Sensor MAC Research Articles

Optimizing the Data Acquisition Cycle Time of a Sensor MAC in Industrial WSNs

To reduce the damage of people and properties in industry fields, the response time of a MAC protocol should be kept as small as possible. Among the solutions suggested by various MAC protocols, shortening the data acquisition cycle time (DACT) is considered as the most effective way of reducing the response time. However, a small DACT is often fails to provide the sensor nodes with a sufficient time duration to transmit their data packets in TDMA-based MAC protocols while it surely increases the degree of contention among the sensor nodes in CSMA-based MAC protocols. In summary, a WSN with a small DACT usually fails to attain the satisfactory level of data transmission efficiency in WSNs. On the contrary, a WSN with a large DACT incurs an excess delay in data packet transmission. Therefore, we propose an analytical study for calculating the expected size of time slots so that an optimized DACT can be found. Our optimized DACT is precisely suited to the level-order data transmission that greatly improves the data transmission efficiency in industrial WSNs. In simulation experiments, it is shown that the proposed approach attains a higher packet deliver ratio than that of other competing approaches. Keywords— data acquisition cycle time, data aggregation, packet delivery ratio, probability distribution function, sharable time slot.

SMAC-Based WSN Protocol-Current State of the Art, Challenges, and Future Directions

Wireless Sensor Networks (WSNS) have become an indispensable tool in this epoch of technological advancements, particularly for progress made in the Internet of things. Wireless sensor nodes are deployed to collect and transmit vital data from the environment to a base station for analysis. Nevertheless, the limited battery power of the sensor nodes is rapidly drained when they stay awake for an extended period. Research has shown that significant sources of energy dissipation of sensor nodes are idle listening, packet collision, control overhead, and overhearing. One optimal solution is employing a low duty cycle mac protocol, particularly the sensor mac (SMAC) protocol. It is essential to have a detailed knowledge of the challenges identified in SMAC and solutions suggested to mitigate these challenges and the future directions. In this paper, we review techniques in SMAC protocols implemented in WSNS. In particular, we provide highlights of recent developments in the schemes used in SMAC for mitigating the challenges in SMAC and present research gaps in SMAC protocol. Finally, we discuss open issues that need to be addressed to advance the design and implementation of SMAC in WSN applications.

A Comprehensive Survey of Energy-Efficient MAC and Routing Protocols for Underwater Wireless Sensor Networks

Underwater wireless sensor networks (UWSNs) have become highly efficient in performing different operations in oceanic environments. Compared to terrestrial wireless sensor networks (TWSNs), MAC and routing protocols in UWSNs are prone to low bandwidth, low throughput, high energy consumption, and high propagation delay. UWSNs are located remotely and do not need to operate with any human involvement. In UWSNs, the majority of sensor batteries have limited energy and very difficult to replace. The uneven use of energy resources is one of the main problems for UWSNs, which reduce the lifetime of the network. Therefore, an energy-efficient MAC and routing techniques are required to address the aforementioned challenges. Several important research projects have been tried to realize this objective by designing energy-efficient MAC and routing protocols to improve efficient data packet routing from Tx anchor node to sensor Rx node. In this article, we concentrate on discussing about different energy-efficient MAC and routing protocols which are presently accessible for UWSNs, categorize both MAC and routing protocols with a new taxonomy, as well as provide a comparative discussion. Finally, we conclude by presenting various current problems and research difficulties for future research.

A Multicast-based MAC Protocol for Improving Data Transmission Efficiency in Industrial WSNs.

In industrial WSNs, attaining the desired level of data transmission efficiency is highly challenging not only for a frequently changing network topology but also for a short data acquisition cycle time. A short data acquisition time often restrains a sensor MAC protocol to incorporate an effective data packet salvaging technique. Therefore, we propose a data transmission technique in which a sending node multicasts data packets to all candidate parents including its primary parent. As a result, the necessity of data retransmission attempts is totally avoided, which greatly improves the data transmission efficiency in industrial WSNs. By simulation experiments, we have shown that the proposed multicast-based MAC protocol surpasses all the competing MAC protocols regarding the successful data packet delivery and power saving with a significant margin

Energy Efficiency In Wireless Sensor Network Using Dynamic Duty Cycle Based Sensor Mac

Wireless Sensor Network is created by a huge number of sensor nodes normally powered by batteries and may not easily recharged. To extend the lifetime of the sensor node is a vital issue while designing a protocol in WSN. However, lowering the energy consumption may result in higher latency. To address on such trade-off issues, this paper proposes Sensor MAC (SMAC) dynamic duty cycle to improve SMAC fixed duty-cycle. S-MAC adjusts the duty-cycle based on dynamic utilization and average sleep delay. The proposed topology which is distributive in nature, controls the technique to schedule the nodes to wakeup time slots, and design a SMAC protocol to get benefitted from this topology control for improving the energy-efficiency, delay, and efficiently handling the spatially-correlated contention. Compared to Fixed SMAC the Dynamic SMAC lowers the Energy consumption in Fixed SMAC and performs very good Energy saving in circular, grid and random topologies.

