QoS-aware routing based on bandwidth estimation for mobile ad hoc networks

Routing protocols for mobile ad hoc networks (MANETs) have been explored extensively in recent years. Much of this work is targeted at finding a feasible route from a source to a destination without considering current network traffic or application requirements. Therefore, the network may easily become overloaded with too much traffic and the application has no way to improve its performance under a given network traffic condition. While this may be acceptable for data transfer, many real-time applications require quality-of-service (QoS) support from the network. We believe that such QoS support can be achieved by either finding a route to satisfy the application requirements or offering network feedback to the application when the requirements cannot be met. We propose a QoS-aware routing protocol that incorporates an admission control scheme and a feedback scheme to meet the QoS requirements of real-time applications. The novel part of this QoS-aware routing protocol is the use of the approximate bandwidth estimation to react to network traffic. Our approach implements these schemes by using two bandwidth estimation methods to find the residual bandwidth available at each node to support new streams. We simulate our QoS-aware routing protocol for nodes running the IEEE 802.11 medium access control. Results of our experiments show that the packet delivery ratio increases greatly, and packet delay and energy dissipation decrease significantly, while the overall end-to-end throughput is not impacted, compared with routing protocols that do not provide QoS support.     

GMCAR: Grid-based multipath with congestion avoidance routing protocol in wireless sensor networks

Recently, the interest in wireless sensor networks has been magnetized in the delay sensitive applications such as real-time applications. These time critical applications crave certain QoS requirements as though end-to-end delay guarantee and network bandwidth reservation. However, the severe resource constraints of the wireless sensor networks pose great challenges that hinder supporting these requirements. In this paper, we propose a Grid-based Multipath with Congestion Avoidance Routing protocol (GMCAR) as an efficient QoS routing protocol that is suited for grided sensor networks. We employ the idea of dividing the sensor network field into grids. Inside each grid, one of the sensor nodes is selected as a master node which is responsible for delivering the data generated by any node in that grid and for routing the data received from other master nodes in the neighbor grids. For each master node, multiple diagonal paths that connect the master node to the sink are stored as routing entries in the routing table of that node. The novelty of the proposed protocol lies behind the idea of incorporating the grids densities along with the hop count into the routing decisions. A congestion control mechanism is proposed in order to relieve the congested areas in case of congestion occurrence. Simulation results show that our proposed protocol has the potential to achieve up to 19.5% energy saving, 24.7% reduction in the delay and up to 8.5% enhancement in the network throughput when compared to another QoS routing protocol. However, when compared to the basic grid-based coordinated routing protocol, it achieves 23% energy saving. In addition, the proposed protocol shows its superiority in achieving better utilization to the available storage.     

Hybrid QoS based routing protocol for inter and intra wireless mesh infrastructure communications

Quality of service (QoS) in wireless mesh networks is an active area of research, which is driven by the increasing demand for real-time and multimedia applications, such as Voice over IP and Video on Demand. In this paper, we propose a novel QoS based routing protocol for wireless mesh infrastructure, called Hybrid QoS Mesh Routing (HQMR). It is composed of two QoS based routing sub-protocols: a reactive multi-metric routing protocol for intra-infrastructure communications and a proactive multi-tree based routing protocol for communications with external networks. The proposed routing protocol enables forwarding real-time and streaming applications with QoS guarantee in a mesh wireless environment, by assigning a specific routing path for each defined service class. To this end, three different QoS service classes are defined, depending on the applications requirements. We analyze in this paper the simulation results of different scenarios conducted on the network simulator ns-3 to demonstrate the effectiveness of the HQMR protocol and to compare it to other routing protocols while forwarding real-time applications with QoS guarantee.     

A DISTRIBUTED QOS ROUTING BASED ON ANT ALGORITHM FOR LEO SATELLITE NETWORK

Low Earth Orbit (LEO) satellites provide short round-trip delays and are becoming in- creasingly important. One of the challenges in LEO satellite networks is the development of specialized and efficient routing algorithms. To satisfy the QoS requirements of multimedia applications, satellite routing protocols should consider handovers and minimize their effect on the active connections. A distributed QoS routing scheme based on heuristic ant algorithm is proposed for satisfying delay bound and avoiding link congestion. Simulation results show that the call blocking probabilities of this al- gorithm are less than that of Shortest Path First (SPF) with different delay bound.     

