Combining Single (Mixed) Metric Approach and Genetic Algorithm for QoS Routing Problem

A hybrid algorithm for the delay constrained least cost path problem is proposed through combination of single (mixed) metric approach and genetic algorithm. Compared with the known genetic algorithm for the same problem, the new algorithm adopts integral coding scheme and new genetic operator, which reduces the search space and improves the efficiency of genetic operation. Meanwhile, the single (mixed) approach accelerates the convergence speed. Simulation results indicate that the proposed algorithm can find near-optimal even optimal solutions within moderate numbers of generations.

Multiple constraints-based QoS multicast routing: model and algorithms

Constraint-based multicast routing, which aims at identifying a path that satisfies a set of quality of service (QoS) constraints, has became a very important research issue in the areas of networks and distributed systems. In general, multi-constrained path selection with or without optimization is a NP-complete problem that can not be exactly solved in polynomial time. Hence, accurate constraints-based routing algorithms with a fast running time are scarce, perhaps even non-existent. The expected impact of such a constrained-based routing algorithm has resulted in the proposal of numerous heuristics and a few exact QoS algorithms. This paper aims to give a thorough, concise and fair evaluation of the most important multiple constraint-based QoS multicast routing algorithms known today, and it provides a descriptive overview and simulation results of these multi-constrained routing algorithms.

QoS Routing Optimization Strategy Using Genetic Algorithm in Optical Fiber Communication Networks

This paper describes the routing problems in optical fiber networks, definesfive constraints, induces and simplifies the evaluation function and fitness function, and proposesa routing approach based on the genetic algorithm, which includes an operator [OMO] to solve the QoSrouting problem in optical fiber communication networks. The simulation results show that theproposed routing method by using this optimal maintain operator genetic algorithm (OMOGA) issuperior to the common genetic algorithms (CGA). It not only is robust and efficient but alsoconverges quickly and can be carried out simply, that makes it better than other complicated GA.

QoS routing based on mobile agent for LEO satellite IP networks

Current quality of service（QoS） routing schemes for low earth orbit（LEO） satellites IP networks either neglect the varying population density or fail to guarantee end-to-end delay.As a remedy,QoS routing protocol based on mobile agent（QoSRP-MA） is proposed.QoSRP-MA is a source-based routing protocol.Once connection requests arrive,QoS mobile agents are dispatched from ingress satellite to explore routes,which migrate using satellite routing tables.Upon arriving in egress satellite,QoS mobile agents migrate back towards ingress satellite to reserve bandwidth.To construct satellite routing tables,load balancing routing algorithm based on mobile agent（LBRA-MA） is presented.In LBRP-MA,at regular intervals mobile agents launched on all satellites migrate autonomously to evaluate path cost and update routing tables.Moreover,path cost between source and destination is evaluated considering satellite geographical position as well as inter-satellite link（ISL） cost.Furthermore,ISL congestion index is considered to update routing table.Through simulations on a Courier-like constellation,it shows that QoSRP-MA can achieve guaranteed end-to-end delay bound with higher throughput,lower connection failing ratio and signaling overhead compared to high performance satellite routing（HPSR） scheme.

Study on the performance of the A*Prune QoS routing algorithm for intelligent optical networks and its improvements

The A＇Prune quality of service （QoS） routing algorithm was proposed to compute K-shortest paths satisfying multiple QoS constraints, The A＇Prune is considered to be one of the practical routing algorithms for intelligent optical networks because of its flexibility in handling many practical constraints, This article gives detailed performance studies of the algorithm through extensive simulation experiments. We found that both the running time and the memory space requirements of the algorithm are large, especially when the network size increases, in this article, we also propose an approach to improving the performance of the A＇Prune algorithm. The improvements should make the A＇Prune algorithm more attractive for practical use in intelligent optical networks.