Optimization Method of Adaptive Backoff and Duty Cycle for S-MAC Protocol in Wireless Sensor Networks

As a matter of fact that the network traffic has a great influence on the binary exponential backoff mechanism, duty cycle mechanism, and fixed transmission power mechanism adopted by the Sensor Medium Access Control (S-MAC) protocol. The paper proposes an Adaptive Backoff and Duty Cycle for S-MAC protocol (ABDC-SMAC). In the backoff mechanism, considering the failure times of channel competitions, the length of buffer queue, and the node residual energy across the board, a cross-control backoff mechanism is proposed. In the duty cycle mechanism, the network traffic is judged by the average network flow factor. Based on the average network flow factor, the value of duty cycle can change around its initial value. In the power control mechanism, the minimum transmission power can be obtained by the Friis formula. At the same time, the exponential formula following the change of network traffic is selected and multiplied by the minimum transmission formula. The simulation results show that the performance of proposed ABDC-SMAC protocol is improved obviously on energy consumption and transmission delay.

Authenblue: A New Authentication Protocol for the Industrial Internet of Things

The Internet of Things (IoT) is where almost anything can be controlled and managed remotely by means of sensors. Although the IoT evolution led to quality of life enhancement, many of its devices are insecure. The lack of robust key management systems, efficient identity authentication, low fault tolerance, and many other issues lead to IoT devices being easily targeted by attackers. In this paper we propose a new authentication protocol called Authenblue that improve the authentication process of IoT devices and Coordinators of Personal Area Network (CPANs) in an Industrial IoT (IIoT) environment. This study proposed Authenblue protocol as a new Blockchain-based authentication protocol. To enhance the authentication process and make it more secure, Authenblue modified the way of generating IIoT identifiers and the shared secret keys used by the IIoT devices to raise the efficiency of the authentication protocol. Authenblue enhance the authentication protocol that other models rely on by enhancing the approach used to generate the User Identifier (UI). The UI values changed from being static values, sensors MAC addresses, to be generated values in the inception phase. This approach makes the process of renewing the sensor keys more secure by renewing their UI values instead of changing the secret key. In this study, Authenblue has been simulated in the Network Simulator 3 (NS3). Simulation results show an improved performance compared to the related work.

VTA-SMAC: Variable Traffic-Adaptive Duty Cycled Sensor MAC Protocol to Enhance Overall QoS of S-MAC Protocol

Sensing and monitoring the physical conditions are basic purposes of Wireless Sensor Networks (WSN). Sensor nodes are the building blocks of WSN and they are battery operated. Battery charging or changing is impossible in harsh areas of deployment, so battery life needs to be maximized by improving the MAC protocol. If the Duty Cycle is selected wisely, it may reduce energy utilizations of a wireless sensor network, but it may impact other factors of WSN as well. Optimum duty cycle for a specific data traffic may not be optimal for other levels of data traffic and it may negatively affect the performance of a wireless sensor network. An adaptive duty cycle algorithm, VTA-SMAC (Variable Traffic-Adaptive Duty Cycle Sensor MAC) is proposed to reduce the problem of idle listening or collisions and to reduce energy consumption of traditional S-MAC protocol. VTA-SMAC algorithm was simulated in Network Simulator NS-2 and simulation results were evaluated to assess the impact of duty cycle variation on performance of S-MAC, particularly energy conservation with condition of varying data traffic. Impact of duty cycle variation in accordance with data traffic were also evaluated on various factors like latency, throughput, collisions, delay, jitter, and packet delivery ratio etc. Trade-off between energy consumption and latency was also studied. Simulation results show that VTA-SMAC improves energy conservation by 19.9 %, 14.4 % and 20.2 % at low, medium, and high traffic, respectively. Latency is also decreased by 10.2 %, 7.5 % and 18.9 % at low, medium, and high traffic, respectively.

