Adaptive Medium Access Control Research Articles

Adaptive MAC Scheme for Interference Management in Ad Hoc IoT Networks

The field of wireless communication has undergone revolutionary changes driven by technological advancements in recent years. Central to this evolution is wireless ad hoc networks, which are characterized by their decentralized nature and have introduced numerous possibilities and challenges for researchers. Moreover, most of the existing Internet of Things (IoT) networks are based on ad hoc networks. This study focuses on the exploration of interference management and Medium Access Control (MAC) schemes. Through statistical derivations and systematic simulations, we evaluate the efficacy of guard zone-based MAC protocols under Rayleigh fading channel conditions. By establishing a link between network parameters, interference patterns, and MAC effectiveness, this work contributes to optimizing network performance. A key aspect of this study is the investigation of optimal guard zone parameters, which are crucial for interference mitigation. The adaptive guard zone scheme demonstrates superior performance compared to the widely recognized Carrier Sense Multiple Access (CSMA) and the system-wide fixed guard zone protocol under fading channel conditions that mimic real-world scenarios. Additionally, simulations reveal the interactions between network variables such as node density, path loss exponent, outage probability, and spreading gain, providing insights into their impact on aggregated interference and guard zone effectiveness.

Adaptive radio propagation model for maximizing performance efficiency in smart city disaster management application

Climate change poses several environmental threats like floods to urban environment; thus, effective and reliable communication of emergency information is needed during massive breakdown of network infrastructure. This paper presents a mobile adhoc network (MANETs) based effective information such as calls, image, and videos communication system that is compatible with current 3GPP and 5G communication network. Here in maintaining connectivity the information is communicated between different MANET nodes in a multi-hop manner. However, designing radio propagation is challenging considering higher local emergency request congestion at different terrain with varying speed of users. The current radio propagation model is designed without considering the effect of line-of-sight between communicating device and are not adaptive to different environment considering urban disaster management environment. This paper develops an adaptive radio propagation (ARP) model namely expressway, city and semiurban. Then, in reducing congestion and improving network performance efficiency the work introduced an adaptive medium access control (AMAC) protocol. The MAC incorporates a dynamic network controller (DNC) to optimize the contention window size in dynamic manner according to current traffic demands. The AMAC protocol achieves much improved throughput with lesser packet loss in comparison with existing MAC (EMAC) model considering different radio propagation model introduced in this work.

Cooperative optimization techniques in distributed MAC protocols – a survey

Purpose Cross-layer approach in media access control (MAC) layer will address interference and jamming problems. Hybrid distributed MAC can be used for simultaneous voice, data transmissions in wireless sensor network (WSN) and Internet of Things (IoT) applications. Choosing the correct objective function in Nash equilibrium for game theory will address fairness index and resource allocation to the nodes. Game theory optimization for distributed may increase the network performance. The purpose of this study is to survey the various operations that can be carried out using distributive and adaptive MAC protocol. Hill climbing distributed MAC does not need a central coordination system and location-based transmission with neighbor awareness reduces transmission power. Design/methodology/approach Distributed MAC in wireless networks is used to address the challenges like network lifetime, reduced energy consumption and for improving delay performance. In this paper, a survey is made on various cooperative communications in MAC protocols, optimization techniques used to improve MAC performance in various applications and mathematical approaches involved in game theory optimization for MAC protocol. Findings Spatial reuse of channel improved by 3%–29%, and multichannel improves throughput by 8% using distributed MAC protocol. Nash equilibrium is found to perform well, which focuses on energy utility in the network by individual players. Fuzzy logic improves channel selection by 17% and secondary users’ involvement by 8%. Cross-layer approach in MAC layer will address interference and jamming problems. Hybrid distributed MAC can be used for simultaneous voice, data transmissions in WSN and IoT applications. Cross-layer and cooperative communication give energy savings of 27% and reduces hop distance by 4.7%. Choosing the correct objective function in Nash equilibrium for game theory will address fairness index and resource allocation to the nodes. Research limitations/implications Other optimization techniques can be applied for WSN to analyze the performance. Practical implications Game theory optimization for distributed may increase the network performance. Optimal cuckoo search improves throughput by 90% and reduces delay by 91%. Stochastic approaches detect 80% attacks even in 90% malicious nodes. Social implications Channel allocations in centralized or static manner must be based on traffic demands whether dynamic traffic or fluctuated traffic. Usage of multimedia devices also increased which in turn increased the demand for high throughput. Cochannel interference keep on changing or mitigations occur which can be handled by proper resource allocations. Network survival is by efficient usage of valid patis in the network by avoiding transmission failures and time slots’ effective usage. Originality/value Literature survey is carried out to find the methods which give better performance.

