Medium Access Control Protocol For Wireless Sensor Networks Research Articles

Conceptual Framework for Future WSN-MAC Protocol to Achieve Energy Consumption Enhancement.

Nowadays, the rapid deployment of Wireless Sensor Networks (WSNs) and the integration of Internet of Things (IoT) technology has enabled their application to grow in various industrial fields in our country. Various factors influence the success of WSN development, particularly improvements in Medium Access Control (MAC) protocols, for which WSNs-IoT are deemed vital. Several aspects should be considered, such as energy consumption reduction, performance, scalability for a large deployment of nodes, and clustering intelligence. However, many protocols address this aspect in a constrained view of handling the medium access. This work presents a state-of-the-art review of recently proposed WSN MAC protocols. Different methods and approaches are proposed to enhance the main performance factors. Various performance issue factors are considered to be the main attribute that the MAC protocol should support. A comparison table is given to provide further details about using these approaches and algorithms to improve performance issues, such as network throughput, end-to-end delay, and packet drop, translated into energy consumption.

Energy-efficient MAC protocols for wireless sensor networks: a survey

Wireless sensor network (WSN) is a network of a large number of battery-powered tiny sensor nodes wirelessly connected together to facilitate a wide range of monitoring applications. As WSN nodes are energy-constrained microelectronic devices, the primary design objective of WSNs is to minimise energy consumption to prolong the network lifetime. To achieve this goal, a range of cross-layer techniques, particularly focusing on medium access control (MAC) sublayer, is proposed targeting different WSN applications. This paper aims to survey low-power WSN MAC protocols, proposed from 2000 to the present, emphasising some general aspects including the issues addressed, the solutions proposed, design principles, strengths, drawbacks and target applications. With this aim, we mainly classify the MAC protocols into three categories: contention-based protocols, time division multiple access (TDMA)-based protocols and hybrid protocols, where the first category is further subdivided into subclasses. The development trends and potential research challenges are also discussed.

Minimizing the Adverse Effects of Asymmetric Links: A Novel Cooperative Asynchronous MAC Protocol for Wireless Sensor Networks.

As Wireless Sensor Networks (WSNs) grow in popularity, researchers are now focusing more on some challenging issues that significantly degrade overall performance, such as energy hole mitigation, link asymmetry minimization, etc. Link asymmetry is a problem that arises when the coverage distance between two adjacent nodes varies. It creates an obstacle to overcome when designing an efficient Medium Access Control (MAC) protocol for WSNs with low duty-cycling. This phenomenon poses an especially difficult challenge for receiver-initiated asynchronous MAC protocols, which are popular due to their relatively higher energy efficiency. Exploiting the benefits of cooperative communication has emerged as one of the viable solutions to overcome this limitation. Cooperative communication in WSNs has received a lot of attention in recent years. Many researchers have worked to create a MAC layer supporting cooperative communication. However, the association of cooperative communication with an asymmetric link is not studied in the literature. In this research work, COASYM-MAC, a cooperative asynchronous MAC protocol for WSNs, is proposed based on a receiver-initiated MAC protocol that uses the fact that nodes have alternate paths between them to reduce link asymmetry. A key feature of the proposed protocol is that the optimal helper node is selected automatically in case of link asymmetry. Simulations exhibited that COASYM-MAC performs significantly better than a state-of-the-art MAC protocol for WSNs that handles asymmetric links, ASYM-MAC.

ETPS-MAC: Energy Traffic Priority Scheduling-based QoS-aware MAC protocol for hierarchical WSNs

ABSTRACTThe 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 Monitoring Systems (SMSs) which is in vision of implementation in every urban and rural areas. The implementation of WSN architecture in SMS needs an intelligent scheduling mechanism that efficiently handles the dynamic traffic load without sacrificing the energy efficiency of network. This paper presents a centralized TDMA scheduling based medium access control (MAC) protocol, called Energy Traffic Priority Scheduling MAC (ETPS-MAC) that accommodates variable traffic load while maintaining Quality-of-Service (QoS) assurance in hierarchical WSNs. The ETPS-MAC protocol employs priority scheduling algorithm which considers two factors for assigning priority, the energy factor and the traffic load factor to avoid packet buffering and maintains minimum data packet delay in case of high traffic load. Moreover, a novel rank-based clustering mechanism in FPS-QMAC 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 ETPS-MAC protocol in terms of energy consumption, transmission delay, data throughput and message complexity when compared with the existing TDMA based MAC protocols.

