Cooperative Medium Access Control Protocol Research Articles

EC-MAC: Energy-Aware Cooperative MAC Protocol in Wireless Sensor Network

Nowadays, cooperative communication algorithms have been utilized in Wireless Sensor Network (WSN) to enhance the overall network performance. As is well known, a WSN needs to consider a number of important factors, such as the energy effectiveness and the longevity of the sensor nodes. The energy-aware cooperative medium access control (EC-MAC) protocol is a novel protocol proposed in this paper for usage in WSNs. EC-MAC protocol allows the source nodes to use the intermediate nodes as relays that can be used to transmit the source's data to the access point (AP). This paper demonstrates how the suggested relay selection method can be used by the EC-MAC protocol to choose the best relay node. After channel state information (CSI) has been calculated and acquired, the best relay should have the highest residual energy and the quickest transmission time. Then, by establishing suitable cooperative links, data transmission from a source node to an AP can be carried out. The effectiveness of the EC-MAC protocol in terms of system energy efficiency is examined in this study using the MATLAB simulation tool and compares the outcomes with other cooperative protocols like Modified Cooperative Access MAC Protocol (MCA-MAC) and Throughput and Energy aware Cooperative MAC Protocol (TEC-MAC) and the performance of WSNs employing the suggested EC-MAC protocol is examined in this research for both ideal and dynamic channel conditions. EC-MAC protocol achieved energy efficiency improvements of 20%, and 40% respectively, more than MCA-MAC and TEC-MAC protocols. The results indicated that EC-MAC protocol offers a higher level of energy efficiency for the WSN than other cooperative protocols currently in use.

Fuzzy Based Prioritized Message Dissemination and Cooperative MAC Protocol for VANET

Fuzzy Based Prioritized Message Dissemination and Cooperative MAC Protocol for VANET

A Contention-Free Cooperative MAC Protocol for Eliminating Heterogenous Collisions in Vehicular Ad Hoc Networks

In vehicular ad hoc networks (VANETs), efficient data dissemination to a specified number of vehicles with minimum collisions and limited access delay is critical for accident prevention in road safety. However, packet collisions have a significant impact on access delay, and they may lead to unanticipated link failure when a range of diversified collisions are combined due to complex traffic conditions and rapid changes in network topology. In this paper, we propose a distributed contention-free cooperative medium access control (CFC-MAC) protocol to reduce heterogenous collisions and unintended access delay in stochastic traffic scenarios. Firstly, we develop a cooperative communication system model and cooperative forwarding mechanism to explore the optimum road path between the source and destination by identifying the potential cooperative vehicles. Secondly, we propose a vectorized trajectory estimation mechanism to suppress merging collisions by identifying the relative velocity of vehicles with different speeds in a specific time interval. Based on the case study, typical heterogeneous collisions and aggregated heterogeneous collisions at dissociated positions and associated positions are investigated. In both cases, we propose the corresponding collision-resolving mechanisms by methodically recapturing the colliding time slot or acquiring the available free time slots after identifying the access vehicles and comparing the received signal strengths. Performance analysis for collision probability and access delay is conducted. Finally, the simulation results show that the proposed protocol can achieve deterministic access delay and a minimal collision rate, substantially outperforming the existing solutions.

An adaptive and cooperative MAC protocol for safety applications in cognitive radio enabled vehicular Ad-hoc networks

Rapid broadcast of safety message (sm) is critical for real-time applications in cognitive radio vehicular ad hoc networks (CR-VANETs). The arrival of primary users (PU) and the relative unpredictability of traffic emerge as network bottleneck constraints, resulting in unreliable broadcast services. The requirement is for a Medium Access Control (MAC) protocol that allows for fair contention, is adaptive, and includes a makeup strategy for rebroadcasting failed transmissions. There are intricate tradeoff optimisation relationships in which a value for the contention window that is inadequate will not result in optimal network performance. In this paper, we develop a dynamic contention window backoff mechanism using Karush–Kuhn–Tucker (KKT) conditions that enhances network performance by modifying the backoff time according to traffic density. Then we amalgamate this algorithm with a cooperative makeup strategy to design a novel adaptive and cooperative MAC protocol that is operable in a dynamic CR-VANET paradigm (ACCRV-MAC). A Markov chain decision model characterises the protocol, and Network Simulator -2 analyses various performance parameters. The study reveals that ACCRV-MAC improves throughput by 38.3% and reduces network latency by 49% compared to existing MAC protocols.

