Multi-channel Medium Access Control Protocol Research Articles

MDP-Based MAC Protocol for WBANs in Edge-Enabled eHealth Systems

In recent years, eHealth systems based on the Internet of Things (IoT) have attracted considerable attention. The wireless body area network (WBAN) is an essential technology of eHealth systems. A major challenge in WBAN is the design of the medium access control (MAC) protocol, which plays a significant role in avoiding collisions, enhancing the energy efficiency, maximizing the network life, and improving the quality of service (QoS) as well as the quality of experience (QoE). In this study, we apply the mobile edge computing (MEC) network architecture to an eHealth system and design a multi-channel MAC protocol for WBAN based on the Markov decision process (MDP). In this protocol, the channel condition and the reward value are considered. By continuously interacting with the environment, the optimal channel resource allocation strategy is generated. Simulation results indicate that the proposed WBAN MAC protocol can adaptively assign different channels to the sensor nodes for data transmission, thereby reducing the collision rate, decreasing the energy consumption, improving the channel utilization, and enhancing the system throughput and QoE.

Graph coloring-based multichannel MAC protocol in distributed underwater acoustic sensor networks

In this paper, the multichannel medium access control (MAC) problem in distributed underwater acoustic sensor networks (UASNs) were investigated. Compared with single-channel MAC protocols in terrestrial radio networks, there exist multichannel hidden terminal problem and long-delay hidden terminal problem in multichannel MAC protocol due to long propagation delay in UASNs. In addition, energy constraint makes channel allocation a challenging problem in distributed UASNs. To solve these aforementioned problems, a new multichannel MAC protocol, called graph coloring-based multichannel MAC protocol (GCMAC) is present. The protocol GCMAC is a synchronized MAC protocol which splits the time into three phases, namely, channel negotiation phase, channel selecting phase and data transmission phase. Specially, the rule for selecting channel is carefully designed based on graph coloring theory to avoid collision and maximize the utilization rate of channels in channel selecting phase. Simulation results show that GCMAC can greatly improve the system throughput and energy efficiency by effectively solving the hidden terminal problems and channel allocation problem.

An Adaptive and Spectrally Efficient Multi-Channel Medium Access Control Protocol for Dynamic Ad Hoc Networks.

Medium access control (MAC) protocols in ad hoc networks have evolved from single-channel independent transmission mechanisms to multi-channel concurrent mechanisms to efficiently manage the demands placed on modern networks. The primary aim of this study is to compare the performance of popular multi-channel MAC (MMAC) protocols under saturated network traffic conditions and propose improvements to the protocols under these conditions. A novel, dynamically adaptive MMAC protocol was devised to take advantage of the performance capabilities of the evaluated protocols in changing wireless ad hoc network conditions. A simulation of the familiar MAC protocols was developed based on a validated simulation of the IEEE 802.11 standard. Further, the behaviors and performances of these protocols are compared against the proposed MMAC protocols with a varying number of ad hoc stations and concurrent wireless channels in terms of throughput, Jain's fairness index, and channel access delay. The results show that the proposed MMAC protocol, labeled E-SA-MMAC, outperforms the existing protocols in throughput by up to 11.9% under a constrained number of channels and in channel access delays by up to 18.3%. It can be asserted from these observations that the proposed approach provides performance benefits against its peers under saturated traffic conditions and other factors, such as the number of available wireless channels, and is suitable for dynamic ad hoc network deployments.

An enhanced synchronized multi-channel MAC scheme to improve throughput in VANET

The development of autonomous driving and intelligent transportation demands, fast, reliable and efficient data transmission for various applications in vehicular ad hoc network (VANET). This poses great challenges to the design of a media access control (MAC) protocol that can adapt to the frequent topological shifts. IEEE 1609.4 defines the multi-channel MAC layer implementation in VANET. The multi-channel operation works on a fixed synchronization interval that alternates between a control channel and service channels. The fixed interval leads to poor utilization of limited spectrum resources. In this paper, a multi-channel reliable MAC protocol (MCRMAC), that uses both the control channel and service channel irrespective of the interval to ensure proper and efficient throughput utilization in VANET is proposed. The simulations reveal the performance of the proposed scheme and it outperforms IEEE 1609.4 in terms of throughput.

