It is a hot issue in communication research field to select the best network for Heterogeneous Wireless Networks(HWNs),and it is also a difficult problem to reduce the handoff number of vertical handoff.In order to so...It is a hot issue in communication research field to select the best network for Heterogeneous Wireless Networks(HWNs),and it is also a difficult problem to reduce the handoff number of vertical handoff.In order to solve this problem,the paper proposes a multiple attribute network selection algorithm based on Analytic Hierarchy Process(AHP)and synergetic theory.The algorithm applies synergetics to network selection,considering the candidate network as a compound system composed of multiple attribute subsystems,and combines the subsystem order degree with AHP weight to obtain entropy of the compound system,which is opposite the synergy degree of a network system.The greater the synergy degree,the better the network performance.The algorithm takes not only the coordination of objective attributes but also Quality of Service(QoS)requirements into consideration,ensuring that users select the network with overall good performance.The simulation results show that the proposed algorithm can effectively reduce the handoff number and provide uses with satisfactory QoS according to different services.展开更多
Heterogeneous Wireless Network is currently a major area of focus in communication engineering.But the important issue in recent communication is the approachability to the wireless networks while maintaining the qual...Heterogeneous Wireless Network is currently a major area of focus in communication engineering.But the important issue in recent communication is the approachability to the wireless networks while maintaining the quality of service.Today,all the wireless access networks are working in tandem to keep the users always connected to the internet cloud that matches the price affordability and performance goals.In order to achieve seamless connectivity,due consideration has to be given to handoff precision and a smaller number of handoffs.Several researchers have used heuristic approaches to solve this issue.In the present work,a hybrid intelligent algorithm has been suggested for vertical handoff decisions.This hybrid intelligent algorithm is based on dual optimization approach which uses“Particle Swarm Optimization(PSO)”and“Mobile Robustness Optimization(MRO)”techniques for improving the quality of services.This approach performs well even in the failure network conditions and gives the best results in terms of connectivity.The results at the last has been compared with the conventional techniques and it has been observed that the proposed methodology outperforms the existing one.展开更多
Cross-technology interference(CTI)from diverse wireless networks such as ZigBee,Bluetooth,and Wi-Fi has become a severe problem in the 2.4 GHz Industrial Scientific and Medical(ISM)band.Especially,low power and lossy ...Cross-technology interference(CTI)from diverse wireless networks such as ZigBee,Bluetooth,and Wi-Fi has become a severe problem in the 2.4 GHz Industrial Scientific and Medical(ISM)band.Especially,low power and lossy networks are vulnerable to the signal interferences from other aggressive wireless networks when they perform low power operations to conserve the energy consumption.This paper presents CoSense,which accurately detects ZigBee signals with a reliable signal correlation scheme in the presence of the CTI.The key concept of CoSense is to reduce false wake-ups of low power listening(LPL)by identifying the pre-defined ZigBee signatures.Our scheme is robust in the coexistence environment of diverse wireless technologies since the signal correlation works well in bad wireless channel conditions.It achieves standard compliance and transparency without any hardware and firmware changes.We have implemented CoSense on the Universal Software Radio Peripheral(USRP)platform to verify its feasibility.The experimental exploration reveals that CoSense significantly reduces the false-positive and false-negative rate under typical setting and the additional overhead is negligible.The results show that our scheme saves much energy by up to 63%in dynamic network interference scenarios where low-power ZigBee transmissions are overwhelmed by strong Wi-Fi signal interferences.展开更多
In heterogeneous wireless networks with time-varying channels,the video rate is usually adjusted based on the network bandwidth to guarantee ultra-low latency video transmission under an end-to-end target delay constr...In heterogeneous wireless networks with time-varying channels,the video rate is usually adjusted based on the network bandwidth to guarantee ultra-low latency video transmission under an end-to-end target delay constraint.However,the target delay with a fixed value according to historical experience cannot guarantee the quality of video continuously since wireless network bandwidth changes rapidly,especially when the network deteriorates.An alternative scheme is to dynamically set the target delay according to the network status within an acceptable delay range.However,this scheme cannot be ensured in heterogeneous wireless networks with time-varying channels.Thus,to address this issue,a multi-objective optimization algorithm for joint optimization of rate control and target delay is proposed,where the target delay and video rate are jointly adjusted dynamically.Second,to reduce the optimization complexity due to the multi-objective and multi-parameter characteristics,multi-objective optimization algorithm be decomposed and solved by optimizing each independent sub-problem.Finally,the proposed algorithm is verified on a semi-physical simulation platform.Experiments show that the frame loss rate is reduced from 6.65%to 2.06%,and a peak signal-to-noise ratio(PSNR)gain of 18.32%is obtained when the network performance is low.展开更多