I-MAC: In-Body Sensor MAC in Wireless Body Area Networks for Healthcare IoT

The application of Internet-of-Things (IoT) technology in modern healthcare environment has given rise to a new paradigm known as healthcare IoT. The wireless body area network (WBAN) is one of the basic building blocks of IoT-based healthcare system, comprising many wearable (on-body) and implant (in-body) sensors placed in or around patient body connected to a hub for physiological signal monitoring. In in-body sensor-based WBAN, guaranteeing quality-of-service and prolonging network lifetime are major impediments due to the sensor location and limited battery capacity. In this article, we propose a novel energy-efficient medium access control (MAC) protocol for IEEE 802.15.6 standard complaint in-body sensor-based WBAN. Typically, the in-body sensor-based WBAN communication is hub-initiated; however, in case of an emergency event, the in-body sensor node transmits an emergency frame arbitrarily without sensing the channel. This inadvertent in-body sensor-initiated transmission has a very high probability of collision with the ongoing hub-initiated transmission, and/or another in-body sensor-initiated emergency frame transmission. This results in emergency frame retransmission and consequently affects the node's energy consumption and lifetime. To alleviate this issue, we propose a modified superframe structure, in which separate access phases are introduced for the emergency event and regular event. In case of an emergency event, a novel emergency event handling scheme and a ranking and priority assignment protocol is proposed to detect and address the critical event of in-body sensors. To minimize the collision, a scheduled access mechanism is proposed according to the criticality of the node. Performance analysis of the proposed in-body sensor MAC is done in terms of latency and overall power consumption, in case of both emergency and regular events.

Bird-MAC: Energy-Efficient MAC for Quasi-Periodic IoT Applications by Avoiding Early Wake-up

We propose a new MAC protocol for IoT applications, called Bird-MAC, which is highly energy efficient in the applications where IoT sensors report monitoring status in a quasi-periodic manner, as in structural health monitoring and static environmental monitoring. Two key design ideas of Bird-MAC are: (a) no need of early-wake-up of transmitters and (b) taking the right balance between synchronization and coordination costs. The idea (a) is possible by allowing a node (whether it is a transmitter or receiver) to wake up just with its given wake-up schedule, and letting a late bird (which wakes up later) notify its wake-up status to its corresponding early bird (which wakes up earlier), where the early bird just infrequently waits for the late bird's wake-up signal. The idea (b) is realized by designing Bird-MAC to be placed in a scheme between purely synchronous and asynchronous schemes. We provide a rigorous mathematical analysis that is used to choose the right protocol parameters of Bird-MAC. We demonstrate the performance of Bird-MAC through extensive simulations, and real experiments. The experiment on our testbed using a 26 node testbed at an underground parking lot of our office building to monitor its structural health shows that energy consumption is reduced by about up to 45 percent over existing sensor MAC protocols. We also confirm the applicability of Bird-MAC in a challenging and realistic scenario through the experiment on Yeongjong Grand Bridge in South Korea.

An energy efficient IS-MAC based on distributed coordination function (DCF) for wireless passive sensor networks

This work presented the depth analysis on various (MAC) layer protocols and designed algorithm. All these methods have been implemented and modified for the wireless networks. Some existing MAC algorithms are introduced with their problem and evaluation. Lastly, evaluation of various form of WSN behalf of the MAC present algorithms (such as S-MAC, IEEE802.11) to our proposed work. A new MAC algorithm is proposed on the concept of S-MAC issues which have contentions window (CWs) according to carrier - sense his secure in S-MACI & IS-MACI algorithm and capable to modify CW based on the system traffic, energy spent reduced in IS-MAC (Improved Sensor MAC). Same MAC algorithm is modified with DCF-MAC protocol to improve successful data transmission and energy consumption in the network. All the work carried on the NS2 network simulator.

Improving Duty Cycle-based MAC Protocol in Wireless Networks using AI and Machine Learning

Duty cycle of a Medium Access Control (MAC) protocol is made up of sleep phase, wake-up phase and listen phase. MAC protocols usually proposes to optimize the duration of the wake-up and listen phases, in order to increase the duration of the sleep phase, thereby reducing the unwanted energy consumption of the wireless node. In this paper, we propose an Artificial Intelligence (AI) and machine learning (ML) based approach, which uses a hybrid combination of Time Division Multiple Access (TDMA), Bitmap Assisted MAC (BMA) and Sensor MAC (SMAC). The machine learning layer utilizes the duty cycle in the MAC layer, and generates multiple solutions for a given wireless communication. The AI layer then selects the best solution from the generated solutions by incorporating a duty cycle factor in the selection function, thereby optimizing the duty cycle of the protocol. The proposed system shows a 15% improvement in communication speed, and a 10% reduction in energy consumption across multiple communications. We plan to further extend this work for rural India, and apply it to real time agricultural applications.