A Fair and Cooperative MAC Protocol for Heterogeneous Cognitive Radio Enabled Vehicular Ad-Hoc Networks

Advancements in intelligent transportation necessitate a dependable medium access control (MAC) protocol to enable high-priority safety broadcasts. Implementing cognitive radio-based vehicular ad-hoc networks (CR-VANETs) alleviates the significant growth in spectrum demand. The architecture must deploy multiple networks to make CR-VANET viable; however, the MAC design is a substantial challenge. The hardware-limited vehicles have varied characteristics and do not attain the same performance when provided with equal resources, posing a fairness concern. The resource allocation should balance two conflicting objectives: performance should be increased, prioritizing a few users under better conditions, and fairness among users should be emphasized, which reduces the overall performance. This paper presents a Fair and Cooperative MAC protocol for heterogeneous CR-VANETs (FCCR-MAC) to find this balance. In the event of a primary user appearance, cooperation allows pro-active channel switching. In FCCR-MAC, mode selection and retransmission of unsuccessful broadcasts are enabled by including additional control signals. By assisting users in determining the identities of others, cooperation also improves the system’s fairness. Markov Chain and the Karush–Kuhn–Tucker (KKT) conditions are utilized to offer a unified mathematical explanation of the throughput versus fairness trade-off optimization problem. According to the findings, the FCCR-MAC protocol outperforms other protocols with better fairness.

An efficient self‐deployment methodology for maximized coverage of mobile underwater sensor networks

SummaryA well‐optimized and well‐performed communication network protocol is necessary to build successful underwater acoustic sensor networks (UWASNs). But for wired and wireless communication, medium access control (MAC) has a great effect on network performance and optimization. But unlike land‐based MAC protocols, underwater MAC protocols come with various challenges and issues like high propagation delay, limited bandwidth for communication signals, large attenuation in network signals, and the high noise level in signals. It is very challenging to build a well‐optimized underwater MAC protocol. Also, in UWASN, sensor nodes are generally divided into sub‐network parts to reduce the propagation delay of data signals. But this creates the problem of non‐uniform traffic load in sensor nodes. So, considering these issues, dynamic hold time MAC (DHT‐MAC) protocol is proposed here. In this protocol, depending on the distance from the central node, sensor nodes are divided into two sub‐network zones (parent node and child node). Depending on the traffic load and propagation delay, the child nodes can change their respective parent nodes dynamically. Advantage of the proposed method is that, if any of the parent nodes stops working, the child node will connect to the nearest parent node. When collecting the data signals, it has been observed that child nodes have a light traffic load compared to parent nodes. So dynamic cooperative transmission MAC (DCT‐MAC) protocol which is a contention‐based MAC protocol has been used in child nodes and as parent nodes have high traffic load, reservation‐based MAC protocol has been used.

Multi-objective cooperative medium access control protocols in wireless Ad-Hoc networks

Relay-based cooperative communications have been emerging as a novel paradigm in many wireless protocols. The IEEE 802.11 medium access control (MAC) protocols have attracted many cooperative techniques. The relay selection algorithms have a remarkable influence on the design and the performance of the cooperative MAC (CMAC) protocols. Most of the existing algorithms have been designed based on a single objective such as spectrum efficiency and energy efficiency. In this paper, two multi-objective CMAC protocols are proposed: FCGMAC and EECMAC. The FCGMAC employs a multiple relay selection algorithm providing the spectrum efficiency and fairness. The EECMAC exploits a single relay selection improving the energy efficiency and the spectrum efficiency. The proposed protocols have been simulated in the ns-3 network simulator and the simulation results indicate the improvement of network performance according to the design objectives.

