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Multiple QoS modeling and algorithm in computational grid

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Journal of Systems Engineering and Electronics 2007年第2期18卷 412-417页

作者： li Chunlin Feng Meilai li layuan Dept. of Computer Science Wuhan Univ. of Technology Wuhan 430063 P. R. China

Multiple QoS modeling and algorithm in grid system is considered. Grid QoS requirements can be formulated as a utility function for each task as a weighted sum of its each dimensional QoS utility functions. Multiple QoS constraint resource scheduling optimization in computational grid is distributed to two subproblems： optimization of grid user and grid resource provider. Grid QoS scheduling can be achieved by solving sub problems via an iterative algorithm.

关键词： QoS modeling Computational grid Scheduling algorithm.

QoS-aware multicast routing protocol for Ad hoc networks

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Journal of Systems Engineering and Electronics 2006年第2期17卷 417-422页

作者： Sun Baolin li layuan School of Computer Science and Technology Wuhan Univ. of Technology Wuhan 430063. P. R. China Dept. of Mathematics and Physics Wuhan Univ. of Science and Engineering Wuhan 430073. P. R. China

Ad hoe wireless networks consist of mobile nodes interconnected by multihop communication paths. Unlike conventional wireless networks, ad hoc networks have no fixed network infrastructure or administrative support. Due to bandwidth constraint and dynamic topology of mobile ad hoc networks, supporting Quality of Service （QoS） is an inherently complex, difficult issue and very important research issue. MAODV （Multicast Ad hoc Ondemand Distance Vector） routing protocol provides fast and efficient route establishment between mobile nodes that need to communicate with each other. MAODV has minimal control overhead and route acquisition latency. In addition to unicast routing, MAODV supports multicast and broadcast as well. The multicast routing problem with multiple QoS constraints, which may deal with the delay, bandwidth and packet loss measurements is discussed, and a network model for researching the ad hoc network QoS multicast routing problem is described. It presents a complete solution for QoS multicast routing based on an extension of the MAODV routing protocol that deals with delay, bandwidth and packet loss mesurements. The solution is based on lower layer specifics. Simulation results show that, with the proposed QoS multicast routing protocol, end-to-end delay, bandwidth and packet loss on a route can be improved in most of cases. It is an available approach to multicast routing decision with multiple QoS constraints.

关键词： multieast routing routing protocol QoS AODV MAODV.

Distributed QoS multicast routing protocol in ad hoc networks

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Journal of Systems Engineering and Electronics 2006年第3期17卷 692-698页

作者： Sun Baolin li layuan School of Computer Science and Technology Wuhan Univ. of Technology Wuhan 430063 P. R. China Dept. of Mathematics and Physics Wuhan Univ. of Science and Engineering Wuhan 430073 P. R. China

Quality of service （QoS） routing and multicasting protocols in ad hoc networks are face with the challenge of delivering data to destinations through multihop routes in the presence of node movements and topology changes. The multicast routing problem with multiple QoS constraints is discussed, which may deal with the delay, bandwidth and cost metrics, and describes a network model for researching the ad hoc networks QoS multicast routing problem. It presents a distributed QoS multicast routing protocol （DQMRP）. The proof of correctness and complenty analysis of the DQMRP are also given. Simulation results show that the multicast tree optimized by DQMRP is better than other protocols and is fitter for the network situations with frequently changed status and the realtime multimedia application. It is an available approach to multicast routing decision with multiple QoS constraints.

关键词： ad hoc network multicast routing routing protocol QoS.

Distributed QoS multicast routing in networks with imprecise state information

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Journal of Systems Engineering and Electronics 2005年第4期16卷 866-874页

作者： Yan Xin li layuan Dept. of Computer Science Wuhan Univ. of Technology Wuhan 430063 P.R. China

The goal of quality-of-service （QoS） multicast routing is to establish a multicast tree which satisfies certain constraints on bandwidth, delay and other metrics. The network state information maintained at every node is often im- precise in a dynamic environment because of non-negligible propagation delay of state messages, periodic updates due to overhead concern, and hierarchical state aggregation. The existing QoS multicast routing algorithms do not provide satisfactory performance with imprecise state information. We propose a distributed QoS multicast routing scheme based on traffic lights, called QMRI algorithm, which can probe multiple feasible tree branches, and select the optimal or near-optimal branch through the UR or TL mode for constructing a multicast tree with QoS guarantees if it exists. The scheme is designed to work with imprecise state information. The proposed algorithm considers not only the QoS requirements but also the cost optimality of the multicast tree. The correctness proof and the complexity analysis about the QMRI algorithm are also given. In addition, we develop NS2 so that it is able to simulate the imprecise network state information. Extensive simulations show that our algorithm achieves high call-admission ratio and low-cost multicast trees with modest message overhead.

关键词： quality-of-service muting multicast imprecise state traffic lights simulation.

