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1.
In monitoring Wireless Sensor Networks(WSNs),the traffic usually has bursty characteristics when an event occurs.Transient congestion would increase delay and packet loss rate severely,which greatly reduces network performance.To solve this problem,we propose a Burstiness-aware Congestion Control Protocol(BCCP) for wireless sensor networks.In BCCP,the backoff delay is adopted as a congestion indication.Normally,sensor nodes work on contention-based MAC protocol(such as CSMA/CA).However,when congestion occur...  相似文献   

2.
Predictive Congestion Control Protocol for Wireless Sensor Networks   总被引:1,自引:0,他引:1  
Available congestion control schemes, for example transport control protocol (TCP), when applied to wireless networks, result in a large number of packet drops, unfair scenarios and low throughputs with a significant amount of wasted energy due to retransmissions. To fully utilize the hop by hop feedback information, this paper presents a novel, decentralized, predictive congestion control (DPCC) for wireless sensor networks (WSN). The DPCC consists of an adaptive flow and adaptive back-off interval selection schemes that work in concert with energy efficient, distributed power control (DPC). The DPCC detects the onset of congestion using queue utilization and the embedded channel estimator algorithm in DPC that predicts the channel quality. Then, an adaptive flow control scheme selects suitable rate which is enforced by the newly proposed adaptive backoff interval selection scheme. An optional adaptive scheduling scheme updates weights associated with each packet to guarantee the weighted fairness during congestion. Closed-loop stability of the proposed hop-by-hop congestion control is demonstrated by using the Lyapunov-based approach. Simulation results show that the DPCC reduces congestion and improves performance over congestion detection and avoidance (CODA) [3] and IEEE 802.11 protocols.  相似文献   

3.
Recent developments in biosensor and wireless technology have led to a rapid progress in wearable real time health monitoring. Unlike wired networks, wireless networks are subject to more packet loss and congestion. In this paper, we propose a congestion control and service prioritization protocol for real time monitoring of patients’ vital signs using wireless biomedical sensor networks. The proposed system is able to discriminate between physiological signals and assign them different priorities. Thus, it would be possible to provide a better quality of service for transmitting highly important vital signs. Congestion control is performed by considering both the congestion situation in the parent node and the priority of the child nodes in assigning network bandwidth to signals from different patients. Given the dynamic nature of patients’ health conditions, the proposed system can detect an anomaly in the received vital signs from a patient and hence assign more priority to patients in need. Simulation results confirm the superior performance of the proposed protocol. To our knowledge, this is the first attempt at a special-purpose congestion control protocol specifically designed for wireless biosensor networks.  相似文献   

4.
In wireless sensor networks, congestion leads to buffer overflowing, and increases delay. The tradi-tional solutions use rate adjustment to mitigate congestion, thus increasing the delay. A Delay-aware congestion con-trol protocol (DACC) was presented to mitigate congestion and decrease delay. In order to improve the accuracy of the existing congestion detection model which is based on the buffer occupancy of a single node, DACC presents a new model considering both the real-time buffer occupancy and the average transmission time of packets. DACC uses the untapped bits in the IEEE 802.11 Distributed coordination function (DCF) frames header to carry congestion infor-mation. During the congestion alleviation period, DACC presents a channel occupancy mechanism which is based on the real-time buffer occupancy for the purpose of decreas-ing delay and preventing packet loss. Simulation results indicate that in terms of delay, packet delivery ratio, col-lision and buffer load, DACC has comparative advantages than those of 802.11 DCF, Priority-based congestion con-trol protocol (PCCP) and Decoupling congestion control and fairness (DCCF).  相似文献   

5.
Congestion control in wireless sensor networks (WSNs) is crucial. In this article, we discuss congestion control and the adaptive load-aware problem for sensor nodes in WSNs. When the traffic load of a specific node exceeds its the available capacity of the node, a congestion problem occurs because of buffer memory overflow. Congestion may cause serious problems such as packet loss, the consumption of power, and low network throughput for sensor nodes. To address these problems, we propose a distributed congestion control protocol called adaptive load-aware congestion control protocol (ALACCP). The protocol can adaptively allocate the appropriate forwarding rate for jammed sensor nodes to mitigate the congestion load. Through the buffer management mechanism, the congestion index of neighboring sensor nodes, and an adjustment of the adaptive forwarding rate, the degree of congestion is alleviated markedly. The performance in allocating the forwarding rate effectively to neighboring sensor nodes also improves. The ALACCP can avoid packet loss because of traffic congestion, reduce the power consumption of nodes, and improve the network throughput. Simulation results revealed that the proposed ALACCP can effectively improve network performance and maintain the fairness of networks.  相似文献   

