Medium Access Control Sublayer Research Articles

A Beacon and GTS Scheduling Scheme for IEEE 802.15.4 DSME Networks

The IEEE 802.15.4 standard is one of the widely adopted networking specification for realizing different applications of Internet of Things (IoT). It defines several physical layer options and Medium Access Control (MAC) sub-layer protocols for low-power devices supporting low-data rates. One such MAC protocol is the Deterministic and Synchronous Multi-channel Extension (DSME), which addresses the limitation on maximum number of Guaranteed Time Slots (GTSs) in 802.15.4-2011 MAC, and provides channel diversity to increase network robustness. However, beacon scheduling in peer-to-peer networks suffers from beacon slot-collisions when two or more coordinators simultaneously compete for the same vacant beacon slot. In addition, the standard does not explore DSME-GTS scheduling across multiple channels. This paper addresses the beacon slot collision problem by proposing a non-conflicting beacon scheduling mechanism using association order. Further, a distributed multi-channel DSME-GTS schedule is proposed that optimally assigns DSME-GTSs across different channels. The objective is to minimize the number of times-lots used while maximizing the usage of available channels. Through simulations, the proposed mechanisms’ performance is analyzed in terms of energy efficiency, transmission overhead, scheduling efficiency, throughput, and latency and is shown to out-perform the other existing schemes.

Wireless Body Area Networks for Healthcare

Motivated by the increasing need for improved healthcare solutions, wireless body area networks (WBANs) have shown their great potential in revolutionizing the next generation healthcare through enabling continuous monitoring of health status with early detection of abnormal situations. Such networks are able to support a diverse range of applications with traffic rates ranging from several bits per hour up to 10 megabits per second. For the efficient functionality of these applications, each one poses a specific set of quality of service (QoS) requirements to the medium access control (MAC) sub-layer including transmission reliability, timeliness, and throughput. However, energy limitations of WBANs make the satisfaction of these requirements a challenging task. The current paper aims to explore the application trends of WBANs in the health field as well as the salient features of the MAC protocols proposed for this class of networks and to provide a general rule indicating the most suitable MAC technology for WBANs based on the characteristics of the targeted application.

DADC: A Novel Duty-cycling Scheme for IEEE 802.15.4 Cluster-tree-based IoT Applications

The IEEE 802.15.4 standard is one of the widely adopted specifications for realizing different applications of the Internet of Things. It defines several physical layer options and Medium Access Control (MAC) sub-layer for devices with low-power operating at low data rates. As devices implementing this standard are primarily battery-powered, minimizing their power consumption is a significant concern. Duty-cycling is one such power conserving mechanism that allows a device to schedule its active and inactive radio periods effectively, thus preventing energy drain due to idle listening. The standard specifies two parameters, beacon order and superframe order, which define the active and inactive period of a device. However, it does not specify a duty-cycling scheme to adapt these parameters for varying network conditions. Existing works in this direction are either based on superframe occupation ratio or buffer/queue length of devices. In this article, the particular limitations of both the approaches mentioned above are presented. Later, a novel duty-cycling mechanism based on MAC parameters is proposed. Also, we analyze the role of synchronization schemes in achieving efficient duty-cycles in synchronized cluster-tree network topologies. A Markov model has also been developed for the MAC protocol to estimate the delay and energy consumption during frame transmission.

New Standards Initiatives on Ultrawideband [Standards

The IEEE 802.15 Working Group on Wireless Specialty Networks is a working group of the IEEE 802 LAN/ MAN Standards Committee of the IEEE Computer Society. It is chartered to develop interoperability standards addressing wireless networking for emerging Internet of Things applications. Among the many standards the working group has been developing, IEEE 802.15.4, IEEE Standard for LowRate Wireless Networks, is one of the popular ones whose technology is used for many different higher-layer standards, such as ZigBee, Wireless Highway Addressable Remote Transducer (HART), and 6LoWPAN. IEEE 802.15.4 defines the physical layer (PHY) and medium access control (MAC) sublayer specifications for low-data-rate, low-power, and lowcomplexity wireless connectivity with fixed, portable, and moving devices with no or very limited battery consumption requirements. In addition, it defines operating modes that support precision ranging capability, which can be accurate to 1 m.

