时间依赖的混合型网络的分布式路由协议

提出了时间依赖的混合型网络模型(HTDN 模型),有效地描述了网络中链路权值随时间变化的特性,并且网络中的节点可以采用不同的等待策略;并给出了 HTDN 模型的路径优化理论。在此基础上设计了有效的分布式路由协议 DMDRP,能计算出 HTDN 模型中所有节点对之间的最短延时路径,并证明了协议的正确性。最后通过仿真试验,给出了 DMDRP 协议与传统路由方案的性能对比分析。     

A New Enhanced Fast Handover Algorithm in Hierarchical Mobile IPv6 Network

1　Introduction　MobileIPv6requirestheMobileNode (MN)toregisterwiththeHomeAgent (HA)andtheCorre spondentNode (CN)whenitchangesitspointofattachmentintheInternet[1～ 3] .Therefore ,thiscauseMobileIPv6toincurlongdelayintheregis tration process,andaddsignalingtraffictothebackbonenetworkespeciallywhentheHAandCNarefarawayfromtheMN .Inordertominimizethisdelay ,andthesignalingoverhead presentinMobileIPv6,literatures[4～7] proposeHierarchicalMobileIPv6(HMIPv6)architectureandafasthan dover…     

Layout Driven Selection and Chaining of Partial Scan Flip-Flops

In an era of sub-micron technology, routing is becoming a dominant factor in area, timing, and power consumption. In this paper, we study the problem of selection and chaining of scan flip-flops with the objective of achieving minimum routing area overhead. Most of previous work on partial scan has put emphasis on selecting as few scan flip-flops as possible to break all cycles in S-graph. However, the flip-flops that break more cycles are often the ones that have more fanins and fanouts. The area adjacent to these nodes is often crowded in layout. Such selections will cause layout congestion and increase the number of tracks to chain the scan flip-flops. To take layout information into consideration, we propose a matching-based algorithm to solve the problem. First, an initial placement will be performed before scan flip-flops are selected. Then, iteratively, a matching-based algorithm taking the current layout into account is proposed to select and chain the scan flip-flops. Experimental results show that, on the average, our algorithm can reduce 8.1% area overhead as compared with the previously proposed methods that do not utilize the layout information in flip-flop selection.     

Robust position-based routing for wireless ad hoc networks

We consider a wireless ad hoc network composed of a set of wireless nodes distributed in a two dimensional plane. Several routing protocols based on the positions of the mobile hosts have been proposed in the literature. A typical assumption in these protocols is that all wireless nodes have uniform transmission regions modeled by unit disk centered at each wireless node. However, all these protocols are likely to fail if the transmission ranges of the mobile hosts vary due to natural or man-made obstacles or weather conditions. These protocols may fail because either some connections that are used by routing protocols do not exist, which effectively results in disconnecting the network, or the use of some connections causes livelocks. In this paper, we describe a robust routing protocol that tolerates up to roughly 40% of variation in the transmission ranges of the mobile hosts. More precisely, our protocol guarantees message delivery in a connected ad hoc network whenever the ratio of the maximum transmission range to the minimum transmission range is at most .     

稀疏波长变换网络性能分析与研究

文章对动态业务模型下的稀疏波长变换网络性能进行了分析与研究，对波分复用（WDM）网络中引入波长变换器后的网络性能进行了系统的仿真，分析了波长变换器数量、波长变换器位置、波长变换范围以及路由波长算法等因素对网络性能的影响。     

Survivable routing in IP-over-WDM networks: An efficient and scalable local search algorithm

In IP-over-WDM networks, a logical IP network is routed on top of a physical optical fiber network. An important challenge here is to make the routing survivable. We call a routing survivable if the connectivity of the logical network is guaranteed in the case of a failure in the physical network. In this paper we describe FastSurv, a local search algorithm for survivable routing. The algorithm works in an iterative manner: after each iteration it learns more about the structure of the logical graph and in the next iteration it uses this information to improve its solution. The algorithm can take link capacity constraints into account and can be extended to deal with multiple simultaneous link failures and node failures. In a large series of tests we compare FastSurv with current state-of-the-art algorithms for this problem. We show that it can provide better solutions in much shorter time, and that it is more scalable with respect to the number of nodes, both in terms of solution quality and run time.     

A Large 16*16 IF Analog Switch Matrix for Personal Communications Satellites

A 16 input and 16 output channels single chip intermediate frequency range (160 MHz) analog switch matrix for personal communication satellites has been designed and processed by using a commercial 1.2 µm BiCMOS technology. The circuit has low power consumption (,2W) and low insertion loss with maximum output power of 0 dBm.     

Dynamic group multicast routing with bandwidth reservations

Multicasting refers to the transmission of data from a source node to multiple destination nodes in a network. Group multicasting is a generalization of multicasting whereby every member of a group is allowed to multicast messages to other members that belong to the same group. The routing problem in this case involves the construction of a set of low cost multicast trees with bandwidth requirements, one for each member of the group for multicasting messages to other members of the group. In this paper, we examine this routing problem with an additional requirement that member nodes are allowed to join and leave the multicasting group anytime during a session. We call this problem, the dynamic group multicast routing problem (DGMRP). In this paper, we proposed three heuristic algorithms to generate a set of low cost multicast trees with dynamic group membership. Results from our empirical study shows that the one of the proposed algorithms, called Maximum bandwidth bottleneck path selection algorithm (MBBPS), achieves better utilization of bandwidth resources as compared with the other two algorithms which are based on a greedy approach. In addition MBBPS performs better in terms of cost when the bandwidth is not sufficient in the network. Copyright © 2002 John Wiley & Sons, Ltd.     

Structure-reversibility and departure functions of queueing networks with batch movements and state dependent routing

We consider characterizations of departure functions in Markovian queueing networks with batch movements and state-dependent routing in discrete-time and in continuous-time. For this purpose, the notion of structure-reversibility is introduced, which means that the time-reversed dynamics of a queueing network corresponds with the same type of queueing network. The notion is useful to derive a traffic equation. We also introduce a multi-source model, which means that there are different types of outside sources, to capture a wider range of applications. Characterizations of the departure functions are obtained for any routing mechanism of customers satisfying a recurrent condition. These results give a unified view to queueing network models with linear traffic equations. Furthermore, they enable us to consider new examples as well as show limited usages of this kind of queueing networks. This revised version was published online in June 2006 with corrections to the Cover Date.     

CLOS网络型大规模ATM交换结构

首先提出了大规模ＡＴＭ交换网络应满足的基本特性，然后对Ｃｌｏｓ网络型大规模ＡＴＭ交换网络进行了研究，给出了交换网络连接级呼叫的无阻塞条件，论述和分析了一种适合于以信元为单位的分散式路由选择算法。