This paper proposes the application of cloud desktop in network multimedia classroom in colleges. Computer lab as the most important cloud part of the campus cloud, not only assume a variety of the computer courses te...This paper proposes the application of cloud desktop in network multimedia classroom in colleges. Computer lab as the most important cloud part of the campus cloud, not only assume a variety of the computer courses teaching experiments, students self-learning, free on the machine and other tasks, but also as a variety of the paperless examination of the important places. Cloud room is a great feature of the use of virtualization technology, it can be used to virtual software to a lot of hardware features, regardless of the server, network equipment and clients can be virtual with a strong flexibility and scalability. We used these features when designing and in addition, when adding hardware and software equipment. This paper proposes the novel architecture of the system to then give us a novel perspective of building up the multimedia classroom.展开更多
With the development of social economy,the multimedia and network teaching is more and more important in college English teaching,especially in vocational college.It can not only help students to give full play to the...With the development of social economy,the multimedia and network teaching is more and more important in college English teaching,especially in vocational college.It can not only help students to give full play to their collective consciousness and make our English course be full of vitality,but also make the amount of information in class redoubled.For the multimedia and network teaching,there're some problems in English teaching.So the multimedia and network teaching has both necessities and problems.展开更多
A secure communication mechanism is necessary in the applications of Wireless Multimedia Sensor Networks (WMSNs), which is more vulnerable to security attacks due to the presence of multimedia data. Additionally, give...A secure communication mechanism is necessary in the applications of Wireless Multimedia Sensor Networks (WMSNs), which is more vulnerable to security attacks due to the presence of multimedia data. Additionally, given the limited technological resources (in term of energy, computation, bandwidth, and storage) of sensor nodes, security and privacy policies have to be combined with energy-aware algorithms and distributed processing of multimedia contents in WMSNs. To solve these problems in this paper, an energy efficient distributed steganography scheme, which combines steganography technique with the concept of distributed computing, is proposed for secure communication in WMSNs. The simulation results show that the proposed method can achieve considerable energy efficiency while assuring the communication security simultaneously.展开更多
Initially as an extension of cloud computing, fog computing has been inspiring new ideas about moving computing tasks to the edge of networks. In fog, we often repeat the procedure of placing services because of the g...Initially as an extension of cloud computing, fog computing has been inspiring new ideas about moving computing tasks to the edge of networks. In fog, we often repeat the procedure of placing services because of the geographical distribution of mobile users. We may not expect a fixed demand and supply relationship between users and service providers since users always prefer nearby service with less time delay and transmission consumption. That is, a plug-and-play service mode is what we need in fog. In this paper, we put forward a dynamic placement strategy for fog service to guarantee the normal service provision and optimize the Quality of Service (QoS). The simulation results show that our strategy can achieve better performance under metrics including energy consumption and end-to-end latency. Moreover, we design a real Plug-and-Play Fog (PnPF) based on Raspberry Pi and OpenWrt to provide fog services for wireless multimedia networks.展开更多
Based on multimedia and network environment, college English teaching mode can effectively improve the teaching environment of traditional English teaching and students, and expand the capacity of English classroom in...Based on multimedia and network environment, college English teaching mode can effectively improve the teaching environment of traditional English teaching and students, and expand the capacity of English classroom information, and enrich the students’ English culture background. Therefore, as a teacher, we should first of all make efforts to learn new knowledge and teaching methods to improve our English professional quality. Strengthening the multimedia, network technology and educational psychology research, and put themselves in the teaching position. In addition, the college English teaching model based on multimedia and network environment can cultivate students’ independent thinking, autonomous learning, analysis and problem - solving ability, and promote the high efficiency of college English teaching.展开更多