Adaptive Scheduling MAC Protocol in Underwater Acoustic Broadcast Communications for AUV Formation

With the rapid development of autonomous underwater vehicles (AUVs) and the continuous improvement of marine exploration requirements, AUV formation has emerged as a promising technique for performing underwater tasks with greater flexibility, adaptability, and scalability. To achieve AUV formation control, underwater acoustic communication networks (UACNs) are widely used to support information exchange among AUVs. Considering broadcast communications in fully connected mobile UACNs, existing medium access control (MAC) protocols face severe packet collision risk or low reuse efficiency. To improve the timeliness and reliability of the information exchange among AUVs, we develop an efficient scheduling-based adaptive broadcasting MAC (AB-MAC) protocol. The AB-MAC protocol is incompletely centralized, which can be reflected in two aspects. First, to ensure the consistency of the transmission schedule in the network, the AB-MAC protocol selects a control node for each frame to schedule the transmission of all nodes according to the updated network topology. The slot lengths and transmission sequences are changeable in each frame to avoid packet collisions and minimize frame lengths. Second, to further improve the efficiency and robustness of the protocol, all nodes adaptively adjust their transmission time by integrating the information contained in their previously received control packets and ordinary packets. The transmission scheduling problem is formulated as a combinatorial optimization problem, which can be solved by our proposed improved Genetic Algorithm. Numerical results demonstrate that the AB-MAC protocol not only performs well in terms of network throughput and average update interval but also has a high level of robustness even in low-quality underwater acoustic channels.

A roadmap to developing energy-efficient MAC protocol in wireless sensor networks: a case of ADP-MAC development and implementation

Over the past two decades, hundreds of protocols have been developed for diversified applications of WSN corresponding to different layers in the communication stack. Among these, Media Access Control (MAC) layer protocols are of great interest due to providing possibility of optimizing performance parameters. Despite availability of a large number of survey articles, there remains a gap for a tutorial that offers guidelines about the development process of MAC protocol. In this paper, we present a detailed tutorial for developing a MAC protocol starting from the stage of research gap identification and ending at the performance evaluation. We described the journey of development and implementation of a novel asynchronous MAC protocol ADP-MAC (Adaptive and Dynamic Polling MAC) as a case study. ADP-MAC was developed by deploying a novel concept of channel polling interval distributions, and was compared against Synchronized Channel Polling- MAC (SCP-MAC) and lightweight Traffic Auto-Adaptation based MAC (T-AAD). Finally, we proposed major milestones of protocol development along with recommendations about publishing the research.

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.

PeerProbe: Estimating Vehicular Neighbor Distribution With Adaptive Compressive Sensing

Acquiring the geographical distribution of neighbors can support more adaptive media access control (MAC) protocols and other safety applications in Vehicular ad hoc network (VANETs). However, it is very challenging for each vehicle to estimate its own neighbor distribution in a fully distributed setting. In this paper, we propose an online distributed neighbor distribution estimation scheme, called PeerProbe, in which vehicles collaborate with each other to probe their own neighborhood via simultaneous symbol-level wireless communication. An adaptive compressive sensing algorithm is developed to recover a neighbor distribution based on a small number of random probes with non-negligible noise. Moreover, the needed number of probes adapts to the sparseness of the distribution. We implement a prototype system to verify the feasibility of PeerProbe in various typical vehicular channel conditions. We further conduct extensive simulations and the results demonstrate that PeerProbe is lightweight and can accurately recover highly dynamic neighbor distributions in critical channel conditions.

