QoS-aware MAC Research Articles

FROG-MAC: A Fragmentation Based MAC Scheme for Prioritized Heterogeneous Traffic in Wireless Sensor Networks

In most scenarios of wireless sensor networks (WSNs), different traffic types have specific service requirements. None of the previous MAC schemes has been able to provide true pre-emption to the high priority data. This paper introduced a novel data fragmentation scheme for low priority traffic in order to improve the delay performance of high priority traffic in WSN. It is proposed that instead of transmitting the low priority packet as a single unit, it should be transmitted in small fragments with pauses. A MAC protocol FROG-MAC has been designed based on the proposed fragmentation scheme. Simulations over Contiki operating system and testbed experiments over TelosB/Tmote Sky Platform have been performed to evaluate performance of FROG-MAC based on parameters of delay and throughput/packet delivery ratio (PDR). It has been found that FROG-MAC improves the delay and throughput of urgent traffic by reducing its waiting time. For increase in the fragment size, the delay of urgent traffic increases, whereas that of normal traffic reduces. With the increasing network size, the delay for both traffic types increases, and PDR reduces due to the increased network traffic load, collision and retransmissions. The performance of FROG-MAC has also been compared against energy-efficient multi-constrained QoS aware MAC.

Queue and Priority-Aware Adaptive Duty Cycle Scheme for Energy Efficient Wireless Sensor Networks

In Wireless Sensor Networks (WSN), energy efficiency is a fundamental issue that requires attention in the design of communication protocols. Energy waste occurs as a result of collision and idle listening. The widely used mechanism for energy saving in WSN is duty cycling. Duty cycling coordinates the sleep/wake-up time of sensor nodes to maximize the network lifetime while achieving specific application goals such as high throughput or low latency. Most existing works focused more on static duty cycle, which cannot guarantee the desired end-to-end delay at varying network conditions. In applications with specified delay requirements, the duty cycle of every node should be adjusted separately at runtime depending on the network conditions to achieve the desired delay and energy efficiency. In this paper, we present an Energy Efficient and QoS-aware (EEQ) MAC protocol with a duty cycle scheme that adapts the node's duty cycle to the queue size and priority class of a packet to reduce the delay of high priority packets and support time-bounded delivery of priority packets. By checking the queue size and the priority class of packets in the message queue of each node, the node determines whether or not to adjust its duty cycle. In this approach, a node increases the length of its active period in the event of high traffic which provides less waiting time for the packets in the queue. The sender node informs the receiver the duration for which it has to stay awake at the beginning of data transmission, both the sending and the receiver's duty cycle is controlled based on the queue length and the priority of the packets. This approach saves energy and lessen packet latency. Finally, extensive simulation experiments were conducted to evaluate its energy performance within different network topologies. Comparisons with the existing energy-aware MAC protocol verified the effect of EEQ on improving the energy efficiency and extending the lifespan of WSNs.

Energy Efficient Quality Assurance MAC Protocols in WSN

The key aim of the proposed research is to perform an analysis of various QoS aware MAC protocols for WSN based on simulation and literature both. The proposed work represents the designs and methodologies of different MAC protocols. And also classify the various MAC protocols based on media access and allocation of schedule for communication among the sensor nodes. The proposed work performs the analysis by designing, developing and analyzing various quality aware MAC protocols for Wireless sensor network. This paper describes the detailed analysis of different channel access methods of a network. It also depicts detail algorithms of SMAC and describes the procedure of data communication in TMAC, BMAC, and ZMAC. Also, simulate the SMAC and TMAC protocols to analyze energy efficiency as a QoS parameter. The simulation of SMAC and TMAC data transmission is done in network simulator 3 by using various network parameters. In this research the QoS parameters like Energy, Throughput, delay and, latency are analyzed by simulation and literature respectively. A new research always starts with analysis of existing one. So, Analysis of different MAC is useful for the WSN research community to propose and develop a QoS aware MAC protocol.

