The encoding and decoding processes of traffic channel in digital trunking system are studied. On the basis of computer simulation, the BER (bit error ratio) with different RCPC decoding step is analyzed. As a result,...The encoding and decoding processes of traffic channel in digital trunking system are studied. On the basis of computer simulation, the BER (bit error ratio) with different RCPC decoding step is analyzed. As a result, the optimal RCPC decoding step is provided, which gives essential theoretical evidences for the implementation of digital trunking system.展开更多
This paper takes the Sobel operator as example to study parallel sequential algorithm onto a memory-sharing multiprocessor by using a virtual machine. Several different parallel algorithms using function decomposition...This paper takes the Sobel operator as example to study parallel sequential algorithm onto a memory-sharing multiprocessor by using a virtual machine. Several different parallel algorithms using function decomposition and/or data decomposition methods are compared and their performances are analyzed in terms of processor utilization, data traffic, shared memory access, and synchronization overhead. The analysis is validated through a simulation experiment on the virtual machine of 64 parallel processors. Conclusions are presented at the end of this paper.展开更多
This work explores the behavior of both TCP-Reno and TCP-Sack under a simple scenario, where a single TCP source transmits the packets continuously over a single bottleneck node characterized by its queue size, bandwi...This work explores the behavior of both TCP-Reno and TCP-Sack under a simple scenario, where a single TCP source transmits the packets continuously over a single bottleneck node characterized by its queue size, bandwidth and propagation delay. The analysis allows to derive the performance of TCP, the utilization tends to 75% of the bottleneck throughput when the bandwidth×propagation delay pipe becomes very large, while it tends to 100% when the queuing delays are predominant because the queue is never empty. In the transient analysis we show how the initial phase of the session can degrade the performances. These results are proved through simulation.展开更多
in order to project a reliable telecommunication network ,we have to measure the call lossrate of present traffic and to predzct the traffic of hajective network. In this paper we point out that afactor of real commun...in order to project a reliable telecommunication network ,we have to measure the call lossrate of present traffic and to predzct the traffic of hajective network. In this paper we point out that afactor of real communication needs for subscrihas should be added in studying the traffic source char-acterization. Generally, the predicted traffic does not equal to the real demends, Considered asubscriber's psychological facter for attempts in busy-hour, a mathematical medel of probable dertva-tive calls from each real communication demand is given,with which the calling-up probabity, andthe repeating attempt probability of original subscribers on line occupation are calculated and the rela-tionship between the traffic and the real cammunication need is predicted.展开更多
An optical signal-to-noise ratio （OSNR） aware lightpath provisioning mechanism （OSNR-LPM） is proposed for distributed optical networks. This OSNR-LPM takes the OSNR value of the lightwave along the lightpath into ...An optical signal-to-noise ratio （OSNR） aware lightpath provisioning mechanism （OSNR-LPM） is proposed for distributed optical networks. This OSNR-LPM takes the OSNR value of the lightwave along the lightpath into consideration when establishing the lightpath for the connection request using resource reservation protocol-traffic engineering （RSVP-TE）. Moreover, the OSNR-LPM makes full advantages of the OSNR monitoring function in each node and assigns the lightwave by judging the OSNR value carried by the signaling message in order to guarantee the reliable establishment of the lightpath in the data plane. The simulation results show that the OSNR-LPM outperforms other lightpath assignment mechanisms in terms of real blocking probability in the data plane.展开更多
文摘The encoding and decoding processes of traffic channel in digital trunking system are studied. On the basis of computer simulation, the BER (bit error ratio) with different RCPC decoding step is analyzed. As a result, the optimal RCPC decoding step is provided, which gives essential theoretical evidences for the implementation of digital trunking system.
文摘This paper takes the Sobel operator as example to study parallel sequential algorithm onto a memory-sharing multiprocessor by using a virtual machine. Several different parallel algorithms using function decomposition and/or data decomposition methods are compared and their performances are analyzed in terms of processor utilization, data traffic, shared memory access, and synchronization overhead. The analysis is validated through a simulation experiment on the virtual machine of 64 parallel processors. Conclusions are presented at the end of this paper.
基金the National Natural Science Fundation of China!49402004
文摘This work explores the behavior of both TCP-Reno and TCP-Sack under a simple scenario, where a single TCP source transmits the packets continuously over a single bottleneck node characterized by its queue size, bandwidth and propagation delay. The analysis allows to derive the performance of TCP, the utilization tends to 75% of the bottleneck throughput when the bandwidth×propagation delay pipe becomes very large, while it tends to 100% when the queuing delays are predominant because the queue is never empty. In the transient analysis we show how the initial phase of the session can degrade the performances. These results are proved through simulation.
文摘in order to project a reliable telecommunication network ,we have to measure the call lossrate of present traffic and to predzct the traffic of hajective network. In this paper we point out that afactor of real communication needs for subscrihas should be added in studying the traffic source char-acterization. Generally, the predicted traffic does not equal to the real demends, Considered asubscriber's psychological facter for attempts in busy-hour, a mathematical medel of probable dertva-tive calls from each real communication demand is given,with which the calling-up probabity, andthe repeating attempt probability of original subscribers on line occupation are calculated and the rela-tionship between the traffic and the real cammunication need is predicted.
基金supported in part by the National "863" Program of China (Nos. 2009AA01z255 and 2009AA01A345)the National "973" Program of China (No.2007CB310705)+1 种基金the National Natural Science Foundation of China (No. 60932004)the Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 200800130001)
文摘An optical signal-to-noise ratio （OSNR） aware lightpath provisioning mechanism （OSNR-LPM） is proposed for distributed optical networks. This OSNR-LPM takes the OSNR value of the lightwave along the lightpath into consideration when establishing the lightpath for the connection request using resource reservation protocol-traffic engineering （RSVP-TE）. Moreover, the OSNR-LPM makes full advantages of the OSNR monitoring function in each node and assigns the lightwave by judging the OSNR value carried by the signaling message in order to guarantee the reliable establishment of the lightpath in the data plane. The simulation results show that the OSNR-LPM outperforms other lightpath assignment mechanisms in terms of real blocking probability in the data plane.