A QoS Routing Protocol with Bandwidth Allocation in Multichannel Ad Hoc Networks

Mobile multimedia applications have recently generated much interest in mobile ad hoc networks (MANETs) supporting quality-of-service (QoS) communications. Multiple non-interfering channels are available in 802.11 and 802.15 based wireless networks. Capacity of such channels can be combined to achieve higher QoS performance than for single channel networks. The capacity of MANETs can be substantially increased by equipping each network node with multiple interfaces that can operate on multiple non-overlapping channels. However, new scheduling, channel assignment, and routing protocols are required to utilize the increased bandwidth in multichannel MANETs. In this paper, we propose an on-demand routing protocol M-QoS-AODV in multichannel MANETs that incorporates a distributed channel assignment scheme and routing discovery process to support multimedia communication and to satisfy QoS bandwidth requirement. The proposed channel assignment scheme can efficiently express the channel usage and interference information within a certain range, which reduces interference and enhances channel reuse rate. This cross-layer design approach can significantly improve the performance of multichannel MANETs over existing routing algorithms. Simulation results show that the proposed M-QoS-AODV protocol can effectively increase throughput and reduce delay, as compared to AODV and M-AODV-R protocols.     

A Survey of Routing Protocols that Support QoS in Mobile Ad Hoc Networks

The explosive growth in the use of mobile devices coupled with users' desires for real-time applications has provided new challenges in the design of protocols for mobile ad hoc networks. Chief among these challenges to enabling real-time applications for mobile ad hoc networks is incorporating support for quality of service (QoS), such as meeting bandwidth or delay constraints. In particular, it is important that routing protocols incorporate QoS metrics in route finding and maintenance to support end-to-end QoS. This article extensively and exclusively studies the issues involved with QoS-aware routing and presents an overview and comparison of existing QoS-aware routing protocols. In addition, the open issues that must be addressed to fully support QoS-aware routing are discussed.     

QoS routing in ad hoc wireless networks

The emergence of nomadic applications have generated much interest in wireless network infrastructures that support real-time communications. We propose a bandwidth routing protocol for quality-of-service (QoS) support in a multihop mobile network. The QoS routing feature is important for a mobile network to interconnect wired networks with QoS support (e.g., ATM, Internet, etc.). The QoS routing protocol can also work in a stand-alone multihop mobile network for real-time applications. This QoS routing protocol contains end-to-end bandwidth calculation and bandwidth allocation. Under such a routing protocol, the source (or the ATM gateway) is informed of the bandwidth and QoS available to any destination in the mobile network. This knowledge enables the establishment of QoS connections within the mobile network and the efficient support of real-time applications. In addition, it enables more efficient call admission control. In the case of ATM interconnection, the bandwidth information can be used to carry out intelligent handoff between ATM gateways and/or to extend the ATM virtual circuit (VC) service to the mobile network with possible renegotiation of QoS parameters at the gateway. We examine the system performance in various QoS traffic flows and mobility environments via simulation. Simulation results suggest distinct performance advantages of our protocol that calculates the bandwidth information. It is particularly useful in call admission control. Furthermore, “standby” routing enhances the performance in the mobile environment. Simulation experiments show this improvement     

Tabu search based algorithms for bandwidth-delay-constrained least-cost multicast routing

The advent of various real-time multimedia applications in high-speed networks creates a need for quality of service (QoS) based multicast routing. The Steiner tree problem, is a well-known NP-complete problem, provides the mathematical structure behind multicast communications. Two important QoS constraints are the bandwidth constraint and the end-to-end delay constraint. In this paper, we propose various algorithms to solve the bandwidth-delay-constrained least-cost multicast routing problem based on Tabu Search (TS), addressing issues of the selected initial solution and move type as two major building blocks in short-term memory version of Tabu Search and longer-term memory with associated intensification and diversification strategies as advanced Tabu Search techniques. We evaluate the performance and efficiency of the proposed TS-based algorithms in comparison with other existing TS-based algorithms and heuristics on a variety of random generated networks with regard to total tree cost. Finally we identify the most efficient algorithm uncovered by our testing.     

