we present a robust and universal quantum secret sharing protocol with four-qubit decoherence-free （DF） states against collective noise. The transmission＇s safety is ensured by the nonorthogonality of the noiseless...we present a robust and universal quantum secret sharing protocol with four-qubit decoherence-free （DF） states against collective noise. The transmission＇s safety is ensured by the nonorthogonality of the noiseless states traveling on the quantum channel. Although this scheme uses entangled states for encoding, only single-particle product measurements are required.展开更多
In order to enhance the quality of vertical handoff in an overlay wireless network, multiple attributes are taken into account when optimizing the vertical handoff decision including user-based and network-based QoS f...In order to enhance the quality of vertical handoff in an overlay wireless network, multiple attributes are taken into account when optimizing the vertical handoff decision including user-based and network-based QoS factors. In this paper, we develop a novel vertical handoff algorithm in an integrated 3G cellular and Wireless LAN networks. The proposed algorithm can adjust the weight of each QoS attribute dynamically as the networks change, trace the network condition and choose the optimal access point at transient regions. Simulation results show that this algorithm is able to provide accurate handoff decision, resulting in small unnecessary handoff numbers, good performance of throughput and handoff delay in heterogeneous environments.展开更多
To decrease the transmission delay of uplink voice over IP(VoIP)services in IEEE 802.16e sys-tem,a novel strategy which includes a load-balance algorithm and an extended earliest deadline first(EEDF)scheduling algorit...To decrease the transmission delay of uplink voice over IP(VoIP)services in IEEE 802.16e sys-tem,a novel strategy which includes a load-balance algorithm and an extended earliest deadline first(EEDF)scheduling algorithm is proposed.Subsequently,this paper analyzes the performance of the pro-posed strategy in terms of transmission delay of VoIP services,system capacity,throughput and compati-bility with IEEE 802 .16e standard.Finally,simulation experiments are carried out to verify the improve-ment of the proposed strategy.The simulation results match well with the theoretical analysis and showthat the proposed strategy reduces the transmission delay of uplink VoIP services and improves the capaci-ty and throughput.These improvements are remarkable especially when the load of system is heavy.展开更多
基金Supported by the National High-Tech Research,Development Plan of China under Grant Nos.2009AA01Z441National Basic Research Program of China(973 Program 2007CB311100)+3 种基金the National Natural Science Foundation of China under Grant Nos.60873191, 60821001,61003290The Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20091103120014Beijing Natural Science Foundation under Grant Nos.1093015 and 1102004the ISN open Foundation
文摘we present a robust and universal quantum secret sharing protocol with four-qubit decoherence-free （DF） states against collective noise. The transmission＇s safety is ensured by the nonorthogonality of the noiseless states traveling on the quantum channel. Although this scheme uses entangled states for encoding, only single-particle product measurements are required.
基金Acknowledgements This work is supported by Key Program of National Natural Science Foundation of China Grant No. 60832009.
文摘In order to enhance the quality of vertical handoff in an overlay wireless network, multiple attributes are taken into account when optimizing the vertical handoff decision including user-based and network-based QoS factors. In this paper, we develop a novel vertical handoff algorithm in an integrated 3G cellular and Wireless LAN networks. The proposed algorithm can adjust the weight of each QoS attribute dynamically as the networks change, trace the network condition and choose the optimal access point at transient regions. Simulation results show that this algorithm is able to provide accurate handoff decision, resulting in small unnecessary handoff numbers, good performance of throughput and handoff delay in heterogeneous environments.
基金supported by the High Technology Research and Development Programme of China(No.2006AA01Z235)
文摘To decrease the transmission delay of uplink voice over IP(VoIP)services in IEEE 802.16e sys-tem,a novel strategy which includes a load-balance algorithm and an extended earliest deadline first(EEDF)scheduling algorithm is proposed.Subsequently,this paper analyzes the performance of the pro-posed strategy in terms of transmission delay of VoIP services,system capacity,throughput and compati-bility with IEEE 802 .16e standard.Finally,simulation experiments are carried out to verify the improve-ment of the proposed strategy.The simulation results match well with the theoretical analysis and showthat the proposed strategy reduces the transmission delay of uplink VoIP services and improves the capaci-ty and throughput.These improvements are remarkable especially when the load of system is heavy.
