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Author : Ding Li
Publisher :
ISBN 13 :
Total Pages : 139 pages
Book Rating : 4.:/5 (117 download)
Download or read book Localised routing algorithms with quality of service constraints written by Ding Li and published by . This book was released on 2010 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Ding Li
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (757 download)
Download or read book Localised Routing Algorithms with Quality of Service Constraints. Development and Performance Evaluation by Simulation of New Localised Quality of Service Routing Algorithms for Communication Networks Using Residual Bandwidth and Mean End-to-end Delay as written by Ding Li and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Localised QoS routing is a relatively new, alternative and viable approach to solve the problems of traditional QoS routing algorithms which use global state information resulting in the imposition of a large communication overhead and route flapping. They make use of a localised view of the network QoS state in source nodes to select paths and route flows to destination nodes. Proportional Sticky Routing (PSR) and Credit Based Routing (CBR) have been proposed as localised QoS routing schemes and these can offer comparable performances. However, since network state information for a specific path is only updated when the path is used, PSR and CBR operate with decision criteria that are often stale for paths that are used infrequently. The aim of this thesis is to focus on localised QoS routing and contribute to enhancing the scalability of QoS routing algorithms. In this thesis we have developed three new localised QoS routing schemes which are called Score Based QoS Routing (SBR), Bandwidth Based QoS Routing (BBR) and Delay Based Routing (DBR). In some of these schemes, the path setup procedure is distributed and uses the current network state to make decisions thus avoiding problems of staleness. The methods also avoid any complicated calculations. Both SBR and BBR use bandwidth as the QoS metric and mean delay is used as the QoS metric in DBR. Extensive simulations are applied to compare the performance of our proposed algorithms with CBR and the global Dijkstra?s algorithm for different update intervals of link state, different network topologies and using different flow arrival distributions under a wide range of traffic loads. It is demonstrated by simulation that the three proposed algorithms offer a superior performance under comparable conditions to the other localised and global algorithms.
Author : Ahmed S. Alzahrani
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (89 download)
Download or read book Localized Quality of Service Routing Algorithms for Communication Networks written by Ahmed S. Alzahrani and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Quality of Service (QoS) routing considered as one of the major components of the QoS framework in communication networks. The concept of QoS routing has emerged from the fact that routers direct traffic from source to destination, depending on data types, network constraints and requirements to achieve network performance efficiency. It has been introduced to administer, monitor and improve the performance of computer networks. Many QoS routing algorithms are used to maximize network performance by balancing traffic distributed over multiple paths. Its major components include bandwidth, delay, jitter, cost, and loss probability in order to measure the end users' requirements, optimize network resource usage and balance traffic load. The majority of existing QoS algorithms require the maintenance of the global network state information and use it to make routing decisions. The global QoS network state needs to be exchanged periodically among routers since the efficiency of a routing algorithm depends on the accuracy of link-state information. However, most of QoS routing algorithms suffer from scalability problems, because of the high communication overhead and the high computation effort associated with marinating and distributing the global state information to each node in the network. The goal of this thesis is to contribute to enhancing the scalability of QoS routing algorithms. Motivated by this, the thesis is focused on localized QoS routing that is proposed to achieve QoS guarantees and overcome the problems of using global network state information such as high communication overhead caused by frequent state information updates, inaccuracy of link-state information for large QoS state update intervals and the route oscillating due to the view of state information. Using such an approach, the source node makes its own routing decisions based on the information that is local to each node in the path. Localized QoS routing does not need the global network state to be exchanged among network nodes because it infers the network state and avoids all the problems associated with it, like high communication and processing overheads and oscillating behaviour. In localized QoS routing each source node is required to first determine a set of candidate paths to each possible destination. In this thesis we have developed localized QoS routing algorithms that select a path based on its quality to satisfy the connection requirements. In the first part of the thesis a localized routing algorithm has been developed that relies on the average residual bandwidth that each path can support to make routing decisions. In the second part of the thesis, we have developed a localized delay-based QoS routing (DBR) algorithm which relies on a delay constraint that each path satisfies to make routing decisions. We also modify credit-based routing (CBR) so that this uses delay instead of bandwidth. Finally, we have developed a localized QoS routing algorithm for routing in two levels of a hierarchal network and this relies on residual bandwidth to make routing decisions in a hierarchical network like the internet. We have compared the performance of the proposed localized routing algorithms with other localized and global QoS routing algorithms under different ranges of workloads, system parameters and network topologies. Simulation results have indicated that the proposed algorithms indeed outperform algorithms that use the basics of schemes that currently operate on the internet, even for a small update interval of link state. The proposed algorithms have also reduced the routing overhead significantly and utilize network resources efficiently.