A Review of Multi-Channel Medium Access Control Protocols for Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are witnessing a momentum spread especially with the growth of the Internet of Things (IoT) paradigm. Indeed, WSNs are considered as the main enabling infrastructure for IoT networks. Nowadays, the emerging WSNs applications require not only long network lifespan but also considerably high data rate. Consequently, conceiving Multichannel MAC protocols that save the scarceenergy budget of sensor nodes while providing high network throughput is crucial for the emerging WSNs applications. In this paper, a thorough review of recent multichannel MAC protocols is provided along with a classification framework to deeply understand the design aspects for each protocol.

A Review of Multi-Channel Medium Access Control Protocols for Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are witnessing a momentum spread especially with the growth of the Internet of Things (IoT) paradigm. Indeed, WSNs are considered as the main enabling infrastructure for IoT networks. Nowadays, the emerging WSNs applications require not only long network lifespan but also considerably high data rate. Consequently, conceiving Multichannel MAC protocols that save the scarceenergy budget of sensor nodes while providing high network throughput is crucial for the emerging WSNs applications. In this paper, a thorough review of recent multichannel MAC protocols is provided along with a classification framework to deeply understand the design aspects for each protocol.

A Multi-Channel MAC Protocol With Retrodirective Array Antennas in Flying Ad Hoc Networks

In this paper, we propose a multi-channel medium access control (MMAC) protocol for the exploitation of retro-directive array antennas in Flying Ad Hoc Networks (named FA-MMAC). This FA-MMAC employs multiple channels and retro-directive array antennas to adjacent unmanned aerial vehicles (UAVs) to transmit simultaneously over the same channel without causing interference. The channel utilization characteristic of FA-MMAC increases the spatial reuse of channel and thus improve the system performance. The key idea is that UAVs first exchange control packets in control window to select data channels and to align beams before exchanging data packets in the data window. In this way, the hidden-terminal and deafness problems are reduced. UAVs can reserve channels and align beams through a circular directional transmission of control frames so that the protocol can take advantage of the benefits of retro-directive array antennas of spatial reuse and increased coverage without prior knowledge of the locations. We develop both antenna model and channel model for FA-MMAC protocol. Analysis and simulation results show that our proposed FA-MMAC can offer a significant performance gain for both static and mobile scenarios than the existing MMAC and 802.11-based protocols. Our findings reported in this paper provide some insights into the performance of multi-channel Flying Ad Hoc Networks which might help network researchers to contribute in the development of next generation UAVs.

Review of MAC Protocols for Vehicular Ad Hoc Networks.

Vehicular ad hoc networks (VANETs) need to support the timely end-to-end transmissions of safety and non-safety messages. Medium access control (MAC) protocols can ensure fair and efficient sharing of channel resources among multiple vehicles for VANETs, which can provide timely packet transmissions and significantly improve road safety. In this paper, we review the standards of some countries for VANETs. Then, we divide the MAC protocols proposed for VANETs into single-channel MAC protocols and multi-channel MAC protocols according to the number of physical occupied spectrum resources. Both are further discussed based on their hierarchical structures, i.e., distributed and centralized structures. General design and optimization mechanisms of these commonly used MAC protocols for VANETs are reviewed. From the viewpoint of 7 aspects, we compare the advantages and disadvantages of these typical MAC protocols. Finally, we discuss the open issues to improve the MAC performance and future work on MAC design for VANETs.

SFM-MAC: Multichannel MAC Protocol for Underwater Sensor Networks Based on Underwater Passive Localization Mechanisms