Designing and Implementing a Lightweight WSN MAC Protocol for Smart Home Networking Applications

Wireless sensor networks (WSNs) represent a promising solution in the fields of the Internet of Things (IoT) and machine-to-machine networks for smart home applications. However, to feasibly deploy wireless sensor devices in a smart home environment, four key requirements must be satisfied: stability, compatibility, reliability routing, and performance and power balance. In this study, we focus on the unreliability problem of the IEEE 802.15.4 WSN medium access control (MAC), which is caused by the contention-based MAC protocol used for channel access. This problem results in a low packet delivery ratio, particularly in a smart home network with only a few sensor nodes. In this paper, we first propose a lightweight WSN protocol for a smart home or an intelligent building, thus replacing the IEEE 802.15.4 protocol, which is highly complex and has a low packet delivery ratio. Subsequently, we describe the development of a discrete event system model for the WSN by using a GRAFCET and propose a development platform based on a reconfigurable FPGA for reducing fabrication cost and time. Finally, a prototype WSN controller ASIC chip without an extra CPU and with our proposed lightweight MAC was developed and tested. It enhanced the packet delivery ratio by up to 100%.

Spatial Correlation Based Cross Layer Approach with Routing in Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are more popular due to the use of low cost sensors with their interfaces. In designing of WSNs, energy conservation is a main issue. The nodes available in WSNs use battery as limited energy source. Various techniques have been proposed to improve the energy efficiency in WSNs. Energy efficient Medium Access Control (MAC) protocol is required for obtaining higher energy efficiency during difficult operating conditions, where node failure and link failures are common. Cross layer approach between data link and network layer is adapted in the proposed work. In the proposed work, the MAC protocols such as Correlation based Collaborative MAC (CC-MAC), CC-MAC combined with Hybrid MAC, Hybrid MAC, Hybrid MAC combined with sensor MAC have been considered for analysis. Two popular routing protocols such as Ad hoc On-demand Distance Vector, Ad hoc On-demand Multipath Distance Vector are also considered to identify the routing performance of the network. The Parameters such as end-to-end delay, packet drop, packet delivery ratio, throughput, energy efficiency are considered to measure the network performance. These parameters are acting as a primary and secondary attributes to design an efficient MAC protocols for WSNs.

The design of a ultra-low power RF wakeup sensor for wireless sensor networks

In wireless sensor networks (WSNs) duty cycling has been an imperative choice to reduce idle listening but it introduces sleep delay Thus, the conventional WSN medium access control protocols are bound by the energy-latency tradeoff. To break through the tradeoff, we propose a radio wave sensor called radio frequency (RF) wakeup sensor that is dedicated to sense the presence of a RF signal. The distinctive feature of our design is that the RF wakeup sensor can provide the same sensitivity but with two orders of magnitude less energy than the underlying RF module. With RF wakeup sensor a sensor node no longer requires duty cycling. Instead, it can maintain a sleep state until its RF wakeup sensor detects a communication signal. According to our analysis, the response time of the RF wakeup sensor is much shorter than the minimum transmission time of a typical communication module. Therefore, we apply duty cycling to the RF wakeup sensor to further reduce the energy consumption without performance degradation. We evaluate the circuital characteristics of our RF wakeup sensor design by using Advanced Design System 2009 simulator. The results show that RF wakeup sensor allows a sensor node to completely turn off their communication module by performing the around-the-clock carrier sensing while it consumes only 0.07% energy of an idle communication module.

Has Time Come to Switch From Duty-Cycled MAC Protocols to Wake-Up Radio for Wireless Sensor Networks?

Duty-cycled Medium Access Control (MAC) protocols certainly improve the energy efficiency of wireless networks. However, most of these protocols still suffer from severe degrees of overhearing and idle listening. These two issues prevent optimum energy usage, a crucial aspect in energy-constrained wireless networks such as wireless sensor networks (WSNs). Wake-up radio (WuR) systems drastically reduce these problems by completely switching off the nodes' microcontroller unit (MCU) and main radio transceiver until a secondary, extremely low-power receiver is triggered by a particular wireless transmission, the so called wake-up call. Unfortunately, most WuR studies focus on theoretical platforms and/or custom-built simulators. Both these factors reduce the associated usefulness of the obtained results. In this paper, we model and simulate a real, recent, and promising WuR hardware platform developed by the authors. The simulation model uses time and energy consumption values obtained in the laboratory and does not rely on custom-built simulation engines, but rather on the OMNET++ simulator. The performance of the WuR platform is compared to four of the most well-known and widely employed MAC protocols for WSN under three real-world network deployments. The paper demonstrates how the use of our WuR platform presents numerous benefits in several areas, from energy efficiency and latency to packet delivery ratio and applicability, and provides the essential information for serious consideration of switching duty-cycled MAC-based networks to WuR.