Performance Analysis of Wireless Local Area Network for a High-/Low-Priority Traffic Ratio at Different Numbers of Access Categories

The performance of Wireless Local Area Network (WLAN) is highly dependent on the processes that are implemented in the Medium Access Control (MAC) sublayer regulated by the IEEE 802.11 standard. In turn, various parameters affect the performance of the MAC sublayer, the most important of which is the number of stations in the network and the offered load. With the massive growth of multimedia traffic, research of the network performance depending on traffic types is relevant. In this paper, we present the impact of a high-/low-priority traffic ratio on WLAN performance with different numbers of access categories. The simulation results show different impact of high-/low-priority traffic ratio on the performance of the MAC sublayer of wireless LANs depending on different network-sizes and on network conditions. Performance of the large network with two access categories and with the prevalent high-priority traffic is significantly higher than in the case of using four categories on the MAC sublayer. This allows us to conclude that the performance improvement of the large network with the prevalent high-priority traffic can be achieved by an adaptive adjustment of the access categories number on the MAC sublayer.

A Comprehensive Worst Case Bounds Analysis of IEEE 802.15.7

Visible Light Communication (VLC) has been emerging as a promising technology to address the increasingly high data-rate and time-critical demands that the Internet of Things (IoT) and 5G paradigms impose on the underlying Wireless Sensor Actuator Networking (WSAN) technologies. In this line, the IEEE 802.15.7 standard proposes several physical layers and Medium Access Control (MAC) sub-layer mechanisms that support a variety of VLC applications. Particularly, at the MAC sub-layer, it can support contention-free communications using Guaranteed Timeslots (GTS), introducing support for time-critical applications. However, to effectively guarantee accurate usage of such functionalities, it is vital to derive the worst-case bounds of the network. In this paper, we use network calculus to carry out the worst-case bounds analysis for GTS utilization of IEEE 802.15.7 and complement our model with an in-depth performance analysis. We also propose the inclusion of an additional mechanism to improve the overall scalability and effective bandwidth utilization of the network.

Cross Layer Relay Selection in Device-to-Device Communication

Cross layer optimization for relay assisted wireless communication is important as it caters for parameters in more than one layer thereby a more holistic insight to the performance of proposed algorithms is realised. Due to the nature of the wireless channel, the availability of perfect channel state information may not be guaranteed. Moreover for relay selection algorithms, where mobile user equipment are used as relays, optimizing a relay defined utility can motivate relaying. This work proposes a cross layer stable matching based relay selection algorithm for relay assisted device-to-device communication. The cross layer parameter defined by this work is a function of data rate at the physical layer and queueing state information at the media access control sub-layer. The selection problem is modelled as an optimization problem for which stable matching is used to suitably allocate relay-enabled user equipment to source-destination pairs. To evaluate the performance of the proposed algorithm, spectral efficiency, energy efficiency and fairness were used as performance metrics. The proposed cross layer algorithm was compared with the best source-relay selection algorithm, best relay-destination selection algorithm and a random selection algorithm. Unlike other works, our proposed algorithm is channel uncertainty aware. The proposed cross layer selection algorithm was shown through simulations to offer improved spectral efficiency performance of 16% over the random selection algorithm. Furthermore, there was a fairness improvement of 0.01 and 0.02 over the best source—relay and the best relay—destination selection algorithms respectively.

