Efficient Packet Scheduling Technique for Data Merging in Wireless Sensor Networks

Wireless Sensor Networks(WSNs) has become a popular research topic due to its resource constraints. Energy consumption and transmission delay is crucial requirement to be handled to enhance the popularity of WSNs. In order to overcome these issues, we have proposed an Efficient Packet Scheduling Technique for Data Merging in WSNs. Packet scheduling is done by using three levels of priority queue and to reduce the transmission delay. Real-time data packets are placed in high priority queue and Non real-time data packets based on local or remote data are placed on other queues. In this paper, we have used Time Division Multiple Access(TDMA) scheme to efficiently determine the priority of the packet at each level and transmit the data packets from lower level to higher level through intermediate nodes. To reduce the number of transmission, efficient data merge technique is used to merge the data packet in intermediate nodes which has same destination node. Data merge utilize the maximum packet size by appending the merged packets with received packets till the maximum packet size or maximum waiting time is reached. Real-time data packets are directly forwarded to the next node without applying data merge. The performance is evaluated under various metrics like packet delivery ratio, packet drop, energy consumption and delay based on changing the number of nodes and transmission rate. Our results show significant reduction in various performance metrics.

Modeling and Control for Wireless Networked Control System

In this paper, the stabilization problem is considered for the class of wireless networked control systems （WNCS）. An indicator is introduced in the WNCS model. The packet drop sequences in the indicator are represented as states of a Markov chain. A new discrete Markov switching system model integrating 802.11 protocol and new scheduling approach for wireless networks with control systems are constructed. The variable controller can be obtained easily by solving the linear matrix inequality （LMI） with the use of the Matlab toolbox. Both the known and unknown dropout probabilities are considered. Finally, a simulation is given to show the feasibility of the proposed method.

Grid-based energy-aware routing in wireless sensor networks

The model of energy cost in a wireless sensor network （WSN）environment is built, and the energy awareness and the wireless interference mainly due to different path loss models are studied. A special case of a clustering scheme, a twodimensional grid clustering mechanism, is adopted. Clusterheads are rotated evenly among all sensor nodes in an efficient and decentralized manner, based on the residual energy in the battery and the random backoff time. In addition to transmitting and receiving packets within the sensors＇ electrical and amplification circuits, extra energy is needed in the retransmission of packets due to packet collisions caused by severe interference. By analysis and mathematical derivation, which are based on planar geometry, it is shown that the total energy consumed in the network is directly related to the gridstructure in the proposed grid based clustering mechanism. The transmission range is determined by cluster size, and the path loss exponent is determined by nodal separation. The summation of overall interference is caused by all the sensors that are transmitting concurrently. By analysis and simulation, an optimal grid structure with the corresponding grid size is presented, which balances between maximizing energy conservation and minimizing overall interference in wireless sensor networks.

On Minimizing Delay with Probabilistic Splitting of Traffic Flow in Heterogeneous Wireless Networks

In the paper,we propose a framework to investigate how to effectively perform traffic flow splitting in heterogeneous wireless networks from a queue point.The average packet delay in heterogeneous wireless networks is derived in a probabilistic manner.The basic idea can be understood via treating the integrated heterogeneous wireless networks as different coupled and parallel queuing systems.The integrated network performance can approach that of one queue with maximal the multiplexing gain.For the purpose of illustrating the effectively of our proposed model,the Cellular/WLAN interworking is exploited.To minimize the average delay,a heuristic search algorithm is used to get the optimal probability of splitting traffic flow.Further,a Markov process is applied to evaluate the performance of the proposed scheme and compare with that of selecting the best network to access in terms of packet mean delay and blocking probability.Numerical results illustrate our proposed framework is effective and the flow splitting transmission can obtain more performance gain in heterogeneous wireless networks.

An Efficient Billing Scheme for Trusted Nodes Using Fuzzy Logic in Wireless Sensor Networks

Extending the lifetime of the wireless sensor networks (WSNs), where recharging sensors is not always possible, has been a major concern for researchers for the past decade. In this paper, we study the cooperation between nodes in wireless sensor networks in forwarding packets to others, and we propose a new collaboration technique which stimulates intermediate nodes to forward packets toward their destination. Some nodes show selfish behavior by denying the forwarding packets to other nodes in commercial networks in an effort to preserve their own energy. This paper applies a technique which is used to prolong the network lifetime, based on a node’s energy and trust value, and additionally incorporates fuzzy logic, which stimulates nodes to forward packets by rewarding cooperation. According to simulation results, the proposed approach surpasses the Nuglets (virtual currency) approach and the Reputation approach in network energy and thus prolongs the network lifetime. Additionally, our proposed approach demonstrates better results in the number of dropped packets, PDR and forwarded packets to neighboring nodes.

