A new core-based shared tree algorithm, viz core-cluster combination-based shared tree （CCST） algorithm and the weighted version （i.e. w-CCST algorithm） are proposed in order to resolve the channel resources waste...A new core-based shared tree algorithm, viz core-cluster combination-based shared tree （CCST） algorithm and the weighted version （i.e. w-CCST algorithm） are proposed in order to resolve the channel resources waste problem in typical source-based multicast routing algorithms in low earth orbit （LEO） satellite IP networks. The CCST algorithm includes the dynamic approximate center （DAC） core selection method and the core-cluster combination multicast route construction scheme. Without complicated onboard computation, the DAC method is uniquely developed for highly dynamic networks of periodical and regular movement. The core-cluster combination method takes core node as the initial core-cluster, and expands it stepwise to construct an entire multicast tree at the lowest tree cost by a shortest path scheme between the newly-generated core-cluster and surplus group members, which results in great bandwidth utilization. Moreover, the w-CCST algorithm is able to strike a balance between performance of tree cost and that of end-to-end propagation delay by adjusting the weighted factor to meet strict end-to-end delay requirements of some real-time multicast services at the expense of a slight increase in tree cost. Finally, performance comparison is conducted between the proposed algorithms and typical algorithms in LEO satellite IP networks. Simulation results show that the CCST algorithm significantly decreases the average tree cost against to the others, and also the average end-to-end propagation delay ofw-CCST algorithm is lower than that of the CCST algorithm.展开更多
随着通信技术的不断发展,基于IP的Gb数据传输(简称Gb over IP)成为GSM-R网络的研究焦点。重点围绕GSM-R系统中BSC/PCU设备以Gb over IP方式接入核心网的方案开展研究,针对BSC/PCU与核心网设备异地设置时,BSC侧无法感知跨传输系统后链路...随着通信技术的不断发展,基于IP的Gb数据传输(简称Gb over IP)成为GSM-R网络的研究焦点。重点围绕GSM-R系统中BSC/PCU设备以Gb over IP方式接入核心网的方案开展研究,针对BSC/PCU与核心网设备异地设置时,BSC侧无法感知跨传输系统后链路中断,导致保护倒换机制未触发引起业务中断的问题,提出3种解决方案,并进行方案比选与优化,为GSM-R系统BSC/PCU设备以Gb over IP方式对接核心网方案提供操作指导及优化建议,以满足铁路移动通信系统多场景下的组网需求。展开更多
基金National Natural Science Foundation of China （60532030, 10577005, 60625102） Innovation Foundation of Aerospace Science and Technology of China
文摘A new core-based shared tree algorithm, viz core-cluster combination-based shared tree （CCST） algorithm and the weighted version （i.e. w-CCST algorithm） are proposed in order to resolve the channel resources waste problem in typical source-based multicast routing algorithms in low earth orbit （LEO） satellite IP networks. The CCST algorithm includes the dynamic approximate center （DAC） core selection method and the core-cluster combination multicast route construction scheme. Without complicated onboard computation, the DAC method is uniquely developed for highly dynamic networks of periodical and regular movement. The core-cluster combination method takes core node as the initial core-cluster, and expands it stepwise to construct an entire multicast tree at the lowest tree cost by a shortest path scheme between the newly-generated core-cluster and surplus group members, which results in great bandwidth utilization. Moreover, the w-CCST algorithm is able to strike a balance between performance of tree cost and that of end-to-end propagation delay by adjusting the weighted factor to meet strict end-to-end delay requirements of some real-time multicast services at the expense of a slight increase in tree cost. Finally, performance comparison is conducted between the proposed algorithms and typical algorithms in LEO satellite IP networks. Simulation results show that the CCST algorithm significantly decreases the average tree cost against to the others, and also the average end-to-end propagation delay ofw-CCST algorithm is lower than that of the CCST algorithm.
文摘随着通信技术的不断发展,基于IP的Gb数据传输(简称Gb over IP)成为GSM-R网络的研究焦点。重点围绕GSM-R系统中BSC/PCU设备以Gb over IP方式接入核心网的方案开展研究,针对BSC/PCU与核心网设备异地设置时,BSC侧无法感知跨传输系统后链路中断,导致保护倒换机制未触发引起业务中断的问题,提出3种解决方案,并进行方案比选与优化,为GSM-R系统BSC/PCU设备以Gb over IP方式对接核心网方案提供操作指导及优化建议,以满足铁路移动通信系统多场景下的组网需求。