How to design an energy-efficient algorithm to maximize the network lifetime in complicated scenarios is a critical problem for heterogeneous wireless sensor networks(HWSN).In this paper, a clustering-tree topology co...How to design an energy-efficient algorithm to maximize the network lifetime in complicated scenarios is a critical problem for heterogeneous wireless sensor networks(HWSN).In this paper, a clustering-tree topology control algorithm based on the energy forecast(CTEF) is proposed for saving energy and ensuring network load balancing, while considering the link quality, packet loss rate, etc. In CTEF, the average energy of the network is accurately predicted per round(the lifetime of the network is denoted by rounds) in terms of the difference between the ideal and actual average residual energy using central limit theorem and normal distribution mechanism, simultaneously. On this basis, cluster heads are selected by cost function(including the energy, link quality and packet loss rate) and their distance.The non-cluster heads are determined to join the cluster through the energy, distance and link quality. Furthermore, several noncluster heads in each cluster are chosen as the relay nodes for transmitting data through multi-hop communication to decrease the load of each cluster-head and prolong the lifetime of the network. The simulation results show the efficiency of CTEF. Compared with low-energy adaptive clustering hierarchy(LEACH), energy dissipation forecast and clustering management(EDFCM) and efficient and dynamic clustering scheme(EDCS)protocols, CTEF has longer network lifetime and receives more data packets at base station.展开更多
Convergence and collaboration of heterogeneous networks in the next generation public mobile networks will be a subject of universal significance. Convergence of heterogeneous networks, as an effective approach to imp...Convergence and collaboration of heterogeneous networks in the next generation public mobile networks will be a subject of universal significance. Convergence of heterogeneous networks, as an effective approach to improve the coverage and capacity of public mobile network, to enable communication services, to provide Internet access and to enable mobile computing from everywhere, has drawn widespread attention for its good prospects in application. Construction of security system for wireless heterogeneous networks and development of new security models, key security techniques and approaches are critical and mandatory in heterogeneous networks development. Key technology of wireless heterogeneous networks security covers security routing protocol, access authentication, intrusion detection system, cooperative communication between nodes, etc.展开更多
An improved LEACH for heterogeneous wireless sensor networks is proposed.Nodes are distributed in a sensing area that is divided into a number of same equilateral hexagons.Heterogeneous nodes act as the cluster heads ...An improved LEACH for heterogeneous wireless sensor networks is proposed.Nodes are distributed in a sensing area that is divided into a number of same equilateral hexagons.Heterogeneous nodes act as the cluster heads and ordinary nodes act as those cluster sensors in all clusters.The structure of WSNs is a two-layer structure.The upper layer consists of all cluster heads and the lower layer consists of all ordinary sensors managed by their corresponding cluster heads.The cluster heads and the ordinary sensors establish their pairwise keys respectively through utilizing different methods.The arithmetic balances energy expense among all kinds of nodes,saves the node energy,and prolongs the life of wireless sensor networks.Additionally,Analysis demonstrates that the security of wireless sensor networks has been improved obviously even with some heterogeneous nodes.展开更多
Heterogeneous wireless sensor networks(HWSNs)are vulnerable to malware propagation,because of their low configuration and weak defense mechanism.Therefore,an optimality system for HWSNs is developed to suppress malwar...Heterogeneous wireless sensor networks(HWSNs)are vulnerable to malware propagation,because of their low configuration and weak defense mechanism.Therefore,an optimality system for HWSNs is developed to suppress malware propagation in this paper.Firstly,a heterogeneous-susceptible-exposed-infectious-recovered-susceptible(HSEIRS)model is proposed to describe the state dynamics of heterogeneous sensor nodes(HSNs)in HWSNs.Secondly,the existence of an optimal control problem with installing antivirus on HSNs to minimize the sum of the cumulative infection probabilities of HWSNs at a low cost based on the HSEIRS model is proved,and then an optimal control strategy for the problem is derived by the optimal control theory.Thirdly,the optimal control strategy based on the HSEIRS model is transformed into corresponding Hamiltonian by the Pontryagin’s minimum principle,and the corresponding optimality system is derived.Finally,the effectiveness of the optimality system is validated by the experimental simulations,and the results show that the infectious HSNs will fall to an extremely low level at a low cost.展开更多