Energy Efficient and QoS Aware Framework for Video Transmission over Wireless Sensor Networks

Wireless Multimedia Sensor Networks (WMSNs), is a network of sensors, which are limited in terms of memory, computing, bandwidth, and battery lifetime. Multimedia transmission over WSN requires certain QoS guarantees such as huge amount of bandwidth, strict delay and lower loss ratio that makes transmitting multimedia is a complicated task. However, adopting cross-layer approach in WMSNs improves quality of service of WSN under different environmental conditions. In this work, an energy efficient and QoS aware framework for transmitting multimedia content over WSN (EQWSN) is presented, where packet, queue and path scheduling were introduced. It adapts the application layer parameter of video encoder to current wireless channel state, and drops less important packets in case of network congestion according to packet type. Finally, the path scheduling differentiates packets types/priority and route them through different paths with different QoS considering network lifetime. Simulation results show that the new scheme EQWSN transmits video quality with QoS guarantees in addition to prolonging network lifetime.

A Cross-Layer Optimization Framework for Energy Efficiency in Wireless Sensor Networks

We consider the extension of network lifetime of battery driven wireless sensor networks by splitting the sensing area into uniform clusters and implementing heterogeneous modulation schemes at different members of the clusters. A cross-layer optimization has been proposed to reduce total energy expenditure of the network;at network layer, routing is done through uniform clusters;at MAC layer, each sensor node of the cluster is assigned fixed or variable time slots and at physical layer different member of the clusters is assigned different modulation techniques. MATLAB simulation proved substantial network lifetime gains.

Packet Tracer软件在无线网络技术实验教学中的应用

介绍了Packet Tracer软件包含的无线网络仿真设备及其加密认证技术。借助Packet Tracer软件完成了无线网络技术课程的实验教学,由无线网卡、无线接入点和无线路由器构成无线网络,通过对无线网络的配置介绍了仿真实验过程。学生通过完成仿真实验,培养了组建、使用和管理无线网络的技能,加深了对无线网络技术理论及概念的掌握和理解。

基于Packet Tracer的无线网络组建实验研究

无线计算机网络的组建是高职计算机网络技术专业重点教学内容之一,本文结合当前高职无线计算机网络实验教学的现状,提出一种采用Packet Tracer网络模拟软件来完成无线网络组建实验的有效方法,并在Packet Tracer虚拟平台下设计了网络拓扑结构,构建了虚拟的无线网络环境,对相关设备进行了配置,最终对实验结果进行了验证。

基于PacketTracer6.2的虚拟无线网络实验室的应用研究

无线网络是近些年高速发展的一种组网技术,文章中首先提出了采用Packet Tracer6.2构建虚拟无线网络实验室环境,然后阐述了三种无线组网方式,最后比对了传统无线网络实验室和利用Packet Tracer6.2建立的虚拟无线网络实验室的优缺点。

Cisco Packet Tracer在交换机路由器配置实践中的应用

Cisco Packet Tracer是由Cisco公司推出的一款针对学习网络设备的安装与配置课程的入门级网络模拟器软件,它可以帮助学习计算机网络技术专业的学生和相关技术人员快速有效地掌握设备的配置与管理的基础知识,是计算机仿真技术和计算机网络技术的完美结合。本文从该软件的使用角度出发,分析了它的特点,使用方法和应用场合,并利用几个具体的实例验证了它在交换机路由器配置实践中起到的重要作用。

Efficient Broadcast Retransmission Based on Network Coding for InterPlaNetary Internet

In traditional wireless broadcast networks,a corrupted packet must be retransmitted even if it has been lost by only one receiver.Obviously,this is not bandwidth-efficient for the receivers that already hold the retransmitted packet.Therefore,it is important to develop a method to realise efficient broadcast transmission.Network coding is a promising technique in this scenario.However,none of the proposed schemes achieves both high transmission efficiency and low computational complexity simultaneously so far.To address this problem,a novel Efficient Opportunistic Network Coding Retransmission(EONCR)scheme is proposed in this paper.This scheme employs a new packet scheduling algorithm which uses a Packet Distribution Matrix(PDM)directly to select the coded packets.The analysis and simulation results indicate that transmission efficiency of EONCR is over 0.1,more than the schemes proposed previously in some simulation conditions,and the computational overhead is reduced substantially.Hence,it has great application prospects in wireless broadcast networks,especially energyand bandwidth-limited systems such as satellite broadcast systems and Planetary Networks(PNs).

A Novel Transceiver Architecture Based on Wavelet Packet Modulation for UWB-IR WSN Applications

In last few years, several recent developments concern a new proposed techniques of communication for WSN (Wireless Sensors Network) using a complex methods and technics. This network is considered a future platform for many applications like: medical, agriculture, industrial, monitoring and others. The challenge of this work consists in proposing a new design of transceiver for WSN based on IDWPT (Inverse Discrete Wavelet Packet Transform) in emitter and DWPT (Discrete Wavelet Packet Transform) in receiver for mono and multi users using AWGN Channel. We will propose in this paper, a new concept of impulse radio communication for multiband orthogonal communication for UWB (Ultra-wideband) applications. The main objective of this work is to present a new form of pulse communication adapted to low through-put short-range applications and is scalable according to the type of use but also the number of sensors.