A BP Network Control Approach for QoS-Aware MAC in Cloud Robotics

The basic idea of Cloud Robotics is dynamically uploading the compute-intensive applications to the cloud, which greatly enhances the intelligence of robots for the high processing and parallel ability of cloud. However, for the nature of uncertainty of mobility, different kinds of applications on robot may have different Quality of service (QoS). The paper proposes a BP network for QoS-aware MAC(BPFD-MAC) in Cloud Robotics form a view control theory, which can support both absolute and relative QoS guarantees while the energy saving. The hard and soft QoS constraints are de-coupled by normalized into a two-level cascade feedback loop. The former is Active Time Loop (AT-Loop) to enforce the absolute QoS guarantee for real-time application and the later is Contention Window Loop (CW-Loop) to enforce the relative QoS guarantee for Best Effort traffics. Finally, the Back-propagating (BP) neuron network based PID is used for self-tuning parameters and controller design. The hardware experiments demonstrate the feasibility of BPFD-MAC. Comparing with FD-MAC, BPFD-MAC has new feature of absolute QoS support and further developed two advantages:In the condition of heavy loads, BPFD have about 18% great throughput and 14% great power efficient; and in light load, BPFD have lower total energy consumption.

UrgMAC: A New Traffic and QoS-aware Cross-Layer MAC protocol for Wireless Multimedia Sensor Networks

urgMAC: A New Traffic and QoS-aware Cross-Layer MAC protocol for Wireless Multimedia Sensor Networks

Cascade self‐tuning control architecture for QoS‐aware MAC in WSN

Wireless sensor network (WSN) has proposed requirements more than just data collection and transmission. Different types of traffics call for different quality of service (QoS) demands. However, for the nature of uncertainty of wireless link and unpredictability of traffic transmission, it is very hard to distribute resources to different traffics precisely ahead of time. Based on the cascade self-tuning control, this study proposes the cascade self-tuning architecture for FD-MAC (CSFD-MAC) architecture. Taking the advantage of feedback theory, CSFD-MAC decouples contention window (CW) adaption and active time (AT) adaption into two separated cascading control loops. CW controller aims for the absolute node-to-node delay to a fixed value and AT controller guarantees the relative delay ratio. The software simulations illustrate the validity of controller design and the hardware experiments demonstrate the ability of CSFD-MAC in the absolute delay control as well as the proportional delay differentiation. More important, CSFD-MAC which takes AT as a controlled variable, not only has a much more superior performance in the metrics of delay and throughput compared with other QoS-aware MAC, but also has the advantage of efficient power management.

A Critical Review of Quality of Service Models in Mobile Ad hoc Networks

Quality of service (QoS) provisioning in mobile ad hoc networks (MANETs) consists of providing a complex functionality in a harsh environment where resources are scarce. Thus, it is very challenging to build an efficient solution to address this issue. The proposed solutions in the literature are broadly classified into four categories, namely: QoS routing protocols, QoS signalling, QoS-aware MAC protocols and QoS models, which are the main concern of our study. The contribution of this paper is threefold: Firstly, we propose a set of guidelines to deal with the challenges facing QoS models design in ad hoc networks. Secondly, we propose a new taxonomy for QoS models in ad hoc networks. Finally, we provide an in-depth survey and discussion of the most relevant proposed frameworks.

QoS‐Aware MAC protocols utilizing sectored antenna for wireless sensor networks‐based smart grid applications

SummaryWireless sensor networks (WSNs) are the most commonly deployed technology in smart grid environments owing to their advantages including low cost and successful adoption in various harsh smart grid environments. However, providing the quality of service (QoS) requirements of smart grid applications with WSNs is difficult because of the power constraints of sensor nodes and unreliable wireless links. In order to meet the QoS requirements of smart grid applications using WSNs, in this paper, we first propose a QoS‐aware omnidirectional antenna‐based medium access control (QODA‐MAC). Then, in order to investigate the impact of using sectored antennas on meeting QoS requirements, we also propose another QoS‐aware four‐sectored antenna‐based MAC protocol (QFSA‐MAC). The aim of the proposed approaches is to increase channel utilization with efficient service differentiation considering traffic flows with different requirements as well as providing reliable and fast delivery of data. We measure the performance of QODA‐MAC and QFSA‐MAC by making extensive simulations and compare them with each other. The results show that QFSA‐MAC outperforms the QODA‐MAC protocol and satisfies QoS requirements of smart grid applications by achieving significant improvement in terms of latency, energy consumption and data delivery. Copyright © 2016 John Wiley & Sons, Ltd.