Performance Evaluation of Wireless Sensor Network MAC protocols with Early Sleep problem

Energy efficiency and increased throughput are the two major goals in the design of MAC protocols in wireless sensor networks (WSNs). The traditional sensor-MAC (S-MAC) and timeout-MAC (T-MAC) protocols have been proposed to achieve these dual desirable goals by proper scheduling of duty cycles. Although these protocols have been proved to excel the performance when compared with their predecessor protocols for MANETs, the idea of duty cycling, if not tuned carefully may not work well in some linear chain topologies. We, in this paper investigated the 'early sleep' problem in specific topologies which results in undesirable extended latency in packets delivery. In this paper, we evaluated the performance of T-MAC protocol with early sleep problem. As a solution to this problem, this work also proposes a disable extended timeout MAC (DETMAC) protocol that helps the forwarding nodes towards the sink node to adaptively re-schedule their sleep/wakeup timing. It is shown through simulation results that our proposed DETMAC protocol outperforms in the terms of throughput and energy efficiency when compared to T-MAC and its variants.

Research on Underwater Wireless Sensor Network and MAC Protocol and Location Algorithm

In recent years, underwater wireless sensor networks (UWSNs) have received extensive attention due to their application in the development of marine resources. The underwater acoustic channel has a long delay, low bandwidth, and highly dynamic changes in the underwater environment so that the existing technologies and protocols in the traditional wireless sensor network cannot be directly applied to underwater. This paper studies the medium access control (MAC) protocol and positioning technology of UWSNs and introduces the typical underwater line sensor network MAC protocol. Aiming at the problem of spatial fairness caused by the propagation characteristics of the underwater acoustic channel and the triple terminal problem caused by the long propagation delay in UWSNs, and effectively implementing the multi-channel mechanism, an underwater multi-channel based on a single transceiver is proposed, which is SFM-MAC. The existing underwater positioning algorithms are divided into two categories, centralized positioning algorithm and distributed positioning algorithm, and each type of algorithm is briefly explained. In this paper, the Markov chain is used to construct the reservation model of the control channel, and the theoretical analysis of multi-channel throughput is given. The theoretical throughput of the multi-channel MAC protocol under the condition of reserved collision is obtained. Finally, this paper verifies the actual performance of SFM-MAC through simulation experiments.

MDA-SMAC: An Energy-Efficient Improved SMAC Protocol for Wireless Sensor Networks

In sensor medium access control (SMAC) protocol, sensor nodes can only access the channel in the scheduling and listening period. However, this fixed working method may generate data latency and high conflict. To solve those problems, scheduling duty in the original SMAC protocol is divided into multiple small scheduling duties (micro duty MD). By applying different micro-dispersed contention channel, sensor nodes can reduce the collision probability of the data and thereby save energy. Based on the given micro-duty, this paper presents an adaptive duty cycle (DC) and back-off algorithm, aiming at detecting the fixed duty cycle in SMAC protocol. According to the given buffer queue length, sensor nodes dynamically change the duty cycle. In the context of low duty cycle and low flow, fair binary exponential back-off (F-BEB) algorithm is applied to reduce data latency. In the context of high duty cycle and high flow, capture avoidance binary exponential back-off (CA-BEB) algorithm is used to further reduce the conflict probability for saving energy consumption. Based on the above two contexts, we propose an improved SMAC protocol, micro duty adaptive SMAC protocol (MDA-SMAC). Comparing the performance between MDA-SMAC protocol and SMAC protocol on the NS-2 simulation platform, the results show that, MDA-SMAC protocol performs better in terms of energy consumption, latency and effective throughput than SMAC protocol, especially in the condition of more crowded network traffic and more sensor nodes.

Self-adaptive implicit contention window adjustment mechanism for QoS optimization in wireless sensor networks

Synchronous contention-based medium access control (MAC) protocols play a vital role in the delay guarantee essentially required by many recent delay-sensitive applications. Great efforts have been made to improve the end-to-end delay by means of optimizing the medium access performance. However, their effectiveness is still constrained by the contradiction between reducing the collision probability and idle listening duration. Instead of traditional tradeoff strategies, developing a way to further alleviate the contradiction is definitely beneficial for further improving the medium access performance. To this end, a self-adaptive implicit contention window adjustment mechanism for SMAC (Sensor MAC) is proposed based on the investigation of the medium competition behavior impacting the medium access delay and delay jitter, from the perspective of any given contending node. We mathematically derive the expected medium access delay for revealing the strengths and weaknesses of typical dynamic contention window mechanisms. Moreover, it is discovered that their delay-oriented optimizing window only offers fairly limited improvement in the medium access performance since the uniformly random slot-selection mechanism results in high delay jitter and the contradiction between reducing the collision probability and idle listening duration. In order to overcome this drawback, furthermore, an optimization model of the node contention priority distribution is proposed to alleviate the aforementioned contradiction by means of optimizing slot-selection mechanism. Finally, a self-adaptive implicit contention window adjustment (SICA) mechanism is designed integrating delay-oriented optimizing contention window, contention priority optimization model with the estimation method of contenders' number. Through simulations in OMNeT++, the results demonstrate that the proposed SMAC-SICA outperforms its peers in terms of delay guarantee, energy efficiency and throughput.

