Proposed Medium Access Control Protocol Research Articles

Load-balanced and energy-aware opportunistic routing with adaptive duty cycling for multi-channel WSNs

By increasing the internet of things (IoT) applications, multi-channel wireless sensor networks (WSNs) are widely used as a promising technology. Due to power constraints in WSNs, increasing the network’s lifetime is a challenging issue that must be satisfied in any design, obviously medium-access control (MAC) and routing protocols. In this paper, we proposed a joint MAC and routing mechanism that improves power consumption as well as both end-to-end delay and packet delivery ratio. For the proposed MAC protocol, adaptive sleep–wake scheduling based on nodes’ utilization and energy level helps a sender to avoid multiple synchronization and competition periods for any data transmission. In addition, by prioritizing channels based on the number of competing nodes and channels’ utilization, the proposed method prevents channels’ saturation. Thus, network load will be balanced over different channels. Furthermore, the opportunistic routing is restricted by a forwarding zone to increase the route quality, which balances loads among different next-hop candidates. Simulation results show the performance improvement of the proposed method over the most similar works ( MORR protocol and SLOR protocol).

MAC Protocol for Underwater Sensor Networks Using EM Wave With TDMA Based Control Channel

Underwater communication (UWC) growing over the past few decades is the major tool for exploring the vast underwater space. Research and development of UWC networks are dominantly acoustic (Ac) wave based due to its long coverage capability. However, the demand of low latency and high throughput applications, and the emergence of short-range UWCs in modern times has drawn attention towards the development of electromagnetic (EM) wave based underwater sensor networks (UWSNs). In light of this, this paper proposes novel medium access control (MAC) protocols by integrating EM-based communications in UWSNs. Proposed protocols use one TDMA-based control channel and one or multiple data channel(s) for control and data packet transmissions respectively. The control channel uses EM wave, while the data channels use either EM or Ac wave for communications. Proposed MAC protocols are developed considering both protocol interference model and physical interference model by taking both propagation delay and underwater channel impairments into account. Performance of the protocols is evaluated through extensive simulations in terms of throughput, packet collision rate, waiting time, energy requirement and network coverage. Impact of system parameters including offered load, network size, data packet size, control packet power, water conductivity and channel bandwidth are analyzed thoroughly. A comprehensive feasibility study by comparing the proposed MAC protocols with the traditional protocols as well as with the full Ac-wave based counterpart is also presented for further validations.

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 Novel Synchronous MAC Protocol for Wireless Sensor Networks with Performance Analysis.

Synchronous medium access control (MAC) protocols are highly essential for wireless sensor networks (WSN) to support transmissions with energy saving, quality services, and throughput in industrial, commercial and healthcare applications. In this paper, a synchronous channel access mechanism is designed, where sensors can reserve the contention free data transmission slots in different available channels. To reduce the delay of data transmission among the nodes in the mesh topology, a linear programming problem (LPP) model is designed to select suitable relay nodes. Moreover, the performance of the proposed MAC is analyzed and our models are validated with simulation and analytical results. The results show that our proposed MAC protocol outperforms the IEEE 802.15.4e MAC mechanism in terms of throughput, reliability, delay, energy, packet drop rate and transmission success rate.

MAC protocol for indoor optical wireless networks

Optical wireless communication has emerged as a promising candidate for future high data rate indoor applications such as virtual reality. Even though physical layer of optical wireless networks has rapidly developed during last decade, upper layer architecture that harness the physical layer capabilities has not yet been developed in the same pace. To this end, the authors develop a novel contention-based medium access control (MAC) protocol that accompanies a service differentiation mechanism and a dynamic contention window tuning algorithm. The proposed service differentiation mechanism can identify the diverse traffic types and facilitate their throughput and delay requirements. To add more robustness to the contention-based MAC protocol which depends on contention windows to avoid collisions, the authors also propose an algorithm that dynamically changes the contention window sizes to suit the congestion level. They analyse the performance of the proposed MAC protocol under diverse network configurations and they show that it is far more effective to use end-user network metrics such as throughput in dynamic adaptation algorithms in addition to collision rate due to the wide range of traffic types present in the network. The proposed results demonstrate that the proposed MAC protocol can handle next-generation traffic types and their stringent latency requirements in an effective manner.

A Full-Duplex MAC Protocol Based on Buffer Status Report for Successive Full-Duplex Link Setup

Full-duplex radio is the next-generation wireless technology that can transmit and receive frames simultaneously over the same channel. Recently, as self-interference cancellation technologies have evolved, full-duplex radio has become possible. In this letter, we propose a new medium access control (MAC) protocol designed for full-duplex radio. In the proposed MAC protocol, the downlink station on a full-duplex link uses an acknowledgment frame to report its buffer status information to the access point (AP). Then, the AP can establish a successive full-duplex link to provide a transmission opportunity to the station without contention. Our performance analysis and simulation results indicate that the proposed MAC protocol achieves throughput gains compared to existing studies.

