一种新颖的无线传感器网络的MAC协议

通过对MAC协议运行原理、具有的优缺点、目前所存在的问题以及网络中信道接入机制和能效问题进行分析的基础上,给出一种侦听/睡眠和CDMA相结合的混合MAC协议,此协议采用周期性侦听/睡眠机制和CDMA技术来保证数据的流畅传输,从而实现能量的有效利用.最后,利用仿真软件NS2证明新方法的优越性和高效性.     

A Cooperative MAC Protocol for QoS Enhancement in Wireless USB Networks

Wireless USB (WUSB) is the USB technology merged with WiMedia PHY/MAC based on success of wired USB, and it can be applied to various mobile applications such as laptop, cellular phone, etc. Also, WUSB can provide the better user convenience than wired USB applications as well as be applied to the legacy USB application, since it provides high speed connection between host and devices for the compatibility with USB 2.0 specification and removes the cable among devices using the USB protocol. However the current WUSB protocol can’t prevent the QoS degradation occurred by mobile nodes with low data rate. This problem causes the critical problems in QoS provisioning to isochronous streams and mobile applications. Therefore, we propose a new cooperative MAC protocol for WUSB network with virtual MIMO (multi input multi output) link. Based on instantaneous channel state information among WUSB devices, our proposed protocol can intelligently select the transmission path with higher data rate between WUSB host and WUSB device as well as between WUSB device and WUSB device. Thus our proposed protocol can provide advanced QoS with minimum delay for real-time multimedia services.     

Network Lifetime Enhancement of Wireless Sensor Networks Using EFRP Protocol

This paper presents a novel transceiver architecture for in-band full duplex radio. A transceiver for full duplex radio requires a self-interference (SI) canceler to remove the SI occurring from the transmitter to the receiver, and a full duplex transceiver generally has two SI cancelers: one at the analog RF stage and the other at the baseband stage. The output from the SI canceler at the RF stage includes much residual SI, and it decreases the number of bits allocated to the analog baseband signal at the analog-to-digital converter. A 1-tap analog baseband SI canceler that uses a replica signal including only the direct path component of the residual SI has been presented for preventing degradation. However, the architecture cannot remove the SI well due to the high Ricial K-factor. To address the problem, the presented architecture has an SI canceler at the analog baseband stage, and this canceler employs a replica signal that is output from a digital-to-analog converter. Because the replica signal is generated in the digital domain, the architecture can generate a multipath replica signal, and improved performance can be expected. Numerical and theoretical analyses are shown to validate the effectiveness of the presented architecture.

     

A Novel QoS Based Secure Unequal Clustering Protocol with Intrusion Detection System in Wireless Sensor Networks

Wireless sensor network (WSN) becomes a hot research topic owing to its application in different fields. Minimizing the energy dissipation, maximizing the network lifetime, and security are considered as the major quality of service (QoS) factors in the design of WSN. Clustering is a commonly employed energy-efficient technique; however, it results in a hot spot issue. This paper develops a novel secure unequal clustering protocol with intrusion detection technique to achieve QoS parameters like energy, lifetime, and security. Initially, the proposed model uses adaptive neuro fuzzy based clustering technique to select the tentative cluster heads (TCHs) using three input parameters such as residual energy, distance to base station (BS), and distance to neighbors. Then, the TCHs compete for final CHs and the optimal CHs are selected using the deer hunting optimization (DHO) algorithm. The DHO based clustering technique derives a fitness function using residual energy, distance to BS, node degree, node centrality, and link quality. To further improve the performance of the proposed method, the cluster maintenance phase is utilized for load balancing. Finally, to achieve security in cluster based WSN, an effective intrusion detection system using a deep belief network is executed on the CHs to identify the presence of intruders in the network. An extensive set of experiments were performed to ensure the superior performance of the proposed method interms of energy efficiency, network lifetime, packet delivery ratio, average delay, and intrusion detection rate.