Rapid penetration of small customized wireless devices and enormous growth of wireless communication technologies has already set the stage for large-scale deployment of wireless sensor networks. Offering precise qual...Rapid penetration of small customized wireless devices and enormous growth of wireless communication technologies has already set the stage for large-scale deployment of wireless sensor networks. Offering precise quality of service (QoS) for multimedia transmission over sensor networks has not received significant attention. However offering some better QoS for wireless multimedia over sensor networks raises significant challenges. In this paper, we propose an adaptive Cross-Layer multi-channel QoS-MAC protocol to support energy-efficient, high throughput, and reliable data transmission in Wireless Multimedia Sensor Network (WMSNs). Our proposed protocol use benefit of TDMA and CSMA/CA to adaptively assign channels and timeslots to active multimedia sensor nodes in clusters. Simulations show that the proposed system achieves the performance objectives of WMSNs with increased network throughput at the cost of a small control and energy overhead.展开更多
Wireless mesh network (WMN) research is an emerging field in network communications. However, WMNs pose several difficulties in the transmission of information, especially time critical applications such as streaming ...Wireless mesh network (WMN) research is an emerging field in network communications. However, WMNs pose several difficulties in the transmission of information, especially time critical applications such as streaming video and audio. In this paper, we provide an overview of several research papers which utilize mesh networks for streaming multimedia. We compare the results of the research and the significance they bring to the field of wireless mesh networks. We then provide possible directions for future research into wireless mesh networks as they apply to streaming multimedia.展开更多
Traditional Wireless Sensor Networks(WSNs)comprise of costeffective sensors that can send physical parameters of the target environment to an intended user.With the evolution of technology,multimedia sensor nodes have...Traditional Wireless Sensor Networks(WSNs)comprise of costeffective sensors that can send physical parameters of the target environment to an intended user.With the evolution of technology,multimedia sensor nodes have become the hot research topic since it can continue gathering multimedia content and scalar from the target domain.The existence of multimedia sensors,integrated with effective signal processing and multimedia source coding approaches,has led to the increased application of Wireless Multimedia Sensor Network(WMSN).This sort of network has the potential to capture,transmit,and receive multimedia content.Since energy is a major source in WMSN,novel clustering approaches are essential to deal with adaptive topologies of WMSN and prolonged network lifetime.With this motivation,the current study develops an Enhanced Spider Monkey Optimization-based Energy-Aware Clustering Scheme(ESMO-EACS)for WMSN.The proposed ESMO-EACS model derives ESMO algorithm by incorporating the concepts of SMO algorithm and quantum computing.The proposed ESMO-EACS model involves the design of fitness functions using distinct input parameters for effective construction of clusters.A comprehensive experimental analysis was conducted to validate the effectiveness of the proposed ESMO-EACS technique in terms of different performance measures.The simulation outcome established the superiority of the proposed ESMO-EACS technique to other methods under various measures.展开更多
The delay and DVBMT problem is known to be NP-complete. In this paper,an efficient distributed dynamic multicast routing algorithm was proposed to produce routing trees with delay and delay variation constraints. The ...The delay and DVBMT problem is known to be NP-complete. In this paper,an efficient distributed dynamic multicast routing algorithm was proposed to produce routing trees with delay and delay variation constraints. The proposed algorithm is fully distributed,and supports the dynamic reorganizing of the multicast tree in response to changes for the destination. Simulations demonstrate that our algorithm is better in terms of tree delay and routing success ratio as compared with other existing algorithms,and performs excellently in delay variation performance under lower time complexity,which ensures it to support the requirements of real-time multimedia communications more effectively.展开更多
With the development of the times, modem education technology constantly emerges, and modern college English classroom begins to tend to use multimedia network for teaching. One is that multimedia network teaching can...With the development of the times, modem education technology constantly emerges, and modern college English classroom begins to tend to use multimedia network for teaching. One is that multimedia network teaching can enrich English teaching content. Two is that multimedia network teaching can make teaching process become full ofvigour, highlighting the dominant position of students in the classroom. Three, multimedia network teaching is conducive to improving the comprehensive quality of English teachers. In view of this, university English teaching should positively introduce multimedia network technology in teaching process, in order to promote English teaching quality to obtain great improvement.展开更多