ASMAC: An Adaptive Slot Access MAC Protocol in Distributed VANET

The media access control (MAC) protocol is responsible for channel resource sharing and conflict management in the communication process in VANET, which is of great significance for ensuring efficient and reliable communication. The existing MAC protocol with fixed time slot allocation cannot solve the problem of time slot resource exhaustion or waste when the traffic density is unbalanced. In this paper, we propose an adaptive time slot access MAC protocol in distributed VANET (ASMAC). ASMAC adapts the access time slot according to the driving direction of the vehicle and the traffic density ratio to improve the time slot access efficiency. In the ASMAC protocol, the frame is divided into several time slots based on TDMA, and the time slots in a frame are divided into two time slot sets according to the driving direction. The vehicle selects a time slot access corresponding to the time slot set. When the vehicle finds that there is no accessible time slot in the time slot set, it accesses the available time slot in the reverse time slot set to improve the efficiency of time slot access. In this paper, the analysis and simulation results of highway and four-way intersection scenarios are given and the validity of the ASMAC protocol is verified by comparing with the VeMAC and SAMD protocols.

Improving communication protocols in smart cities with transformers

Adaptive medium access control (MAC) protocols are essential in the context of Vehicular AdHoc Networks (Vanets) because of the rapid changes in topology caused by the high mobility of nodes. In this work, we propose an adaptive version of the Slotted-ALOHA (S-ALOHA) protocol, where the transmission probability is constantly adjusted based on estimates of the number of vehicles in the coverage area. These values are computed using deep learning models for time series prediction. One challenge for implementing this approach is that the inputs to the models are noisy since they are also estimates based on the protocol’s operation itself. To address this problem, we propose a new training scheme where we add noise, similar to that produced by the protocol’s operation, to the inputs of the training examples as a form of regularization. Our experiments show that the regularized models perform close to the theoretical optimal where the number of vehicles in the area is always known.

Efficient MAC Adaptive Protocol on Wireless Sensor Network

Wireless Sensor Networks (WSNs) have attracted a lot of attention from the research community and industry in recent years. WSNs maintenance associated with battery replacement can increase system operating costs, especially for wireless sensor networks located in hard-to-reach and dangerous places. In this study, an adaptive Medium Access Control (MAC) is proposed that can regulate the period of data acquisition and transmission. In contrast to conventional MAC, the applied adaptive MAC regulates the data transmission period based on the estimated energy use in the previous cycle. This study focuses on comparing energy efficiency between conventional and adaptive MAC. Energy usage information is retrieved directly on the sensor node. In star topology, the proposed MAC can increase the lifetime of the sensor network up to 6.67% in a star topology. In the hierarchical topology, the proposed MAC can increase network energy efficiency up to 9.17%. The resulting increase in network throughput is 17.73% for the Star network and 33.81% for the Hierarchy network. The star topology without implementing adaptive MAC has the lowest throughput of 0.188 kb/s. The highest throughput is achieved by a hierarchical topology that applies MAC with a throughput of 2.157 kb/s.

A flexible and adaptive medium access control protocol for improving quality of service in vehicular ad-hoc networks

Designing MAC (Medium Access Control) protocols for VANETs is a difficult task due to the inherently unstable nature of these networks when compared to traditional ad hoc networks (high node speed, position changes that lead to disconnections, signal losses, etc.). In recent years, several standardization efforts have been made by the IEEE in association with the scientific community in this area and they proposed the 1609.4 MAC protocol in the IEEE WAVE (Wireless Access in Vehicular Environments) stack. The aim of our work is to improve the quality of service and overall performances of this 1609.4 MAC protocol by proposing three mechanisms. First, we introduce an equity algorithm that aims to ensure more fairness between nodes. We also adapt the SCH (Service CHannel) interval to the network's needs with a dynamic SCH interval mechanism. Finally, we propose an emergency mechanism that aims to ensure the transmission of critical safety packets when dangerous events occur on the road. The results of our simulations show a significant improvement of the protocol's performances in terms of throughput, packet loss and critical packet delivery rates under several scenarios.