A network selection optimization algorithm based on the Markov decision process(MDP)is proposed so that mobile terminals can always connect to the best wireless network in a heterogeneous network environment.Consideri...A network selection optimization algorithm based on the Markov decision process(MDP)is proposed so that mobile terminals can always connect to the best wireless network in a heterogeneous network environment.Considering the different types of service requirements,the MDP model and its reward function are constructed based on the quality of service(QoS)attribute parameters of the mobile users,and the network attribute weights are calculated by using the analytic hierarchy process(AHP).The network handoff decision condition is designed according to the different types of user services and the time-varying characteristics of the network,and the MDP model is solved by using the genetic algorithm and simulated annealing(GA-SA),thus,users can seamlessly switch to the network with the best long-term expected reward value.Simulation results show that the proposed algorithm has good convergence performance,and can guarantee that users with different service types will obtain satisfactory expected total reward values and have low numbers of network handoffs.展开更多
The future network world will be embedded with different generations of wireless technologies,such as 3G,4G and 5G.At the same time,the development of new devices equipped with multiple interfaces is growing rapidly i...The future network world will be embedded with different generations of wireless technologies,such as 3G,4G and 5G.At the same time,the development of new devices equipped with multiple interfaces is growing rapidly in recent years.As a consequence,the vertical handover protocol is developed in order to provide ubiquitous connectivity in the heterogeneous wireless environment.Indeed,by using this protocol,the users have opportunities to be connected to the Internet through a variety of wireless technologies at any time and anywhere.The main challenge of this protocol is how to select the best access network in terms of Quality of Service(QoS)for users.For that,many algorithms have been proposed and developed to deal with the issue in recent studies.However,all existing algorithms permit only the selection of one access network from the available networks during the vertical handover process.To cope with this problem,in this paper we propose a new approach based on k-partite graph.Firstly,we introduce k-partite graph theory to model the vertical handover problem.Secondly,the selection of the best path is performed by a robust and lightweight mechanism based on cost function and Dijkstra’s algorithm.The experimental results show that the proposed approach can achieve better performance of QoS than the existing algorithms for FTP traffic and video streaming.展开更多
The Vertical Handover(VHO)is one of the most vital features provided for the heterogeneous mobile networks.It allows Mobile Users(MUs)to keep ongoing sessions without disruption while they continuously move between di...The Vertical Handover(VHO)is one of the most vital features provided for the heterogeneous mobile networks.It allows Mobile Users(MUs)to keep ongoing sessions without disruption while they continuously move between different Radio Access Technologies(RATs)such as Wireless Fidelity(Wi-Fi),Global System for Mobile Communication(GSM),Universal Mobile Telecommunications System(UMTS),Long Term Evolution(LTE)and Fifth Generation(5G).In order to fulfill this goal,the VHO must comply to three main phases:starting of collecting the required information and then passing it for decision phase to obtain the best available RAT for performing VHO by execution phase eventually.However,the execution phase still encounters some security issues which are exploited by hackers in launching malicious attacks such as ransomware,fragmentation,header manipulation,smurf,host initialization,reconnaissance,eavesdropping,Denial of Service(DoS),spoofing,Man in the Middle(MITM)and falsification.This paper thoroughly studies the recent security issues for hundreds VHO approaches found in the literature and comes up with a secure procedure to enhance VHO security during execution phase.A numerical analysis results of the proposed procedure are effectively evaluated in terms of security and signaling cost.Compared with the recent related work found in literature,the analysis demonstrates that the security is successfully improved by 20%whereas signaling cost is maintained as in non-proposed procedure.展开更多
A heterogeneous wireless sensor network comprises a number of inexpensive energy constrained wireless sensor nodes which collect data from the sensing environment and transmit them toward the improved cluster head in ...A heterogeneous wireless sensor network comprises a number of inexpensive energy constrained wireless sensor nodes which collect data from the sensing environment and transmit them toward the improved cluster head in a coordinated way. Employing clustering techniques in such networks can achieve balanced energy consumption of member nodes and prolong the network lifetimes.In classical clustering techniques, clustering and in-cluster data routes are usually separated into independent operations. Although separate considerations of these two issues simplify the system design, it is often the non-optimal lifetime expectancy for wireless sensor networks. This paper proposes an integral framework that integrates these two correlated items in an interactive entirety. For that,we develop the clustering problems using nonlinear programming. Evolution process of clustering is provided in simulations. Results show that our joint-design proposal reaches the near optimal match between member nodes and cluster heads.展开更多
