HitPeers conotitute a scalable and highly efficient P2P file sharing system in which all the data file can be shared. The center of HitPeers is the Category Tree (CT). CT collects the published information with catego...HitPeers conotitute a scalable and highly efficient P2P file sharing system in which all the data file can be shared. The center of HitPeers is the Category Tree (CT). CT collects the published information with category. It is flexible enough to let users customize their own local CT. Its hierarchy helps users to find the information they desire most conveniently. To increase the robustness and retain the efficiency, HitPeers will divide the tree into disjoint parts. Every part is a subtree. Some special nodes named Onodes will take charge of the subtree and play the role of a service provider. HitPeers produce more and more Onodes to meet the service demands in the internet scale distributed environment. This paper will show the profile of the whole system.展开更多
By importing the idea of P2P,and transmitting messages among clients directly into the client-server architecture,a new hybrid architecture was presented with the help of AOI technology and message category.Theoretica...By importing the idea of P2P,and transmitting messages among clients directly into the client-server architecture,a new hybrid architecture was presented with the help of AOI technology and message category.Theoretical analysis of this architecture was presented in detail.A series of simulation experiments was carried out to verify its effectiveness.Results indicate that the new architecture produces less server message workload than traditional architectures,which can improve the scalability of DVE systems.展开更多
Nowadays, because of its wide bandwidth and high communication capability, the optical fiber is more and more used for high data rate transmission of information in railway environments. Conventionally, only one servi...Nowadays, because of its wide bandwidth and high communication capability, the optical fiber is more and more used for high data rate transmission of information in railway environments. Conventionally, only one service is sent over the fiber at a time. However, many different services can be simultaneously conveyed in railway stations such as passenger information service, cellular phone, Wi-Fi... The objective of the work proposed in this paper is to demonstrate the potential benefits of transmitting radio signals over fiber in a railway environment. The main idea is to exploit the full capacity of the fiber by transmitting multiple services using the same fiber. Since, different services are operating in different frequency bands; we propose a new multiplexing technique called Mode Group Diversity Multiplexing （MGDM） to ensure the transmission of multiple services using the same fiber, without additional infrastructure. There are numerous advantages of the proposed technique, e.g., faster and reliable data exchange, high resolution video surveillance capability, high data rate information exchange in railway stations. We present, in this paper, the physical characteristics of optical fibers, performance of MGDM multiplexing technique, and the influence of the laser excitation conditions at the entrance of the fiber on the performances of the system.展开更多
文摘HitPeers conotitute a scalable and highly efficient P2P file sharing system in which all the data file can be shared. The center of HitPeers is the Category Tree (CT). CT collects the published information with category. It is flexible enough to let users customize their own local CT. Its hierarchy helps users to find the information they desire most conveniently. To increase the robustness and retain the efficiency, HitPeers will divide the tree into disjoint parts. Every part is a subtree. Some special nodes named Onodes will take charge of the subtree and play the role of a service provider. HitPeers produce more and more Onodes to meet the service demands in the internet scale distributed environment. This paper will show the profile of the whole system.
基金Sponsored by the National Basic Research Program of China(Grant No.2002CB312200)the National Natural Science Foundation of China(Grant No.60575036)
文摘By importing the idea of P2P,and transmitting messages among clients directly into the client-server architecture,a new hybrid architecture was presented with the help of AOI technology and message category.Theoretical analysis of this architecture was presented in detail.A series of simulation experiments was carried out to verify its effectiveness.Results indicate that the new architecture produces less server message workload than traditional architectures,which can improve the scalability of DVE systems.
文摘Nowadays, because of its wide bandwidth and high communication capability, the optical fiber is more and more used for high data rate transmission of information in railway environments. Conventionally, only one service is sent over the fiber at a time. However, many different services can be simultaneously conveyed in railway stations such as passenger information service, cellular phone, Wi-Fi... The objective of the work proposed in this paper is to demonstrate the potential benefits of transmitting radio signals over fiber in a railway environment. The main idea is to exploit the full capacity of the fiber by transmitting multiple services using the same fiber. Since, different services are operating in different frequency bands; we propose a new multiplexing technique called Mode Group Diversity Multiplexing （MGDM） to ensure the transmission of multiple services using the same fiber, without additional infrastructure. There are numerous advantages of the proposed technique, e.g., faster and reliable data exchange, high resolution video surveillance capability, high data rate information exchange in railway stations. We present, in this paper, the physical characteristics of optical fibers, performance of MGDM multiplexing technique, and the influence of the laser excitation conditions at the entrance of the fiber on the performances of the system.