Hybrid MAC Protocol for UAV-Assisted Data Gathering in a Wireless Sensor Network

A wireless sensor network (WSN) that deploys an unmanned aerial vehicle (UAV) for the data gathering process differs from the common WSN system. In a UAV-WSN, the sensor nodes have a limited time to communicate with the UAV. Thus, the sensor nodes have to contend with each other to transmit their data to the UAV within a short amount of time. The fairness among the contended nodes is degraded, which affects the network performance in terms of throughput and packet delivery ratio (PDR). To overcome this issue, an effective protocol that can maintain or increase fairness among nodes is needed. This paper proposes a novel protocol named HP-MAC which is a hybrid medium access control (MAC) protocol for data gathering in a UAV-WSN. This proposed scheme works by setting the UAV to periodically send a beacon frame to sensor nodes in order to inform its presence, then each sensor node that receives the beacon frame contends to send a registration frame to the UAV. A second beacon frame then transmitted by the UAV to the registered nodes regarding their transmission schedule. HP-MAC uses CSMA/CA during the registration process of the sensor nodes and allocates the registered sensor nodes time slots in the data gathering process. The time-slot scheme is used to determine the transmission schedule of each sensor based on their priority during the registration process. The results show that the proposed MAC protocol achieved fairness while enhancing network performance in terms of PDR and throughput.

Full-duplex MAC protocol using buffer status reports during unused uplink periods in WLAN

Full-duplex radio is a promising technique for next-generation wireless local area networks, because it can greatly increase the throughput by transmitting and receiving signals simultaneously within the same frequency band. Since conventional medium access control (MAC) protocols have been designed for half-duplex radio, they are not suitable for full-duplex radio. Therefore, we propose a novel MAC protocol to fully utilize full-duplex radio. The proposed MAC protocol consists of two periods: contention and scheduling. In the contention period, stations compete for channel access and report their buffer status information (BSI) and hidden stations to the access point (AP). Then, in the scheduling period, the AP provides transmission opportunities to stations without contention. One of the salient features of the proposed MAC protocol is that it utilizes unused uplink periods. Consequently, stations can report their BSI and hidden stations to the AP without time overhead. To evaluate the performance of the proposed MAC protocol, we performed an analytical evaluation and simulations. The evaluation results show that the proposed MAC protocol outperforms existing full-duplex MAC protocols.

PROLEMus: A Proactive Learning-Based MAC Protocol Against PUEA and SSDF Attacks in Energy Constrained Cognitive Radio Networks

Malicious users can exploit vulnerabilities in cognitive radio networks (CRNs) and cause heavy performance degradation by denial of service (DoS) attacks. During operation, cognitive radios (CRs) spend a considerable amount of time to identify idle (free) channels for transmission. In addition, CRs also need additional security mechanisms to prevent malicious attacks. Proactive model predictive control (MPC)-based medium access control (MAC) protocols for CRs can quicken the idle channel identification by predicting future states of channels in advance. This provides enough time for CRs to carry out other calculations like DoS attack detection. However, such external detection techniques use additional power that makes them inappropriate for energy constrained applications. As a solution, this paper proposes a proactive learning-based MAC protocol (PROLEMus) that shows immunity to two prominent CR-based DoS attacks, namely, primary user emulation attack (PUEA) and spectrum sensing data falsification (SSDF) attack, without any external detection mechanism. PROLEMus shows an average of 6.2%, 8.9%, and 12.4% improvement in channel utilization, backoff rate, and sensing delay, respectively, with low prediction errors (≤1.8%) saving 19.65% energy, when compared to recently proposed MAC protocols like ProMAC aided with additional DoS attack detection mechanism.

Energy-Perceptive MAC for Wireless Power and Information Transfer

Energy harvesting technology using radio frequency signals in a wireless local area network is a promising way to provide energy with devices in a wireless network. In this letter, we propose a novel distributed medium access control (MAC) protocol for both wireless power transfer and wireless information transfer based on carrier sense multiple access with enhanced collision avoidance. In the proposed protocol, the power beacon adjusts the energy transmission opportunity according to the stations’ energy level. The proposed MAC protocol improves data throughput and effectively provides energy to stations with minimal energy loss.

Frequency Domain Coordination MAC Protocol for Full-Duplex Wireless Networks

A full-duplex radio allows packets to be transmitted and received simultaneously using self-interference cancellation technologies. Thus, it can double the channel capacity compared with the half-duplex radio. Since conventional medium access control (MAC) protocols were designed for the half-duplex radio, the potential capacity of the full-duplex radio cannot be utilized. In this letter, we propose a full-duplex MAC protocol using frequency domain coordination to fully utilize the full-duplex radio and to increase coordination efficiency. The proposed MAC protocol uses subchannels to efficiently collect transmission requests from stations and to schedule packet transmissions without competition. Our evaluation results show that the throughput of the proposed MAC protocol significantly outperforms previous studies.