     

A Novel Trust-Aware Geographical Routing Scheme for Wireless Sensor Networks

Wireless sensor networks are vulnerable to a wide set of security attacks, including those targeting the routing protocol functionality. The applicability of legacy security solutions is disputable (if not infeasible), due to severe restrictions in node and network resources. Although confidentiality, integrity and authentication measures assist in preventing specific types of attacks, they come at high cost and, in most cases, cannot shield against routing attacks. To face this problem, we propose a secure routing protocol which adopts the geographical routing principle to cope with the network dimensions, and relies on a distributed trust model for the detection and avoidance of malicious neighbours. A novel function which adaptively weights location, trust and energy information drives the routing decisions, allowing for shifting emphasis from security to path optimality. The proposed trust model relies on both direct and indirect observations to derive the trustworthiness of each neighboring node, while it is capable of defending against an increased set of routing attacks including attacks targeting the indirect trust management scheme. Extensive simulation results reveal the advantages of the proposed model.     

A Novel Subspace Approach for Cooperative Localization in Wireless Sensor Networks Using Range Measurements

Estimating the positions of sensor nodes is a fundamental and crucial problem in wireless sensor networks. In this paper, three novel subspace methods for node localization in a fully connected network are devised with the use of range measurements. Biases and mean square errors of the sensor node position estimates are also derived. Computer simulations are included to contrast the performance of the proposed algorithms with the conventional subspace positioning method, namely, classical multidimensional scaling, as well as Cramer-Rao lower bound.     

A Novel Routing Protocol for Supporting QoS for Ad Hoc Mobile Wireless Networks

The main purposes of this article are to lessen the influence of the fastchanging network topology, rapidly varying bandwidth information, and the increasing size of routing tables onquality of service routing. Based on DSDV (Destination-Sequenced Distance-Vector) routing protocol formaintaining up-to-date routing information, the related research has to update routing tables when networktopology changes; moreover, the routing tables must be updated periodically even though the networktopology has not changed. To put emphasis on QoS routing, they also have to exchange routing tables by thetime of bandwidth information changes. Furthermore, the size of routing tables increases with the numberof mobile nodes; therefore, the precious wireless bandwidth is wasted on transmitting the large-scalerouting tables. In this article, we propose an on-demand-based QoS routing protocol to mitigate theseproblems and to achieve the QoS requirement. The goal of this article is to discover an optimal routewith minimum time delay for transmitting real-time data from a source node hop by hop to adestination node under some predefined constraints. Our contributions are as follows: our researchprovides a rigorous bandwidth definition and bandwidth application, a broad view of bandwidth calculationand reservation, minimizing the size of control packets and the number of control packet transmissions,and an efficient QoS routing protocol.     

一种基于服务质量的节能无线传感器网络MAC协议

为了平衡网络能耗与QoS,提出了一种基于服务质量的节能MAC协议-QE-MAC.该协议一方面采用由Hill等人提出的低能量载波侦听技术降低节点能耗,另一方面,采用冲突避免、回复确认、区分优先级和失败重传等机制确保分组传输的可靠性,以及使用业务固定短周期发起策略来解决分组接收的时延过大问题.模拟实验和测试结果都表明,QE-MAC能够以较低的网络能耗提供良好的QoS.     

WSNs的QoS整体框架研究

关于WSNs中QoS的研究以前都是孤立的,或是特定在某些功能层上的研究,或是特别指定某些应用场景的研究。而论文根据WSNs的参考体系结构,分层讨论了QoS需求的定义以及低层QoS需求对高层QoS需求的影响,从而得出一个整体的QoS框架,然后根据各个QoS需求之间的关系,分析它们之间是否有权衡点以及怎样找到这种权衡关系,以便深入理解WSNs中各QoS需求的互相作用。当无线传感器网络中存在需要考虑QoS支持的业务时,应用设计者能够参照制定详细的QoS需求,系统工程师可以参考评估各个QoS需求之间的权衡关系,从而进行网络的整体设计。     

A Novel Sub-regional Key Distribution Scheme for Distributed Wireless Sensor Networks

International Journal of Wireless Information Networks - Security is critical to any networks, including WSNs. The packets are transmitted hop by hop in WSNs over a broadcasting medium, which makes...     

