Optimal timeslot and channel allocation considering fairness for multicell CDMA/TDD systems

The CDMA/TDD system is a highly attractive solution to support the next generation cellular mobile systems which provide unbalanced multimedia services between downlink and uplink. In this paper, we analyze the interference for downlink and uplink timeslots in a multicell CDMA/TDD system. We also mathematically formulate an optimal timeslot and channel allocation problem considering capacity fairness among cells, which is to maximize the system capacity under the given traffic unbalance, and propose an efficient algorithm based on the simulated annealing technique. Extensive experimental results show that the proposed scheme yields a good performance, and fairness among cells improves with a decrease in the system capacity.     

SUPANET中的物理帧时槽交换技术

文中从分析未来“三网合一”的需求和现有基于DWDM交换技术存在的问题出发,提出了用以太网的介质访问控制(MAC)子层的帧格式作为物理帧格式,以最大长度的MAC帧传输时间作为基本时槽的“物理帧时槽交换(PFTS)技术”,并以此作为实现下一代单物理层用户传输平面体系结构(SUPA)的基础。文中提供了实现：PFTS的技术框架,详细地讨论了PFTS交换原理和服务质量保障机制,简要地分析PFTS相对于已有的物理层交换技术的优越性。     

Performance analysis of an adaptive,energy-efficient MAC protocol for wireless sensor networks

We propose an adaptive and energy-efficient TDMA-based MAC protocol that significantly reduces energy consumption in the network, while efficiently handling network traffic load variations and optimizing channel utilization through a timeslot stealing mechanism and a timeslot reassignment procedure. We have analytically derived the average delay performance of our MAC protocol, with and without the timeslot stealing mechanism. Our delay model, validated via simulations, shows that the timeslot stealing mechanism can substantially improve the protocol throughput in scenarios with varying and asymmetric traffic patterns. Evaluation results show that the timeslot reassignment procedure is efficient in handling the longer timescale changes in the traffic load, while the timeslot stealing mechanism is better in handling the shorter timescale changes in the traffic patterns.     

Bandwidth guaranteed call admission in TDMA/CDMA ad hoc wireless networks

This paper first studied the timeslot assignment problem in time division multiple access/code division multiple access (TDMA/CDMA) wireless ad hoc networks. Given a path P, we prove that a timeslot assignment providing one unit of bandwidth on P can be found in O(P) time if such an assignment exists. The results have been extended to the case that P can provide two units of bandwidth. Based on the timeslot assignment for the special cases, an efficient slot assignment algorithm with O(P²k) is proposed for general cases, where k is the number of slots in a TDMA frame. Then, the timeslot assignment algorithm is integrated into a quality of service (QoS) call admission scheme for QoS call requests. Extensive simulations are conducted and the results have demonstrated the superior performance of our method.     

论"单物理层的用户数据传输平面体系结构网络"--SUPANET

文中从未来“三网合一”的需求出发，分析了现有的三层和两层通信子网体系结构存在用户数据传输效率低、难以保障各类数据的服务质量的缺点，提出了从Intemet逐步向单物理层的用户数据传输平面体系结构网络(SUPANET)过渡。重点讨论了SUPANET保证服务质量的相关技术，对其核心技术——“物理帧时槽交换技术”也进行了简要的介绍。     

TD—LTE时隙配置及优化

采用转换点配置法,提出TD—LTE在同半帧及异半帧场景下的特殊时隙配置,能够很好地规避与TD—SCDMA的交叉时隙干扰。首次提出单GP优化法,无论是常规CP还是扩展CP,均尽可能地压缩同半帧和异半帧配置下的GP时隙,有效提高了特殊时隙的利用率,非常有利于解决TD—LTE网络建设中的系统规划和优化问题。     

Differentiating QoS and Un-conflicting Channel-timeslot Allocation Algorithm in WDM

A new effective and reliable channel-timeslot allocation algorithm has been proposed, which is applied in WDM optical networks using fiber as their media to allocate the operational request. This new algorithm can differentiate the priority of all requests and avoid conflict and collision in the process of distributing channel and timeslot for the data waiting for transmission. The method in calculating the best wavelength channel and the best timeslot number is simply given. The algorithm is carried out in a math language. On the basis of the experiment results, the performance and feasibility of the algorithm are analyzed, which prove that the allocation method can reach the requirements of an algorithm both in space complexity and time complexity.     

HFC宽带接入网故障恢复能力的研究

1 引言现代通信正在向宽带化、数字化、智能化、个人化和综合业务化的方向发展.宽带用户接入技术已成为当前通信界的研究热点之一。有线电视网已逐步升级为光纤同轴电缆混合(Hybrid Fiber/Coax,HFC)网络,HFC网具有频带宽和用户覆盖面广等优势,是为家庭用户提供宽带接入的重要手段之一,为宽带信息进入家庭铺平了“最后一公里”。     

NGI／NGN体系结构及其服务质量保障机制研究

本文在深入分析国内外开展的下一代Intemet(NGI)或下一代网络(NGN)相关研究工作的基础上,重点研究了NGI/NGN体系结构及其服务质量保障机制.重点阐述了笔者所在的四川省网络通信技术重点实验室提出的一种潜在的NGI体系结构框架-SUPA(单物理层用户数据传输与交换平台体系结构).研究结果表明,SUPA使得较容易实现从Internet到NGI的平滑过渡,并能够提供更好的服务质量保障.     

基于FPGA的程控数字交换网络设计

数字交换网络在程控数字交换系统中占有重要的地位.其容量的大小、可靠性直接关系到整个系统的交换能力及系统的可靠性.目前在交换局中运行的程控交换设备,其数字交换网络大多采用专用芯片来实现,容量有限,扩展性差,成本较高.介绍一种采用FPGA技术实现的单芯片4K*4K容量的无阻塞交换网络设计,具有容量大、交换能力强、稳定可靠,成本低等优点,大大提升了交换网络的整体性能.