Proportional throughput differentiationwith cognitive load-control on WSN channels

Wireless sensor networks are nowadays used in various applications to facilitate monitoring and actuation tasks, e.g., for smart grids and industrial automation. Some of these applications require guarantees or at least assurances on reliability. Such applications expect predictable throughput and delay, which are hard to maintain in environments with changing radio conditions. QoS-aware MAC protocols capable of handling such environments are well explored. They require however protocol changes and are therefore difficult to deploy. This paper presents an application layer forwarding service that offers proportional differentiation while limiting network load to preserve high utilization and predictability. Demands for capacity are expressed as fractions of the overall channel throughput. We show that this service can be implemented with a cognitive load controller (CLC) based on fuzzy logic and quality assessed with utility functions for application layer packet loss and throughput. We evaluate the CLC for 802.15.4 with CSMA/CA through NS-3 simulations showing that it offers the intended service while adjusting load for high overall throughput and low delay.

Comparative Study on Priority Based QOS Aware Mac Protocols for WSN

In Wireless Sensor Network (WSN), QoS (Quality of Service) in sensor application plays a very important role. QoS based routing is required to ensure the best use of nodes in WSN. In this paper, a comparative study of QoS based routing in Media Access Control (MAC) protocols are presented based on the traits to solve problems like prioritization, timeliness, reliability etc. The study mainly focuses on some priority based QoS protocols used in WSN and a comparison among them. The study reveals that among the five mentioned protocols; QMAC, PRIMA, DB-MAC, RAP, GTS; PRIMA shows the best performance in the category of Packet Prioritization, Scheduling Scheme, Queue Type, Energy Awareness and QoS.

Cross Layer Adaptation for QoS in WSN

In this paper, we propose QoS aware MAC protocol for Wire- less Sensor Networks and its cross layer extension to network layer for providing QoS in delay sensitive WSN scenarios. In WSNs, there can be two types of traffic one is event driven traffic which requires immedi- ate attention and another is periodic reporting. Event driven traffic is classified as Class I(delay sensitive) traffic and periodic reporting is clas- sified as Class II(Best Effort) Traffic. MAC layer adaptation can take place in terms of (i) Dynamic contention window adjustment per class, (ii) Reducing the delay suffered by difference in Sleep schedules(DSS) of communicating nodes by dynamically adjusting Duty Cycle based on Utilization and DSS delay of class I traffic, (iii) Different DIFS (DCF Inter Frame Spacing) per class, (iv) Adjusting all the three schemes pro- pose d above simultaneously. Cross layer extension is also proposed, in which MAC layer uses ne twork layer's next hop information for better adaptation of duty cycle based on DSS delay. Routing protocols can uti- lize MAC layer parameter DSS delay to select the routes which offer least DSS delay latency, there by minimizing the overall end-to-end delay.

Design and implementation of a QoS-aware MAC protocol for Wireless Multimedia Sensor Networks

Wireless Multimedia Sensor Networks (WMSNs) have entered the class of Wireless Sensor Networks (WSNs) to meet the multimedia requirements of new emerging applications, such as surveillance and telepresence. Combining the traditional scalar sensors used in WSN nodes with tiny cameras and microphones, WMSNs commonly carry heterogeneous traffic with different Quality of Service (QoS) requirements. In order to deliver heterogeneous traffic with different requirements in highly resource constrained sensor networks, QoS provisioning and service differentiation become unavoidable. In this paper first we discuss the QoS-provisioning in sensor networks and evaluate the efficiency of existing QoS-aware MAC protocols. As a result of this evaluation, next we design and implement a QoS-aware MAC protocol for WMSNs, Diff-MAC, which integrates different methods to meet the requirements of QoS provisioning to deliver heterogeneous traffic and provides a fair all-in-one QoS-aware MAC protocol. Diff-MAC aims to increase the utilization of the channel with effective service differentiation mechanisms while providing fair and fast delivery of the data. Performance evaluation results of Diff-MAC, obtained through extensive simulations, show significant improvements, in terms of latency, data delivery and energy efficiency, compared to two other existing protocols. Implementation of Diff-MAC on Imote2 platform also reveals that the protocol with moderate complexity can be easily implemented on the resource constrained motes.