Yang, Q.; Dong, W.; Xu, Z., and Huang, X., 2020. SFM-MAC: Multichannel MAC protocol for underwater sensor networks based on underwater passive localization mechanisms. Journal of Coastal Research, 36(6), 1332–1342. Coconut Creek (Florida), ISSN 0749-0208.With the continuous development of ocean research in recent years, underwater acoustic sensor networks, as the extension of terrestrial wireless sensor networks (WSNs), play an increasingly important role in ocean and coastal research. To solve the problem of spatial unfairness caused by spatiotemporal uncertainty of underwater acoustic signal propagation in underwater WSNs and improve the throughput of underwater networks, this paper proposes a slotted-floor multichannel medium access control (SFM-MAC) protocol based on a single transceiver. SFM-MAC uses an underwater passive localization algorithm to obtain location information and then transforms spatiotemporal information to avoid the synchronization of the whole network to reduce the spatiotemporal uncertainty of underwater networks; further, it uses request to send (RT)/channel announcement/channel listening/clear to send (CTS) handshaking mechanism to avoid multichannel hidden terminal problems and achieve fair access. In addition, the paper uses the Markov chain to construct the reservation model of control channels, and theoretically analyzes and calculates the theoretical throughput of the multichannel MAC protocol under the condition of reserved collision. Simulation experiments show that the network fairness index of SFM-MAC is 15% higher than that of traditional RTS/ CTS protocols. The effective network throughput of SFM-MAC in different business scenarios is 60–70% and 12–15% higher than the single-channel underwater MAC protocol SF acquisition multiple access and the multichannel underwater MAC protocol, respectively.

A multi-channel load awareness-based MAC protocol for flying ad hoc networks

Flying ad hoc network (FANET) is a promising and special mobile Ad hoc network, connecting large number of flying unmanned aerial vehicles (UAVs) on battlefield through wireless link. Designing a multi-priority traffic differentiated medium access control (MAC) protocol with low delay, large capacity, high flexibility, and strong scalability is a great challenge in the researches and applications of FANETs. In order to overcome the disadvantages in IEEE 802.11 distributed coordination function (DCF) and time division multiple access (TDMA) protocols, a novel multi-channel load awareness-based MAC protocol for FANETs is presented in this paper. The multi-priority queueing and service mechanism, and the multi-channel load-based backoff mechanism involved in the protocol are intensively described. We further model the multi-priority queueing and service mechanism by the multi-class queueing theory, and model the backoff mechanism using the Markov chain model. Simulation results show that the protocol can differentiate services for different priorities in FANETs according to real-time channel state, providing effective QoS guarantee for transmissions of various information, and the network bandwidth resource is efficiently utilized.

An enhanced synchronized multi-channel MAC scheme to improve throughput in VANET

The development of autonomous driving and intelligent transportation demands, fast, reliable and efficient data transmission for various applications in vehicular ad hoc network (VANET). This poses great challenges to the design of a media access control (MAC) protocol that can adapt to the frequent topological shifts. IEEE 1609.4 defines the multi-channel MAC layer implementation in VANET. The multi-channel operation works on a fixed synchronization interval that alternates between a control channel and service channels. The fixed interval leads to poor utilization of limited spectrum resources. In this paper, a multi-channel reliable MAC protocol (MCRMAC), that uses both the control channel and service channel irrespective of the interval to ensure proper and efficient throughput utilization in VANET is proposed. The simulations reveal the performance of the proposed scheme and it outperforms IEEE 1609.4 in terms of throughput.

Index-Based Channel Hopping for Multi-Rendezvous Multi-Channel MAC

Multi-channel Medium Access Control (MAC) protocols aim to transmit in parallel on distinct channels in order to increase spectrum utilization. In this letter, we consider dynamic multi-channel access problem with independent and stochastically identical channels. We formulate the problem as a Restless Multi-Armed Bandit (RMAB) process and propose a novel load-adaptive frequency hopping method, namely Index-Based Channel Hopping (IBCH) algorithm, with the goal of optimal spectrum allocation and throughput maximization. We classify previous efforts by their spectrum decision mechanisms and rendezvous characteristics as single- and multi-rendezvous protocols. Later on, we compare performance of IBCH with various protocols from both rendezvous classes at varying transmission range, network size and spectrum availability. Simulation results show that IBCH significantly outperforms other spectrum assignment methods from both rendezvous classes.