A new medium access control mechanism for energy optimization in WSN: traffic control and data priority scheme

Over the last few years, energy optimization in wireless sensor networks (WSNs) has drawn the attention of both the research community and actual users. Sensor nodes are powered by attached batteries that are considered as a critical aspect of sensor nodes design. Besides, the constraint of the limited battery capacity is associated with the concern on how to reduce the energy consumption of nodes to extend the network lifetime. In this context, the purpose of this study is to implement an adaptive medium access control (MAC) for energy saving and traffic control enhancement. This program was designed to arrange nodes into two priority groups according to their traffic rate and data transmission packet delay. This fuzzy algorithm depends on their queue length where it is implemented into the carrier sense multiple access with collision avoidance (CSMA/CA) algorithm. However, other types of nodes should send their data during the contention-free period with a GTS reallocation scheme. Those nodes are classified as low priority access to the medium, and their data transmission is scheduled using time division multiple access methods. Moreover, this proposed scheme dynamically adjusts the contention access period length to ensure that nodes can complete their data transmission during the same super-frame. Simulation results are done using the network simulator tool (NS-2), and it has improved efficiency regarding the IEEE-802.15.4 standard.

EA-MAC: A QoS Aware Emergency Adaptive MAC Protocol for Intelligent Scheduling of Packets in Smart Emergency Monitoring Applications

The evolution of the wireless sensor network (WSN) in recent years has reached its greatest heights and applications are increasing day by day, one such application is Smart Emergency Monitoring Systems (SMESs) which is in vision of implementation in every urban and rural areas. The implementation of WSN architecture in the Smart Monitoring Systems needs an intelligent scheduling mechanism that efficiently handles the high traffic load as well as the emergency traffic load without sacrificing the energy efficiency of the network. However, the traditional scheduling algorithms such as First Come First Served (FCFS), Round Robin, and Shortest Job First (SJF) cannot meet the requirements of high traffic load in SMESs. To address these shortcomings, this paper presents Emergency Adaptive Medium Access Control protocol (EA-MAC), a fuzzy priority scheduling based Quality-of-service (QoS)-aware medium access control (MAC) protocol for hierarchical WSNs. EA-MAC protocol employs the most powerful fuzzy logics to schedule the sensor nodes with both normal and emergency traffic load without any data congestion, and packet loss and maintaining the better QoS which is considered to be more important in SMESs applications. Moreover, a novel rank-based clustering mechanism in EA-MAC protocol prolongs the network lifetime by minimizing the distance between the Cluster Head (CH) and the Base Station (BS). Both analytical and simulation models demonstrate the superiority of the EA-MAC protocol in terms of energy consumption, transmission delay and data throughput when compared with the existing Time Division Multiple Access (TDMA) based MAC protocols such as LEACH protocol and Cluster Head Election Mechanism-Based On Fuzzy Logic (CHEF) protocol.

An Adaptive Channel Division MAC Protocol for High Dynamic UAV Networks

Nowadays, unmanned aerial vehicle (UAV) has captured great attentions for its versatility, flexibility, and low-cost. In this paper, we consider a high altitude platform (HAP) assisted UAV network towards Internet of Things (IoT), where high dynamic UAVs can transmit real-time IoT data to remote ground control center via the HAP. Because of the movement characteristic of UAVs, the number of UAVs within the HAP coverage and the traffic load change frequently, which poses new challenges for the Media Access Control (MAC) protocol in this network. To make full use of the channel resources and guarantee the communication performance of multiple UAVs, we firstly propose an adaptive channel division MAC (ACD-MAC) protocol for this high dynamic UAV network, where the relative length of control channel interval to service channel interval, denoted by channel allocation parameter, can be flexibly adjusted according to the number of UAVs and traffic load. Then, based on a Markov model, we give an algorithm to calculate the optimal channel allocation parameter in the proposed ACD-MAC protocol. Finally, simulation results show that the proposed ACD-MAC protocol can achieve a lower end-to-end delay and a higher throughput performance in such a high dynamic UAV network than the traditional fixed channel division MAC protocol.

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.