QoS in Wireless Multimedia Sensor Networks: A Layered and Cross-Layered Approach

The emergence of wireless multimedia sensor networks (WMSN) has given birth to several civilian as well as defense applications. Some of the interesting applications employing low cost sensor nodes to manipulate rich multimedia content include traffic monitoring, border surveillance, smart homes, environment and habitat monitoring. Unlike the traditional sensor networks which are aimed at maximizing network lifetime by decreasing energy utilization, the main objective of WMSNs is optimized delivery of multimedia content along with energy efficiency. Multimedia communications in WMSNs, has stringent delay and high bandwidth requirement as compared to scalar data transfer in WSNs. Fulfilling these constraints in resource and energy constrained WMSNs is a huge challenge. In WMSNs, each layer of the protocol stack is responsible and fully involved in providing QoS guarantees. There is a need for new schemes at each layer of the protocol stack- from advanced coding techniques that reduce encoder complexity and achieve maximum compression to dynamic routing and MAC protocols that provide service differentiation and reduce end-to-end latency. In wireless sensor networks, where all layers have dependency on each other, QoS guarantees are possible through the cross layer interaction of different layers. This paper gives an overview of the different existing layered schemes in WMSNs, followed by a discussion on the significance and efficiency gains that can be achieved from cross layer interactions in WMSNs along with the review of the existing cross layer approaches. Finally, we identify the open research issues which have not been adequately addressed so far.     

A Cross-Layer Channel Access and Routing Protocol for Medical-Grade QoS Support in Wireless Sensor Networks

One of principal design issues of a Wireless Sensor Network (WSN) for medical information systems is to classify received packets based on their priorities and guarantees so that they can be transmitted reliably, thus satisfying QoS requirements. In addition, when the target WSN requires multi-hop communications and the traffic load increases significantly, it is challenging to support both load balancing and suitable QoS at the same time. In this paper, we propose a new reliable protocol termed Cross-layer Channel Access and Routing (CCAR), which simultaneously supports both MAC and routing operations for medical-grade QoS provisions. CCAR initially determines the routing path with the lowest traffic load and low latency using newly defined channel quality factors. Concurrently, the source node allocates the predefined QoS Access Category to each packet and reserves the channel along the route. In addition, CCAR introduces an effective route maintenance scheme to avoid link failures in bottlenecked intermediate nodes, which prevents unnecessary packet drops and route rediscovery evocations. Finally, through both simulation studies and real test-bed experiments, we evaluate the performance of CCAR by comparing it with other conventional protocols, demonstrating that the proposed protocol can more efficiently support medical-grade QoS packets, especially when the network is heavily loaded.     

无线传感器网络密钥预分配蜂窝模型

要达到无线传感器网络的安全通信,必须对网络中节点之间的通讯数据用密钥进行必要的加密。文章使用蜂窝模型分组方案,把节点按照预测的地理位置关系分组,给处于相同组或是相邻组的节点之间分配共享密钥,使节点的分组模式和查询更符合节点广播特征。蜂窝模型密钥预分配机制极大的提高密钥利用率,减少了密钥分配和维护代价,使传感器网络的安全性和连通性极大的提高。     

一种低时延的无线传感器网络MAC协议

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.     

