Network virtualization is an enabling technology of running multiple virtual networks on a shared substrate network. It aims to deal with the ossification of current network architecture. As a crucial component of net...Network virtualization is an enabling technology of running multiple virtual networks on a shared substrate network. It aims to deal with the ossification of current network architecture. As a crucial component of network virtualization, virtual network embedding(VNE) can efficiently and effectively allocates the substrate resource to proposed virtual network requests. According to the optimization strategy, VNE approaches can be classified into three categories: exact, heuristic and meta-heuristic solution. The VNE exact solution is the foundation of its corresponding heuristic and meta-heuristic solutions. This paper presents a survey of existing typical VNE exact solutions, and open problems for the future research of VNE exact solutions are proposed.展开更多
Virtual network embedding problem which is NP-hard is a key issue for implementing software-defined network which is brought about by network virtualization. Compared with other studies which focus on designing heuris...Virtual network embedding problem which is NP-hard is a key issue for implementing software-defined network which is brought about by network virtualization. Compared with other studies which focus on designing heuristic algorithms to reduce the hardness of the NP-hard problem we propose a robust VNE algorithm based on component connectivity in large-scale network. We distinguish the different components and embed VN requests onto them respectively. And k-core is applied to identify different VN topologies so that the VN request can be embedded onto its corresponding component. On the other hand, load balancing is also considered in this paper. It could avoid blocked or bottlenecked area of substrate network. Simulation experiments show that compared with other algorithms in large-scale network, acceptance ratio, average revenue and robustness can be obviously improved by our algorithm and average cost can be reduced. It also shows the relationship between the component connectivity including giant component and small components and the performance metrics.展开更多
In order to reduce cost and complexity,fiber-wireless(FiWi) networks emerge,combining the huge amount of available bandwidth of fiber networks and the flexibility,mobility of wireless networks.However,there is still a...In order to reduce cost and complexity,fiber-wireless(FiWi) networks emerge,combining the huge amount of available bandwidth of fiber networks and the flexibility,mobility of wireless networks.However,there is still a long way to go before taking fiber and wireless systems as fully integrated networks.In this paper,we propose a network visualization based seamless networking scheme for FiWi networks,including hierarchical model,service model,service implementation and dynamic bandwidth assignment(DBA).Then,we evaluate the performance changes after network virtualization is introduced.Throughput for nodes,bandwidth for links and overheads leaded by network virtualization are analyzed.The performance of our proposed networking scheme is evaluated by simulation and real implementations,respectively.The results show that,compared to traditional networking scheme,our scheme has a better performance.展开更多
Telemedicine's greatest problem is not found in software and hardware. Many can make software and hardware work. It has for long been clear that telemedicine has diffusion problems. Focus should be shifted over to th...Telemedicine's greatest problem is not found in software and hardware. Many can make software and hardware work. It has for long been clear that telemedicine has diffusion problems. Focus should be shifted over to the humanware. Telemedicine means work is done by virtual organizations. For the future of telemedicine, organizational issues will represent a challenge. Organizations consist of humans in interaction. In Norwegian telemedicine projects, organizational problems were identified and solutions to the problems were designed. More than 40 publications show numerous organizational consequences and numerous types of organizational consequences. When it comes to the solving telemedicine's organizational problems, learning from the experience others have is important. It is not necessary for all to invent what the organizational problems are. Organizing health care around the physical telecommunication networks is associated with the concept of network organization. The electronic networks become an infrastructure around which single health care providers are distributed. Such network organization means a formation of alliances between organizations. Centralization and decentralization are important terms for all organizing. Telemedicine makes the question of centralization or decentralization relevant. Telemedicine requires collaboration between participating parties. Obtaining the benefits of telemedicine is dependent on implementing the right measures for good collaboration. We know there are problems with telemedicine virtual organizations, but solutions to these problems exist. For the future of telemedicine, doing work with organization is important. Skilled managers have an important role to play.展开更多
基金supported by the National Basic Research Program of China(973 Program)under Grant 2013CB329104the National Natural Science Foundation of China under Grants 61372124 and 61427801the Key Projects of Natural Science Foundation of Jiangsu University under Grant 11KJA510001
文摘Network virtualization is an enabling technology of running multiple virtual networks on a shared substrate network. It aims to deal with the ossification of current network architecture. As a crucial component of network virtualization, virtual network embedding(VNE) can efficiently and effectively allocates the substrate resource to proposed virtual network requests. According to the optimization strategy, VNE approaches can be classified into three categories: exact, heuristic and meta-heuristic solution. The VNE exact solution is the foundation of its corresponding heuristic and meta-heuristic solutions. This paper presents a survey of existing typical VNE exact solutions, and open problems for the future research of VNE exact solutions are proposed.
基金supported in part by the National Natural Science Foundation of China under Grant No.61471055
文摘Virtual network embedding problem which is NP-hard is a key issue for implementing software-defined network which is brought about by network virtualization. Compared with other studies which focus on designing heuristic algorithms to reduce the hardness of the NP-hard problem we propose a robust VNE algorithm based on component connectivity in large-scale network. We distinguish the different components and embed VN requests onto them respectively. And k-core is applied to identify different VN topologies so that the VN request can be embedded onto its corresponding component. On the other hand, load balancing is also considered in this paper. It could avoid blocked or bottlenecked area of substrate network. Simulation experiments show that compared with other algorithms in large-scale network, acceptance ratio, average revenue and robustness can be obviously improved by our algorithm and average cost can be reduced. It also shows the relationship between the component connectivity including giant component and small components and the performance metrics.
基金supported by National Natural Science Foundation of China under Grant No.61240040
文摘In order to reduce cost and complexity,fiber-wireless(FiWi) networks emerge,combining the huge amount of available bandwidth of fiber networks and the flexibility,mobility of wireless networks.However,there is still a long way to go before taking fiber and wireless systems as fully integrated networks.In this paper,we propose a network visualization based seamless networking scheme for FiWi networks,including hierarchical model,service model,service implementation and dynamic bandwidth assignment(DBA).Then,we evaluate the performance changes after network virtualization is introduced.Throughput for nodes,bandwidth for links and overheads leaded by network virtualization are analyzed.The performance of our proposed networking scheme is evaluated by simulation and real implementations,respectively.The results show that,compared to traditional networking scheme,our scheme has a better performance.
文摘Telemedicine's greatest problem is not found in software and hardware. Many can make software and hardware work. It has for long been clear that telemedicine has diffusion problems. Focus should be shifted over to the humanware. Telemedicine means work is done by virtual organizations. For the future of telemedicine, organizational issues will represent a challenge. Organizations consist of humans in interaction. In Norwegian telemedicine projects, organizational problems were identified and solutions to the problems were designed. More than 40 publications show numerous organizational consequences and numerous types of organizational consequences. When it comes to the solving telemedicine's organizational problems, learning from the experience others have is important. It is not necessary for all to invent what the organizational problems are. Organizing health care around the physical telecommunication networks is associated with the concept of network organization. The electronic networks become an infrastructure around which single health care providers are distributed. Such network organization means a formation of alliances between organizations. Centralization and decentralization are important terms for all organizing. Telemedicine makes the question of centralization or decentralization relevant. Telemedicine requires collaboration between participating parties. Obtaining the benefits of telemedicine is dependent on implementing the right measures for good collaboration. We know there are problems with telemedicine virtual organizations, but solutions to these problems exist. For the future of telemedicine, doing work with organization is important. Skilled managers have an important role to play.