A Survey on MAC Protocols for Duty-cycled Wireless Sensor Networks

After more than two decades of their introduction, Wireless Sensor Networks (WSNs) remain an active research topic due to their wide range applications in areas such as healthcare, military, monitoring and surveillance systems. In most applications, sensor nodes are constrained in energy supply and communication bandwidth. Therefore, novel techniques to reduce energy inefficiencies and for efficient use of the limited bandwidth resources are essential. Such constraints combined with dense network deployment pose several challenges to the design and management of WSNs and require energy-awareness at all layers of the networking protocol stack. For instance, at the Data-Link layer, low duty cycle Medium Access Control (MAC) protocols trade off latency for energy efficient operation. In this paper, we present a survey of state-of-the-art low duty cycle MAC protocols. We first outline the design challenges for MAC protocols in WSNs. Then, we present a comprehensive survey of the most prominent and recent MAC protocols. These protocols are classified into synchronous and asynchronous based on their mode of operation. Finally, the paper highlight open research problems in MAC layer for WSNs.

Ambient intelligence context-based cross-layer design in wireless sensor networks.

By exchanging information directly between non-adjacent protocol layers, cross-layer (CL) interaction can significantly improve and optimize network performances such as energy efficiency and delay. This is particularly important for wireless sensor networks (WSNs) where sensor devices are energy-constrained and deployed for real-time monitoring applications. Existing CL schemes mainly exploit information exchange between physical, medium access control (MAC), and routing layers, with only a handful involving application layer. For the first time, we proposed a framework for CL optimization based on user context of ambient intelligence (AmI) application and an ontology-based context modeling and reasoning mechanism. We applied the proposed framework to jointly optimize MAC and network (NET) layer protocols for WSNs. Extensive evaluations show that the resulting optimization through context awareness and CL interaction for both MAC and NET layer protocols can yield substantial improvements in terms of throughput, packet delivery, delay, and energy performances.

Efficient Cluster Mobility Support for TDMA-Based MAC Protocols in Wireless Sensor Networks

Node mobility is a key feature of using Wireless Sensor Networks (WSNs) in many sensory applications, such as healthcare. The Medium Access Control (MAC) protocol should properly support the mobility in the network. In particular, mobility is complicated for contention-free protocols like Time Division Multiple Access (TDMA). An efficient access to the shared medium is scheduled based on the node's local neighborhood. This neighborhood may vary over time due to node movement or other dynamics. In scenarios including body-area networking, for instance, some clusters of nodes move together, creating further challenges but also opportunities. This article presents a MAC protocol, MCMAC, that provides efficient support for cluster mobility in TDMA-based MAC protocols in WSNs. The proposed protocol exploits a hybrid contention-free and contention-based communication approach to support cluster mobility. This relieves the protocol from rescheduling demand due to frequent node movements. Moreover, we propose a listening scheduling mechanism to avoid idle listening to mobile nodes that leads to a considerable energy saving for sensor nodes. The protocol is validated by performing several experiments in a real-world large-scale deployment including several mobile clusters. The protocol is also evaluated by extensive simulation of networks with various scales and configurations.

Energy Efficient MAC Protocols for Wireless Sensor Network: A Survey

Wireless Sensor Network (WSN) is an attractive choice for a variety of applications as no wired infrastructure is needed. Other wireless networks are not as energy constrained as WSNs, because they may be plugged into the mains supply or equipped with batteries that are rechargeable and replaceable. Among others, one of the main sources of energy depletion in WSN is communications controlled by the Medium Access Control (MAC) protocols. An extensive survey of energy efficient MAC protocols is presented in this article. We categorise WSN MAC protocols in the following categories: controlled access (CA), random access (RA), slotted protocols (SP) and hybrid protocols (HP). We further discuss how energy efficient MAC protocols have developed from fixed sleep/wake cycles through adaptive to dynamic cycles, thus becoming more responsive to traffic load variations. Finally we present open research questions on MAC layer design for WSNs in terms of energy efficiency