For node awakening in wireless multi-sensor networks, an algorithm is put forward for three dimensional tar- get tracking. To monitor target dynamically in three dimensional area by controlling nodes, we constract vir...For node awakening in wireless multi-sensor networks, an algorithm is put forward for three dimensional tar- get tracking. To monitor target dynamically in three dimensional area by controlling nodes, we constract vir- tual force between moving target and the current sense node depending on the virtual potential method, then select the next sense node with information gain function, so that when target randomly move in the specific three dimensional area, the maximum sensing ratio of motion trajectory is get with few nodes. The proposed algorithm is verified from the simulations.展开更多
In the era of rapid technological development, business English teaching methods are in the development and changes and multimedia network technology gradually appeared. It has brought great convenience to business En...In the era of rapid technological development, business English teaching methods are in the development and changes and multimedia network technology gradually appeared. It has brought great convenience to business English teaching.This paper starts from the feasibility and necessity of multimedia network teaching in Business English to discuss the advantages of multimedia network Teaching Business English. Finally, it is to put forward multimedia network teaching mode, to provide practical recommendations for the majority of business English teacher during the multimedia network teaching.展开更多
With the development of the times, modem education technology constantly emerges, and modern college English classroom begins to tend to use multimedia network for teaching. One is that multimedia network teaching can...With the development of the times, modem education technology constantly emerges, and modern college English classroom begins to tend to use multimedia network for teaching. One is that multimedia network teaching can enrich English teaching content. Two is that multimedia network teaching can make teaching process become full of vigour, highlighting the dominant position of students in the classroom. Three, multimedia network teaching is conducive to improving the comprehensive quality of English teachers. In view of this, university English teaching should positively introduce multimedia network technology in teaching process, in order to promote English teaching quality to obtain great improvement.展开更多
To find out an effective way to improve higher vocational college students' reading abilities, the author designs an experiment that applying the multimedia and network technologies in the higher vocational public En...To find out an effective way to improve higher vocational college students' reading abilities, the author designs an experiment that applying the multimedia and network technologies in the higher vocational public English reading teaching to test whether the multimedia teaching mode is more effective than the traditional teaching mode in enhancing vocational college students' reading performance. The contrastive experiment is done for one semester and the experiment shows that if applying multimedia and network technologies in higher vocational public English reading teaching, creating authentic language environment, it can improve the classroom efficiency, improve students' English reading ability, thus forming the student-centered modem higher vocational public English reading teaching mode,展开更多
Channel parameters estimation in an orthogonal for the receiver station is a multi-dimensional (MD) frequency division multiple access (OFDMA) system optimization problem, because every user node has a separate lo...Channel parameters estimation in an orthogonal for the receiver station is a multi-dimensional (MD) frequency division multiple access (OFDMA) system optimization problem, because every user node has a separate local oscillator and every transmitter to receiver link has individual carrier frequency offset (CFO) and channel impulse response (CIR) parameters. In order to reduce the computational complexity for MD optimization, a time domain CFOs and CIRs estimation algorithm over the OFDMA based wireless multimedia sensor networks (WMSN) is proposed in this paper. In this algorithm, the receiver station can decouple the signal from every node by correlation based on specially designed training sequences, so that the MD optimization problem is simplified to an 1-D optimal problem. It is proved that the multiple CFOs can be identified from the correlation result using the phase shift of the consecutive training se- quences. Based on the CFOs estimation result, the CIRs can then he estimated according to the minimum mean square error (MMSE) criterion. The theoretic analysis and simulation results show that the proposed algorithm can effectively decouple the signal from different user nodes and the bit error rate (BER) per- formance curves are close to the ideal estimation when the user number is not large.展开更多