In order to achieve low-latency and high-reliability data gathering in heterogeneous wireless sensor networks(HWSNs),the problem of multi-channel-based data gathering with minimum latency(MCDGML),which associates with...In order to achieve low-latency and high-reliability data gathering in heterogeneous wireless sensor networks(HWSNs),the problem of multi-channel-based data gathering with minimum latency(MCDGML),which associates with construction of data gathering trees,channel allocation,power assignment of nodes and link scheduling,is formulated as an optimization problem in this paper.Then,the optimization problem is proved to be NP-hard.To make the problem tractable,firstly,a multi-channel-based low-latency(MCLL)algorithm that constructs data gathering trees is proposed by optimizing the topology of nodes.Secondly,a maximum links scheduling(MLS)algorithm is proposed to further reduce the latency of data gathering,which ensures that the signal to interference plus noise ratio(SINR)of all scheduled links is not less than a certain threshold to guarantee the reliability of links.In addition,considering the interruption problem of data gathering caused by dead nodes or failed links,a robust mechanism is proposed by selecting certain assistant nodes based on the defined one-hop weight.A number of simulation results show that our algorithms can achieve a lower data gathering latency than some comparable data gathering algorithms while guaranteeing the reliability of links,and a higher packet arrival rate at the sink node can be achieved when the proposed algorithms are performed with the robust mechanism.展开更多
Due to the heterogeneity and versatility of emerging services and applications in wireless networks,it has been a great challenge to improve the system performance with both the awareness of service characteristics an...Due to the heterogeneity and versatility of emerging services and applications in wireless networks,it has been a great challenge to improve the system performance with both the awareness of service characteristics and the balance of the traffic between adjacent networks.This paper is committed to solve this problem by introducing a Service-aware Proactive Vertical Handoff(SPVH) algorithm in Heterogeneous Wireless Networks(HWN).A Bandwidth Requirement Prediction Model(BRPM) is illustrated at first,which is adaptive to the system condition variants to forecast traffic requests.Moreover,by adopting a service-aware objective utility function,each user can optimize the vertical handover decisions with awareness of the related supporting networks and service characteristics.Since the decision process is executed with consideration of BRPM predictions,the SPVH algorithm can avoid congestion in HWN through a proactive method.The experiment results show that the proposed SPVH can solidly enhance the system performance in terms of service access ratio,average access delay,system throughput,usage ratio of spectrum resource,and eventually achieve higher network utility.展开更多
The state of art pertaining to vertical handover decisions in next-generation wireless networks provides a detailed overview of vertical handover studies.This paper classifies the research initiatives under the vertic...The state of art pertaining to vertical handover decisions in next-generation wireless networks provides a detailed overview of vertical handover studies.This paper classifies the research initiatives under the vertical handover decision mechanism for heterogeneous wireless networks.A fair comparison of traditional and recent techniques is drafted to obtain direction of the vertical handover decision.Several issues related to seamless support on mobility management techniques have been described in the literature.The next-generation wireless network promises to offer enhanced data services compared to other networks in mobile communication.Since all next generation network(NGN)is an IP-based network,challenges drive toward providing quality of service in the handover process.The necessity of handover process is a seamless connection.The handover operations that minimize or even target the elimination of delay in new network connection establishment are most welcomed.However,frequent disconnection and inefficient seamless handovers result in handover operation failures.Most of the existing methods on handover decisions are based on mobile-controlled handovers.Here,the decisions are in-corporate in the mobile devices.Several mobile-controlled handovers take a single parameter or two or more additional parameters as a combination to evaluate the policy decision.These approaches are carefully studied and classified.展开更多
基金Supported by the Major State Basic Research Development Program of China(973 Program)(No.2013CB329005)the National Natural Science Foundation of China(No.61171094)+1 种基金the National Science & Technology Key Project(No.2011ZX03001-006-02.No.2011ZX03005004-03)the Key Project of Jiangsu Provincial Natural Science Foundation(No.BK2011027)
文摘It is a hot issue in communication research field to select the best network for Heterogeneous Wireless Networks(HWNs),and it is also a difficult problem to reduce the handoff number of vertical handoff.In order to solve this problem,the paper proposes a multiple attribute network selection algorithm based on Analytic Hierarchy Process(AHP)and synergetic theory.The algorithm applies synergetics to network selection,considering the candidate network as a compound system composed of multiple attribute subsystems,and combines the subsystem order degree with AHP weight to obtain entropy of the compound system,which is opposite the synergy degree of a network system.The greater the synergy degree,the better the network performance.The algorithm takes not only the coordination of objective attributes but also Quality of Service(QoS)requirements into consideration,ensuring that users select the network with overall good performance.The simulation results show that the proposed algorithm can effectively reduce the handoff number and provide uses with satisfactory QoS according to different services.