Author : Fahd M. Aldosari
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (798 download)
Download or read book New Quality of Service Routing Algorithms Based on Local State Information written by Fahd M. Aldosari and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The exponential growth of Internet applications has created new challenges for the control and administration of large-scale networks, which consist of heterogeneous elements under dynamically changing traffic conditions. These emerging applications need guaranteed service levels, beyond those supported by best-effort networks, to deliver the intended services to the end user. Several models have been proposed for a Quality of Service (QoS) framework that can provide the means to transport these services. It is desirable to find efficient routing strategies that can meet the strict routing requirements of these applications. QoS routing is considered as one of the major components of the QoS framework in communication networks. In QoS routing, paths are selected based upon the knowledge of resource availability at network nodes and the QoS requirements of traffic. Several QoS routing schemes have been proposed that differ in the way they gather information about the network state and the way they select paths based on this information. The biggest downside of current QoS routing schemes is the frequent maintenance and distribution of global state information across the network, which imposes huge communication and processing overheads. Consequently, scalability is a major issue in designing efficient QoS routing algorithms, due to the high costs of the associated overheads. Moreover, inaccuracy and staleness of global state information is another problem that is caused by relatively long update intervals, which can significantly deteriorate routing performance. Localized QoS routing, where source nodes take routing decisions based solely on statistics collected locally, was proposed relatively recently as a viable alternative to global QoS routing. It has shown promising results in achieving good routing performance, while at the same time eliminating many scalability related problems. In localized QoS routing each source-destination pair needs to determine a set of candidate paths from which a path will be selected to route incoming flows. The goal of this thesis is to enhance the scalability of QoS routing by investigating and developing new models and algorithms based on the localized QoS routing approach. For this thesis, we have extensively studied the localized QoS routing approach and demonstrated that it can achieve a higher routing performance with lower overheads than global QoS routing schemes. Existing localized routing algorithms, Proportional Sticky Routing (PSR) and Credit-Based Routing (CBR), use the blocking probability of candidate paths as the criterion for selecting routing paths based on either flow proportions or a crediting mechanism, respectively. Routing based on the blocking probability of candidate paths may not always reflect the most accurate state of the network. This has motivated the search for alternative localized routing algorithms and to this end we have made the following contributions. First, three localized bandwidth-constrained QoS routing algorithms have been proposed, two are based on a source routing strategy and the third is based on a distributed routing strategy. All algorithms utilize the quality of links rather than the quality of paths in order to make routing decisions. Second, a dynamic precautionary mechanism was used with the proposed algorithms to prevent candidate paths from reaching critical quality levels. Third, a localized delay-constrained QoS routing algorithm was proposed to provide routing with an end-to-end delay guarantee. We compared the performance of the proposed localized QoS routing algorithms with other localized and global QoS routing algorithms under different network topologies and different traffic conditions. Simulation results show that the proposed algorithms outperform the other algorithms in terms of routing performance, resource balancing and have superior computational complexity and scalability features.
