) have been proposed. Some recently developed protocols focus on sensor networks with low traffic requirements are based on so-called preamble sampling or low-power listening. The WiseMAC protocol is one of the first of this kind and still is one of the most energy-efficient MAC protocols for WSNs with low or varying traffic requirements. However, the high energy-efficiency of WiseMAC has shown to come at the cost of a very limited maximum throughput. In this paper, we evaluate the properties and characteristics of a WiseMAC implementation in simulation and on real sensor hardware. We investigate on the energy-consumption of the prototype using state-of-the-art evaluation methodologies. We further propose and examine an enhancement of the protocol designed to improve the traffic-adaptivity of WiseMAC. By conducting both simulation and real-world experiments, we show that the WiseMAC extension achieves a higher maximum throughput at a slightly increased energy cost both in simulation and real-world experiments.

On the Performance of Distributed Polling Service-based Medium Access Control

It has been shown in the literature that many MAC protocols for wireless networks have a considerable control overhead, which limits their achievable throughput and delay performance. In this paper, we study the problem of improving the efficiency of MAC protocols. We first analyze the popular p- Persistent CSMA scheme and show that it does not achieve 100% throughput.Motivated by insights from polling system theory, we then present three polling service-based MAC schemes, termed PSMACs, for improved performance. The main idea is to serve multiple data frames after a successful contention resolution, thus amortizing the high control overhead and making the protocols more efficient. We present analysis and simulation studies of the proposed schemes. Our results show that PSMAC can effectively improve the throughput and delay performance of p-Persistent CSMA, as well as providing energy savings. We also observe that PSMAC is more efficient for handling the more general and challenging bursty traffic and outperforms p-Persistent CSMA with respect to fairness.

Provisioning link layer proportional service differentiation in wireless networks with smart antennas

In this paper, we present a collision free MAC protocol for wireless networks with smart antennas that provides proportional service differentiation to various classes of traffic based on their respective bandwidth demand. The proposed protocol works for diverse physical parameters such as number of interfaces at each node, number of communication frequencies, and antenna beamwidth. To the best of our knowledge, this is the first work that provides link layer differentiated services for wireless networks with smart antennas and explores the influence of the physical parameters and network topology on the performance of the MAC layer.

An efficient packet sensing MAC protocol for wireless networks

The Group Allocation Multiple Access with Packet-Sensing (GAMA-PS) protocol for scheduling real-time and datagram traffic in a wireless LAN is specified and analyzed. By maintaining a dynamically-sized cycle that changes in length depending on the amount of network traffic, GAMA-PS is able to efficiently control channel access while ensuring that there are no collisions of data packets. Each cycle contains a contention period and a group-transmission period; a station with data to send competes for membership in the “transmission group” by using packet sensing to successfully complete an RTS/CTS message exchange during the contention period. Once a station is a member of the transmission group, it is able to transmit a collision-free data packet during each cycle; as long as a station has data to send, it maintains its position in the group.