基金Deepak Dahiya would like to thank Deanship of Scientific Research at Majmaah University for supporting this work under Project No.R-2022-74.
文摘Heterogeneous Wireless Network is currently a major area of focus in communication engineering.But the important issue in recent communication is the approachability to the wireless networks while maintaining the quality of service.Today,all the wireless access networks are working in tandem to keep the users always connected to the internet cloud that matches the price affordability and performance goals.In order to achieve seamless connectivity,due consideration has to be given to handoff precision and a smaller number of handoffs.Several researchers have used heuristic approaches to solve this issue.In the present work,a hybrid intelligent algorithm has been suggested for vertical handoff decisions.This hybrid intelligent algorithm is based on dual optimization approach which uses“Particle Swarm Optimization(PSO)”and“Mobile Robustness Optimization(MRO)”techniques for improving the quality of services.This approach performs well even in the failure network conditions and gives the best results in terms of connectivity.The results at the last has been compared with the conventional techniques and it has been observed that the proposed methodology outperforms the existing one.
基金the National Research Foundation of Korea(NRF)grantfunded by the Korea Government(MSIT)(No.NRF-2018R1C1B5038818).
文摘Cross-technology interference(CTI)from diverse wireless networks such as ZigBee,Bluetooth,and Wi-Fi has become a severe problem in the 2.4 GHz Industrial Scientific and Medical(ISM)band.Especially,low power and lossy networks are vulnerable to the signal interferences from other aggressive wireless networks when they perform low power operations to conserve the energy consumption.This paper presents CoSense,which accurately detects ZigBee signals with a reliable signal correlation scheme in the presence of the CTI.The key concept of CoSense is to reduce false wake-ups of low power listening(LPL)by identifying the pre-defined ZigBee signatures.Our scheme is robust in the coexistence environment of diverse wireless technologies since the signal correlation works well in bad wireless channel conditions.It achieves standard compliance and transparency without any hardware and firmware changes.We have implemented CoSense on the Universal Software Radio Peripheral(USRP)platform to verify its feasibility.The experimental exploration reveals that CoSense significantly reduces the false-positive and false-negative rate under typical setting and the additional overhead is negligible.The results show that our scheme saves much energy by up to 63%in dynamic network interference scenarios where low-power ZigBee transmissions are overwhelmed by strong Wi-Fi signal interferences.
基金supported by the National Natural Science Foundation for Young Scholars of China(61801120)the Fujian Natural Science Foundation(2018J05104)。
文摘In heterogeneous wireless networks with time-varying channels,the video rate is usually adjusted based on the network bandwidth to guarantee ultra-low latency video transmission under an end-to-end target delay constraint.However,the target delay with a fixed value according to historical experience cannot guarantee the quality of video continuously since wireless network bandwidth changes rapidly,especially when the network deteriorates.An alternative scheme is to dynamically set the target delay according to the network status within an acceptable delay range.However,this scheme cannot be ensured in heterogeneous wireless networks with time-varying channels.Thus,to address this issue,a multi-objective optimization algorithm for joint optimization of rate control and target delay is proposed,where the target delay and video rate are jointly adjusted dynamically.Second,to reduce the optimization complexity due to the multi-objective and multi-parameter characteristics,multi-objective optimization algorithm be decomposed and solved by optimizing each independent sub-problem.Finally,the proposed algorithm is verified on a semi-physical simulation platform.Experiments show that the frame loss rate is reduced from 6.65%to 2.06%,and a peak signal-to-noise ratio(PSNR)gain of 18.32%is obtained when the network performance is low.