Author : Abdulbaset H. T. Mohammad
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (879 download)
Download or read book Localised Routing Algorithms in Communication Networks with Quality of Service Constraints written by Abdulbaset H. T. Mohammad and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Quality of Service (QoS) is a profound concept which is gaining increasing attention in the Internet industry. Best-effort applications are now no longer acceptable in certain situations needing high bandwidth provisioning, low loss and streaming of multimedia applications. New emerging multimedia applications are requiring new levels of quality of services beyond those supported by best-effort networks. Quality of service routing is an essential part in any QoS architecture in communication networks. QoS routing aims to select a path among the many possible choices that has sufficient resources to accommodate the QoS requirements. QoS routing can significantly improve the network performance due to its awareness of the network QoS state. Most QoS routing algorithms require maintenance of the global network's state information to make routing decisions. Global state information needs to be periodically exchanged among routers since the efficiency of a routing algorithm depends on link-state information accuracy. However, most QoS routing algorithms suffer from scalability due to the high communication overhead and the high computation effort associated with maintaining accurate link state information and distributing global state information to each node in the network. The ultimate goal of this thesis is to contribute towards enhancing the scalability of QoS routing algorithms. Towards this goal, the thesis is focused on Localised QoS routing algorithms proposed to overcome the problems of using global network state information. Using such an approach, the source node makes routing decisions based on the local state information for each node in the path. Localised QoS routing algorithms avoid the problems associated in the global network state, like high communication and processing overheads. In Localised QoS routing algorithms each source node maintains a predetermined set of candidate paths for each destination and avoids the problems associated with the maintenance of a global network state by using locally collected flow statistics and flow blocking probabilities.
Author : Turki A. Alghamdi
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (89 download)
Download or read book Novel Localised Quality of Service Routing Algorithms written by Turki A. Alghamdi and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The growing demand on the variety of internet applications requires management of large scale networks by efficient Quality of Service (QoS) routing, which considerably contributes to the QoS architecture. The biggest contemporary drawback in the maintenance and distribution of the global state is the increase in communication overheads. Unbalancing in the network, due to the frequent use of the links assigned to the shortest path retaining most of the network loads is regarded as a major problem for best effort service. Localised QoS routing, where the source nodes use statistics collected locally, is already described in contemporary sources as more advantageous. Scalability, however, is still one of the main concerns of existing localised QoS routing algorithms. The main aim of this thesis is to present and validate new localised algorithms in order to develop the scalability of QoS routing. Existing localised routing, Credit Based Routing (CBR) and Proportional Sticky Routing (PSR), use the blocking probability as a factor in selecting the routing paths and work with either credit or flow proportion respectively, which makes impossible having up-to-date information. Therefore our proposed Highest Minimum Bandwidth (HMB) and Highest Average Bottleneck Bandwidth History (HABBH) algorithms utilise bandwidth as the direct QoS criterion to select routing paths. We introduce an Integrated Delay Based Routing and Admission Control mechanism. Using this technique Minimum Total Delay (MTD), Low Fraction Failure (LFF) and Low Path Failure (LPF) were compared against the global QoS routing scheme, Dijkstra, and localised High Path Credit (HPC) scheme and showed superior performance. The simulation with the non-uniformly distributed traffic reduced blocking probability of the proposed algorithms. Therefore, we advocate the algorithms presented in the thesis, as a scalable approach to control large networks. We strongly suggest that bandwidth and mean delay are feasible QoS constraints to select optimal paths by locally collected information. We have demonstrated that a few good candidate paths can be selected to balance the load in the network and minimise communication overhead by applying the disjoint paths method, recalculation of candidate paths set and dynamic paths selection method. Thus, localised QoS routing can be used as a load balancing tool in order to improve the network resource utilization. A delay and bandwidth combination is one of the future prospects of our work, and the positive results presented in the thesis suggest that further development of a distributed approach in candidate paths selection may enhance the proposed localised algorithms.
Author : Elmabrook B. M. Mustafa
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (89 download)
Download or read book Some New Localized Quality of Service Models and Algorithms for Communication Networks written by Elmabrook B. M. Mustafa and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Quality of Service (QoS) routing approach is gaining an increasing interest in the Internet community due to the new emerging Internet applications such as real-time multimedia applications. These applications require better levels of quality of services than those supported by best effort networks. Therefore providing such services is crucial to many real time and multimedia applications which have strict quality of service requirements regarding bandwidth and timeliness of delivery. QoS routing is a major component in any QoS architecture and thus has been studied extensively in the literature. Scalability is considered one of the major issues in designing efficient QoS routing algorithms due to the high cost of QoS routing both in terms of computational effort and communication overhead. Localized quality of service routing is a promising approach to overcome the scalability problem of the conventional quality of service routing approach. The localized quality of service approach eliminates the communication overhead because it does not need the global network state information. The main aim of this thesis is to contribute towards the localised routing area by proposing and developing some new models and algorithms. Toward this goal we make the following major contributions. First, a scalable and efficient QoS routing algorithm based on a localised approach to QoS routing has been developed and evaluated. Second, we have developed a path selection technique that can be used with existing localized QoS routing algorithms to enhance their scalability and performance. Third, a scalable and efficient hierarchical QoS routing algorithm based on a localised approach to QoS routing has been developed and evaluated.