Energy Consumption Reduction in S-MAC Protocol for Wireless Sensor Network

Wireless Sensor Networks (WSNs) have emerged as one of the prominent area of research in the recent times. Sensor-MAC (S-MAC) protocol is one of the Medium Access Control(MAC)protocols, which follows the idea of periodic listen and sleep. In other words, node is active till the time it receives the data packets, otherwise it goes in sleep mode by turning its radio off. However, this protocol lacks in energy conservation due to unnecessary listening to the channel in idle mode.In this paper, we have proposed a new analytical model in which energy is reduced on the basis of the activities it performs in the active mode. A comparison is made between all the different possibilities which can occur at a node, when it listens unnecessarily to the medium. Various energy consuming modes of S-MAC protocol such as transmission, reception, sensing and listening are considered. The proposed work results in the minimizing the energy and reducing the delay in time as compared to that of basic S-MAC protocol.

Effect of Increasing Number of Nodes on Performance of SMAC, CSMA/CA and TDMA in MANETs

The importance of Wireless Sensor Network (WSN) increases due to deployment for geographical, environmental and surveillance purpose in war fields. WSN facing several challenges due to its complex nature including key problems, such as routing and medium access control protocols. Several approaches were proposed for the performance evaluation of WSN on the basis of these issues due to the fact that MAC layer access protocols have a great impact on the performance of WSN. In this paper, we investigated the performance evaluation of three well known MAC Access protocols, i.e. sensor medium access control protocol (SMAC), carrier sense multiple access with collision avoidance (CSMA/CA), and time division multiple access (TDMA) over adhoc on demand distance vector (AODV) routing protocol. The number of simulation scenarios were carried out by using NS- 2, the simulation metrics used are throughput, end-to-end delay and energy consumed. Simulation results showed that SMAC out perform CSMA/CA and TDMA by consuming less energy, less end to end delay and high throughput due to contention based approach to access the medium for transmission.

Setting strategy of delay-optimization-oriented SMAC contention window size.

Some frame components, such as SYNC (frame synchronization) and RTS/CTS (Ready to Send/Clear to Send), are not taken into consideration when the traditional setting strategies conduct the optimization of SMAC (Sensor MAC) contention window size. This paper proposes mathematical models that allow the analysis of data packets forwarding delay within one SMAC virtual cluster. Simulation results in OMNeT++ show good agreements with the proposed mathematical models, validating the models’ correctness. The curve analyses of the models confirm the existence of delay-optimization-oriented contention window size that is closely related to the number of simultaneously contending nodes. Afterwards, it is shown that SYNC, RTS/CTS and EIFS (Extended InterFrame Space) have impacts on the optimal contention window size and expected delivery delay to various degrees, as well as throughput and energy efficiency. One ideal setting strategy of delay-optimization-oriented SMAC contention window size requires the combination of the network scale, SYNC, RTS/CTS and EIFS. Additionally, it is demonstrated that the proposed setting strategy makes contributions to the improvement in the existing SMAC extensions when they are integrated with each other, in terms of the end-to-end delay, throughput and energy consumption.

An Energy Efficient MAC Protocol for Wireless Passive Sensor Networks

Medium Access Control (MAC) protocol is one of the key network protocols that ensure Wireless Sensor Networks (WSNs) maintain high performance during communication. MAC protocol design plays an important role in improving the performances of the whole network. First, Wireless Passive Sensor Networks (WPSNs) and MAC protocols are introduced in this paper. Second, some existing MAC protocols are introduced. Sensor MAC (S-MAC) protocol is analyzed and existing improved backoff algorithms are introduced. A new MAC protocol called Improved Sensor MAC (IS-MAC) is then proposed to solve the problem that the contention window (CW) during carrier sense is fixed in S-MAC protocol. IS-MAC protocol is able to adjust CW in terms of network load, so energy consumption can be decreased. Finally, according to the simulation results on NS2, the proposed protocol has better performance in terms of throughput and energy consumption.