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An Efficient handoff Decision Algorithm for vertical handoff Between WWAN and WLAN

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Journal of Computer Science & Technology 2007年第1期22卷 114-120页

作者：刘敏李忠诚过晓冰 Institute of Computing Technology Chinese Academy of Sciences Beijing 100080 China Lenovo Corporate Research Beijing 100085 China Graduate University of the Chinese Academy of Sciences Beijing 100039 China

vertical handoff is one significant challenge for mobility management in heterogeneous wireless networks. Compared with horizontal handoff, vertical handoff involves different wireless network technologies varying widely in terms of bandwidth, delay, coverage area, power consumption, etc. In this paper, we analyze the signal strength model of mobile node and present a new vertical handoff decision algorithm. This algorithm can adapt to the change of mobile node＇s velocity and improve the handoff efficiency significantly. We analyze the algorithm＇s performance and the effect of different parameters on handoff triggering. In addition, we propose three performance evaluation models and verify the algorithm＇s feasibility and effectiveness in simulations.

关键词： heterogeneous wireless network vertical handoff horizontal handoff

vertical handoff ALGORITHM IN HETEROGENEOUS NETWORKS FOR REDUCING INTERFERENCE

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Journal of Electronics(China) 2009年第1期26卷 71-79页

作者： Xie Shengdong Wu Meng Communication and Information Engineering Institute Nanjing University of Posts and Telecommunications Nanjing 210003 China

A vertical handoff decision algorithm in heterogeneous networks composed of CDMA Cell Networks (CN) and Wireless Local Area Network (WLAN) is proposed to minimize the total inter- ference in CDMA. The scope of WLAN is determined by minimizing interference and each commu- nicating node shall handoff to WLAN as soon as it enters the scope. We first propose a model for heterogeneous networks, and based on it we obtain the close-form expression of interference. In order to minimize interference, we use simulation annealing method to get the WLAN radius, which is called basic algorithm. In order to reduce the interference further, we improve the basic and get the enhanced algorithm. Through numerical computing, we analyze the interference in condition of different call arrive rates, and results show that the enhanced can reduce interference more greatly than the basic.

关键词： Hybrid networks vertical handoff Interference Simulation annealing

An Optimized vertical handoff Algorithm Based on Markov Process in Vehicle Heterogeneous Network

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China Communications 2015年第4期12卷 106-116页

作者： MA Bin DENG Hong XIE Xianzhong LIAO Xiaofeng School of Computer Science and Technology Chongqing University of Posts and Telecommunications College of Computer Science Chongqing University

In order to solve the problem the existing vertical handoff algorithms of vehicle heterogeneous wireless network do not consider the diversification of network's status, an optimized vertical handoff algorithm based on markov process is proposed and discussed in this paper. This algorithm takes into account that the status transformation of available network will affect the quality of service(Qo S) of vehicle terminal's communication service. Firstly, Markov process is used to predict the transformation of wireless network's status after the decision via transition probability. Then the weights of evaluating parameters will be determined by fuzzy logic method. Finally, by comparing the total incomes of each wireless network, including handoff decision incomes, handoff execution incomes and communication service incomes after handoff, the optimal network to handoff will be selected. Simulation results show that: the algorithm proposed, compared to the existing algorithm, is able to receive a higher level of load balancing and effectively improves the average blocking rate, packet loss rate and ping-pang effect.

关键词： vehicle heterogeneous network vertical handoff markov process fuzzy logic multi-attribute decision

A Novel vertical handoff Algorithm with Dynamic Weights in Wireless Heterogeneous Networks

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China Communications 2010年第5期7卷 70-76页

作者： Liu Xia Zhao Fangming Jiang Lingge College of Merchant Marine Shanghai Maritime University Shanghai 200135 P. R. China School of Electronic and Electrical Engineering Shanghai Second Polytechnic University Shanghai 201209 P. R. China Department of Electronic Engineering Shanghai Jiao Tong University Shanghai 200240 P. R. China

In order to enhance the quality of vertical handoff in an overlay wireless network, multiple attributes are taken into account when optimizing the vertical handoff decision including user-based and network-based QoS factors. In this paper, we develop a novel vertical handoff algorithm in an integrated 3G cellular and Wireless LAN networks. The proposed algorithm can adjust the weight of each QoS attribute dynamically as the networks change, trace the network condition and choose the optimal access point at transient regions. Simulation results show that this algorithm is able to provide accurate handoff decision, resulting in small unnecessary handoff numbers, good performance of throughput and handoff delay in heterogeneous environments.

关键词： vertical handoff multiple attrbute dynamic weight heterogeneous networks

A Novel vertical handoff Algorithm Based on Fuzzy Logic in Aid of Grey Prediction Theory in Wireless Heterogeneous Networks

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Journal of Shanghai Jiaotong university(Science) 2012年第1期17卷 25-30页

作者：刘侠蒋铃鸽 Department of Electronic Engineering Shanghai Jiaotong University College of Merchant Marine Shanghai Maritime University

To coordinate the various access technologies in the 4G communication system,intelligent vertical handoff algorithms are *** paper mainly deals with a novel vertical handoff decision algorithm based on fuzzy logic with the aid of grey theory and dynamic weights *** grey prediction theory(GPT) takes 4 sampled received signal strengths as input parameters,and calculates the predicted received signal strength in order to reduce the call dropping *** fuzzy logic theory based quantitative decision algorithm takes 3 quality of service(QoS)metric,received signal strength(RSS),available bandwidth(BW),and monetary cost (MC)of candidate networks as input *** weight of each QoS metrics is adjusted along with the networks changing to trace the network *** final optimized vertical handoff decision is made by comparing the quantitative decision values of the candidate *** results demonstrate that the proposed algorithm provides high performance in heterogeneous as well as homogeneous network environments.