Author : Carnegie Mellon University. Computer Science Department
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (14 download)
Download or read book Quality-of-service Routing in Integrated Services Networks written by Carnegie Mellon University. Computer Science Department and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "Future integrated services networks will support multiple classes of service to meet the diverse quality-of-service (QoS) requirements of applications. To meet these end-to-end QoS requirements, strict resource constraints may have to be imposed on the paths being used. QoS routing refers to a set of protocols and algorithms that can select paths that satisfy such constraints while achieving high network throughput. QoS routing is challenging because (1) different service classes employ different resource sharing models, (2) service classes dynamically share link resources, and (3) selecting paths that meet multiple QoS constraints is a complex algorithmic problem. This dissertation shows QoS routing in integrated services networks is both desirable and feasible. To support this claim, this dissertation develops an integrated QoS routing framework that has two components. The first component consists of routing algorithms for individual service classes that support either bandwidth guarantees, delay guarantees, or high throughput. By exploiting the relationship between QoS constraints, we develop polynomial routing algorithms for traffic classes that require stringent end-to-end performance guarantees. By coupling routing with finer-time scale resource management mechanisms such as congestion control and scheduling, we develop routing algorithms that achieve high throughput for best-effort traffic and low blocking rate for guaranteed traffic. By striking an appropriate balance between per-flow resource consumption and the distribution of network load, these algorithms improve resource utilization efficiency and network throughput under dynamic load conditions. In a network that supports multiple classes of service, best-effort flows can experience congestion or even starvation if guaranteed flows are not routed appropriately. The second component of the proposed QoS routing framework is an effective inter-class resource sharing mechanism that also takes into consideration the link load of best-effort traffic while routing guaranteed flows. This mechanism is simple in the sense that it influences routing decisions by changing the link costs used for guaranteed traffic without requiring any change to the routing algorithms employed for individual service classes. In various scenarios, we observed significant performance improvements for best-effort traffic without sacrificing any performance for guaranteed traffic."
Author : Carnegie-Mellon University. Computer Science Dept
Publisher :
ISBN 13 :
Total Pages : 153 pages
Book Rating : 4.:/5 (395 download)
Download or read book Quality-of-service Routing in Integrated Services Networks written by Carnegie-Mellon University. Computer Science Dept and published by . This book was released on 1998 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "Future integrated services networks will support multiple classes of service to meet the diverse quality-of-service (QoS) requirements of applications. To meet these end-to-end QoS requirements, strict resource constraints may have to be imposed on the paths being used. QoS routing refers to a set of protocols and algorithms that can select paths that satisfy such constraints while achieving high network throughput. QoS routing is challenging because (1) different service classes employ different resource sharing models, (2) service classes dynamically share link resources, and (3) selecting paths that meet multiple QoS constraints is a complex algorithmic problem. This dissertation shows QoS routing in integrated services networks is both desirable and feasible. To support this claim, this dissertation develops an integrated QoS routing framework that has two components. The first component consists of routing algorithms for individual service classes that support either bandwidth guarantees, delay guarantees, or high throughput. By exploiting the relationship between QoS constraints, we develop polynomial routing algorithms for traffic classes that require stringent end-to-end performance guarantees. By coupling routing with finer-time scale resource management mechanisms such as congestion control and scheduling, we develop routing algorithms that achieve high throughput for best-effort traffic and low blocking rate for guaranteed traffic. By striking an appropriate balance between per-flow resource consumption and the distribution of network load, these algorithms improve resource utilization efficiency and network throughput under dynamic load conditions. In a network that supports multiple classes of service, best-effort flows can experience congestion or even starvation if guaranteed flows are not routed appropriately. The second component of the proposed QoS routing framework is an effective inter-class resource sharing mechanism that also takes into consideration the link load of best-effort traffic while routing guaranteed flows. This mechanism is simple in the sense that it influences routing decisions by changing the link costs used for guaranteed traffic without requiring any change to the routing algorithms employed for individual service classes. In various scenarios, we observed significant performance improvements for best-effort traffic without sacrificing any performance for guaranteed traffic."