Performance enhancement of IEEE 802.15.4 by employing RTS/CTS and frame concatenation

IEEE 802.15.4 has been widely accepted as the de facto standard for wireless sensor networks (WSNs). However, as in their current solutions for medium access control (MAC) sub-layer protocols, channel efficiency has a margin for improvement, in this study, the authors evaluate the IEEE 802.15.4 MAC sub-layer performance by proposing to use the request-/clear-to-send (RTS/CTS) combined with frame concatenation and block acknowledgement (BACK) mechanism to optimise the channel use. The proposed solutions are studied in a distributed scenario with single-destination and single-rate frame aggregation. The throughput and delay performance is mathematically derived under channel environments without/with transmission errors for both the chirp spread spectrum and direct sequence spread spectrum physical layers for the 2.4 GHz Industrial, Scientific and Medical band. Simulation results successfully verify the authors’ proposed analytical model. For more than seven TX (aggregated frames) all the MAC sub-layer protocols employing RTS/CTS with frame concatenation (including sensor BACK MAC) allow for optimising channel use in WSNs, corresponding to 18–74% improvement in the maximum average throughput and minimum average delay, together with 3.3–14.1% decrease in energy consumption.

☆Improving IEEE 802.15.4 channel access performance for IoT and WSN devices

IEEE 802.15.4 is a well-known protocol for low power, low rate wireless personal area networks that determines the specifications for the physical layer and the media access control sub-layer. However, IEEE 802.15.4 suffers from several limitations that play a role in reducing its performance such as using a default maximum backoff (macMaxCsmaBackoffs) value for channel access. In terms of energy efficiency, complexity, delay, using a default macMaxCsmaBackoffs does not provide optimum performance in every channel condition. For this reason, we built an adaptive channel access model, ACAMRO that maximizes channel utilization via adjusting macMaxCsmaBackoffs according to channel conditions. ACAMRO provides higher throughput which yields up to a 120% performance gain compared to the default IEEE 802.15.4 setup. It provides an implementation requiring low memory space that is less than 20 kBytes. Measured results show that ACAMRO achieves significant throughput increase, and a low complexity solution for Internet of Things devices.

A novel multi-objective optimizer framework for TDMA-based medium access control in IoT

Recently, cross-layer optimization has been emphasized by researchers for Internet of Things (IoT) where billions of devices communicate intelligently making every day communication highly informative. Medium Access Control (MAC) sub-layer is part of data link layer in IoT protocol stack. The energy consumption of things is greatly affected by MAC protocol which controls the node radio functionalities. In this article, we propose the design of an efficient MAC for IoT by minimizing its energy consumption at various levels. The minimization model is subject to reduction in distortion levels while simultaneously extending network lifetime. This article synthesizes and optimizes MAC layer of IoT based protocols using a novel delta diagram synthesizer and accurately captures both the high heterogeneity of the IoT and the impact of the Internet as part of the MAC layer architecture. Furthermore a novel hybrid Whale-Artificial Bee Colony optimizer framework is proposed to obtain optimal nodes based on energy consumption and the communication parameters among things, by exploiting the interrelations among different layer functionalities in the IoT. This novel system saves considerable computation resources of the resource constrained IoT devices and adapts to various data sources with different distortion levels rapidly.

Scalability Validation of the Posting Access Method through UPPAAL-SMC Model-Checker

The standard IEEE 802.15.6 provides a new phys-ical layer (PHY) and medium access control sublayer (MAC) specifications that support several challenges of wireless body area networks (WBANs). The posting is the access method of the IEEE 802.15.6 MAC protocol that is used by the hub to send data to the nodes. In this paper, we use a formal method to evaluate the posting access method under the WBANs stochastic environment. Based on the statistical model checking (SMC) toolset UPPAAL-SMC, we model and evaluate the behavior of the posting access method in terms of scalability. The evaluation results showed that according to the allocated time intervals, the energy consumption, and the throughput the scalability was validated.

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.