A Novel Energy-Efficient Contention-Based MAC Protocol Used for OA-UWSN.

A hybrid optical-acoustic underwater wireless sensor network (OA-UWSN) was proposed to solve the problem of high-speed transmission of real-time video and images in marine information detection. This paper proposes a novel energy-efficient contention-based media access control (MAC) protocol (OA-CMAC) for the OA-UWSN. Based on optical-acoustic fusion technology, our proposed OA-CMAC combines the postponed access mechanism in carrier sense multiple access with collision avoidance (CSMA/CA) and multiplexing-based spatial division multiple access (SDMA) technology to achieve high-speed and real-time data transmission. The protocol first performs an acoustic handshake to obtain the location information of a transceiver node, ensuring that the channel is idle. Otherwise, it performs postponed access and waits for the next time slot to contend for the channel again. Then, an optical handshake is performed to detect whether the channel condition satisfies the optical transmission, and beam alignment is performed at the same time. Finally, the nodes transmit data using optical communication. If the channel conditions do not meet the requirements for optical communication, a small amount of data with high priority is transmitted through acoustic communication. An evaluation of the proposed MAC protocol was performed with OMNeT++ simulations. The results showed that when the optical handshaking success ratio was greater than 50%, compared to the O-A handshake protocol in the literature, our protocol could result in doubled throughput. Due to the low energy consumption of optical communication, the node’s lifetime is 30% longer than that of pure acoustic communication, greatly reducing the network operation cost. Therefore, it is suitable for large-scale underwater sensor networks with high loads.

Design and Performance Analysis of Cognitive WLAN MAC Protocol

Cognitive radio networks (CRN) rely upon dynamic spectrum access that allows spectrum to be used efficiently. The role of the medium access control (MAC) protocol in CRN is to distribute efficiently the spectrum among the users. We propose a MAC protocol for cognitive wireless local area network (WLAN) that allows an unlicensed secondary user (SU) to opportunistically access and transmit data on the licensed channel owned by the primary user (PU). The proposed MAC protocol is an adaptation of IEEE 802.11 distributed coordination function. Extensive performance evaluation of the cognitive WLAN MAC protocol has been carried out as follows. First, a Markov chain model of the cognitive WLAN MAC protocol is developed. By solving our model we derive saturated throughput, packet delay, channel busy probability, conditional collision probability of SU, and interference to PU. Extension of our model for the case of multiple PUs under lightly loaded condition is also carried out. Further, we analyze the energy efficiency of the cognitive WLAN MAC protocol. We calculate the optimal sensing time interval for the SUs and the corresponding sensing energy incurred by the SUs. Effect of imperfect channel sensing on the performance of the proposed protocol is investigated. We validate our model by comparing the analytical results with simulation.

DCO-MAC: A Hybrid MAC Protocol for Data Collection in Underwater Acoustic Sensor Networks.

In underwater acoustic sensor networks (UASNs), medium access control (MAC) is an important issue because of its potentially significant effect on the network performance. However, designing a suitable MAC protocol for the UASN is challenging because of the specific characteristics of the underwater acoustic channel and network, such as limited available bandwidth, long propagation delay, high bit-error-rate, and sparse network topology. In addition, as the traffic load is non-uniformly distributed in a UASN for data collection, it is essential to consider the application feature for the MAC protocol. In this paper, we propose a MAC protocol in a data-collection-oriented UASN, abbreviated as the DCO-MAC protocol. In the proposed protocol, the network is partitioned into two kinds of sub-networks according to the traffic load. A contention-based MAC protocol is used in the sub-network with a light traffic load, while a reservation-based MAC protocol is used in the sub-network with a heavy traffic load. Meanwhile, the DCO-MAC protocol supports the access of mobile nodes. The theoretical analysis and simulation results demonstrate that, in a UASN for data collection, the proposed MAC protocol outperforms the other existing MAC protocols, in terms of the network throughput, end-to-end packet delay, energy overhead, and fairness.