Fast Q-Learning for Improved Finite Length Performance of Irregular Repetition Slotted ALOHA

In this paper, we study the problem of designing adaptive Medium Access Control (MAC) solutions for wireless sensor networks (WSNs) under the Irregular Repetition Slotted ALOHA (IRSA) protocol. In particular, we optimize the degree distribution employed by IRSA for finite frame sizes. Motivated by characteristics of WSNs, such as the restricted computational resources and partial observability, we model the design of IRSA as a Decentralized Partially Observable Markov Decision Process (Dec-POMDP). We have theoretically analyzed our solution in terms of optimality of the learned IRSA design and derived guarantees for finding near-optimal policies. These guarantees are generic and can be applied in resource allocation problems that exhibit the waterfall effect , which in our setting manifests itself as a severe degradation in the overall throughput of the network above a particular channel load. Furthermore, we combat the inherent non-stationarity of the learning environment in WSNs by advancing classical Q-learning through the use of virtual experience (VE), a technique that enables the update of multiple state-action pairs per learning iteration and, thus, accelerates convergence. Our simulations confirm the superiority of our learning-based MAC solution compared to traditional IRSA and provide insights into the effect of WSN characteristics on the quality of learned policies.

Emergency traffic adaptive MAC protocol for wireless body area networks based on prioritization.

This paper proposes an emergency Traffic Adaptive MAC (eTA-MAC) protocol for WBANs based on Prioritization. The main advantage of the protocol is to provide traffic ranking through a Traffic Class Prioritization-based slotted-Carrier Sense Multiple Access/Collision Avoidance (TCP-CSMA/CA) scheme. The emergency traffic is handled through Emergency Traffic Class Provisioning-based slotted-CSMA/CA (ETCP-CSMA/CA) scheme. The emergency-based traffic adaptivity is provided through Emergency-based Traffic Adaptive slotted-CSMA/CA (ETA-CSMA/CA) scheme. The TCP-CSMA/CA scheme assigns a distinct, minimized and prioritized backoff period range to each traffic class in every backoff during channel access in Contention Access Period (CAP). The ETCP-CSMA/CA scheme delivers the sporadic emergency traffic that occurs at a single or multiple BMSN(s) instantaneously, with minimum delay and packet loss. It does this while being aware of normal traffic in the CAP. Then, the ETA-CSMA/CA scheme creates a balance between throughput and energy in the sporadic emergency situation with energy preservation of normal traffic BMSNs. The proposed protocol is evaluated using NS-2 simulator. The results indicate that the proposed protocol is better than the existing Medium Access Control (MAC) protocols by 86% decrease in packet delivery delay, 61% increase in throughput, and a 76% decrease in energy consumption.

FM‐MAC: A fast‐mobility adaptive MAC protocol for wireless sensor networks

AbstractAs a subset of the internet of things, wireless sensor networks (WSNs) are increasingly composed of mobile nodes (MNs) to meet the emerging needs. However, nodes mobility presents significant challenges to the design of effective communication protocols, especially at the medium access control (MAC) sublayer. Interestingly, the existing mobility support MAC solutions consider only scenarios requiring slow mobility. Nowadays, some WSN applications require employing high‐speed MNs for some specific tasks. Consequently, the mobility impact is sharp as the existing solutions could no longer guarantee the quality‐of‐service requirements. To deal with high‐speed mobility, we propose in this paper a fast‐mobility adaptive MAC (FM‐MAC) protocol. The FM‐MAC protocol adopts the contention‐based access approach and introduces new mechanisms to enhance both mobility and communication management in WSNs. Our proposal consists of four contributions, ie, (1) an improved algorithm for autonomous mobility‐detection, (2) a new intercluster handover mechanism, (3) a priority‐based contention mechanism prioritizing MNs to access the medium, and finally, (4) a multichannel communication strategy intended to enhance the throughput and communication management aspects. Extensive simulations are conducted to compare FM‐MAC protocol with existing well‐known mobility‐aware MAC protocols. Results and discussion disclose that FM‐MAC performs better in both static and mobile scenarios in terms of reliability, latency, and energy saving. As expected, the advantage of FM‐MAC over its counterparts becomes more evident as the mobility speed increases.

Design of an adaptive medium access control protocol for wireless body area networks with heterogeneous sensors

The IEEE 802.15.6 standard emerged as the most suitable standard that fits the special requirements of wireless body area networks. It provides flexibility to designers by recommending the use of several medium access control layer techniques, but does not specify how to combine some or all these recommended techniques to form the most efficient wireless body area network medium access control for a specific scenario. Our goal here is to design a wireless body area network medium access control that provides an optimal combination of these basic techniques that are available in the standard, by taking into consideration the variability and heterogeneity of the sensors. The performance of the proposed techniques is evaluated using some of the standard performance measures such as throughput, delay, and energy consumption.