A Heuristic Algorithm for QoS Multicast Routing

In recent years, QoS multicast routing has continued to be a very important research topic in the areas of networks. This paper presents a heuristic algorithm for the QoS multicast routing (HAQMR). This heuristic algorithm deals with delay and bandwidth constraints and has low cost. The HAQMR attempts to significantly reduce the overhead for constructing a multicast tree, the proof for correctness of the HAQMR is given, and the performance of the HAQMR is evaluated by simulations. The study shows that HAQMR provides an available approach to QoS multicast routing.

Void Aware Position Based Opportunistic Routing for QoS in Mobile Ad Hoc Networks

The unique anywhere, anytime wireless communication support offers, tremendous potential for the next generation of applications in a Mobile Ad-hoc Network (MANET). The Quality of Service (QoS) has been the ever demanding task of wireless communication to satisfy the application requirements. Geographical routing employs a greedy forwarding technique to deliver the packets to the destination and to owe the communication void, it fails to render the expected level of QoS. Opportunistic routing technique effectively utilizes the advantages of broadcasting nature of the wireless medium and selects a set of forwarding candidates instead of relying on a greedy node. To improve the efficiency of QoS routing in sparse and highly dynamic network topology, this paper proposes the Void-Aware Position based Opportunistic Routing (VAPOR). The VAPOR maintains 2-hop neighbor information to take a routing decision, but it is limited to 1-hop information when the node density is high. It efficiently balances the storage overhead and communication delay due to void and it increases the network throughput even under a sparse network. To provide a certain assurance level for packet reachability, VAPOR decides the potential forwarders based on the forwarding probability that measures link stability, capacity, and connectivity factor. It adaptively favors a path that avoids frequent link failure and unreliable link usage. By limiting the propagation area of duplicate packets, VAPOR reduces wastage of network resources, and ittakes the advantage of concurrent batch forwarding to avoid further duplication and unnecessary delay.

Multicast routing algorithm of multiple QoS based on widest-bandwidth

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

New Ad Hoc QoS Multicast Routing Protocol

The application environments of wireless Ad hoc networks require that it should support Quality of Service (QoS). However, that is very difficult because of the inherent characteristics of the wireless channel and the frequent changes of network topology caused by nodes movement. An Ad hoc QoS Multicasting (AQM) protocol can solve this problem by previously reserving the neighbor nodes for tracking resource availability. By considering QoS restrictions of transport delay, loss ratio, bandwidth requirement, delay jitter, and throughout, and by finding the adaptive routing, the AQM protocol can obviously improve the efficiency of multicastsession. The results of network simulation show that QoS is essentially applicable to Ad hoc networks.

An Algorithm Based on Mobile Agent for Delay Constrained Least Cost Unicast Routing

The delay constrained least cost path problem with imprecise delay information is discussed, and a distributed heuristic algorithm without any assumption of imprecise state information is presented. The algorithm employs mobile agents to search feasible paths in parallel and requires limited network state information kept at each node. The simulations indicate that the presented solution provides better call acceptance probability and better fairness between short paths and long paths. And the algorithm can tolerate high degree of delay imprecision.

Internet QoS: Architectures, Strategies and Mechanisms

As an extensive study of Internet QoS, a framework for emerging Internet QoS strategies is presented. Integrated service (Intserv/RSVP), Differentiated service (Diffserv), MPLS, and QoS routing, are overviewed. The key issues and relationship of these QoS architectures are discussed. Some algorithms in IP QoS implementation and unsolved problems are also studied in this paper. Furthermore, a new strategies of incorporating Intserv with Diffserv to archive end-to-end QoS is proposed. It is also discussed why MPLS and QoS routing are introduced into this framework, how they differ from and relate to other schemes and where they fit into the Diffserv architecture. The timescales of different QoS strategies are also studied and some proposals for QoS routing deployment are given.

Improved ant colony-based multi-constrained QoS energy-saving routing and throughput optimization in wireless Ad-hoc networks

In order to establish a route supporting multi-constrained quality of service（QoS）, increase network throughput and reduce network energy consumption, an improved ant colony-based multi-constrained QoS energy-saving routing algorithm（IAMQER） is proposed. The ant colony algorithm, as one of the available heuristic algorithms, is used to find the optimal route from source node to destination node. The proposed IAMQER algorithm, which is based on the analysis of local node information such as node queue length, node forwarding number of data packets and node residual energy, balances the relationship between the network throughput and the energy consumption, thus improving the performance of network in multi-constrained QoS routing. Simulation results show that this IAMQER algorithm can find the QoS route that reduce average energy consumption and improves network packet delivery ratio under the end-to-end delay and packet loss ratio constraints.