A ring-based multicast routing topology with QoS support in wireless mesh networks

Wireless mesh networking (WMN) is an emerging technology for future broadband wireless access. The proliferation of the mobile computing devices that are equipped with cameras and ad hoc communication mode creates the possibility of exchanging real-time data between mobile users in wireless mesh networks. In this paper, we argue for a ring-based multicast routing topology with support from infrastructure nodes for group communications in WMNs. We study the performance of multicast communication over a ring routing topology when 802.11 with RTS/CTS scheme is used at the MAC layer to enable reliable multicast services in WMNs. We propose an algorithm to enhance the IP multicast routing on the ring topology. We show that when mesh routers on a ring topology support group communications by employing our proposed algorithms, a significant performance enhancement is realized. We analytically compute the end-to-end delay on a ring multicast routing topology. Our results show that the end-to-end delay is reduced about 33 %, and the capacity of multicast network (i.e., maximum group size that the ring can serve with QoS guarantees) is increased about 50 % as compared to conventional schemes. We also use our analytical results to develop heuristic algorithms for constructing an efficient ring-based multicast routing topology with QoS guarantees. The proposed algorithms take into account all possible traffic interference when constructing the multicast ring topology. Thus, the constructed ring topology provides QoS guarantees for the multicast traffic and minimizes the cost of group communications in WMNs.     

A hierarchical multilayer QoS routing system with dynamic SLAmanagement

This paper proposes a hierarchical multilayer QoS routing system with dynamic SLA management for large-scale IP networks. Previously, the promising approach to provide QoS in large-scale IP networks using a mixture of DiffServ-based QoS management and MPLS-based traffic engineering has been actively discussed. However, the introduction of QoS exacerbates the already existing scalability problems of the standard IP routing protocols. In order to address this issue, we propose a new scalable routing framework based on hierarchical QoS-aware path computation. We augment the existing OSPF and CR-LDP protocols to support hierarchical QoS routing, QoS aggregation, and QoS reservation in our MPLS-DiffServ-based hierarchical routing network. In order to provide additional flexibility and cost-efficiency, we augment the network with a policy server which is capable of dynamically handling SLAs between the networks and providing load balancing management within the network. We implement a prototype of the proposed framework and study its performance with a virtual network simulator and specially designed QoS routing algorithm simulator. In our simulations, we evaluate both the implementation complexity and algorithms performance; the results demonstrate the efficiency of the framework and its advantages over the existing proposals     

Passive cluster-based multipath routing protocol for wireless sensor networks

Energy efficiency and quality of service (QoS) are both essential issues in the applications of wireless sensor networks (WSNs) all along, which are mainly reflected in the development of routing and MAC protocols. However, there is little design for achieving the dual performances simultaneously. In this paper, we develop a practical passive cluster-based node-disjoint many to one multipath routing protocol to satisfy the requirements of energy efficiency and QoS in practical WSNs. Passive clustering approach is put to use in the first round, while active clustering technique is taken in the other rounds. Implementation of smart delay strategy makes the cluster distribute uniformly, as well as lessen the number of nodes that have taken part in routing. Among cluster heads, a node-disjoint many to one multipath routing discovery algorithm, which is composed of the optimal path searching process and multipath expansion process, is implemented to find multiple paths at the minimum cost. The simulation results show the proposed protocol achieved very good performance both in energy efficiency and QoS.     

QUORUM—Quality of Service in Wireless Mesh Networks

Wireless mesh networks (WMNs) can provide seamless broadband connectivity to network users with low setup and maintenance costs. To support next-generation applications with real-time requirements, however, these networks must provide improved quality of service guarantees. Current mesh protocols use techniques that fail to accurately predict the performance of end-to-end paths, and do not optimize performance based on knowledge of mesh network structures. In this paper, we propose QUORUM, a routing protocol optimized for WMNs that provides accurate QoS properties by correctly predicting delay and loss characteristics of data traffic. QUORUM integrates a novel end-to-end packet delay estimation mechanism with stability-aware routing policies, allowing it to more accurately follow QoS requirements while minimizing misbehavior of selfish nodes.     