基金supported by National Natural Science Foundation of China(61304256)Zhejiang Provincial Natural Science Foundation of China(LQ13F030013)+4 种基金Project of the Education Department of Zhejiang Province(Y201327006)Young Researchers Foundation of Zhejiang Provincial Top Key Academic Discipline of Mechanical Engineering and Zhejiang Sci-Tech University Key Laboratory(ZSTUME01B15)New Century 151 Talent Project of Zhejiang Province521 Talent Project of Zhejiang Sci-Tech UniversityYoung and Middle-aged Talents Foundation of Zhejiang Provincial Top Key Academic Discipline of Mechanical Engineering
文摘How to design an energy-efficient algorithm to maximize the network lifetime in complicated scenarios is a critical problem for heterogeneous wireless sensor networks(HWSN).In this paper, a clustering-tree topology control algorithm based on the energy forecast(CTEF) is proposed for saving energy and ensuring network load balancing, while considering the link quality, packet loss rate, etc. In CTEF, the average energy of the network is accurately predicted per round(the lifetime of the network is denoted by rounds) in terms of the difference between the ideal and actual average residual energy using central limit theorem and normal distribution mechanism, simultaneously. On this basis, cluster heads are selected by cost function(including the energy, link quality and packet loss rate) and their distance.The non-cluster heads are determined to join the cluster through the energy, distance and link quality. Furthermore, several noncluster heads in each cluster are chosen as the relay nodes for transmitting data through multi-hop communication to decrease the load of each cluster-head and prolong the lifetime of the network. The simulation results show the efficiency of CTEF. Compared with low-energy adaptive clustering hierarchy(LEACH), energy dissipation forecast and clustering management(EDFCM) and efficient and dynamic clustering scheme(EDCS)protocols, CTEF has longer network lifetime and receives more data packets at base station.
基金the Jiangsu Natural Science Foundation under Grant No.BK2007236Jiangsu Six-Categories Top Talent Fundunder Grand No.SJ207001
文摘Convergence and collaboration of heterogeneous networks in the next generation public mobile networks will be a subject of universal significance. Convergence of heterogeneous networks, as an effective approach to improve the coverage and capacity of public mobile network, to enable communication services, to provide Internet access and to enable mobile computing from everywhere, has drawn widespread attention for its good prospects in application. Construction of security system for wireless heterogeneous networks and development of new security models, key security techniques and approaches are critical and mandatory in heterogeneous networks development. Key technology of wireless heterogeneous networks security covers security routing protocol, access authentication, intrusion detection system, cooperative communication between nodes, etc.
文摘An improved LEACH for heterogeneous wireless sensor networks is proposed.Nodes are distributed in a sensing area that is divided into a number of same equilateral hexagons.Heterogeneous nodes act as the cluster heads and ordinary nodes act as those cluster sensors in all clusters.The structure of WSNs is a two-layer structure.The upper layer consists of all cluster heads and the lower layer consists of all ordinary sensors managed by their corresponding cluster heads.The cluster heads and the ordinary sensors establish their pairwise keys respectively through utilizing different methods.The arithmetic balances energy expense among all kinds of nodes,saves the node energy,and prolongs the life of wireless sensor networks.Additionally,Analysis demonstrates that the security of wireless sensor networks has been improved obviously even with some heterogeneous nodes.
