To reduce the potential signaling traffic in IP multimedia subsystem （IMS）, the session establishment procedures were investigated. The serving call session eontrol function （S-CSCF） is the major bottleneck in IMS...To reduce the potential signaling traffic in IP multimedia subsystem （IMS）, the session establishment procedures were investigated. The serving call session eontrol function （S-CSCF） is the major bottleneck in IMS and the existing 3GPP service triggering algorithm （STA） based on initial filter eriteria （iFC） increases the end-to-end session setup delay remarkably. To reduce the session setup delay and improve the system performanee, a SIP response message based filter criteria （rFC） was proposed. Based on the rFC, a SIP response message based STA （RSTA） was further proposed. The modeling and theoretical analysis of 3GPP STA and RSTA were presented. Simulation results show that, compared with 3GPP STA, the RSTA can avoid the additional signaling traffie load of the S-CSCF and application server （AS） effectively, reduce the session setup delay eonsiderably, increase the throughput of the S-CSCF and improve the quality of service （QoS） of IMS network.展开更多
The modeling of Application Triggering Architecture （ATA） in the IP Multimedia Sub- system （IMS） is presented. The session setup delay and system throughput are employed as the measurement to investigate the perfo...The modeling of Application Triggering Architecture （ATA） in the IP Multimedia Sub- system （IMS） is presented. The session setup delay and system throughput are employed as the measurement to investigate the performance of ATA and the Serving Call Session Control Punction （S-CSCF）. With theoretical analysis and simulation results, we find that, the number of the ASs （Application Servers）, the use of the subsequent Filter Criteria （sFC） and the arrival rate have heavy impact on the session setup delay and the S-CSCF is the major bottleneck in IMS network. The results are useful in constructing IMS network. At last, we propose several possible solutions to reduce the session setup delay and decrease the load of the S-CSCF.展开更多
An efficient and practical method is developed for the trifluoromethylation of enamides using Umemoto's reagent as the trifluoromethylating reagent. These reactions proceeded under visible light irradiation withou...An efficient and practical method is developed for the trifluoromethylation of enamides using Umemoto's reagent as the trifluoromethylating reagent. These reactions proceeded under visible light irradiation without any photocatalyst at room temperature in good chemical yields.展开更多
基金Supported by National Science Fund for Distinguished Young Scholars (No. 60525110)National Basic Research Program of China (No.2007CB307100, 2007CB307103)+1 种基金Program for New Century Excellent Talents in University (No. NCET-04-0111 )Development Fund Project for Electronic and Information Industry (Mobile Service and Application System Based on 3G)
文摘To reduce the potential signaling traffic in IP multimedia subsystem （IMS）, the session establishment procedures were investigated. The serving call session eontrol function （S-CSCF） is the major bottleneck in IMS and the existing 3GPP service triggering algorithm （STA） based on initial filter eriteria （iFC） increases the end-to-end session setup delay remarkably. To reduce the session setup delay and improve the system performanee, a SIP response message based filter criteria （rFC） was proposed. Based on the rFC, a SIP response message based STA （RSTA） was further proposed. The modeling and theoretical analysis of 3GPP STA and RSTA were presented. Simulation results show that, compared with 3GPP STA, the RSTA can avoid the additional signaling traffie load of the S-CSCF and application server （AS） effectively, reduce the session setup delay eonsiderably, increase the throughput of the S-CSCF and improve the quality of service （QoS） of IMS network.
基金Supported by the National Science Fund for Distinguished Young Scholars (No.60525110)the National 973 Program (No.2007CB307100, 2007CB307103)+2 种基金the Program for New Century Excellent Talents in University (No. NCET-04-0111)the Development Fund Project for Electronic and Information Industry (Mobile Service and Application System Based on 3G)the National Spe-cific Project for Hi-Tech Industrialization and Information Equipments (Mobile Intelligent Network Supporting Value-added Data Services)
文摘The modeling of Application Triggering Architecture （ATA） in the IP Multimedia Sub- system （IMS） is presented. The session setup delay and system throughput are employed as the measurement to investigate the performance of ATA and the Serving Call Session Control Punction （S-CSCF）. With theoretical analysis and simulation results, we find that, the number of the ASs （Application Servers）, the use of the subsequent Filter Criteria （sFC） and the arrival rate have heavy impact on the session setup delay and the S-CSCF is the major bottleneck in IMS network. The results are useful in constructing IMS network. At last, we propose several possible solutions to reduce the session setup delay and decrease the load of the S-CSCF.
基金supported by the National Natural Science Foundation of China(2147208481421091)+2 种基金the Qing Lan Project of Jiangsu Province and State Key Laboratory of Bioorganic & Natural Products ChemistryShanghai Institute of Organic ChemistryChinese Academy of Sciences
文摘An efficient and practical method is developed for the trifluoromethylation of enamides using Umemoto's reagent as the trifluoromethylating reagent. These reactions proceeded under visible light irradiation without any photocatalyst at room temperature in good chemical yields.