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.     

Advertising interdomain QoS routing information

To enable end-to-end quality-of-service (QoS) guarantees in the Internet, based on the border gateway protocol (BGP), interdomain QoS information advertising, and routing are important. However, little research has been done in this area so far. Two major challenges, scalability and heterogeneity, make the QoS extension to BGP difficult. In the existing routing schemes, static and instantaneous QoS metrics, such as link capacity and available bandwidth, are used to represent QoS routing information, but neither of them can solve the two challenges well. In this paper, BGP is extended to advertise available bandwidth and delay information of routes, but, instead of using the traditional deterministic metrics, a series of statistical metrics, available bandwidth index (ABI), delay index (DI), available bandwidth histogram (ABH), and delay histogram (DH), are defined and applied to QoS information advertising and routing. Two major contributions of the proposed statistical metrics are: 1) QoS information is abstracted into one or several probability intervals and, thus, the heterogeneous and dynamic QoS information can be represented more flexibly and precisely and 2) by capturing the statistical property of the detailed distribution of QoS information, these new metrics are efficient and they can highly decrease the message overhead in routing, thereby making the QoS advertising and routing scalable. Our extensive simulations confirm both contributions of the QoS extension to BGP very well. Moreover, besides BGP, these statistical metrics can be applied to other networks and protocols to represent QoS information in a more scalable and precise way.     

Traffic prediction-based routing algorithm over structured P2P networks

Routing has always been a great challenge for structured Peer-to-Peer (P2P) networks. There are a lot of representative structured routing algorithms for P2P networks, but these algorithms do not guarantee the quality of service (QoS) for real-time P2P applications. Addressing this challenge, a traffic prediction-based structured routing algorithm over P2P networks (TPSR) is proposed. Our contributions are described as below. We firstly analyze P2P traffic features and then build a wavelet neural-network predicting model. Secondly, we employ the traffic prediction model to predict the future state of each peer, such as normal or congestion, and let each peer update its routing table. In this way the requesting peers always get a resource list which contains the best resource peers. Simulation results demonstrate that TPSR has higher transmission success rate and lower end to end delay than other structured routing algorithms. Thus, TPSR can guarantee the QoS for real-time P2P applications.     

Energy-aware and quality of service-based routing in wireless sensor networks and vehicular ad hoc networks

Wireless Sensor Networks (WSNs) have increasingly been used for remote monitoring tasks. Limited capabilities of sensor nodes in terms of communication, computation, and storage, present challenges to protocols designed for WSNs. Due to the severe energy constraint of sensor nodes, among the major concerns is the problem of designing efficient energy-aware routing protocols. Numerous routing protocols have been proposed in the literature. Cluster-based routing protocols for large-scale WSNs have some advantages as compared to a flat network topology. Clustering results in a reduced number of messages that propagate through the network in order to accomplish a sensing task. It also offers improved power control. Quality of Service (QoS) is becoming an important feature of data routing in WSNs. QoS is required for real-time data transmission when the result of a sensing task is dependent not only on the correct sensing of the environment but also on the timely delivery of the event notification to the monitoring center, the Sink. The emergency preparedness and response class of applications, for instance, impose delay requirements on the delivery of event notification messages. Transmitting video and imaging data poses certain bandwidth, delay, and jitter requirements on the routing protocols. Vehicular Ad Hoc Networks (VANETs) are envisioned to improve intervehicle coordination and become a part of intelligent transport systems with an ultimate goal of increasing safety on the roads and improving travel comfort. VANETs may include WSNs that are placed along the sides of roads and provide monitoring of road conditions. Routing protocols for VANETs also aim at satisfying end-to-end QoS requirements. This paper first discusses energy-efficient clustering routing protocols for WSNs, followed by approaches aimed at satisfying QoS in WSNs and VANETS. Lastly, a discussion and comparison of features of the selected routing protocols and QoS-based approaches is presented.     