Throughput performance of NOMA in WLANs with a CSMA MAC protocol

The existing medium access control (MAC) protocols are not able to utilize the full opportunities from power-domain non-orthogonal multiple access (NOMA) technique in wireless local area networks (WLANs). In this paper, we propose a carrier sense multiple access (CSMA) MAC protocol to increase downlink throughput by utilizing the opportunities offered by NOMA technique in downlink access of WLANs. For downlink transmission, an algorithm is developed to select an optimal user-set with appropriate power allocation from a randomly selected user-set. We then develop an analytical model to compute the uplink and downlink throughputs of a WLAN under the proposed MAC protocol by modelling the WLAN system as a discrete time Markov chain. The uplink and downlink throughputs of a WLAN under the proposed MAC protocol are determined by means of the analytical model and the accuracy of the analytical model is verified via extensive simulation. It is demonstrated that the proposed NOMA based MAC protocol improves the downlink throughput significantly compared to an orthogonal multiple access (OMA) based traditional CSMA MAC protocol without reducing the uplink throughput considerably. For a reasonable configuration, the downlink throughput gain is found to be more than 250%. We also study the throughput performance of the proposed MAC protocol for different transmit power levels, user medium access rates, data rates, path loss exponents and number of users in WLAN. We find that the throughput gain obtained by the proposed MAC protocol increases with increasing the transmit power and decreases with increasing the data rates and path loss. However, the change in the throughput gain obtained by the proposed MAC protocol is not significant for increasing the number of users and the user medium access rate.

Wi-Fi and Wireless Power Transfer Live Together

Power Beacons (PBs) can transfer energy wirelessly to devices in a wireless powered communication network. When PBs are deployed in an IEEE 802.11 Wireless LAN (WLAN), the energy transfer of PBs may interfere with the Wi-Fi stations if Wi-Fi stations and PBs share the same frequency band. In this letter, to resolve this interference problem, we propose a new Medium Access Control (MAC) protocol for IEEE 802.11 Wi-Fi stations to efficiently coexist with PBs. PBs contend just as Wi-Fi stations to gain opportunity for transferring energy and determine its operation based on the average energy level of stations. It is demonstrated that the throughput of the proposed MAC protocol is superior to that of IEEE 802.11 WLAN without interference control.

Collaborative Link-Aware Protocols for Energy-Efficient and QoS Wireless Body Area Networks Using Integrated Sensors

Integrated sensor systems are the promising solutions to the multiprobe design of biomedical sensors for energy efficient wireless body area networks (WBANs). To improve energy efficiency and communication quality-ofservice (QoS) of integrated sensor hubs, a cross-layered energyaware resource allocation (CLEAR) is proposed to exploit the characteristics of medium access control (MAC) and physical (PHY) layers of WBANs. The proposed MAC protocol applies a twin-token bucket model and real-time scheduling to the active superframe interleaving and beacon shifting techniques defined in the IEEE 802.15.6 standard. In addition, the proposed period transformation controlling task end-to-end delay improves the QoS while reducing packet collisions. The proposed PHY protocol is a hybrid of the transmit power control (TPC) and link adaption (LA) strategies, which coordinates the receiver and transmitter with link parameters including data rate, bit error ratio, receiver sensitivity, transmission power, modulation, etc. It adapts the link quality due to human postures or movements to meet the required QoS while minimizing the energy consumption of the transceiver front-end. Experimental results show that CLEAR outperforms existing methods in terms of packet delivery ratio, delay, bandwidth utilization, and energy consumption. In particular, CLEAR reduces average end-to-end delay by 21% as compared to existing methods, and saves an average of 18% of energy consumption over the TPC and LA-based methods at a power of -25 dBm while achieving a maximum 0.05 packet error ratio.

Energy efficient MAC protocol for wireless full-duplex networks

The wireless full-duplex (FD) nodes can transmit and receive at the same time using the same frequency-band. Currently, the latest FD media access control (MAC) protocols mainly focus on how to convert the physical layer gains of FD nodes to the throughput gain of wireless FD networks, but pay little attention to the energy consumptions of FD nodes. In this paper, we propose an energy efficient FD MAC protocol. According to the values of self-interference cancellation coefficients corresponding to the nodes of each FD pair and the signal propagation attenuation, the proposed protocol can adaptively select the communication mode of the FD pair between the full-duplex and half-duplex. Also, the minimum transmit power for FD nodes can be obtained to achieve high energy efficiency. We develop an analytical model to characterize the performance of our protocol. The numerical results show that the proposed MAC protocol can optimize the system throughput and reduce the transmission energy consumptions of nodes simultaneously as compared with those of the existing works.

Power Control Based Multiuser Full-Duplex MAC Protocol for the Next Generation Wireless Networks

Continuously increasing the data rate in wireless networks is required to satisfy the ever-increasing service demands. Full-duplex (FD), a promising technology for wireless networks, is able to double the data rate theoretically. Although several researchers study the physical (PHY) and medium access control (MAC) protocols of FD technology, there are few study focusing on the multiuser MAC protocol design for the next generation wireless networks. In this paper, a power control (PC) based multiuser FD MAC protocol, named PC MU-FuPlex, is proposed. Moreover, the probability of establishing FD link is formulated specifically. The simulation results demonstrate that the proposed MAC protocol significantly improves the saturation throughput up to 200% compared to that without PC in higher modulation.