Traceback in wireless sensor networks with packet marking and logging

In a hostile environment, sensor nodes may be compromised and then be used to launch various attacks. One severe attack is false data injection which is becoming a serious threat to wireless sensor networks. An attacker uses the compromised node to flood the network and exhaust network resources by injecting a large number of bogus packets. In this paper, we study how to locate the attack node using a framework of packet marking and packet logging. We propose a combined packet marking and logging scheme for traceback （CPMLT）. In CPMLT, one packet can be marked by up to M nodes, each node marks a packet with certain probability. When one packet is marked by M nodes, the next marking node will log this packet. Through combining packet marking and logging, we can reconstruct the entire attack path to locate the attack node by collecting enough packets. In our simulation, CPMLT achieves fast traceback with little logging overhead.

QoS-guaranteed packet scheduling in wireless networks

To guarantee the quality of service （QoS） of a wireless network, a new packet scheduling algorithm using cross-layer design technique is proposed in this article. First, the demand of packet scheduling for multimedia transmission in wireless networks and the deficiency of the existing packet scheduling algorithms are analyzed. Then the model of the QoS-gnaranteed packet scheduling （QPS） algorithm of high speed downlink packet access （HSDPA） and the cost function of packet transmission are designed. The calculation method of packet delay time for wireless channels is expounded in detail, and complete steps to realize the QPS algorithm are also given. The simulation results show that the QPS algorithm that provides the scheduling sequence of packets with calculated values can effectively improve the performance of delay and throughput.

基于加权质心算法的无线传感网络丢包节点定位技术

针对无线传感网络中丢包节点的定位问题,提出一种基于加权质心算法的定位技术.分析无线传感网络节点分布和拓扑结构后,采用RSSI的测距模型改进加权质心算法,经测距模型将RSSI值转换成丢包节点与周围节点的距离,采用加权质心定位算法求解WSN丢包节点定位误差,以3个锚节点作为圆心,锚节点距离作为半径构建圆,计算3个圆交点的坐标后,求出由3个交点构建三角形的质心位置平均值,该值为WSN丢包节点定位坐标,实现无线传感网络丢包节点定位.实验结果表明:该方法应用效果较好,其平均转发率为98.18%,平均检测率为98.36%,能有效定位出WSN丢包节点,提高了WSN网络的稳定性,使得WSN数据传输更加可靠,保障了WSN数据传输质量.

基于节点路径重构和ELM的无线通信网络DDoS攻击源追踪

在无线通信网络中,DDoS攻击通常涉及大量的攻击者和恶意节点,并以多种形式发起攻击。攻击流量经过中间节点和反射/放大攻击等技术手段后变得更加复杂,追踪其溯源路径和确定唯一的攻击源变得复杂。为此,文中研究基于节点路径重构和ELM的无线通信网络DDoS攻击源追踪方法。通过正则化方式优化ELM的参数,检测获取DDoS攻击数据包;采用路由器标记算法标记DDoS攻击数据包,在无线通信网络域间重构攻击节点路径,获取DDoS攻击源位置,完成无线通信网络DDoS攻击源追踪。实验结果证明:文中方法可精准检测获取DDoS攻击数据包,并完成攻击数据包的标记,且可有效重构攻击节点路径,追踪到DDoS攻击源。

CCI-based link quality estimation mechanism for wireless sensor networks under non-perceived packet loss

This paper proposes a chip correlation indicator （CCI）-based link quality estimation mechanism for wireless sensor networks under non-perceived packet loss. On the basis of analyzing all related factors, it can be concluded that signal-to-noise rate （SNR） is the main factor causing the non-perceived packet loss. In this paper, the relationship model between CCI and non-perceived packet loss rate （NPLR） is established from related models such as SNR versus packet success rate （PSR）, CCI versus SNR and CCI-NPLR. Due to the large fluctuating range of the raw CCI, Kalman filter is introduced to do de-noising of the raw CCI. The cubic model and the least squares method are employed to fit the relationship between CCI and SNR. In the experiments, many groups of comparison have been conducted and the results show that the proposed mechanism can achieve more accurate measurement of the non-perceived packet loss than existing approaches. Moreover, it has the advantage of decreasing extra energy consumption caused by sending large number of probe packets.

GSM-R核心网改造综合技术研究与应用

目前中国铁路行业无线通信系统主要采用GSM-R移动通信系统,该系统主要为无线接入网和核心网两部分。其中核心网部分主要负责该无线网络系统的核心数据交换和处理,其可靠性和安全性至关重要。该文对探讨核心网改造过程中核心网设备组网模式、割接业务系统内容、测试及保护模式进行研究,通过研究提高既有线路割接效率,减少施工过程中对既有设备的影响,降低行车安全风险,为今后同类型的施工提供宝贵的经验。

SPN接入设备与5G网络融合的无线通信研究

深入研究中国移动的切片分组网(Slicing Packet Network,SPN)接入设备与5G网络的融合,通过对SPN和5G网络技术的概述,详细探讨其在无线通信领域的结合,并通过行业案例分析展示了其在政务外网、教育专网、医疗专网、金融/银行专网及交通专网等领域的实际应用。通过对SPN接入设备与5G网络融合技术的综述、示例分析、应用与前景的讨论,为无线通信领域的未来发展提供深刻见解,为相关领域的实际应用提供有益参考。