Jitter is one of the most important issues for multimedia real time services in future mobile ad hoc networks(MANET). A thorough theoretical analysis of the destination buffer for smoothing the jitter of the real ti...Jitter is one of the most important issues for multimedia real time services in future mobile ad hoc networks(MANET). A thorough theoretical analysis of the destination buffer for smoothing the jitter of the real time service in MANET is given. The theoretical results are applied in moderate populated ad hoc networks in our simulation, the simulation results show that by predicting and adjusting destination buffer in our way, Jitter will be alleviated in large part and this will contribute much to the quality of service (QOS) in MANET.展开更多
Wireless multimedia sensor network (WMSN) consists of sensors that can monitor multimedia data from its surrounding, such as capturing image, video and audio. To transmit multimedia information, large energy is requir...Wireless multimedia sensor network (WMSN) consists of sensors that can monitor multimedia data from its surrounding, such as capturing image, video and audio. To transmit multimedia information, large energy is required which decreases the lifetime of the network. In this paper we present a clustering approach based on spectral graph partitioning (SGP) for WMSN that increases the lifetime of the network. The efficient strategies for cluster head selection and rotation are also proposed.展开更多
In multimedia cellular networks, when a Mobile Host requests multimedia services, it may experience hand-offs to several cells before the request is completely served. If a target cell cannot provide adequate bandwidt...In multimedia cellular networks, when a Mobile Host requests multimedia services, it may experience hand-offs to several cells before the request is completely served. If a target cell cannot provide adequate bandwidth for a service request, instead of directly dropping the request, the MH is put into the handoff queue and hopefully the requested bandwidth can be satisfied by later released bandwidth. Obviously, it is important to properly assign priorities for queued handoff of MHs based on their inborn dynamics to avoid unnecessary dropping. In this paper, we present a dynamic handoff priority adjustment scheme which applied a handoff queuing scheme to dynamically adjust handoff priority based on receiving signal strength, service class, and mobility of Mobile Hosts. In addition, idle bandwidth reserved by inactive MHs is reallocated to urgent handoff MHs to reduce the call dropping probability. The goal of the proposed dynamic handoff priority adjustment scheme is to further reduce call dropping probability while still maintaining high bandwidth utilization and acceptable call blocking probability on multimedia cellular networks.展开更多
Wireless Multimedia Sensor Networks (WMSNs) are comprised of small embedded audio/video motes capable of extracting the surrounding environmental information, locally processing it and then wirelessly transmitting it ...Wireless Multimedia Sensor Networks (WMSNs) are comprised of small embedded audio/video motes capable of extracting the surrounding environmental information, locally processing it and then wirelessly transmitting it to sink/base station. Multimedia data such as image, audio and video is larger in volume than scalar data such as temperature, pressure and humidity. Thus to transmit multimedia information, more energy is required which reduces the lifetime of the network. Limitation of battery energy is a crucial problem in WMSN that needs to be addressed to prolong the lifetime of the network. In this paper we present a clustering approach based on Spectral Graph Partitioning (SGP) for WMSN that increases the lifetime of the network. The efficient strategies for cluster head selection and rotation are also proposed as part of clustering approach. Simulation results show that our strategy is better than existing strategies.展开更多
文摘This paper proposes the application of cloud desktop in network multimedia classroom in colleges. Computer lab as the most important cloud part of the campus cloud, not only assume a variety of the computer courses teaching experiments, students self-learning, free on the machine and other tasks, but also as a variety of the paperless examination of the important places. Cloud room is a great feature of the use of virtualization technology, it can be used to virtual software to a lot of hardware features, regardless of the server, network equipment and clients can be virtual with a strong flexibility and scalability. We used these features when designing and in addition, when adding hardware and software equipment. This paper proposes the novel architecture of the system to then give us a novel perspective of building up the multimedia classroom.
文摘With the development of social economy,the multimedia and network teaching is more and more important in college English teaching,especially in vocational college.It can not only help students to give full play to their collective consciousness and make our English course be full of vitality,but also make the amount of information in class redoubled.For the multimedia and network teaching,there're some problems in English teaching.So the multimedia and network teaching has both necessities and problems.