무선센서네트워크에서 QoS 지원을 위한 다중계층 MAC 프로토콜

본 논문에서는 무선센서 네트워크에서 전송될 데이터의 QoS를 인지하여 이를 지원하는 다중 계층 QAML-MAC(QoS Aware Multi-layer MAC) 프로토콜을 제안한다. 제안된 프로토콜은 노드들의 에너지를 효율적으로 사용함으로 전체 네트워크의 수명을 늘이는 방법 중의 하나인 sleep-awake 구조를 기반으로 한다. 이를 위하여 노드에 입력되는 데이터를 전송 응급성에 따라 우선순위 클래스로 나누어 저장한다. 또한 cross-layer 개념을 도입하여 동일한 목적지로 향하는 데이터를 재정돈한다. 제안된 MAC 프로토콜은 기존 관련 프로토콜의 문제점인 지연(delay)을 줄이는 동시에 실시간의 멀티미디어 트래픽 혹은 미리 정해진 필드 모니터링과 같은 응용에서 임계값을 초과하는 데이터와 같은 우선순위가 높은 데이터를 빠르게 전송함으로써 전송에 응급한 데이터를 먼저 전송할 수 있는 장점을 가진다. 뿐만 아니라 각 노드에서 전송할 우선순위 데이터가 존재하지 않을 경우 idle listen에 있어서 다중의 계층을 사용함으로 데이터전송에서의 충돌을 줄임으로 노드에서 소모하는 에너지를 줄이며, 결국 전체 네트워크 수명을 늘일 수 있는 장점을 가진다. In this paper, we propose an QoS aware multi-layer MAC(QAML-MAC) protocol in a wireless sensor networks. Since the proposed protocol is based on the sleep-awake architecture, which save node's energy to prolong the entire network lifetime. For this purpose the QAML-MAC first classifies incoming data according to their transmission urgency and then saves them. The protocol also adapts the cross-layer concept to re-arrange the order of transmission with the same destination. So the delay can be decreased, which can not be obtained with the previous related protocols. And high priority data such as real-time multimedia or critical value in the field monitoring applications can be transmitted quickly, Furthermore the proposed protocol has advantage of decreasing transmitted data collisions using multiple layers of idle listening when there is no high-priority data. So energy consumptions of sensor nodes can be saved and the network lifetime can be prolonged.

QoS-aware MAC protocols for wireless sensor networks: A survey

The adoption of wireless sensor networks by applications that require complex operations, ranging from health care to industrial monitoring, has brought forward a new challenge of fulfilling the quality of service (QoS) requirements of these applications. However, providing QoS support is a challenging issue due to highly resource constrained nature of sensor nodes, unreliable wireless links and harsh operation environments. In this paper, we focus on the QoS support at the MAC layer which forms the basis of communication stack and has the ability to tune key QoS-specific parameters, such as duty cycle of the sensor devices. We explore QoS challenges and perspectives for wireless sensor networks, survey the QoS mechanisms and classify the state of the art QoS-aware MAC protocols together with discussing their advantages and disadvantages. According to this survey, we observe that instead of providing deterministic QoS guarantees, majority of the protocols follow a service differentiation approach by classifying the data packets according to their type (or classes) and packets from different classes are treated according to their requirements by tuning the associated network parameters at the MAC layer. Design tradeoffs and open research issues are also investigated to point out the further possible research directions in the field of QoS provisioning in wireless sensor networks at the MAC layer.

MQ-MAC: A Multi-Constrained QoS-Aware Duty Cycle MAC for Heterogeneous Traffic in Wireless Sensor Networks

Energy conservation is one of the striking research issues now-a-days for power constrained wireless sensor networks (WSNs) and hence, several duty-cycle based MAC protocols have been devised for WSNs in the last few years. However, assimilation of diverse applications with different QoS requirements (i.e., delay and reliability) within the same network also necessitates in devising a generic duty-cycle based MAC protocol that can achieve both the delay and reliability guarantee, termed as multi-constrained QoS, while preserving the energy efficiency. To address this, in this paper, we propose a Multi-constrained QoS-aware duty-cycle MAC for heterogeneous traffic in WSNs (MQ-MAC). MQ-MAC classifies the traffic based on their multi-constrained QoS demands. Through extensive simulation using ns-2 we evaluate the performance of MQ-MAC. MQ-MAC provides the desired delay and reliability guarantee according to the nature of the traffic classes as well as achieves energy efficiency.