RUF-MAC: Related and Urgent First MAC for Wireless Sensor Networks

Medium Access Control (MAC) protocols of Wireless Sensor Network (WSN) are often required to have special characteristics in concrete applications. Related and Urgent message should be sent First (RUF) is a typical scenario in many applications of WSN. In this paper, we focus on presenting a MAC protocol for RUF applications in WSN. First of all, through analysis, some concrete cases of RUF scenario are listed, from which 4 common requirements of MAC protocols are summed up. Then a novel RUF-MAC is devised to meet these requirements. By modifying the frame structure of IEEE 802.15.4 standards, new algorithms are presented for the assignment and adjustment of time slots, of which some measures are introduced into RUF-MAC, such as sub-frames competition, priority assignment and adaptive period adjustment. The simulation results of data from RUF scenario show that the performance of RUF-MAC is better than that of other MAC protocols for WSN in RUF scenario.

Survey on Latency Issues of Asynchronous MAC Protocols in Delay-Sensitive Wireless Sensor Networks

Energy-efficiency is the main concern in most Wireless Sensor Network (WSN) applications. For this purpose, current WSN MAC (Medium Access Control) protocols use duty-cycling schemes, where they consciously switch a node's radio between active and sleep modes. However, a node needs to be aware of (or at least use some mechanism to meet) its neighbors' sleep/active schedules, since messages cannot be exchanged unless both the transmitter and the receiver are awake. Asynchronous duty-cycling schemes have the advantage over synchronous ones to eliminating the need of clock synchronization, and to be conceptually distributed and more dynamic. However, the communicating nodes are prone to spend more time waiting for the active period of each other, which inevitably influences the one-hop delay, and consequently the cumulative end-to-end delay. This paper reviews current asynchronous WSN MAC protocols. Its main contribution is to study these protocols from the delay efficiency perspective, and to investigate on their latency. The asynchronous protocols are divided into six categories: static wake-up preamble, adaptive wake-up preamble, collaborative schedule setting, collisions resolution, receiver-initiated, and anticipation-based. Several state-of-the-art protocols are described following the proposed taxonomy, with comprehensive discussions and comparisons with respect to their latency.

The Evolution of MAC Protocols in Wireless Sensor Networks: A Survey

Wireless Sensor Networks (WSNs) have become a leading solution in many important applications such as intrusion detection, target tracking, industrial automation, smart building and so on. Typically, a WSN consists of a large number of small, low-cost sensor nodes that are distributed in the target area for collecting data of interest. For a WSN to provide high throughput in an energy-efficient way, designing an efficient Medium Access Control (MAC) protocol is of paramount importance because the MAC layer coordinates nodes' access to the shared wireless medium. To show the evolution of WSN MAC protocols, this article surveys the latest progresses in WSN MAC protocol designs over the period 2002-2011. In the early development stages, designers were mostly concerned with energy efficiency because sensor nodes are usually limited in power supply. Recently, new protocols are being developed to provide multi-task support and efficient delivery of bursty traffic. Therefore, research attention has turned back to throughput and delay. This article details the evolution of WSN MAC protocols in four categories: asynchronous, synchronous, frame-slotted, and multichannel. These designs are evaluated in terms of energy efficiency, data delivery performance, and overhead needed to maintain a protocol's mechanisms. With extensive analysis of the protocols many future directions are stated at the end of this survey. The performance of different classes of protocols could be substantially improved in future designs by taking into consideration the recent advances in technologies and application demands.

An event-driven WSN MAC protocol design based on active node and dynamic time slot allocation

The unique features of wireless sensor networks (WSNs) make them suitable for a wide range of applications in many different areas. However, with many of the protocols and algorithms used in traditional wireless networks, it is usually neither feasible nor possible to apply them directly to WSNs due to the strict resource constraints of tiny sensor nodes. Moreover, application-specific approaches for communication protocols are usually imposed since WSN applications have distinct requirements. In this study, event-driven WSN applications, where a number of sensor nodes are randomly and densely deployed in remote and difficult to reach locations, are targeted. In such applications, energy efficiency and latency are crucial design parameters since replacing or recharging the batteries of sensor nodes is extremely difficult, and any sensed data should be transmitted eventually. Considering this aspect, conventional time division multiple access-based medium access control (MAC) protocols are not well suited, although there are a few MAC protocols specifically designed for event-driven WSNs. In this paper, we introduce a MAC protocol, named modified bit-map--assisted (M-BMA), for event-driven WSN applications, designed by employing a new active node determination method (ANDM) and dynamic time slot allocation approach. Utilizing the proposed ANDM, we present that the M-BMA well supersedes its classical counterpart, offering up to approximately 49% better energy usage as well as up to about 68% fewer message delays.