Author : G Ram Mohana Reddy
Publisher : CRC Press
ISBN 13 : 1315351633
Total Pages : 139 pages
Book Rating : 4.3/5 (153 download)
Download or read book Mobile Ad Hoc Networks written by G Ram Mohana Reddy and published by CRC Press. This book was released on 2016-08-19 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, a lot of work has been done in an effort to incorporate Swarm Intelligence (SI) techniques in building an adaptive routing protocol for Mobile Ad Hoc Networks (MANETs). Since centralized approach for routing in MANETs generally lacks in scalability and fault-tolerance, SI techniques provide a natural solution through a distributed approach for the adaptive routing for MANETs. In SI techniques, the captivating features of insects or mammals are correlated with the real world problems to find solutions. Recently, several applications of bio-inspired and nature-inspired algorithms in telecommunications and computer networks have achieved remarkable success. The main aims/objectives of this book, "Mobile Ad Hoc Networks: Bio-Inspired Quality of Service Aware Routing Protocols", are twofold; firstly it clearly distinguishes between principles of traditional routing protocols and SI based routing protocols, while explaining in detail the analogy between MANETs and SI principles. Secondly, it presents the readers with important Quality of Service (QoS) parameters and explains how SI based routing protocols achieves QoS demands of the applications. This book also gives quantitative and qualitative analysis of some of the SI based routing protocols for MANETs.
Author : Aekkachai Rattanadilokchai
Publisher :
ISBN 13 :
Total Pages : 164 pages
Book Rating : 4.:/5 (458 download)
Download or read book Routing with Inaccurate Link-state Information in a Guaranteed Quality of Service Environment written by Aekkachai Rattanadilokchai and published by . This book was released on 2000 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Yi Yang
Publisher :
ISBN 13 :
Total Pages : 166 pages
Book Rating : 4.:/5 (483 download)
Download or read book Quality of Service Routing Algorithms for Bandwidth-delay Constrained Applications written by Yi Yang and published by . This book was released on 2001 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Srihari Nelakuditi
Publisher : Springer Science & Business Media
ISBN 13 : 1461503833
Total Pages : 114 pages
Book Rating : 4.4/5 (615 download)
Download or read book Localized Quality of Service Routing for the Internet written by Srihari Nelakuditi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: The exponential growth of Internet brings to focus the need to control such large scale networks so that they appear as coherent, almost intelligent, organ isms. It is a challenge to regulate such a complex network of heterogeneous elements with dynamically changing traffic conditions. To make such a sys tem reliable and manageable, the decision making should be decentralized. It is desirable to find simple local rules and strategies that can produce coherent and purposeful global behavior. Furthermore, these control mechanisms must be adaptive to effectively respond to continually varying network conditions. Such adaptive, distributed, localized mechanisms would provide a scalable so lution for controlling large networks. The need for such schemes arises in a variety of settings. In this monograph, we focus on localized approach to quality of service routing. Routing in the current Internet focuses primarily on connectivity and typi cally supports only the "best-effort" datagram service. The routing protocols deployed such as OSPF use the shortest path only routing paradigm, where routing is optimized for a single metric such as hop count or administrative weight. While these protocols are well suited for traditional data applications such as ftp and telnet, they are not adequate for many emerging applications such as IP telephony, video on demand and teleconferencing, which require stringent delay and bandwidth guarantees. The "shortest paths" chosen for the "best effort" service may not have sufficient resources to provide the requisite service for these applications.