6.
Geographic routing protocols forward packets according to the geographical locations of nodes. Thus, the criteria used to select a forwarding node impacts on the performance of the protocols such as energy efficiency and end-to-end transmission delay. In this paper, we propose a congestion aware forwarder selection (CAFS) method for a geographic routing protocol. To design CAFS, we devise a cost function by combining not only the forward progress made to a packet but also the amount of energy required for packet forwarding, forwarding direction, and congestion levels of potential forwarders. Among the potential forwarders, CAFS selects the next forwarder having the minimum cost. In our simulation studies, we compare the performance of CAFS with those of the maximum progress (MP) method and the cost over progress (CoP) method in various network conditions. The results show that compared with MP, the length of a routing path in terms of the number of hops becomes longer when CAFS is used. However, the shorter hop distance helps to avoid unnecessary retransmissions caused by packet loss in a wireless channel. In addition, since CAFS considers congestion levels of candidate forwarders, it reduces the queuing delay in each forwarder. Therefore, CAFS is superior to the MP and the CoP in terms of the energy consumption, end-to-end packet transfer delay, and the successful packet delivery rate.  相似文献   

7.
基于无线传感器网络的跨层拥塞控制协议   总被引:1,自引:0,他引:1       下载免费PDF全文
张玉鹏  刘凯  王广学 《电子学报》2011,39(10):2258-2262
无线传感器网络(WSN)中由拥塞引起的大量分组重传以及重传多次失败后的分组丢弃会导致较长的时延、较高的分组丢失率和较多的能量消耗.为了准确探测和控制网络拥塞,提出了一种基于跨层设计的拥塞控制协议,即上行拥塞控制(UCC)协议.该协议利用节点在媒质接人控制(MAC)层中未占用的缓冲器区间大小和所预测的通信流量作为该节点的...  相似文献   

8.
无线传感器网络优化的任务管理算法研究   总被引:1,自引:0,他引:1  
该文针对多跳分簇无线传感器网络多节点协同式并行处理应用,提出了一种新的基于改进粒子群优化算法的任务管理算法,该算法建立了基于复制的变异操作,并采用基于熵权的逼近理想解的排序法对算法结果进行客观评价与择优。详述了算法的各个要素,仿真结果证实,算法搜索效率高、可获得多目标优化的任务分配与调度解,且比文献中提出的其他算法的解性能优越。  相似文献   

9.
江雪 《中兴通讯技术》2007,13(2):39-41,46
传感器节点能量受限,节能是传感器网络中媒体访问控制(MAC)协议设计的首要问题。采用周期性睡眠机制、自适应侦听机制、串音避免机制和消息传递机制可使得传感器媒体访问控制(S-MAC)协议在网络能耗和时延方面得到改进。对S-MAC协议的改进主要有两种方式:动态调整、区别控制包与数据包的发送条件进行发送。对无线传感器网络,要想设计出一种满足各方面要求的MAC协议是不现实的,可针对不同应用的要求,灵活采用不同的方式,设计出相应的协议。  相似文献   

10.
Wireless Personal Communications - Wireless body sensor networks are now very popular for modern healthcare applications like health monitoring, remote healthcare, emergency healthcare etc. This...  相似文献   

11.
高德云  朱婉婷  方然 《中国通信》2011,8(8):121-129
A Light-Weight Simple Network Management Protocol (LW-SNMP) for the wireless sensor network is proposed, which is a kind of hierarchical network management system including a sink manager, cluster proxies, and node agents. Considering the resource limitations on the sensor nodes, we design new management messages, new data types and new management information base completely. The management messages between the cluster proxy and node agents are delivered as normal data packets. The experiment results show t...  相似文献   

12.
Wireless Personal Communications - Wireless Sensor Network has been widely used in a variety of applications such as; medical, agriculture, military, monitoring environment and so on. In healthcare...  相似文献   

13.
One of the important protocols for increasing the network lifetime in wireless sensor networks (WSNs) is hybrid energy efficient distributed (HEED) protocol. This protocol considers two parameters for deciding the cluster heads, i.e., residual energy and node density and has been designed for the homogeneous WSNs. In this paper, we consider the implementation of HEED for a heterogeneous network. Depending upon the type of nodes, it defines one-level, two-level, and three-level heterogeneity and accordingly the implementation of HEED is referred to as hetHEED-1, hetHEED-2, and hetHEED-3, respectively. We also consider one more parameter, i.e., distance and apply fuzzy logic to determine the cluster heads and accordingly the hetHEED-1, hetHEED-2, and hetHEED-3 are named as HEED-FL, hetHEED-FL-2, hetHEED-FL-3, respectively. The simulation results show that as the level of heterogeneity increases in the network, the nodes remain alive for longer time and the rate of energy dissipation decreases. And also, increasing the heterogeneity level helps sending more packets to the base station and increases the network lifetime. The increase in the network energy increases the network lifetime manifold. In fact, using fuzzy logic, the network lifetime increases by 114.85 % that of the original HEED without any increase in the network energy. Thus, the hetHEED-FL-3 provides the longest lifetime (387.94 % increase) in lifetime at the cost of 19 % increase in network energy), sends maximum number of packets to the base station, and has minimum rate of energy dissipation.  相似文献   