A novel cooperative MAC protocol for safety applications in cognitive radio enabled vehicular ad-hoc networks

Recent developments in intelligent transportation system (ITS) require a reliable medium access control (MAC) protocol to support the high-priority safety message broadcast. The rapid increase in spectrum demand is addressed by implementing cooperation in cognitive radio-based vehicular ad-hoc networks (CR-VANETs). In this paper, a novel cooperative MAC for CR-VANET (CCRV-MAC) is proposed for safety applications. CCRV facilitates collaboration among vehicles to exchange channel status reports for pro-active channel switching in the case of primary user (PU) appearance. Additional control signals are introduced to enable transmission mode selection. The helper nodes rebroadcast failed transmission by employing the proposed cooperative makeup strategy. The protocol is modelled using a Markov chain and is analyzed for various performance parameters using NS-2. It is also compared with two existing MAC protocols. In the results, CCRV shows enhanced throughput and packet delivery ratio. The average delay in CCRV MAC is reduced by approximately 37% compared to existing cognitive radio network (CRN) and vehicular ad-hoc network (VANET) based MAC approaches. Analysis of overhead and delay illustrates the reliability of CCRV as it suffers a maximum average delay of 69 ms under adverse conditions which is well below the permissible limit of 100 ms.

Distributed directional cooperative MAC (DD-CoopMAC) protocol for improving VBR throughput in IEEE 802.11ad WLAN

The IEEE 802.11ad-based wireless local area network (WLAN) has emerged out as a promising network technology that is capable of operating on millimetre wave spectrum. This network is being used in many applications and can be extended to serve many different streams of the networking industry. However, the network still has some glitches with respect to throughput, overhead, etc., which need to be handled to make it more reliable and efficient. In this paper, distributed directional cooperative medium access control (DD-CoopMAC) protocol for improving variable bit rate (VBR) throughput in IEEE 802.11ad WLAN is proposed. In this protocol, information about network stations is intelligently collected; based on this, the relay stations are selected for transmission. Simulation results illustrate that this protocol aids in enhancing the throughput and reducing the related overhead. Also, simulation results show that the proposed DD-CoopMAC has given high throughput and less MAC delay compared with D-CoopMAC and IEEE 802.11ad.

EVC-TDMA: An enhanced TDMA based cooperative MAC protocol for vehicular networks

In order to optimize the communication mechanism in the vehicular adHoc networks (VANETs), this paper presents an enhanced TDMA based cooperative MAC protocol called EVC-TDMA. In EVC-TDMA, when the vehicles need to transmit multi-hop messages, they choose relay nodes dynamically according to the relative speeds and buffer lengths. By monitoring the broadcasting messages, the other nodes can know the buffer lengths of the relay nodes, they will help transmit the relay messages when their buffer are idle or less. Considering the data arrive follows a Poison Point Process, this paper analyzes the nodes' buffer length based on a two-dimension Markov process. The simulation results show that EVC-TDMA can reduce the dropping rate and improve the throughput of the network.

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.

A Multi-Objective Target-Oriented Cooperative MAC Protocol for Wireless Ad-hoc Networks With Energy Harvesting

In this paper, we present a cross layer cooperative medium access control (CMAC) protocol with energy harvesting (EH) capability. The small energy capacity and size of wireless nodes pose a great challenge to the longevity of wireless networks due to the cost of ensuring a reliable communication link between transmitting nodes characterized by path-loss, shadowing and fading effects. Besides, the inability of existing CMAC protocols to exhibit multi-objective target orientation limits their adaptation to the dynamic network requirements. To address this problem, we propose a protocol that harnesses the radio frequency (RF) EH in the physical layer to enhance the throughput, end to end delay, energy efficiency and network lifetime of energy constraint wireless networks. This ensures that beneficial cooperation is achieved in fairness and multi-objective target-oriented protocol. We then investigate the performance of deploying a selective time-switching relaying (TSR) and power-splitting relaying (PSR) schemes in the MAC layer stack for a decode-and-forward (DF) reactive relaying distributed network. In addition, the quality of service requirement, outage probability, and network lifetime optimization techniques, respectively were utilized for optimal power allocation. Also, we propose a distributed and adaptive relay selection algorithm to select the best helper node that improves the network performance and balance the network energy consumption. The results of simulation show that a multi-objective target orientation can be achieved by the proposed EH-CMAC protocol and outperforms EAP-CMAC protocol with respect to throughput, end to end delay, network lifetime and energy efficiency.