Fuzzy Logic QoS Dynamic Source Routing for Mobile Ad Hoc Networks

Considering the characters of dynamic topology and the imprecise state information in mobile ad hoc network,we propose a Fuzzy Logic QoS Dynamic Source Routing(FLQDSR)algorithm based on Dynamic Source Routing(DSR)protocol while adopting fuzzy logic to select the appropriate QoS routing in multiple paths which are searched in parallel.This scheme considers not only the bandwidth and end-to-end delay of routing,but also the cost of the path.On the otherhand the merit of using fuzzy logic is that it can be implemented by hardware.This makes the realization of the schemeeasier and faster.However our algorithm is based on DSR,the maximal hop count should be less than 10,i.e.,the scaleof mobile ad hoc network should not be very large.Simulation results show that FLQDSR can tolerate a high degree of in-formation imprecision by adding the fuzzy logic module which integrates the QoS requirements of application and the rout-ing QoS parameters to determine the most qualified one in every node.

QoS multicast routing protocol in hierarchical wireless MANET

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.

UMR: A utility-maximizing routing algorithm for delay-sensitive service in LEO satellite networks

This paper develops a routing algorithm for delay-sensitive packet transmission in a low earth orbit multi-hop satellite network consists of micro-satellites. The micro-satellite low earth orbit （MS-LEO） network endures unstable link connection and frequent link congestion due to the uneven user distribution and the link capacity variations. The proposed routing algorithm, referred to as the utility maximizing routing （UMR） algorithm, improve the network utility of the MS-LEO network for carrying flows with strict end-to-end delay bound requirement. In UMR, first, a link state parameter is defined to capture the link reliability on continuing to keep the end-to-end delay into constraint; then, on the basis of this parameter, a routing metric is for- mulated and a routing scheme is designed for balancing the reliability in delay bound guarantee among paths and building a path maximizing the network utility expectation. While the UMR algo- rithm has many advantages, it may result in a higher blocking rate of new calls. This phenomenon is discussed and a weight factor is introduced into UMR to provide a flexible performance option for network operator. A set of simulations are conducted to verify the good performance of UMR, in terms of balancing the traffic distribution on inter-satellite links, reducing the flow interruption rate, and improving the network utility.

ASAR: An ant-based service-aware routing algorithm for multimedia sensor networks

Aimed at three basic services(event-driven,data query and stream query),the paper presents a QoS routing model for multimedia sensor networks.Moreover,based on the traditional ant-based algorithm,we propose an ant-based service-aware routing(ASAR)algorithm.The ASAR chooses suitable paths to meet diverse QoS requirements from different kinds of services,thus maximizing network utilization and improving network performance.Finally,extensive simulation is conducted to verify the effectiveness of our solution and we give a detailed discussion on the effects of different system parameters.Compared to the typical routing algorithm in sensor networks and the traditional ant-based algorithm,our ASAR algorithm has better convergence and significantly provides better QoS for multiple types of services in the multimedia sensor networks.

A Heuristic Algorithm for Core Selection in Multicast Routing

With the development of network multimedia technology, more and more real-time multimedia applications need to transmit information using multicast. The basis of multicast data transmission is to construct a multicast tree. The main problem concerning the construction of a shared multicast tree is selection of a root of the shared tree or the core point. In this paper, we propose a heuristic algorithm for core selection in multicast routing. The proposed algorithm selects core point by considering both delay and inter-destination delay variation. The simulation results show that the proposed algorithm performs better than the existing algorithms in terms of delay variation subject to the end-to-end delay bound. The mathematical time complexity and the execution time of the proposed algorithm are comparable to those of the existing algorithms.