14.
本论文在分析无线传感器网络不同于普通有线网络的特征后,提出了一种适用于无线传感器网络的TCP 拥塞控制机制DW-TCP,此机制将TCP拥塞窗口分为拥塞丢包窗口和误码丢包窗口,在链路误码率较高时通过降低发送速率提高数据发送的可靠性,节约无线节点的能源消耗和系统不必要的开销,该机制不但考虑到拥塞丢包对数据发送速率的影响,而且考虑到无线链路中的误码丢包对数据发送速率的影响.  相似文献   

15.
By reducing interferences drastically, time division multiple access (TDMA) based approaches are considered one of the most efficient solutions to optimize resources’ use. The existing protocols, however, address only the latency minimization without considering the waste of energy, which typically results from idle listening or frequent transitions of the radio module between sleep and active modes. Besides, only saturated systems are considered in these protocols, which may imply resources’ underutilization in some practical use cases. In this paper, we present an energy-aware TDMA-based link scheduling protocol, named deterministic link scheduling protocol (DLSP), designed with the aim of achieving both low energy consumption and low latency in wireless sensor networks. DLSP takes advantage of the spatial reuse of interference-free time slots using conflict graphs. Unlike earlier studies that often considered saturated traffic, we propose to relax the saturation assumption in order to maintain good performance when some of the nodes have no data to send. Thus, we propose to define the following transmission periods: a period to send the own data of the nodes and a period to relay packets. The simulation results clearly show the effectiveness of the proposed protocol, in terms of latency and energy consumption, compared to existing approaches.  相似文献   

16.
针对无线传感器网络 MAC 协议的作用与要求,给出一种基于 CDMA 的 MAC 协议改进方案.根据网络负载变化采用周期性的侦听/睡眠机制,使大多数节点处于睡眠状态,节省能耗;同时结合 CDMA 技术给节点分配网内唯一的具有正交性的高速伪随机码(PN)来调制数据信号,使之在时域和频域重叠,实现数据的大规模实时传送.仿真结果表明,协议在保证系统低延时和高吞吐量的同时,能明显减少能量消耗.  相似文献   

17.
传感器网络中的节点存在由于能量耗尽或恶意攻击而丧失作用的威胁,因此需要新节点的加入.利用Bloom Filter技术,提出了一种访问控制协议.本协议不仅便于实现新节点、旧节点的双向认证和密钥协商,而且便于实现节点的加入与撤消.通过性能分析和安全性分析说明了该协议的有效性.  相似文献   

18.
提出了一种与节点位置无关的、能量感知的无线传感器网络覆盖控制协议EACCP(an Energy-Aware Coverage Control Protocol for wireless sensor networks),EACCP采用基于节点分层成簇的思想,根据节点邻居平均能量与自身剩余能量等参数竞选活动节点.理论分析与模拟实验表明EACCP协议不但能够提供高质量的网络覆盖率,而且可以有效地适应于节点能量异构的网络应用场景,并且减少活动节点选取过程中的控制消息开销.  相似文献   

19.
岳宇君  刘解放  刘从新  曾维鲁   《电子器件》2008,31(3):1042-1045
简要分析了无线传感器网络MAC层协议的作用,针对MAC协议在低时延方面的不足,提出了一种低时延的MAC协议(L-MAC).该协议采用汇聚树,在满足低功耗的基础上,减少了时延.理论分析和仿真实验表明L-MAC较好地解决了时延问题.  相似文献   

20.
The unreachability problem (i.e. the so-called void problem) which exists in the greedy routing algorithms has been studied for the wireless sensor networks. However, most of the current research work can not fully resolve the problem (i.e. to ensure the delivery of packets) within their formulation. In this letter, the greedy anti-void routing (GAR) protocol is proposed, which solves the void problem by exploiting the boundary finding technique for the unit disk graph (UDG). The proposed rolling-ball UDG boundary traversal (RUT) is employed to completely guarantee the delivery of packets from the source to the destination node. The proofs of correctness for the proposed GAR protocol are also given at the end of this letter.  相似文献   

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