A Traffic-Aware Energy Efficient Scheme for WSN Employing an Adaptable Wakeup Period

Recently, Wireless Sensor Networks (WSN) have come to require an energy efficiency and a guaranteed delivery delay time, on the contrary to traditional Medium Access Control (MAC) protocols that have mostly aimed for a high throughput. In order to satisfy these new significant requirements, many of the newer WSN MAC protocols employ duty cycled mechanism, in order to improve energy efficient techniques in the MAC layer. This duty cycled mechanism is oriented to the toggling of the transceiver's conditions composed of the wakeup and sleep states. However, regrettably, the channel conditions of a wireless network can be changed anytime according to the traffic congestion. If a high congestion is present, an insufficient wakeup period can cause the successful communication ratio to worsen. This can be a weakness in previous duty cycled mechanisms due to their lack of consideration for the network conditions. Therefore, we have devised and designed an efficient new scheme, the adaptable wakeup period, which can resolve this issue. We present analyses and the simulated results of our work, together with a comparison between the synchronous and asynchronous MAC protocols, using two types of analysis models that we suggest.

A survey and projection on medium access control protocols for wireless sensor networks

Recent advances in wireless communications and sensor technologies have enabled the development of low-cost wireless sensor networks (WSNs) for a wide range of applications. Medium access control (MAC) protocols play a crucial role in WSNs by enabling the sharing of scarce wireless bandwidth efficiently and fairly. This article provides a survey of the literature on MAC protocols for WSNs. We first briefly describe the unique features of WSNs. We then review representative MAC protocols from the following four categories: contention-based protocols, contention-free (scheduled-based) protocols, hybrid protocols , and preamble sampling protocols. Our discussions focus on the background, main features, operation procedures, major design issues, and the advantages and disadvantages of these protocols. We also present an analysis of the inherent and desirable features of the protocols, and the key challenges of MAC technology for WSNs. Finally, we present our view on future research directions for WSN MAC protocols in a reader-friendly way using illustrative diagrams.

Cluster-based mobility adaptive MAC scheme for wireless sensor networks

Due to uncertain running conditions and dynamic fluctuation of network topology, wireless sensor networks (WSNs) always runs in an unexpected open environment. As the theme for the centerpiece, medium access control (MAC) protocol with superior performance is supposed to easily accommodate network changes. Most of the existing MAC protocols for WSNs, which usually provide very had network performance in scenarios involving mobile sensors, are aiming at stationary deployment application. For the energy-constrained attribute, handling mobility in WSNs is facing a significant challenge. In order to overcome these disadvantages, such as latency, extra energy consumption in fast connection for mobile nodes moving from one cluster to another, this paper puts forward a new adaptive mobility-aware MAC protocol named CM-MAC for large scale cluster-based WSNs. CM-MAC protocol proposes 1) a new cluster-head selection algorithm and 2) a priority-based bit-map-assisted (BMA) scheduling strategy. By applying the novel approach, CM-MAC achieves better performance by providing analytical models for CM-MAC, pure BMA [1], and low-energy adaptive clustering hierarchy (LEACH) [2]. CM-MAC performs better than these protocols in terms of energy efficiency and end to end latency in mobile scenarios.

Comparison of Csma Based MAC Protocols of Wireless Sensor Networks

Energy conservation has been an important area of interest in Wireless Sensor networks (WSNs). Medium Access Control (MAC) protocols play an important role in energy conservation. In this paper, we describe CSMA based MAC protocols for WSN and analyze the simulation results of these protocols. We implemented S-MAC, T-MAC, B-MAC, B-MAC+, X-MAC, DMAC and Wise-MAC in TOSSIM, a simulator which unlike other simulators simulates the same code running on real hardware. Previous surveys mainly focused on the classification of MAC protocols according to the techniques being used or problem dealt with and presented a theoretical evaluation of protocols. This paper presents the comparative study of CSMA based protocols for WSNs, showing which MAC protocol is suitable in a particular environment and supports the arguments with the simulation results. The comparative study can be used to find the best suited MAC protocol for wireless sensor networks in different environments.