网际互连协议(Internet Protocol,IP)化技术凭借高带宽和灵活性等优势,为广播电视传输系统带来了新的可能,特别是在广播电视基带架构层,IP化音频(Audio over IP,AoIP)技术可以发挥重要作用,完成从源信号采集到发射的全过程音视频传输任...网际互连协议(Internet Protocol,IP)化技术凭借高带宽和灵活性等优势,为广播电视传输系统带来了新的可能,特别是在广播电视基带架构层,IP化音频(Audio over IP,AoIP)技术可以发挥重要作用,完成从源信号采集到发射的全过程音视频传输任务。基于此,介绍AoIP的相关概念、标准和应用优势,阐述基带架构的组成层次、采集编码和自动化功能,分析其技术特点。在此基础上,详细探讨AoIP技术在基带系统各层面的应用情况,包括AoIP网络部署、音视频流处理、自动化实现和同步方案等,并说明不同应用的效果。展开更多
近年来,广播电视技术转型向网际互连协议(Internet Protocol,IP)化发展的进程逐渐加快,基于IP架构的电视技术系统必将取代传统串行数字接口(Serial Digital Interface,SDI)架构,成为未来电视技术的发展方向。对以互联网协议网关(Interne...近年来,广播电视技术转型向网际互连协议(Internet Protocol,IP)化发展的进程逐渐加快,基于IP架构的电视技术系统必将取代传统串行数字接口(Serial Digital Interface,SDI)架构,成为未来电视技术的发展方向。对以互联网协议网关(Internet Protocol Gateway,IPG)作为关键设备搭建“SDI+IP”混合架构系统的设计方案进行深入分析,阐述电视技术系统从SDI向IP技术转型过程中尽可能实现平稳过渡的思路。展开更多
With the development of Ethernet systems and the growing capacity of modem silicon technology, embedded communication networks are playing an increasingly important role in embedded and safety critical systems. Hardwa...With the development of Ethernet systems and the growing capacity of modem silicon technology, embedded communication networks are playing an increasingly important role in embedded and safety critical systems. Hardware/software co-design is a methodology for solving design problems in processor based embedded systems. In this work, we implemented a new 1-cycle pipeline microprocessor and a fast Ethemet transceiver and established a low cost, high performance embedded network controller, and designed a TCP/IP stack to access the Intemet. We discussed the hardware/software architecture in the forepart, and then the whole system-on-a-chip on Altera Stratix EP1S25F780C6 device. Using the FPGA environment and SmartBit tester, we tested the system＇s throughput. Our simulation results showed that the maximum throughput of Ethemet packets is up to 7 Mbps, that of UDP packets is up to 5.8 Mbps, and that of TCP packets is up to 3.4 Mbps, which showed that this embedded system can easily transmit basic voice and video signals through Ethemet, and that using only one chip can realize that many electronic devices access to the Intemet directly and get high performance.展开更多
Active Queue Management (AQM) is an active research area in the Internet community. Random Early Detection (RED) is a typical AQM algorithm, but it is known that it is difficult to configure its parameters and its ave...Active Queue Management (AQM) is an active research area in the Internet community. Random Early Detection (RED) is a typical AQM algorithm, but it is known that it is difficult to configure its parameters and its average queue length is closely related to the load level. This paper proposes an effective fuzzy congestion control algorithm based on fuzzy logic which uses the pre- dominance of fuzzy logic to deal with uncertain events. The main advantage of this new congestion control algorithm is that it discards the packet dropping mechanism of RED, and calculates packet loss according to a preconfigured fuzzy logic by using the queue length and the buffer usage ratio. Theo- retical analysis and Network Simulator (NS) simulation results show that the proposed algorithm achieves more throughput and more stable queue length than traditional schemes. It really improves a router's ability in network congestion control in IP network.展开更多
In this paper,an algorithm Wireless Multimedia Transmission Control(WMTC) is proposed for multimedia transmission control over wired-wireless networks.The relationship between packet length and packet loss rate in the...In this paper,an algorithm Wireless Multimedia Transmission Control(WMTC) is proposed for multimedia transmission control over wired-wireless networks.The relationship between packet length and packet loss rate in the Gilbert wireless error model is investigated.Furthermore,the algorithm can detect the nature of packet losses by sending large and small packets alternately,and control the sending rate of nodes.In addition,by means of updating factor K,this algorithm can adapt to the changes of network states quickly.Compared with previous algorithms,simulation results show that WMTC can both improve the networks throughput of multimedia transmissions and reduce the congestion loss rate in various situations.展开更多