基金Sponsored by the National Natural Science Foundation of China (No. 60973139, 61170065, 61171053, 61003039,61003236)the Natural Science Foundation of Jiangsu Province (BK2011755, BK2012436)+3 种基金Scientific & Technological Support Project of Jiangsu Province (BE2011844,BE2011189)Jiangsu Provincial Research Scheme of Natural Science for Higher Education Institutions(12KJB520009)Science & Technology Innovation Fundfor Higher Education Institutions of Jiangsu Province(CXZZ11-0405)the Peak of Six Major Talent inJiangsu Province (2010DZXX026)
文摘A secure communication mechanism is necessary in the applications of Wireless Multimedia Sensor Networks (WMSNs), which is more vulnerable to security attacks due to the presence of multimedia data. Additionally, given the limited technological resources (in term of energy, computation, bandwidth, and storage) of sensor nodes, security and privacy policies have to be combined with energy-aware algorithms and distributed processing of multimedia contents in WMSNs. To solve these problems in this paper, an energy efficient distributed steganography scheme, which combines steganography technique with the concept of distributed computing, is proposed for secure communication in WMSNs. The simulation results show that the proposed method can achieve considerable energy efficiency while assuring the communication security simultaneously.
基金supported by JSPS KAKENHI Grant Numbers JP16K00117, JP19K20250 and KDDI Foundation
文摘Initially as an extension of cloud computing, fog computing has been inspiring new ideas about moving computing tasks to the edge of networks. In fog, we often repeat the procedure of placing services because of the geographical distribution of mobile users. We may not expect a fixed demand and supply relationship between users and service providers since users always prefer nearby service with less time delay and transmission consumption. That is, a plug-and-play service mode is what we need in fog. In this paper, we put forward a dynamic placement strategy for fog service to guarantee the normal service provision and optimize the Quality of Service (QoS). The simulation results show that our strategy can achieve better performance under metrics including energy consumption and end-to-end latency. Moreover, we design a real Plug-and-Play Fog (PnPF) based on Raspberry Pi and OpenWrt to provide fog services for wireless multimedia networks.
文摘Based on multimedia and network environment, college English teaching mode can effectively improve the teaching environment of traditional English teaching and students, and expand the capacity of English classroom information, and enrich the students’ English culture background. Therefore, as a teacher, we should first of all make efforts to learn new knowledge and teaching methods to improve our English professional quality. Strengthening the multimedia, network technology and educational psychology research, and put themselves in the teaching position. In addition, the college English teaching model based on multimedia and network environment can cultivate students’ independent thinking, autonomous learning, analysis and problem - solving ability, and promote the high efficiency of college English teaching.
文摘Rapid penetration of small customized wireless devices and enormous growth of wireless communication technologies has already set the stage for large-scale deployment of wireless sensor networks. Offering precise quality of service (QoS) for multimedia transmission over sensor networks has not received significant attention. However offering some better QoS for wireless multimedia over sensor networks raises significant challenges. In this paper, we propose an adaptive Cross-Layer multi-channel QoS-MAC protocol to support energy-efficient, high throughput, and reliable data transmission in Wireless Multimedia Sensor Network (WMSNs). Our proposed protocol use benefit of TDMA and CSMA/CA to adaptively assign channels and timeslots to active multimedia sensor nodes in clusters. Simulations show that the proposed system achieves the performance objectives of WMSNs with increased network throughput at the cost of a small control and energy overhead.
文摘Wireless mesh network (WMN) research is an emerging field in network communications. However, WMNs pose several difficulties in the transmission of information, especially time critical applications such as streaming video and audio. In this paper, we provide an overview of several research papers which utilize mesh networks for streaming multimedia. We compare the results of the research and the significance they bring to the field of wireless mesh networks. We then provide possible directions for future research into wireless mesh networks as they apply to streaming multimedia.
