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1.
Power management is an important issue in wireless sensor networks (WSNs) because wireless sensor nodes are usually battery powered, and an efficient use of the available battery power becomes an important concern specially for those applications where the system is expected to operate for long durations. This necessity for energy efficient operation of a WSN has prompted the development of new protocols in all layers of the communication stack. Provided that, the radio transceiver is the most power consuming component of a typical sensor node, large gains can be achieved at the link layer where the medium access control (MAC) protocol controls the usage of the radio transceiver unit. MAC protocols for sensor networks differ greatly from typical wireless networks access protocols in many issues. MAC protocols for sensor networks must have built‐in power conservation, mobility management, and failure recovery strategies. Furthermore, sensor MAC protocols should make performance trade‐off between latency and throughput for a reduction in energy consumption to maximize the lifetime of the network. This is in general achieved through duty cycling the radio transceiver. Many MAC protocols with different objectives were proposed for wireless sensor networks in the literature. Most of these protocols take into account the energy efficiency as a main objective. There is much more innovative work should be done at the MAC layer to address the hard unsolved problems. In this paper, we first outline and discuss the specific requirements and design trade‐offs of a typical wireless sensor MAC protocol by describing the properties of WSN that affect the design of MAC layer protocols. Then, a typical collection of wireless sensor MAC protocols presented in the literature are surveyed, classified, and described emphasizing their advantages and disadvantages whenever possible. Finally, we present research directions and identify open issues for future medium access research. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

2.
Wireless sensor networks (WSNs) have significant potential in many application domains, ranging from precision agriculture and animal welfare to home and office automation. Although sensor network deployments have only begun to appear, the industry still awaits the maturing of this technology to realize its full benefits. The main constraints to large‐scale commercial adoption of WSN have been the lack of available network management and control tools, such as for determining the degree of data aggregation prior to transforming it into useful information, localizing the sensors accurately so that timely emergency actions can be taken at an exact location, routing data by reducing sensor energy consumption, and scheduling data packets so that data are sent according to their priority and fairness. Moreover, to the best of our knowledge, no integrated network management solution comprising efficient localization, data scheduling, routing, and data aggregation approaches exists in the literature for a large‐scale WSN. Thus, we introduce an integrated network management framework comprising sensor localization, routing, data scheduling, and data aggregation for a large‐scale WSN. Experimental results show that the proposed framework outperforms an existing approach that comprises only localization and routing protocols in terms of localization energy consumption, localization error, end‐to‐end delay, packet loss ratio, and network energy consumption. Moreover, the proposed WSN management framework has potential in building a future “Internet of Things”. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

3.
Wireless Sensor Networks nowadays find wide variety of applications especially in real time. Innovative methods of energy efficient protocols and transmission reduction techniques keep improving to enhance the lifetime of the sensor nodes as they are powered by non-rechargeable batteries. Multi hop transmission and data aggregation are major techniques to reduce the power spent by the sensor node. In this paper, we propose a new ribbon structure for the existing multi hop WSN topologies with modified media access control mechanism called co-operative MAC. The ribbon structure is proposed to reap benefits of PEGASIS and APTEEN protocols. The low power consumption as in PEGASIS is maintained but the number of data packets transmitted is reduced by half. In the proposed scheme, only one of the two nodes along the parallel path involves in data transmission alternating roles in every cycle of aggregation. However, for values sensed above threshold, the inactive node interferes with normal cycle and gets its data transmitted to the sink node. This algorithm is compared with cluster based and chain based protocols and the simulation results show significant energy savings.  相似文献   

4.
Routing in a low duty‐cycled wireless sensor network (WSN) has attracted much attention recently because of the challenge that low duty‐cycled sleep scheduling brings to the design of efficient distributed routing protocols for such networks. In a low duty‐cycled WSN, a big problem is how to design an efficient distributed routing protocol, which uses only local network state information while achieving low end‐to‐end (E2E) packet delivery delay and also high packet delivery efficiency. In this paper, we study low duty‐cycled WSNs wherein sensor nodes adopt pseudorandom sleep scheduling for energy saving. The objective of this paper is to design an efficient distributed routing protocol with low overhead. For this purpose, we design a simple but efficient hop‐by‐hop routing protocol, which integrates the ideas of multipath routing and gradient‐based routing for improved routing performance. We conduct extensive simulations, and the results demonstrate the high performance of the proposed protocol in terms of E2E packet delivery latency and packet delivery efficiency as compared with existing protocols. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