Reliable adaptive multicast protocol in wireless Ad hoc networks

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Journal of Systems Engineering and Electronics 2006年第1期17卷 187-192页

作者： Sun Baolin li layuan School of Computer Science and Technology Wuhan Univ. of Technology Wuhan 430063 P. R. China Dept. of Mathematics and Physics Wuhan Inst. of Science and Technology Wuhan 430073 P. R. China

In wireless ad hoe network environments, every link is wireless and every node is mobile. Those features make data lost easily as well as multicasting inefficient and unreliable. Moreover, Efficient and reliable multicast in wireless ad hoe network is a difficult issue. It is a major challenge to transmission delays and packet losses due to link changes of a multicast tree at the provision of high delivery ratio for each packet transmission in wireless ad hoe network environment. In this paler, we propose and evaluate Reliable Adaptive Multicast Protocol （RAMP） based on a relay node concept. Relay nodes are placed along the multieast tree. Data recovery is done between relay nodes. RAMP supports a reliable multicasting suitable for mobile ad hoe network by reducing the number of packet retransmissions. We compare RAMP with SRM （Scalable Reliable Multicast）. Simulation results show that the RAMP has high delivery ratio and low end-to-end delay for packet transmsission.

关键词： muhicast multicast protocol reliable muhicast wireless ad hoc networks.

Self Fault-Tolerance of Protocols: A Case Study

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Journal of Systems Engineering and Electronics 2000年第3期11卷 28-34页

作者： li, layuan li, Chunlin Dept. of Computer Science & Technology Wuhan Transportation University 430063 P. R. China

The prerequisite for the existing protocols' correctness is that protocols can be normally operated under the normal conditions, rather than dealing with abnormal conditions. In other words, protocols with the fault-tolerance can not be provided when some fault occurs. This paper discusses the self fault-tolerance of protocols. It describes some concepts and methods for achieving self fault-tolerance of protocols. Meanwhile, it provides a case study, investigates a typical protocol that does not satisfy the self fault-tolerance, and gives a new redesign version of this existing protocol using the proposed approach.

关键词： Protocols Self fault-tolerance Formal method Multimedia communications Protocol engineering.

QoS multicast routing protocol in hierarchical wireless MANET

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Science in China(Series F) 2008年第2期51卷 196-212页

作者： li layuan li Chunlin Department of Computer Science Wuhan University of Technology Wuhan 430063 China

A wireless MANET is a self-configurable network in which mobile, battery-powered devices dynamically create and change the network topology without relying on any intrastructure or administrative support. It offers unique benefits for certain environments, but there are still several open issues to be resolved before realizing these benefits, including QoS routing, multicasting, and mobility management. Specifically, an efficient QoS multicast routing protocol is needed, This paper presents a hierarchical QoS multicast routing protocol （QMRP） for mobile ad hoc networks. It can provide QoS-sensitive routes in a scalable and flexible way, in the network environment with mobility. In the proposed QMRP scheme, each local node only needs to maintain local multicast routing information and/or summary information of other clusters （or domains） but does not require any global ad hoc network states to be maintained. The QMRP also allows any ad hoc group member to join/leave the multicast group dynamically and supports multiple QoS constraints. This paper presents formal description and main procedures for realizing routing decision process of the QMRP and the proof of correctness and complexity analysis of the protocol. The performance measures of QMRP are evaluated using simulation. The simulation results verify the efficiency and availability of QMRP.

关键词： wireless ad hoc networks QoS routing multicast hierarchical routing mobile wireless networks

Multicast routing algorithm of multiple QoS based on widest-bandwidth

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Journal of Systems Engineering and Electronics 2006年第3期17卷 642-647页

作者： Chen Niansheng li layuan Dong Wushi School of Computer Science Wuhan Univ. of TechnlogyWuhan 430063 R. R. China Dept. of Computer Science Hubei Normal Univ. Wuhan 435002 P. R. China

A multicast routing algorithm of multiple QoS constraints based on widest-bandwidth （MRQW） which takes available bandwidth as the prime metric, considering the constraints of the surplus energy of the node, delay and delay jitter, is presented. The process of routing based on MRQW is provided for as well. Correctness proof and the complexity analysis of the MRQW are also given in the paper. Simulation results show that the MRQW has a good performance in creating multicast trees. It not only satisfys multiple QoS constraints but also makes multicast links have larger available bandwidth

关键词： computer network Ad hoc networks, QoS multicast routing, available bandwidth.

Authenticating QoS-Guaranteed Multicast Route Discovery for Ad hoc Networks

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China Communications 2007年第1期4卷 48-55页

作者： Mingxi, Yang layuan, li Yiwei, Fang Wuhan Univ Technol Sch Comp Sci & Tech Wuhan 430070 Peoples R China Huazhong Univ Sci & Technol Dept Elect & Inf Eng Wuhan 430074 Peoples R China

This paper presents SEQMRAN,a novel secure efficient QoS multicast route discovery protocol for mobile ad hoc *** protocol relies entirely on one-time signature mechanism,HORSEI,with very efficient signing and verifying,and we do this by improving the HORSE protocol through the introduction of intermediate hash *** main purpose of SEQMRAN is to provide source authentication for QoS multicast routing discovery messages in MANET by constructing multicast tree with QoS and authentication constrains in mobile ad hoc *** performance measure of SEQMRAN is evaluated using network simulator *** results represent that SEQMRAN produces less end-to -end packet latency than RSA public key encryption based secure routing scheme,and it is a feasible approach to securing multicast routing with multiple QoS constrains for mobile ad hoc networks.

关键词： ad hoc maodv QoS security route