基金National Natural Science Foundation of China(No.61772018)Zhejiang Provincial Natural Science Foundation of China(No.LZ22F020002)。
文摘Heterogeneous wireless sensor networks(HWSNs)are vulnerable to malware propagation,because of their low configuration and weak defense mechanism.Therefore,an optimality system for HWSNs is developed to suppress malware propagation in this paper.Firstly,a heterogeneous-susceptible-exposed-infectious-recovered-susceptible(HSEIRS)model is proposed to describe the state dynamics of heterogeneous sensor nodes(HSNs)in HWSNs.Secondly,the existence of an optimal control problem with installing antivirus on HSNs to minimize the sum of the cumulative infection probabilities of HWSNs at a low cost based on the HSEIRS model is proved,and then an optimal control strategy for the problem is derived by the optimal control theory.Thirdly,the optimal control strategy based on the HSEIRS model is transformed into corresponding Hamiltonian by the Pontryagin’s minimum principle,and the corresponding optimality system is derived.Finally,the effectiveness of the optimality system is validated by the experimental simulations,and the results show that the infectious HSNs will fall to an extremely low level at a low cost.
基金partially supported by Nation Science Foundation of China (61661025, 61661026)Foundation of A hundred Youth Talents Training Program of Lanzhou Jiaotong University (152022)
文摘A network selection optimization algorithm based on the Markov decision process(MDP)is proposed so that mobile terminals can always connect to the best wireless network in a heterogeneous network environment.Considering the different types of service requirements,the MDP model and its reward function are constructed based on the quality of service(QoS)attribute parameters of the mobile users,and the network attribute weights are calculated by using the analytic hierarchy process(AHP).The network handoff decision condition is designed according to the different types of user services and the time-varying characteristics of the network,and the MDP model is solved by using the genetic algorithm and simulated annealing(GA-SA),thus,users can seamlessly switch to the network with the best long-term expected reward value.Simulation results show that the proposed algorithm has good convergence performance,and can guarantee that users with different service types will obtain satisfactory expected total reward values and have low numbers of network handoffs.
文摘The future network world will be embedded with different generations of wireless technologies,such as 3G,4G and 5G.At the same time,the development of new devices equipped with multiple interfaces is growing rapidly in recent years.As a consequence,the vertical handover protocol is developed in order to provide ubiquitous connectivity in the heterogeneous wireless environment.Indeed,by using this protocol,the users have opportunities to be connected to the Internet through a variety of wireless technologies at any time and anywhere.The main challenge of this protocol is how to select the best access network in terms of Quality of Service(QoS)for users.For that,many algorithms have been proposed and developed to deal with the issue in recent studies.However,all existing algorithms permit only the selection of one access network from the available networks during the vertical handover process.To cope with this problem,in this paper we propose a new approach based on k-partite graph.Firstly,we introduce k-partite graph theory to model the vertical handover problem.Secondly,the selection of the best path is performed by a robust and lightweight mechanism based on cost function and Dijkstra’s algorithm.The experimental results show that the proposed approach can achieve better performance of QoS than the existing algorithms for FTP traffic and video streaming.
文摘The Vertical Handover(VHO)is one of the most vital features provided for the heterogeneous mobile networks.It allows Mobile Users(MUs)to keep ongoing sessions without disruption while they continuously move between different Radio Access Technologies(RATs)such as Wireless Fidelity(Wi-Fi),Global System for Mobile Communication(GSM),Universal Mobile Telecommunications System(UMTS),Long Term Evolution(LTE)and Fifth Generation(5G).In order to fulfill this goal,the VHO must comply to three main phases:starting of collecting the required information and then passing it for decision phase to obtain the best available RAT for performing VHO by execution phase eventually.However,the execution phase still encounters some security issues which are exploited by hackers in launching malicious attacks such as ransomware,fragmentation,header manipulation,smurf,host initialization,reconnaissance,eavesdropping,Denial of Service(DoS),spoofing,Man in the Middle(MITM)and falsification.This paper thoroughly studies the recent security issues for hundreds VHO approaches found in the literature and comes up with a secure procedure to enhance VHO security during execution phase.A numerical analysis results of the proposed procedure are effectively evaluated in terms of security and signaling cost.Compared with the recent related work found in literature,the analysis demonstrates that the security is successfully improved by 20%whereas signaling cost is maintained as in non-proposed procedure.