Author : Alba Xifra Porxas
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (112 download)
Download or read book Virtualization-enabled Adaptive Routing for QoS-aware Software-Defined Networks written by Alba Xifra Porxas and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: [ANGLÈS] Software-Defined Networking (SDN) has been recognized as the next-generation networking paradigm. It is a fast-evolving technology that decouples the network data plane, which are the network devices that forward traffic, from the network control plane, which is the software logic that controls ultimately how traffic is forwarded through the network. A logically centralized controller is responsible for all the control decisions and communication among the forwarding elements. It allows to control the network behavior from a single high level control program. However, Software-Defined Networks use many of its network resources inefficiently, which leads to over-loading network links, congestion in the queues and end-to-end packet delays. Consequently, it becomes clear that routing decisions affect the overall performance of a communication's network. Performance is determined in terms of Quality of Service guarantees, i.e. throughput, average packet delay, jitter and losses. Thus, a QoS-aware routing algorithm is required. Current traffic engineering techniques and state-of-the-art routing algorithms do not effectively use the merits of SDNs, such as global centralized visibility, real-time fast decisions, control and data plane decoupling, network management simplification and portability. In this thesis, we developed two new QoS-aware routing algorithms that exploit the advantages that SDN brings to improve the network performance. Two different scenarios have been studied: a centralized and a distributed models. The centralized scenario simplifies the management of complex flows and the customization, but scalability issues arise. In contrast, the distributed scenario is more scalable, but there may be state inconsistency and increase of shared information. In general, a centralized approach is better for data centers or home networks, whereas a distributed approach is better for large scale networks, e.g. cloud environments. First, the centralized SDN controller model is discussed, for which a multi-tenancy management framework is proposed to fulfill the quality-of-services (QoSs) requirements through tenant isolation, prioritization and flow allocation. A network virtualization algorithm is provided to isolate and prioritize tenants from different clients. Furthermore, a novel routing scheme, called QoS-aware Virtualization-enabled Routing (QVR), is presented. It combines the proposed virtualization technique and a QoS-aware framework to enable flow allocation with respect to different tenant applications. Simulation results confirm that the proposed QVR algorithm surpasses the conventional algorithms with less traffic congestion and packet delay. This facilitates reliable and efficient data transportation in generalized SDNs. Therefore, it yields to service performance improvement for numerous applications and enhancement of client isolation. Second, a distributed SDN controller model is analyzed. The network is divided into different clusters, and hierarchically split in two levels. This architecture leads to smaller sizes of routing tables in the switches, and substantially lesser calculations and updates of routing tables from the controller. Moreover, a new algorithm is developed, called QoS-aware Reinforcement Learning Routing (QRLR), where reinforcement learning is applied to the routing problem. The modeling of the reward function calculation solution allows the customization of the different requirements for each type of traffic, thus providing flexibility and adaptability to different flows and its requirements.
Author : Keqin Zhu
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (137 download)
Download or read book QoS-based Multicast Routing for Real-time Communications written by Keqin Zhu and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis studies the distributed multicast routing algorithms that provide quality of service (QoS) guarantees in networks. It focuses on the delay constrained minimum cost tree (or constrained Steiner tree) problem; that is, it constructs a multicast tree that not only meets the constrained end-to-end delay requirements but also is the minimum cost multicast tree. This problem is known to be NP-complete. The existing distributed multicast routing algorithms that are based on heuristics do not consider a network environment where node failures occur. As a result, these algorithms will fail to complete the construction of a multicast tree when node failures occur during the construction period. Moreover, they will fail to maintain the constructed multicast tree if node failures occur after the construction period and during the on-going multicast session. In both cases, these algorithms will have to be restarted. We propose two new distributed delay constrained multicast routing algorithms that provide QoS guarantees even in networks where node failures occur. One is shortest path (SP) based and the other is minimum spanning tree (MST) based. They are capable of constructing a delay constrained multicast tree when node failures occur during the tree construction period and recovering from any node failure in a multicast tree during the on-going multicast session without interrupting the running traffic on the unaffected portion of the tree. The proposed SP-based or MST-based algorithms perform the failure recovery efficiently, which give better performance in terms of the number of exchanged messages and the convergence time than the existing distributed SP-based or MST-based delay constrained multicast routing algorithms in a network where node failures occur, respectively. The existing distributed delay constrained multicast routing algorithms can be classified either as an MST-based heuristic or as a SP-based heuristic. Two representative algorithms i.e., DKPP and DSPH are MST and SP based heuristics, respectively. The MST based algorithms like DKPP run with a high message and time complexity of O(n3). (Abstract shortened by UMI.).
Author : Meongchul Song
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (436 download)
Download or read book Algorithms for Multiconstrained Quality-of-service Paths and Restoration written by Meongchul Song and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Finally, we considered failure-resilient QoS routing. Providing efficient recovery from network failures is crucial to guarantee stable QoS services. We studied restoration paths for QoS routing problem and proved that the problem is NP-hard.