OEC-MAC: A Novel OFDMA Based Efficient Cooperative MAC Protocol for VANETS

In vehicular ad hoc networks (VANETs), mobility between vehicles can cause rapid topology changes with frequent disconnections, which result in collisions and packet losses that make communications unstable. Alternatively, cooperative transmission can increase the reliability of communication by eliminating these problems in VANETS. In heavy traffic conditions, carrier sense multiple access with collision avoidance (CSMA/CA) suffers from collision, and it is not effective when high data rate is required. Therefore, orthogonal frequency division multiple access (OFDMA) is proposed. With the use of OFDMA, throughput is increased and delay is decreased by reducing the probability of collision in high traffic scenario. In this study, a novel OFDMA based efficient cooperative MAC protocol (OEC-MAC) is proposed for VANETs. Subcarrier channels assignment and access mechanisms are provided. The mechanism is presented not only for choosing the appropriate transmission mode but also for selecting the optimum relay. New control messages are defined to support cooperative communication. The performance of OEC-MAC protocol is examined by providing analytical analysis based on Markov chain model. Numerical results are demonstrated, which reveal that OEC-MAC protocol ensures a remarkable increase in throughput and also satisfies the strict delay requirement of 100 ms in VANETs for safety messages (sm). In addition, communication reliability is increased by reducing the packet dropping rate (PDR). Numerical results are compared with existing protocols, and a quantitative comparison is provided. It has been seen form results that proposed OEC-MAC protocol is better than existing schemes, especially under heavy traffic scenarios.

Mobility Aware Co-operative MAC Protocol for Reliable Transmission in VANET

The Medium Access Control (MAC) etiquette is liable for partaking the communal medium amongst the competing nodules. The unique characteristics of VANET enforce many restrictions onto the MAC protocol design. The main aims of a VANET MAC protocol are fairness, Quality of Service (QoS), reliability and so on. In case of V2V communication in VANET, if the target vehicle is not reachable, then packets may not be transmitted correctly. In this paper, a Mobility Aware Cooperative MAC protocol (MAC-MAC) for successful transmission in VANET is proposed. In this protocol, when data is transmitted from V2V, the packet error rate (PER) and packet delivery ratio (PDR) metrics are checked at the receiver end. Depending on these values, the transmission mode of the source is changed as DIRECT or COOPERATIVE. In cooperative mode, the source selects the potential relay nodes based on the residence time and distance to the receiver. By experimental results, it is shown that the proposed MAC-MAC protocol has reduced packet drops, delay and overhead with increased packet delivery ratio.

An Efficient Distributed Single-hop Relay Supporting (EDSRS) MAC Protocol for Wireless Sensor Networks

Background & Objective: Wireless communication has immensely grown during the past few decades due to significant demand for mobile access. Although cost-effective as compared to their wired counterpart, maintaining good quality-of-service (QoS) in these networks has always remained a challenge. Multiple-input Multiple-output (MIMO) systems, which consists of multiple transmitter and receiver antennas, have been widely acknowledged for their QoS and transmit diversity. Though suited for cellular base stations, MIMO systems are not suited for small-sized wireless nodes due to their hardware complexity, cost, and increased power requirements. Cooperative communication that allows relays, i.e. mobile or fixed nodes in a communication network, to share their resources and forward other node’s data to the destination node has substituted the MIMO systems nowadays. To harness the full benefit of cooperative communication, appropriate relay node selection is very important. This paper presents an efficient single-hop distributed relay supporting medium access control (MAC) protocol (EDSRS) that works in the single-hop environment and improves the energy efficiency and the life of relay nodes without compensating the throughput of the network. Methods: The protocol has been simulated using NS2 simulator. The proposed protocol is compared with energy efficient cooperative MAC protocol (EECOMAC) and legacy distributed coordination function (DCF) on the basis of throughput, energy efficiency, transmission delay and an end to end delay with various payload sizes. Result and Conclusion: The result of the comparison indicates that the proposed protocol (EDSRS) outperforms the other two protocols.