基金supported by National Natural Science Foundation of China(Nos.61304131 and 61402147)Grant of China Scholarship Council(No.201608130174)+2 种基金Natural Science Foundation of Hebei Province(Nos.F2016402054 and F2014402075)the Scientific Research Plan Projects of Hebei Education Department(Nos.BJ2014019,ZD2015087 and QN2015046)the Research Program of Talent Cultivation Project in Hebei Province(No.A2016002023)
文摘A heterogeneous wireless sensor network comprises a number of inexpensive energy constrained wireless sensor nodes which collect data from the sensing environment and transmit them toward the improved cluster head in a coordinated way. Employing clustering techniques in such networks can achieve balanced energy consumption of member nodes and prolong the network lifetimes.In classical clustering techniques, clustering and in-cluster data routes are usually separated into independent operations. Although separate considerations of these two issues simplify the system design, it is often the non-optimal lifetime expectancy for wireless sensor networks. This paper proposes an integral framework that integrates these two correlated items in an interactive entirety. For that,we develop the clustering problems using nonlinear programming. Evolution process of clustering is provided in simulations. Results show that our joint-design proposal reaches the near optimal match between member nodes and cluster heads.
基金This work was supported by the Natural Science Foun-dation of China(Nos.U1334210 and 61374059).
文摘In order to achieve low-latency and high-reliability data gathering in heterogeneous wireless sensor networks(HWSNs),the problem of multi-channel-based data gathering with minimum latency(MCDGML),which associates with construction of data gathering trees,channel allocation,power assignment of nodes and link scheduling,is formulated as an optimization problem in this paper.Then,the optimization problem is proved to be NP-hard.To make the problem tractable,firstly,a multi-channel-based low-latency(MCLL)algorithm that constructs data gathering trees is proposed by optimizing the topology of nodes.Secondly,a maximum links scheduling(MLS)algorithm is proposed to further reduce the latency of data gathering,which ensures that the signal to interference plus noise ratio(SINR)of all scheduled links is not less than a certain threshold to guarantee the reliability of links.In addition,considering the interruption problem of data gathering caused by dead nodes or failed links,a robust mechanism is proposed by selecting certain assistant nodes based on the defined one-hop weight.A number of simulation results show that our algorithms can achieve a lower data gathering latency than some comparable data gathering algorithms while guaranteeing the reliability of links,and a higher packet arrival rate at the sink node can be achieved when the proposed algorithms are performed with the robust mechanism.
基金Sponsored by the National Natural Science Foundation of China for Young Scholar(Grant No. 61001115)the Key Project of National Natural Science Foundation of China (Grant No. 60832009)+1 种基金the Beijing Natural Science Foundation of China (Grant No. 4102044 )the Fundamental Research Funds for the Central Universities of China(Grant No. 2012RC0126)
文摘Due to the heterogeneity and versatility of emerging services and applications in wireless networks,it has been a great challenge to improve the system performance with both the awareness of service characteristics and the balance of the traffic between adjacent networks.This paper is committed to solve this problem by introducing a Service-aware Proactive Vertical Handoff(SPVH) algorithm in Heterogeneous Wireless Networks(HWN).A Bandwidth Requirement Prediction Model(BRPM) is illustrated at first,which is adaptive to the system condition variants to forecast traffic requests.Moreover,by adopting a service-aware objective utility function,each user can optimize the vertical handover decisions with awareness of the related supporting networks and service characteristics.Since the decision process is executed with consideration of BRPM predictions,the SPVH algorithm can avoid congestion in HWN through a proactive method.The experiment results show that the proposed SPVH can solidly enhance the system performance in terms of service access ratio,average access delay,system throughput,usage ratio of spectrum resource,and eventually achieve higher network utility.
文摘The state of art pertaining to vertical handover decisions in next-generation wireless networks provides a detailed overview of vertical handover studies.This paper classifies the research initiatives under the vertical handover decision mechanism for heterogeneous wireless networks.A fair comparison of traditional and recent techniques is drafted to obtain direction of the vertical handover decision.Several issues related to seamless support on mobility management techniques have been described in the literature.The next-generation wireless network promises to offer enhanced data services compared to other networks in mobile communication.Since all next generation network(NGN)is an IP-based network,challenges drive toward providing quality of service in the handover process.The necessity of handover process is a seamless connection.The handover operations that minimize or even target the elimination of delay in new network connection establishment are most welcomed.However,frequent disconnection and inefficient seamless handovers result in handover operation failures.Most of the existing methods on handover decisions are based on mobile-controlled handovers.Here,the decisions are in-corporate in the mobile devices.Several mobile-controlled handovers take a single parameter or two or more additional parameters as a combination to evaluate the policy decision.These approaches are carefully studied and classified.