无线传感器网络S-MAC协议研究

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。     

A Novel Heuristic Approach Based Trust Worthy Architecture for Wireless Sensor Networks

A Wireless Sensor Networks (WSNs) consist of spatially distributed autonomous sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants. WSNs are more vulnerable to attacks and failures due to the involvement of many numbers of tiny sensor nodes. As the technology is tremendously increasing in the recent past, the implementation of this for various time critical applications is quite interesting and challenging. Moreover, WSNs have no specific hierarchical structures, leads to security and maintenance problems. Trust in WSN is defined as the degree of belief or confidence about the nodes based on the past interactions and observations has which become a mandatory requirement for reliable communication in WSN under security constraints. In this paper, we propose a Heuristic Approach based Trust Worthy Architecture for WSN that considers the challenges of the system and focus on the collaborative mechanism for trust evaluation and maintenance. Our proposed Architecture could also be capable of fulfilling critical security, reliability, mobility and performance requirements for reliable communication while being readily adaptable to different applications. The simulation results of the proposed architecture outperformed the recent trust worthy architecture using the analysis of the performance requirements such as communication overhead, memory requirements and energy consumption.     

A Key Pre-distribution Scheme for Wireless Sensor Networks Using Hexagonal Deployment knowledge

To insure security for the messages sent among sensor nodes, it is important to establish keys for encryption to nodes which have had no prior direct contact with each other in wireless sensor networks. To solve the problem above, several key pre-distribution schemes have been proposed. In this paper, we present a novel key pre-distribution scheme using hexagonal deployment knowledge, in which the q-composite keys scheme has been improved. By using hexagonal division over the deploy- ment region, the probability of sharing common keys be- tween each sub-region and its neighboring sub-regions are equal, so the keys for encryption can be generated efficiently. The analytic results show that the scheme we pre-sented can achieve a higher connection probability of any two neighboring nodes than previous schemes, and net- work resilience against node capture can be substantially improved.     

A Tracking-Assisted Routing Scheme for Wireless Sensor Networks

Wireless sensor networks (WSNs) offer much promise for target tracking and environmental monitoring. While many WSN routing protocols have been proposed to date, most of these focus on the mobility of observers and assume that targets are fixed. However, in reality, many applications require for sensing data to be propagated from multiple mobile targets to multiple mobile observers. In addition, WSNs often operate under strict energy constraints, and therefore reducing energy dissipation is also an important issue. In this paper, we present a grid-based routing scheme known as TRENS. First, we address the issue of the WSN comprising multiple mobile targets and observers—with TRENS being the first scheme of its kind to use tracking technology to increase the efficiency of routing procedures in the context of dynamic topology. Next, we introduce a shortcutting approach to resolve energy issues by optimizing routing paths and thus decreasing communication costs and latency. Finally, we conduct extensive simulations to show how TRENS conserves energy and performs better than other grid-based schemes.     

A Centralized MAC Protocol for QoS Support in UWB-Based Wireless Networks

In this paper we introduce a novel MAC protocol that provides Quality of Service (QoS) support for multimedia traffic in UWB-based wireless local area networks. The proposed protocol allocates transmission opportunities to QoS and best effort traffic using a set of scheduling and resource control algorithms. The algorithms account for the UWB characteristics such as the co-existence of multiple simultaneous transmissions as well as the possibility of dynamically assigning the nodes' transmission rate and power. The simulation results show that the proposed protocol can provide QoS support while optimizing resource utilization. Yuechun Chu received her B.Sc. degree in electrical engineering from Shanghai University, China, in 1996 and M.Sc. degree in electrical engineering from University of Science and Technology of China in 1999. She is currently pursuing the Ph.D. degree in the department of electrical and computer engineering at the University of Massachusetts Amherst. Her research interests include MAC protocol design for UWB-based networks, wireless multimedia applications, and architectures and protocols for wireless networks with QoS guarantees. Aura Ganz is currently an Associate Professor and Director of the Multimedia Networks Laboratory at the ECE Department, University of Massachusetts at Amherst. She has experience in topics related to multimedia wireless networks, optical networks and ubiquitous computing. The research results are validated by a combination of analytical, simulation and prototyping tools. She has published a book “Multimedia Wireless Networks: Technologies, Standards and QoS” (Prentice Hall) and authored over one hundred and fifty peer reviewed publications. Dr. Ganz received her BSc, MSc and Ph.D degrees in Computer Science from the Technion in Israel.