RECV‐MAC: a novel reliable and efficient cooperative MAC protocol for VANETs

In vehicular ad hoc networks (VANETs), mobility among vehicles can result in rapid topology changes with frequent link breakage and unstable communications, which cause collision and packet loss. Conversely, cooperative transmission can improve communication reliability and can enhance communication rate with lower delay by alleviating wireless channel impairments caused by mobility in VANETs. In this study, a novel reliable and efficient cooperative medium access control protocol for VANETs (RECV-MAC) is proposed. Since a random access mechanism is suitable and efficient because of the dynamic and open nature of VANETs, authors used the random access approach, i.e. carrier sense multiple access with collision avoidance, which is used by IEEE 802.11p. The RECV-MAC protocol is compatible with IEEE 802.11p. New control messages are introduced to support cooperative communication. The mechanism is defined to choose suitable transmission mode as well as to select optimal helper. To investigate the performance of RECV-MAC protocol, Markov chain model-based analytical analysis is provided. The RECV-MAC protocol is validated by numerical results which demonstrate that RECV-MAC protocol improves the performance with higher throughput, enhances the reliability of communication by decreasing packet dropping rate (PDR), and decreases delay, in particular, satisfies the delay constraint of 100 ms for sm.

Energy‐efficiency‐based CMAC protocol with hybrid time–power splitting relaying for wireless ad‐hoc networks

This work presents a new cross-layer cooperative medium access control (CMAC) protocol with hybrid radio frequency (RF) energy-harvesting (EH) capability to enhance the energy efficiency and network lifetime of energy-constrained wireless ad-hoc networks. The proposed protocol employs an adaptive transmission process and integrates the hybrid time-power splitting wireless EH technique at the relay node. The relay node can also assist using its own power (traditional cooperation) provided its battery level is sufficiently adequate and there is no need for RF-EH. The best transmission mode among direct transmission, cooperative transmission and TPSR cooperation is selected based on power allocation. Two techniques namely the outage probability quality-of-service requirement and transmit power optimisation are considered. In addition, the distributed relay selection process is proposed to select the best helper based on location, residual energy and EH information that can significantly enhance the energy efficiency and network lifetime of the wireless network. The results indicate that the proposed protocol can extend the lifetime and improves the energy efficiency of the network.

An enhanced cooperative MAC protocol for hybrid PLC/wireless systems

In this study, the merge of a cooperative protocol with packet correction techniques at the link layer level is proposed. The resulting protocol, named Enhanced Cooperative Medium Access Control protocol (EHCMAC), can improve data communication reliability in-home and broadband hybrid power line communication/wireless systems. More specifically, after unsuccessful transmissions, the proposed protocol tries to correct corrupted packets, at the link layer before performing the retransmission request. In case this correction fails, the relay availability for retransmitting packets is exploited and, when the relay assistance is not enough to ensure successful retransmission, the EHCMAC performs a second packet correction attempt at the link layer. The effectiveness of the EHCMAC protocol is supported by performance analyses of in-home broadband PLC/wireless systems under its adoption. Overall, numerical and theoretical results show that the use of the proposed protocol is capable of remarkably reducing the need for packet retransmissions and the packet loss ratio. More specifically, as the bit error ratio at the link layer decreases, the number of retransmissions and packet losses tend to zero faster when the proposed protocol is adopted.

Performance Analysis of a Novel Distributed C-ARQ Scheme for IEEE 802.11 Wireless Networks

It is well-known that the cooperative communication and error control technology can improve the network performance, but most existing cooperative MAC protocols have not focused on how to cope with the contention process caused by cooperation and how to reduce the bad influence of channel packet error rate on the system performance. Inspired by this, this paper first modifies and improves the basic rules of the IEEE 802.11 Medium Access Control (MAC) protocol to optimize the contention among the multi-relay in a cooperative ARQ scheme. Secondly, a hybrid ARQ protocol with soft combining is adopted to make full use of the effective information in the error data packet and hence improve the ability of the receiver to decode the data packet correctly. The closed expressions of network performance including throughput and average packet transmission delay in a saturated network are then analyzed and derived by establishing a dedicated two-dimensional Markov model and solving its steady-state distribution. Finally, the performance evaluation and superiority of the proposed protocol are validated in different representative study cases through MATLAB simulations.