A Performance-to-Cost Analysis of IEEE 802.15.4 MAC With 802.15.4e MAC Modes

The IEEE 802.15.4 standard is one of the widely adopted networking specification for Internet of Things (IoT). It defines several physical layer (PHY) options and medium access control (MAC) sub-layer protocols for interconnection of constrained wireless devices. These devices are usually battery-powered and need to support requirements like low-power consumption and low-data rates. The standard has been revised twice to incorporate new PHY layers and improvements learned from implementations. Research in this direction has been primarily centered around improving the energy consumption of devices. Recently, to meet specific Quality-of-Service (QoS) requirements of different industrial applications, the IEEE 802.15.4e amendment was released that focuses on improving reliability, robustness and latency. In this paper, we carry out a performance-to-cost analysis of Deterministic and Synchronous Multi-channel Extension (DSME) and Time-slotted Channel Hopping (TSCH) MAC modes of IEEE 802.15.4e with 802.15.4 MAC protocol to analyze the trade-off of choosing a particular MAC mode over others. The parameters considered for performance are throughput and latency, and the cost is quantified in terms of energy. A Markov model has been developed for TSCH MAC mode to compare its energy costs with 802.15.4 MAC. Finally, we present the applicability of different MAC modes to different application scenarios.

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.

An accurate and complete performance modeling of the IEEE 802.11p MAC sublayer for VANET

This paper proposes an analytical model for the throughput, channel access delay, and queueing delay of the IEEE 802.11p enhanced distributed channel access (EDCA) mechanism in the medium-access control (MAC) sublayer. In order to make the proposed analytical model explicitly solvable and to avoid computation complexity caused by most of existing 3-D or 4-D Markov-chain-based analytical models, a combination of 2-D and 1-D Markov chain model is used. The 2-D Markov chain is established to model the backoff procedure of each access category (AC) queue, deriving a relationship between the transmission probability and collision probability for each AC queue. Afterwards, a 1-D discrete-time Markov chain is established to model the contention period caused by the distinction of four different arbitration inter-frame space (AIFS) and contention window (CW) values, deriving another relationship between the transmission probability and collision probability of each AC queue. In order to consider both saturated and non-saturated cases, an infinite-long 1-D Markov chain model is used. In the proposed analytical model, all the features in the EDCA such as different CW and AIFS for each AC, various saturation status, internal collision, backoff counter freezing, up-to-date standard parameters, and initial-carrier-sensing procedure are taken into consideration. Based on the two Markov models, we further derive performance models which describe the relationships between the network parameters and channel access performance metrics in terms of normalized throughput, channel access delay, and queueing delay, respectively. The proposed analytical model applies to both basic access mode and request-to-send/clear-to-send (RTS/CTS) access mode, and is suitable for four access categories of traffic in the IEEE 802.11p. The proposed model can be employed to analyze the performance of real-world vehicular network. Simulation results are shown to verify the accuracy and effectiveness of the proposed analytical model.

MLMAC-HEAP: A Multi-Layer MAC Protocol for Wireless Sensor Networks Powered by Ambient Energy Harvesting

Limited availability of energy is the most crucial constraint of wireless sensor networks (WSN). Most power consuming part of WSN node is transreceiver and operation of transreciever to access medium is controlled by the medium access control (MAC) sublayer of the open systems interconnection (OSI) model. In WSN, till now, most of the present MAC protocols have addressed issues related to power saving. Because of energy constraints, performance is often not a focused design parameter in these MAC protocols. However, recent advances in energy harvesting technology have made it possible to obtain energy from the environment to solve energy limitations. So in this paper, a new multi layer based MAC protocol, MLMAC-HEAP is designed for solar energy harvesting criterion considering performance as the mainly focused parameter. Performance is illustrated in terms of throughput. This paper evaluates the performance of MLMAC-HEAP as a function of energy harvesting rate and number of nodes in network and results are compared and shown to outperform well known MAC protocols. Then, the paper analyses the protocol for various traffic models. Based on application-level requirements, optimization is also done for number of layers.