Author : Muhammad Nur Rizal
Publisher :
ISBN 13 :
Total Pages : 193 pages
Book Rating : 4.:/5 (11 download)
Download or read book Quality of Service Routing for Wireless Sensor Network written by Muhammad Nur Rizal and published by . This book was released on 2014 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last few years, the development of sensor networks has gained increasing importance due to their potential to support challenging research in a wide range of applications, and this has led to a new era of Multi-Objective Quality of Service Routing (MoQSR). This MoQSR is a routing algorithm that aims to satisfy multiple quality of service (QoS). MoQSR has the potential to support Wireless Sensor Network (WSN) applications that have different data which have quality and requirements. MoQSR enables the data communication protocols to provide a service differentiation mechanism that can capture the requirements of heterogeneous traffic. A key distinguishing feature of MoQSR is its ability to differentiate the required data related to each type of traffic and to provide a route selection that is based on differentiating QoS requirements according to the data type. In fact, a WSN has limitations in energy supply and capabilities to ensure real-time guarantees because it poses a low duty cycle and transmission range. Most approaches related to data communication protocols are designed to deal with energy trade-off and not much has been done to optimise quality of service (QoS). Past research and current studies of QoS routing schemes only focus on a limited number of aspects of QoS. These studies do not provide a generic approach/scheme to encompass all attributes of QoS, and have limited support for meeting application specific needs. Thus, it is critical for QoS routing to factor in different application requirements. Therefore, in this dissertation, I propose, develop and validate a new QoS based routing for WSN, named Throughput Delay Guaranteed Routing Algorithm (TeGaR). Our TeGaR is based on differentiating QoS requirements according to the data type, which provides customised QoS metrics for each traffic category. It is modular and uses geographic information, which helps the routing algorithm create the best path to the destination node (BS). Our TeGaR aims to adapt to the requirements of heterogeneous traffic by using traffic diversity, the priority based delivery mechanism with multi-queuing policy and the route differentiation based Fitness Function method, which considers the quality of nodes matching the requirements of data categories. TeGaR is able to find a best node for a certain data category, while considering energy efficiency, reliability, latency and traffic congestion to cast QoS metrics as a multi-objective attribute. However, there are some areas in which the performance of the proposed TeGaR can be enhanced. First, to address the 'energy hole problem' due to an imbalance of energy consumption in the network, according to the nature of many-to-one routing in WSNs, I propose a non-uniform transmission range strategy, namely Transmission Range Extension based on the neighbourhood Size (TReNs). TReNs allows the nodes to extend their transmission range to a certain level when the number of neighbours decreases below a certain level. This extended approach is able to distribute energy consumption evenly, thus avoiding an early network dysfunction. Second, to reduce the data flooding or unguided packet transmission, due to the characteristic of non-uniform node deployment and link instability in WSNs, I propose and develop a self-adaptation routing region approach, namely the Rule-based Learning Adaptation Approach for Routing Regions (RuLeARR) that aims to control the area (region) of routing for individual communication between nodes. In this way, packet detouring or data flooding can be reduced, thus decreasing routing overheads and the duration for data delivery, further saving energy. Third, to improve the benefits of adaptation of the routing region approach that copes with minor changes in the network QoS parameters, I integrate situation awareness into the routing region algorithm, to develop Situation Aware and Self-Adaptive Routing Regions (SASARR). The SASARR uses a fuzzy logic to represent approximate and imprecise context of the changes of the network dynamic to represent a fine-grained and gradual adaptation for routing region. SASARRR extends the RuLeARR approach in order to provide a higher level of accuracy and granularity, thus improving QoS performance in a cost-efficient manner. We validate all the approaches discussed above by conducting extensive experimental simulation. This evaluation clearly demonstrates the ability of the TeGaR scheme, with its extended approaches (TReNs, RuLeARR and SASARRR), to satisfy multiple QoS requirements according to different application requirements, while coping with the challenges due to the nature of data communication characteristics in WSNs. These approaches make a significant contribution to the overall efficiency and effectiveness of the QoS differentiating routing. The contribution of this thesis has resulted in one international peer reviewed paper and additional material for further publication.