关键词： fuzzy logic theory grey prediction algorithm quantitative decision vertical handoff

Adaptive vertical handoff algorithm in heterogeneous networks

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The Journal of China Universities of Posts and Telecommunications 2007年第1期14卷 22-25,44页

作者： XIE Sheng-dong WU Meng Communication and Information Engineering Institute Nanjing University of Posts and Telecommunications Nanjing 210003 China

The integration of cellular network （CN） and wireless local area network （WLAN） is the trend of the next generation mobile communication systems, and nodes will handoff between the two kinds of networks. The received signal strength （RSS） is the dominant factor considered when handoff occurs. In order to improve the handoff efficiency, this study proposes an adaptive decision algorithm for vertical handoff on the basis of fast Fourier transform （FFT）. The algorithm makes handoff decision after analyzing the signal strength fluctuation which is caused by slow fading through FFT. Simulations show that the algorithm reduces the number of handoff by 35%, shortens the areas influenced by slow fading, and enables the nodes to make full use of WLAN in communication compared with traditional algorithms.

关键词： vertical handoff signal strength slow fading fast Fourier transform

A QoS-aware vertical handoff algorithm based on predictive network information

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Journal of Central South University 2012年第8期19卷 2187-2193页

作者：郭云松谭冠政 A.S.M.LIBDA 马丽强 School of Information Science and Engineering Central South University Electric Power Research Institute Shanxi Ele ctric Power Company

In converged heterogeneous wireless networks, vertical handoff is an important issue in radio resource management and occurs when an end user switches from one network to another （e.g., from wireless local area network to wideband code division multiple access）. Efficient vertical handoff should allocate network resources efficiently and maintain good quality of service （QoS） for the end users. The objective of this work is to determine conditions under which vertical handoff can be performed. The channel usage situation of each access network is formulated as a birth-death process with the objective of predicting the avaliable bandwidth and the blocking probability. A reward function is used to capture the network bandwidth and the blocking probability is expressed as a cost function. An end user will access the certain network which maximizes the total function defined as the combination of the reward fimction and the cost function. Simulation results show that the proposed algorithm can significantly improve the network performance, including higher bandwidth for end users and lower new call blocking and handoff call blocking probability for networks.

关键词： heterogeneous wireless network vertical handoff quality of service (QoS) birth-death process

SAE-TOPSIS algorithm for vertical handoff decision in heterogeneous wireless networks

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High Technology Letters 2012年第4期18卷 382-386页

作者：刘胜美 Pan Su Mi Zhengkun Broadband Wireless Communication and Sensor Network Technology Key Laboratory of Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 P. R. China

An improved technique for order preference by similarity to ideal solution （TOPSIS） algorithm, SAE-TOPSIS, is proposed for the vertical handoff decision in heterogeneous wireless networks. The signal to interference plus noise ratio （SINR） effects, analytic hierarchy process （AHP） and infor- mation entropy （SAE） weight method were introduced into the algorithm. handoff decision meeting the multi-attribute quality of service （QoS） requirement is made according to an attribute matrix and weight vector using the TOPSIS algorithm. The simulation results have shown that the proposed algo- rithm can provide satisfactory performance fitted to the characteristics of the traffic.

关键词： heterogeneous wireless networks vertical handoff technique for order preferenceby similarity to ideal solution (TOPSIS) analytic hierarchy process (AHP) entropy signal to in-terference plus noise ratio (SINR)

An improved multiplicative exponent weighting vertical handoff algorithm for WLAN/WCDMA heterogeneous wireless networks

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Engineering Sciences 2012年第1期10卷 86-90页

作者： Liu Shengmei Pan Su Mi Zhengkun Meng Qingmin Xu Minghai Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of EducationNanjing University of Posts and TelecommunicationsNanjing 210003China

An improved MEW （ muhiplicative exponent weighting） algorithm, SLE-MEW is proposed for vertical handoff decision in heterogeneous wireless networks. It introduces the SINR（ signal to interference plus noise ratio） effects, LS （least square） and information entropy method into the algorithm. An attribute matrix is constructed considering the SINR in the source network and the equivalent SINR in the target network, the required bandwidth, the traffic cost and the available bandwidth of participating access networks. handoff decision meeting multi-attribute QoS（quality of serv- ice） requirement is made according to the traffic features. The subjective weight relation of decision elements is determined with LS method. The information entropy method is employed to derive the objective weights of the evaluation criteria, and lead to the comprehensive weight. Finally decision is made using MEW algorithm based on the attribute matrix and weight vector. Four 3GPP（ the 3rd generation partnership project） defined traffic classes are considered in performance evaluation. The simulation results have shown that the proposed algorithm can provide satisfactory performance fitting to the characteristics of the traffic.

关键词： heterogeneous wireless networks vertical handoff MEW LS SINR