INTEGRATION OF RANKED MULTIPLE ACCESS AND ADVANCE COMPUTING FOR IOT-BASED BOLD CITIES USING COMBINATIONAL IOT

The Internet of Things (IoT) is associated with rising technology that extends to attach a large number of devices along and to the Internet. Based on this IoT, a smart town is enabled with time period observance, omnipresent sensing, universal connectivity, and intelligent informatics and management. Associate degree IoT-based smart town offers various good services to all types of users, therefore increasing the usage of public transportation, health care, surroundings, and entertainment. The combination of transformation, computation, and store has an important role in the development of versatile and effective IoT in smart cities. However, with the introduction of Radical Massive networking (RMN) and Mobile Line computing (MLC). In doing, therefore, economical multiple access and advanced computing need to be addressed within the physical layer and Medium Access Control sublayer. Here we propose an extensible and continuous IoT framework that integrates Radical Massive networking (RMN) -based ranked multiple access and advanced computing between MLC and cloud to support the smart town view. The suggested framework will reduce the end-to-end delay and consumption of energy. Additionally, we tend to discuss a variety of open analysis problems in implementing the proposed framework.

Enhanced time‐slotted channel hopping

AbstractWith the development of technology for the Internet of Things (IoT), a large number of mobile, intelligent sensors are being connected to the Internet. The IoT is a heterogeneous environment. In industrial environments, wireless technologies coexist on the same frequency and generate different kinds of traffic. The use of different wireless technologies that are not designed to be compatible with each other causes an external interference problem, which degrades the system performance. The medium access control (MAC) sublayer protocols must be carefully designed to overcome such a problem. The time‐slotted channel‐hopping (TSCH) mode, which is dedicated for industrial applications, can mitigate such a problem because it uses the channel‐hopping technique. Because these channels are subjected to different levels of interference, this may greatly degrade the system performance when wireless sensors with mobility devices hop blindly from one channel to another. This paper improves the reliability of communications of the TSCH MAC sublayer protocol, proposed by the IEEE 802.15.4e standard, in wireless sensor networks, by applying a new, dynamic blacklisting technique. The technique selects and uses only high‐quality channels and blacklists those with low quality. The proposed solution has been simulated using Network Simulator 3. The results show significant improvements in terms of throughput, energy, and reliability.

Performance Evaluation and Delay-Power Trade-off Analysis of ZigBee Protocol

In this paper, we analyze the superframe structure of the Medium Access Control (MAC) sublayer of IEEE 802.15.4 protocol (ZigBee), designed for Low-Rate Wireless Personal Area Networks (LR-WPANs), and evaluate the effects of the inactive portion of a superframe on average delay, and average power consumption. The four-dimensional Markov chain-based analysis of the slotted Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) algorithm presented in this work considers backoff freezing and acknowledged packet transmission that are not studied in the existing works. The analytical results prove that the performance of LR-WPANs depends significantly on the length of a superframe's active portion. We introduce a variable-Superframe duration-Beacon interval Ratio (SBR), which is utilized by tuning a few MAC parameters to achieve 35 percent reduced delay, on an average, compared to the existing state of the art. The results show that the proposed model also yields improved performance in terms of power consumption, for short and medium contention windows. In addition to the proposed analysis, this work provides optimized superframe order values that achieve trade-offs between delay and power consumption as demanded by user-provided QoS requirements corresponding to different contexts.

Medium Access Control Protocols for Power Line Communication: A Survey

In the literature, the majority of research efforts in power line communication (PLC) has been focused on the physical layer in order to deal with issues such as the time varying behavior of loads in electric power systems, the presence of high power impulsive noise, the occurrence of impedance mismatching, the widespread use of unshielded power cables, and the existence of coupling losses. While some works have also been carried out on the PLC medium access control (MAC) sublayer, there are scopes for further research to address the novel demands associated with cyber physical systems that need to mitigate unfairness in resource sharing, collisions and starvation, among other issues which may degrade data communication quality. In this paper, we provide a comprehensive survey regarding the state-of-the-art of MAC protocols for PLC systems, including an overview of existing PLC MAC research results and an organization of current PLC MAC protocols in terms of type of protocols, applications, and main research focus. Moreover, we present modern PLC technologies and standards, highlighting their MAC sublayer characteristics and providing a detailed comparative analysis of PLC MAC protocols in the context of current and emerging PLC applications. Finally, we identify future trends within the scope of the MAC sublayer for PLC systems with a view to stimulating additional research efforts on PLC MAC design.