5.
Energy‐efficient Zigbee‐based wireless sensor network (WSN) occupies a major role in emergency‐based applications. The foremost drawback of such applications is maintaining the battery power because frequent changing is not possible in those conditions. In the earlier days, several researches created new model MAC protocols in terms of increase the lifetime of the WSN. But still, there is a research gap particularly in emergency applications. In order to improve the lifetime of such applications, we introduced a novel hybrid MAC protocol, namely, special purpose energy‐efficient contention‐based hybrid MAC (SPEECH‐MAC) protocol. This protocol includes dual hop concept considerably to save the energy. Both the single hop network and the dual hop networks are developed, and the results are analyzed. Prioritization mechanism for SPEECH‐MAC protocol is introduced to analyze the emergency conditions in detail. In summary, according to the simulation, the calculated parameters are total residual energy, end‐to‐end delay, packet drop, packet delivery ratio, and network throughput.  相似文献   

6.
In‐network aggregation is crucial in the design of a wireless sensor network (WSN) due to the potential redundancy in the data collected by sensors. Based on the characteristics of sensor data and the requirements of WSN applications, data can be aggregated by using different functions. MAX—MIN aggregation is one such aggregation function that works to extract the maximum and minimum readings among all the sensors in the network or the sensors in a concerned region. MAX—MIN aggregation is a critical operation in many WSN applications. In this paper, we propose an effective mechanism for MAX—MIN aggregation in a WSN, which is called Sensor MAX—MIN Aggregation (SMMA). SMMA aggregates data in an energy‐efficient manner and outputs the accurate aggregate result. We build an analytical model to analyze the performance of SMMA as well as to optimize its parameter settings. Simulation results are used to validate our models and also evaluate the performance of SMMA. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

7.

Wireless sensor network (WSN) is a group of small power-constrained nodes that sense data and communicate it to the base station (BS). These nodes cover a vast region of interest (ROI) for several purposes according to the application need. The first challenge encountered in WSNs is how to cover the ROI perfectly and send the monitored data to the BS. Although the energy introduced during setup phase and the violation of energy fairness constraint of dynamic routing topologies, they achieve high network performance in terms of coverage and connectivity. In this paper, we categorize the applications of WSN based on different aspects to show the major protocol design issues. Thus, the energy efficiency of the recent proactive routing protocols is studied from different angles. The energy overhead and energy fairness of each protocol were carefully analyzed. The most energy efficient routing protocols for homogeneous proactive networks were studied and compared to highlight the research challenges and existing problems in this area. The results proved that energy overhead and route selection are the most effective aspects of network lifetime and network efficiency.

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8.
Mobile ad hoc networks (MANETs) are characterized by random, multi‐hop topologies that do not have a centralized coordinating entity or a fixed infrastructure that may change rapidly over time. In addition, mobile nodes operate with portable and finite power sources. In this work, we propose an energy‐efficient routing protocol for MANETs to minimize energy consumption and increase the network's consistency. Traditional works mainly focused on the shortest path‐based schemes to minimize energy, which might result into network failure because some nodes might exhaust fast as they are used repetitively, while some other nodes might not be used at all. This can lead to energy imbalance and to network life reduction. We propose an energy‐efficient ad hoc on‐demand routing protocol that balances energy load among nodes so that a minimum energy level is maintained among nodes and the network life increases. We focused on increasing the network longevity by distributing energy consumption in the network. We also compared the simulation results with a popular existing on‐demand routing protocol in this area, AODV, to establish the superiority of our approach. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

9.
Odd networks were introduced in the context of graph theory. However, their potential as fault‐tolerant multiprocessor networks has been shown. Broadcasting is one of the most important communication primitives used in multiprocessor networks. In this letter, we introduce efficient one‐to‐all broadcasting schemes of odd networks for one‐port and all‐port models. We show the broadcasting time of the former is 2d?2 and that of the latter is d–1. The total time steps taken by the proposed algorithms are optimal.  相似文献   

10.
This paper investigates a cross-layer design approach for minimizing energy consumption and maximizing network lifetime (NL) of a multiple-source and single-sink (MSSS) WSN with energy constraints. The optimization problem for MSSS WSN can be formulated as a mixed integer convex optimization problem with the adoption of time division multiple access (TDMA) in medium access control (MAC) layer, and it becomes a convex problem by relaxing the integer constraint on time slots. Impacts of data rate, link access and routing are jointly taken into account in the optimization problem formulation. Both linear and planar network topologies are considered for NL maximization (NLM). With linear MSSS and planar single-source and single-sink (SSSS) topologies, we successfully use Karush-Kuhn-Tucker (KKT) optimality conditions to derive analytical expressions of the optimal NL when all nodes are exhausted simultaneously. The problem for planar MSSS topology is more complicated, and a decomposition and combination (D&C) approach is proposed to compute suboptimal solutions. An analytical expression of the suboptimal NL is derived for a small scale planar network. To deal with larger scale planar network, an iterative algorithm is proposed for the D&C approach. Numerical results show that the upper-bounds of the network lifetime obtained by our proposed optimization models are tight. Important insights into the NL and benefits of cross-layer design for WSN NLM are obtained.  相似文献   