文摘Traditional Wireless Sensor Networks(WSNs)comprise of costeffective sensors that can send physical parameters of the target environment to an intended user.With the evolution of technology,multimedia sensor nodes have become the hot research topic since it can continue gathering multimedia content and scalar from the target domain.The existence of multimedia sensors,integrated with effective signal processing and multimedia source coding approaches,has led to the increased application of Wireless Multimedia Sensor Network(WMSN).This sort of network has the potential to capture,transmit,and receive multimedia content.Since energy is a major source in WMSN,novel clustering approaches are essential to deal with adaptive topologies of WMSN and prolonged network lifetime.With this motivation,the current study develops an Enhanced Spider Monkey Optimization-based Energy-Aware Clustering Scheme(ESMO-EACS)for WMSN.The proposed ESMO-EACS model derives ESMO algorithm by incorporating the concepts of SMO algorithm and quantum computing.The proposed ESMO-EACS model involves the design of fitness functions using distinct input parameters for effective construction of clusters.A comprehensive experimental analysis was conducted to validate the effectiveness of the proposed ESMO-EACS technique in terms of different performance measures.The simulation outcome established the superiority of the proposed ESMO-EACS technique to other methods under various measures.
文摘The delay and DVBMT problem is known to be NP-complete. In this paper,an efficient distributed dynamic multicast routing algorithm was proposed to produce routing trees with delay and delay variation constraints. The proposed algorithm is fully distributed,and supports the dynamic reorganizing of the multicast tree in response to changes for the destination. Simulations demonstrate that our algorithm is better in terms of tree delay and routing success ratio as compared with other existing algorithms,and performs excellently in delay variation performance under lower time complexity,which ensures it to support the requirements of real-time multimedia communications more effectively.
文摘With the development of the times, modem education technology constantly emerges, and modern college English classroom begins to tend to use multimedia network for teaching. One is that multimedia network teaching can enrich English teaching content. Two is that multimedia network teaching can make teaching process become full ofvigour, highlighting the dominant position of students in the classroom. Three, multimedia network teaching is conducive to improving the comprehensive quality of English teachers. In view of this, university English teaching should positively introduce multimedia network technology in teaching process, in order to promote English teaching quality to obtain great improvement.
文摘For node awakening in wireless multi-sensor networks, an algorithm is put forward for three dimensional tar- get tracking. To monitor target dynamically in three dimensional area by controlling nodes, we constract vir- tual force between moving target and the current sense node depending on the virtual potential method, then select the next sense node with information gain function, so that when target randomly move in the specific three dimensional area, the maximum sensing ratio of motion trajectory is get with few nodes. The proposed algorithm is verified from the simulations.
文摘In the era of rapid technological development, business English teaching methods are in the development and changes and multimedia network technology gradually appeared. It has brought great convenience to business English teaching.This paper starts from the feasibility and necessity of multimedia network teaching in Business English to discuss the advantages of multimedia network Teaching Business English. Finally, it is to put forward multimedia network teaching mode, to provide practical recommendations for the majority of business English teacher during the multimedia network teaching.
文摘With the development of the times, modem education technology constantly emerges, and modern college English classroom begins to tend to use multimedia network for teaching. One is that multimedia network teaching can enrich English teaching content. Two is that multimedia network teaching can make teaching process become full of vigour, highlighting the dominant position of students in the classroom. Three, multimedia network teaching is conducive to improving the comprehensive quality of English teachers. In view of this, university English teaching should positively introduce multimedia network technology in teaching process, in order to promote English teaching quality to obtain great improvement.
基金This work is supported in part by the National Natural Science Foundation of China (No.60273078) and Doctor Fund of Hebei Province of China Grant (No. 05547010D-3 to LIU Jiemin.60573127).