QA-MAC: QoS-Aware MAC Protocol for Wireless Sensor Networks

In this paper, we present a QoS-aware MAC protocol (QA-MAC) for cluster based wireless sensor networks (WSNs). QA-MAC is a TDMA-based scheduling protocol that minimizes the energy consumption in multi-hop WSNs and provides Quality of Service (QoS). A dynamic scheduling algorithm according to the number of member nodes, node traffics, and traffic priorities is suggested. The selected cluster head allocates time slots for all member nodes in the first TDMA schedule period of each round. During the second schedule period in each round, the cluster head makes a schedule for all data transmission. The proposed QA-MAC (QoS-Aware MAC) could save energy, reduce transmission delay, and support QoS.

A novel Qos-aware MAC scheme using optimal retransmission for wireless networks

This paper proposes a novel medium access control scheme for low cost, single-hop wireless networks where the source nodes have a transmitter module but no receiver module and hence they can only transmit data to a sink but cannot receive any control signals, like an ACK or NAK, from any other node. The goal of the proposed scheme is to provide QoS (in terms of packet delivery probability) to the nodes in such a network, where the existing schemes like polling or scheduled transmissions, CSMA and ARQ will be ineffective because of the unavailability of a receiver module at the nodes. The proposed scheme uses distributed control and allows the nodes to transmit each packet an optimal number of times at random instants in time within the packet generation interval. We define two optimization problems based on minimizing total network traffic and maximizing the delivery probability of the class of nodes requiring the highest QoS, respectively, and develop mathematical formulae and efficient algorithms to solve them. Numerical analysis and simulation results show that our scheme can provide high QoS to networks of different sizes.

Efficient silence suppression and call admission control through contention-free medium access for VoIP in WiFi networks

In view of the rapidly growing trend of migrating customers from traditional wired phones to mobile phones and then to VoIP services in the recent past, there is a tremendous demand for wireless technologies to support VoIP, specially on WiFi technologies which have already matured commercially. This has put forth great research challenges in the area of wireless VoIP. In this article we have addressed two core issues, efficient silence suppression and call admission control, in QoS provisioning for VoIP services in WiFi networks. In this connection we present a QoS-aware wireless MAC protocol called hybrid contention-free access (H-CFA) and a VoIP call admission control technique called the traffic stream admission control (TS-AC) algorithm. The H-CFA protocol is based on a novel idea that combines two contention-free wireless medium access approaches, round-robin polling and TDMA-like time slot assignment, and provides substantial multiplexing capacity gain through silence suppression of voice calls. The TS-AC algorithm ensures efficient admission control for consistent delay bound guarantees and further maximizes the capacity through exploiting the voice characteristic so that it can tolerate some level of non-consecutive packet loss. We expose the benefits of our schemes through numerical results obtained from simulations.

Performance analysis for IEEE 802.11e EDCF service differentiation

Having been originally developed as an extension of the wired local area networks, IEEE 802.11 lacks support for quality-of-service (QoS) and differential services. Since its introduction, various extensions and modifications have been studied to address this current need and the IEEE 802.11 Task Group E is responsible for developing a QoS-aware MAC protocol that considers several service differentiation mechanisms. However, the performance of service differentiation has only been evaluated by simulation. The analytical model that calculates the differential service performance corresponding to the contention parameter configuration has not been found yet. In this paper, we first briefly explain the enhanced distributed coordination function (EDCF) access method of IEEE 802.11e. We then introduce an analytical model, which can be used to calculate the traffic priority, throughput, and delay corresponding to the configuration of multiple DCF contention parameters under the saturation condition. A detailed simulation is provided to validate the proposed model. Finally, using the analytical model, we analyze the effect on service differentiation for each contention parameter. The contention parameters can be configured appropriately at each station to achieve specific needs of service differentiation for applications.