11.
In IEEE 802.15.4/ZigBee Wireless Sensor Networks (WSNs) a specific node (called the PAN coordinator or sink) controls the whole network. When the network operates in a multi-hop fashion, the position of the PAN coordinator has a significant impact on the performance: it strongly affects network energy consumption for both topology formation and data routing. The development of efficient self-managing, self-configuring and self-regulating protocols for the election of the node that coordinates and manages the IEEE 802.15.4/ZigBee WSN is still an open research issue. In this paper we present a cross-layer approach to address the problem of PAN coordinator election on topologies formed in accordance with the IEEE 802.15.4. Our solution combines the network formation procedure defined at the MAC layer by the IEEE 802.15.4 standard with a topology reconfiguration algorithm operating at the network layer. We propose a standard-compliant procedure (named PAN coordinator ELection – PANEL) to self-configure a IEEE 802.15.4/ZigBee WSN by electing, in a distributed way, a suitable PAN coordinator. A protocol implementing this solution in IEEE 802.15.4 is also provided. Performance results show that our cross-layer approach minimizes the average number of hops between the nodes of the network and the PAN coordinator allowing to reduce the data transfer delay and determining significant energy savings compared with the performance of the IEEE 802.15.4 standard.  相似文献   

12.
As different types of wireless networks are converging into an all-IP network, i.e., the Internet, it can be expected that in the near future video-on-demand (VoD) will be widely applied to many interesting services, and users can access these services using heterogeneous terminals via heterogeneous wired/wireless access networks. Many periodic broadcasting protocols have been proposed to reduce the implementation cost of VoD systems. However, most of the protocols assumed homogeneity for user terminals, while in practice, user terminals are usually quite different in their processing power, buffer space, and power. To address this problem, a few periodic broadcasting protocols providing the same video quality for all heterogeneous clients have been proposed recently. In this paper, we proposed a novel heterogeneous VoD broadcasting technique called Catch and Rest (CAR) to accommodate bandwidth heterogeneity without sacrificing user video quality. Then, we provide mathematic analysis to calculate the client bandwidth and buffer space requirements of CAR. Finally, we present our performance evaluation results for CAR. Our results show that under the same system resources (i.e., server and network bandwidth), CAR provides more uniform and acceptable service latency for all heterogeneous clients compared to previous works.  相似文献   

13.
As the Internet grows in size and complexity, network managers face a significant challenge in trying to understand the behaviour of routing protocols in large networks. In this paper, we present a tool called VLNT (visualizing large network topologies), which helps network managers to analyse complex routing topologies. A key contribution of our system is a novel hybrid layout algorithm, which significantly reduces the computation time required to layout large network topologies in comparison to conventional layout approaches. In addition our algorithm includes a novel termination criterion that avoids unnecessary iterations when optimizing the network layout. We demonstrate how the visualization features of VLNT can be used to analyse and improve BGP routing topologies, and provide examples using real‐life routing data. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

14.
传感器网络被认为是21世纪最重要的技术之一,它将对人类未来的生活产生深远影响,其中MAC协议是WSN通信协议中最为突出也是最为重要的关键协议之一。无线传感器网络具有节点的电源能量和硬件资源受限的特点,因此设计高能效的MAC协议是MAC协议研究中具有挑战性的研究课题。基于以上目的,本文采用了CSMA机制和分簇路由协议的优点,改进了传统的MAC协议提出了OCR-MAC协议,并利用MATLAB进行了仿真,仿真结果表明,改进后的OCR-MAC协议在节能和网络数据传输方面性能更加优越。  相似文献   

15.
无线传感器网络是一种由大量廉价微型传感器节点组成,并通过无线通信方式形成的多跳自组织网络,可用于对其部署区域的某些物理量进行智能监测。由于传感器节点数目较大,MAC协议是保证无线传感器网络高效通信的关键网络协议之一。另一方面,因为传感器节点受到电源能量有限、通信能力有限、计算和存储能力有限等现实条件的限制,传感器网络中的MAC协议又具有一些独特之处。对无线传感器网络MAC协议的研究现状进行较全面的考察,分析比较其中的几种典型MAC协议,并提出了该领域的发展趋势和未来工作的一些思路。  相似文献   