An Adaptive High-Throughput Multichannel MAC Protocol for VANETs

IEEE 802.11p standard, operating over the 75-MHz spectrum at 5.9-GHz band with one control channel (CCH) and six service channels (SCHs), has been poised to provide V2X services over vehicular ad hoc networks (VANETs). However, due to the absence of central coordinator and the nature of high vehicular mobility, it is difficult to achieve reliable multichannel coordination and adaptive resource reservation to make full use of SCHs, resulting in dramatic throughput degradation. To mitigate this, in this article, we propose an adaptive high-throughput multichannel medium access control (MAC) protocol, namely, AHT-MAC, which can effectively handle the data transmissions over SCHs. With AHT-MAC, the data transmission range (TR) is adjusted according to the beacon TR over the CCH so that a transmitting node can determine proper communication candidates and prepare available resources for both communication nodes before transmissions. Moreover, the communication coordination is done through a two-way handshake. During the handshake, adaptive resource reservation is realized following the proposed resource sharing mechanism, where nodes first utilize as much resource as possible and then share them with others proactively. To increase the success probability of the communication handshake, a request conflict resolution mechanism is also designed to nullify improper handshakes. Therefore, AHT-MAC can reduce the resource wastage due to handshake failures and extra overheads for retransmission requests. Our performance analysis shows that AHT-MAC can significantly improve the system throughput and reduce the channel access period.

An adaptive and cooperative MAC protocol in vehicular ad hoc network: design and performance analysis

Vehicular ad hoc network is the key technology to enable the intelligent transportation system. VANET should provide reliable broadcasting to support the safety-related application. It is also required to effectively transmit service-related data. With the rapid development of the internet of vehicles, medium access control (MAC) protocols for VANET are expected to be more adaptive and scalable to the network size; so that the MAC protocol can operate effectively in supporting the massive number of connections. This paper proposes a multi-channel MAC protocol, namely AC-MAC, that enables multi-hop transmission of safety application data leveraging cooperation among vehicles. The proposed MAC protocol ensures the reliability of safety message transmission and the effective utilisation of channel resources. Moreover, the MAC mechanism also has the ability to adapt to different network conditions.

An adaptive and cooperative MAC protocol in vehicular ad hoc network: design and performance analysis

Vehicular ad hoc network is the key technology to enable the intelligent transportation system. VANET should provide reliable broadcasting to support the safety-related application. It is also required to effectively transmit service-related data. With the rapid development of the internet of vehicles, medium access control (MAC) protocols for VANET are expected to be more adaptive and scalable to the network size; so that the MAC protocol can operate effectively in supporting the massive number of connections. This paper proposes a multi-channel MAC protocol, namely AC-MAC, that enables multi-hop transmission of safety application data leveraging cooperation among vehicles. The proposed MAC protocol ensures the reliability of safety message transmission and the effective utilisation of channel resources. Moreover, the MAC mechanism also has the ability to adapt to different network conditions.

Energy and spectral efficient SMC‐MAC protocol in distributed cognitive radio networks

Communication industry demands the frameworks, which allow significant improvement in energy efficiency with spectral efficiency, however, these two do not always coincide and may even conflict sometimes in cognitive radio networks. In addition to this, the distributed network structures are preferred over centralised structures due to ease of deployment as well as less information exchange between the cognitive users which reduce the network-overhead. Therefore, in this study, the authors have proposed a framework to enhance the spectral as well as energy efficiency by exploiting the novel frame structure in the distributed cognitive radio networks. A self-scheduled multichannel-medium access control (SMC-MAC) protocol has been proposed in which the contention and sharing intervals are exploited for the efficient spectrum and energy utilisation. Moreover, the closed-form expressions of the spectral efficiency, power consumption and energy efficiency for the proposed SMC-MAC protocols are derived. Furthermore, the relation between energy and spectral efficiency for the proposed framework is also derived. The numerically simulated results are presented to validate the proposed work and Monte-Carlo simulations are performed for the random events in order to support the numerically simulated results.