文摘网际互连协议(Internet Protocol,IP)化技术凭借高带宽和灵活性等优势,为广播电视传输系统带来了新的可能,特别是在广播电视基带架构层,IP化音频(Audio over IP,AoIP)技术可以发挥重要作用,完成从源信号采集到发射的全过程音视频传输任务。基于此,介绍AoIP的相关概念、标准和应用优势,阐述基带架构的组成层次、采集编码和自动化功能,分析其技术特点。在此基础上,详细探讨AoIP技术在基带系统各层面的应用情况,包括AoIP网络部署、音视频流处理、自动化实现和同步方案等,并说明不同应用的效果。
文摘With the development of Ethernet systems and the growing capacity of modem silicon technology, embedded communication networks are playing an increasingly important role in embedded and safety critical systems. Hardware/software co-design is a methodology for solving design problems in processor based embedded systems. In this work, we implemented a new 1-cycle pipeline microprocessor and a fast Ethemet transceiver and established a low cost, high performance embedded network controller, and designed a TCP/IP stack to access the Intemet. We discussed the hardware/software architecture in the forepart, and then the whole system-on-a-chip on Altera Stratix EP1S25F780C6 device. Using the FPGA environment and SmartBit tester, we tested the system＇s throughput. Our simulation results showed that the maximum throughput of Ethemet packets is up to 7 Mbps, that of UDP packets is up to 5.8 Mbps, and that of TCP packets is up to 3.4 Mbps, which showed that this embedded system can easily transmit basic voice and video signals through Ethemet, and that using only one chip can realize that many electronic devices access to the Intemet directly and get high performance.
基金Supported by the National High Technology Research and Development of China (863 Program) (No.2003AA121560)the High Technology Research and Development Program of Jiangsu Province (No.BEG2003001).
文摘Active Queue Management (AQM) is an active research area in the Internet community. Random Early Detection (RED) is a typical AQM algorithm, but it is known that it is difficult to configure its parameters and its average queue length is closely related to the load level. This paper proposes an effective fuzzy congestion control algorithm based on fuzzy logic which uses the pre- dominance of fuzzy logic to deal with uncertain events. The main advantage of this new congestion control algorithm is that it discards the packet dropping mechanism of RED, and calculates packet loss according to a preconfigured fuzzy logic by using the queue length and the buffer usage ratio. Theo- retical analysis and Network Simulator (NS) simulation results show that the proposed algorithm achieves more throughput and more stable queue length than traditional schemes. It really improves a router's ability in network congestion control in IP network.
基金Supported by National Natural Science Foundation of China (No.60972038)the Jiangsu Province Universities Natural Science Research Key Grant Project (07KJA 51006)+1 种基金the Open Research Fund of National Mobile Communications Research Laboratory (N200911)Jiangsu Province Graduate Innovative Research Plan (CX09B_149Z)
文摘In this paper,an algorithm Wireless Multimedia Transmission Control(WMTC) is proposed for multimedia transmission control over wired-wireless networks.The relationship between packet length and packet loss rate in the Gilbert wireless error model is investigated.Furthermore,the algorithm can detect the nature of packet losses by sending large and small packets alternately,and control the sending rate of nodes.In addition,by means of updating factor K,this algorithm can adapt to the changes of network states quickly.Compared with previous algorithms,simulation results show that WMTC can both improve the networks throughput of multimedia transmissions and reduce the congestion loss rate in various situations.