16.
Sharon  O. 《IEEE network》2001,15(1):56-65
OSPF and IS-IS are two main standard link state routing protocols designed to operate in various complex network topologies. One aspect that both protocols handle is the reliable dissemination of routing information over broadcast networks such as Ethernet and FDDI. Both protocols suggest different schemes for this purpose and in this article we compare the two. The performance criteria being checked are: the longest arrival time of a routing update packet at all the routers; the average arrival time of routing update packets at all the routers; the total required bandwidth; and the number of memory accesses a router performs, which is evidence of the amount of internal work it performs. We find that in our model of broadcast networks the scheme suggested in IS-IS is more efficient than that of OSPF in terms of the arrival times of routing update packets. In particular, the average arrival time of routing update packets in OSPF is 2-10 times longer than in IS-IS. In terms of the bandwidth each scheme consumes, there are scenarios where OSPF outperforms IS-IS and vice versa. In terms of the number of memory accesses routers perform in each scheme, IS-IS outperforms OSPF  相似文献   

17.
One of the main constraints in wireless sensor networks (WSNs) is the energy consumption. To mitigate this limitation and to prolong network life‐time, stability period and throughput, this paper proposes new cluster‐heads selection protocols, they based on Stable Election Protocol (SEP) and Distributed Energy‐Efficient Clustering (DEEC). We first propose Enhanced Zonal‐SEP (EZSEP) and Zonal Threshold‐DEEC (ZTDEEC) protocols, the proposed protocols are based on dividing the network field into certain zones, this will improve the connectivity of the far normal nodes with the base station (BS). Several evaluation metrics are used to compare between the proposed protocols and the conventional ZSEP and TDEEC protocols such as: network stability, instability period, life‐time and throughput. Considering the same total initial energy, the obtained results show that the proposed EZSEP slightly outperforms the conventional ZSEP in terms of network stability, instability period and life‐time, it achieves enormous improvements in terms of throughput as more nodes can transmit direct to BS. On the other hand, the proposed ZTDEEC provides huge improvements in terms of all the evaluation metrics mentioned above. To further improve the network life‐time and network throughput, we propose Threshold‐based EZSEP (TE‐ZSEP) and Enhanced‐ZTDEEC (EZ‐TDEEC) protocols, in these two new protocols we redefine the threshold formula used in EZSEP and ZTDEEC to consider both weighted energy and weighted distance parameters. By combining the idea of dividing the network field into certain zones and the new threshold formula, the proposed TE‐ZSEP and EZ‐TDEEC protocols can effectively improve the energy consumption in heterogeneous WSN and prolong its life‐time as proved by the obtained results.  相似文献   

18.
Many wireless sensor network (WSN) applications require efficient multimedia communication capabilities. However, the existing communication protocols in the literature mainly aim to achieve energy efficiency and reliability objectives and do not address multimedia communication challenges in WSN. In this paper, comprehensive performance evaluation of the existing transport protocols is performed for multimedia communication in WSN. Performance metrics such as packet delivery rate, end-to-end packet delay, bandwidth and energy efficiency, frame peak signal-to-noise ratio (PSNR), delay-bounded frame PSNR, frame delivery probability, frame end-to-end delay and jitter are investigated. The results clearly show that the existing transport protocols are far from satisfying the requirements of multimedia communication in WSN and hence there is a need for new effective multimedia delivery protocols for WSN.  相似文献   

19.
Inspired by the backbone concept in wired networks, a virtual backbone is expected to bring substantial benefits to routing in wireless sensor networks (WSNs). A connected dominating set (CDS) is used as a virtual backbone for efficient routing and broadcasting in WSNs. Most existing works focus on constructing a minimum CDS, a k‐connect m‐dominating CDS, a minimum routing cost CDS, or a bounded‐diameter CDS. However, the load‐balance factor is not considered for CDSs in WSNs. In this paper, a greedy‐based approximation algorithm is proposed to construct load‐balanced CDS in a WSN. More importantly, we propose a new problem: the Load‐balanced Allocate Dominatee problem. Consequently, we propose an optimal centralized algorithm and an efficient probability‐based distributed algorithm to solve the Load‐balanced Allocate Dominatee problem. For a given CDS, the upper and lower bounds of the performance ratio of the distributed algorithm are analyzed in the paper. Through extensive simulations, we demonstrate that our proposed methods extend network lifetime by up to 80% compared with the most recently published CDS construction algorithm. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

20.
In recent times, there have been many advances in the field of information theory and wireless sensor network (WSN) technologies. Network coding is a new paradigm in data transport and promises to change many aspects of WSN. This paper proposes a network coding multipath routing algorithm in WSN (NC-WSN). It is typically proposed in order to increase the reliability of data transmission or to provide load balancing. We evaluate and compare our technique with several existing approaches by a set of simulations, using different scenarios and topologies. The simulations results suggest that the multipath diversity achieved with our proposition can significantly improve the network response time.  相似文献   

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