Performance analysis of adaptive MAC protocol in VANETs considering the potential impact on throughput and transmission delays

SummaryThe existing adaptive multichannel medium access control (MAC) protocols in vehicular ad hoc networks can adjust themselves according to different vehicular traffic densities. These protocols can increase throughput and guarantee a bounded transmission delay for real‐time safety applications. However, the optimized control channel interval is computed based on the maximum throughput while ignoring the strict safety packet transmission delay requirements. In this paper, we analyze the effects of the throughput and strict safety packet transmission delay with adaptive multichannel MAC protocols, such as connectivity‐aware MAC (CA MAC), adaptive multi‐priority distributed MAC (APDM), multi‐priority supported p‐persistent MAC (MP MAC), and variable control channel interval MAC (VCI) protocols. The performance and analysis results show that: (a) under a low data rate condition, CA MAC does not guarantee a strict safety packet transmission delay; (b) APDM not only satisfies the safety packet transmission requirement, but also provides the lowest safety packet transmission delay; (c) under a high data rate condition, we suggest APDM for use as an adaptive MAC protocol because it allows for high throughput for nonsafety packets and preserves low safety packet transmission delay; (d) under a low data rate condition with various data packet sizes, we suggest MP MAC for high throughput, which satisfies the safety packet transmission requirement; and (e) under low vehicle density and low data rate conditions, VCI can support high throughput. A balance between transmission delay and throughput must be considered to improve the optimal efficiency, reliability, and adaptability.

Multichannel MAC protocol with dynamic backoff contention for distributed cognitive radio networks

Multiuser access is a critical issue in distributed cognitive radio networks (DCRNs), as the collisions among the competing secondary users (SUs) may decrease the network throughput significantly. In order to reduce the collisions, we propose a dynamic backoff algorithm to find an optimal backoff contention window to maximize the network throughput and reduce the channel access delay. Based on the proposed algorithm, a multichannel medium access control (MAC) protocol with dynamic backoff contention (MMAC-DB) is designed. In this protocol, the time duration of each channel is divided into four phases: idle, sensing-sharing, contention, and data transmission. The dynamic backoff algorithm is implemented in the contention phase. Moreover, a duration tradeoff is made between the data transmission phase and the contention phase. The effectiveness of the proposed protocol is examined by extensive simulations, which shows that the proposed protocol can enhance the throughput and reduce the channel access delay.

Performance analysis of multi-channel MAC with single transceiver for the next generation WLAN

As the amount of mobile traffic grows dramatically, the high-density Wi-Fi networking that proposed in the next generation WLAN (NGW) has attracted an increasing attention. However, some new challenges on the medium access control (MAC) layer design are emerging, for example, the multichannel hidden terminal (MHT) and the vicious circle problems. To overcome the challenges, a distributed multichannel MAC protocol based on multiple step reliable channel reservation is proposed, called m-RCR. Under the proposed m-RCR protocol, each node pair can reserve multiple transmission opportunities on data channels using only a single half-duplex transceiver, meanwhile, the control channel (CCH) is reserved to rebroadcast the channel reservation information (CRI). An analytical model is developed by extending the two-dimensional Markov process to describe the node behaviors on the CCH, and the usage of data channels is characterized as the M/M/K queueing model, where we consider the packet arrivals as a Poisson process. Furthermore, the throughput of m-RCR protocol is derived, and the performance optimization is also presented. Without loss of generality, some practical implementation methods are discussed. By conducting extensive simulations on NS-2 simulator, our analytical model is validated and the significant improvement of our proposed m-RCR protocol is demonstrated.

OCA-MAC: A Cooperative TDMA-Based MAC Protocol for Vehicular Ad Hoc Networks.

Cooperative communication is an effective method of improving the transmission performance for vehicular ad hoc networks. However, the rapid movement of vehicles leads to frequent changes in network topology and reduces the probability of successful data transmission on the medium access control (MAC) layer. In this paper, we propose an Optimal Cooperative Ad hoc MAC protocol (OCA-MAC) based on time division multiple access (TDMA). OCA-MAC utilizes multiple cooperative nodes to forward data, so as to improve the probability of successful data transmission. It chooses cooperative nodes according to direct successful transmission probability, communication range between potential helper node and destination node, and available time slot. Meanwhile, in order to avoid excessive transmission redundancy caused by multiple cooperative forwarding, the optimal number of cooperative forwarding nodes is obtained through analysis of a probabilistic model. Simulation results show that OCA-MAC improves the successful data transmission rate and reduces the number of transmission times and transmission delay compared to the multichannel TDMA MAC protocol (VeMAC) and the cooperative ad hoc MAC protocol (CAH-MAC).