文摘To find out an effective way to improve higher vocational college students' reading abilities, the author designs an experiment that applying the multimedia and network technologies in the higher vocational public English reading teaching to test whether the multimedia teaching mode is more effective than the traditional teaching mode in enhancing vocational college students' reading performance. The contrastive experiment is done for one semester and the experiment shows that if applying multimedia and network technologies in higher vocational public English reading teaching, creating authentic language environment, it can improve the classroom efficiency, improve students' English reading ability, thus forming the student-centered modem higher vocational public English reading teaching mode,
基金supported by the National High Technology Research and Development Programme of China(No.2006AA01Z216)
文摘Channel parameters estimation in an orthogonal for the receiver station is a multi-dimensional (MD) frequency division multiple access (OFDMA) system optimization problem, because every user node has a separate local oscillator and every transmitter to receiver link has individual carrier frequency offset (CFO) and channel impulse response (CIR) parameters. In order to reduce the computational complexity for MD optimization, a time domain CFOs and CIRs estimation algorithm over the OFDMA based wireless multimedia sensor networks (WMSN) is proposed in this paper. In this algorithm, the receiver station can decouple the signal from every node by correlation based on specially designed training sequences, so that the MD optimization problem is simplified to an 1-D optimal problem. It is proved that the multiple CFOs can be identified from the correlation result using the phase shift of the consecutive training se- quences. Based on the CFOs estimation result, the CIRs can then he estimated according to the minimum mean square error (MMSE) criterion. The theoretic analysis and simulation results show that the proposed algorithm can effectively decouple the signal from different user nodes and the bit error rate (BER) per- formance curves are close to the ideal estimation when the user number is not large.
文摘Jitter is one of the most important issues for multimedia real time services in future mobile ad hoc networks(MANET). A thorough theoretical analysis of the destination buffer for smoothing the jitter of the real time service in MANET is given. The theoretical results are applied in moderate populated ad hoc networks in our simulation, the simulation results show that by predicting and adjusting destination buffer in our way, Jitter will be alleviated in large part and this will contribute much to the quality of service (QOS) in MANET.
文摘Wireless multimedia sensor network (WMSN) consists of sensors that can monitor multimedia data from its surrounding, such as capturing image, video and audio. To transmit multimedia information, large energy is required which decreases the lifetime of the network. In this paper we present a clustering approach based on spectral graph partitioning (SGP) for WMSN that increases the lifetime of the network. The efficient strategies for cluster head selection and rotation are also proposed.
文摘In multimedia cellular networks, when a Mobile Host requests multimedia services, it may experience hand-offs to several cells before the request is completely served. If a target cell cannot provide adequate bandwidth for a service request, instead of directly dropping the request, the MH is put into the handoff queue and hopefully the requested bandwidth can be satisfied by later released bandwidth. Obviously, it is important to properly assign priorities for queued handoff of MHs based on their inborn dynamics to avoid unnecessary dropping. In this paper, we present a dynamic handoff priority adjustment scheme which applied a handoff queuing scheme to dynamically adjust handoff priority based on receiving signal strength, service class, and mobility of Mobile Hosts. In addition, idle bandwidth reserved by inactive MHs is reallocated to urgent handoff MHs to reduce the call dropping probability. The goal of the proposed dynamic handoff priority adjustment scheme is to further reduce call dropping probability while still maintaining high bandwidth utilization and acceptable call blocking probability on multimedia cellular networks.
文摘Wireless Multimedia Sensor Networks (WMSNs) are comprised of small embedded audio/video motes capable of extracting the surrounding environmental information, locally processing it and then wirelessly transmitting it to sink/base station. Multimedia data such as image, audio and video is larger in volume than scalar data such as temperature, pressure and humidity. Thus to transmit multimedia information, more energy is required which reduces the lifetime of the network. Limitation of battery energy is a crucial problem in WMSN that needs to be addressed to prolong the lifetime of the network. In this paper we present a clustering approach based on Spectral Graph Partitioning (SGP) for WMSN that increases the lifetime of the network. The efficient strategies for cluster head selection and rotation are also proposed as part of clustering approach. Simulation results show that our strategy is better than existing strategies.