A novel real-time scheme for (m,k)-firm streams in wireless sensor networks

The multimedia transmission based real-time applications have posed a big challenge to wireless sensor networks (WSNs) where both reliability and timeliness need to be guaranteed at the same time, to support an acceptable Quality of Service (QoS). The existing real-time routing protocols, however, are not able to meet the QoS requirements of realtime applications because of the inherent resource constraint of sensor nodes and instability of wireless communication. Therefore, we propose a real-time scheme in this paper, including a QoS-aware routing protocol and a set of fault recovery mechanisms, for (m,k)-firm based real-time applications over WSNs. A local status indicator which is specially devised for (m,k)-firm stream, is used for intermediate nodes to monitor and evaluate their local conditions. The proposed routing protocol takes into account of packet deadline, node condition and remaining energy of next hop, to make optimal forwarding decision. Additionally, according to the stream QoS and node condition, the proposed fault recovery mechanisms are utilized for nodes to handle the congestion, link failure and void problems occurred during transmission and remain the desired reliability and timeliness requirements. The proposed scheme has been well studied and verified through simulations. The results have proved the efficiency of the proposed scheme in terms of high successful transmission ratio, small end-to-end delay and long lifetime of network.     

一种应急通信中业务感知的宽带自组网路由协议

随着科技进步,我国在应急通信系统建设上也正高速发展,当前应急通信网络对多媒体业务有着迫切需求,对网络带宽要求更高。而当网络存在多种不同业务时,传统通用的路由协议不再适用,它们大多以最小跳数为路由度量或者是某个单一度量,未能考虑不同业务的服务质量(Quality of Service, QoS)需求,因而无法同时兼顾不同业务流的传输要求。提出了一种应急通信中业务感知的宽带自组网路由策略,对不同类型业务在路由和转发优先级上进行区分。经多次仿真验证,该策略能使网络在满足应急语音业务QoS需求的同时,也能兼顾承载的视频、数据等其他业务的性能。     

Precomputation schemes for QoS routing

Precomputation-based methods have recently been proposed as an instrument to facilitate scalability, improve response time, and reduce computation load on network elements. The key idea is, in effect, to reduce the time needed to handle an event by performing some computation in advance, i.e., prior to the event's arrival. Such computations are performed as background processes, enabling a solution to be provided promptly upon a request, through a simple, fast procedure. We investigate precomputation methods in the context of quality-of-service (QoS) routing. Precomputation is highly desirable for QoS routing schemes due to the high computational complexity of selecting QoS paths, and the need to provide a satisfactory path promptly upon a request. We consider two major settings of QoS routing. The first case is where the QoS constraint is of the "bottleneck" type, e.g., a bandwidth requirement, and network optimization is sought through hop minimization. The second is the more general setting of "additive" QoS constraints (e.g., delay) and general link costs. The paper mainly focuses on the first setting. We show that, by exploiting the typical hierarchical structure of large-scale networks, a substantial improvement can be achieved in terms of computational complexity. We consider networks with topology aggregation. We show that precomputation is a necessary element for any QoS routing scheme and establish a precomputation scheme appropriate for such settings. We consider the case of additive QoS constraints (e.g., delay) and general link costs. As the routing problem becomes NP-hard, we focus on /spl epsiv/-optimal approximations and derive a precomputation scheme that offers a major improvement over the standard approach.     

基于ACS的无线传感器网络区分服务路由算法

针对无线传感器网络中数据传输的不同要求,将QoS分为3类,根据无线链路的特点提供区分服务。利用博弈论分析了数据传输在延迟、可靠性与网络能量开销之间的关系,基于改进的蚁群优化算法ACS(ant colony system),设计了区分服务路由算法ADSGR(ant colony system based differentiated service and game-theory routing),依据不同QoS要求,选择适当的路由,提高网络的整体性能和资源利用率。实验结果表明,与现有算法相比,该算法在数据传输的延迟、可靠性和能量开销上具有更好的性能。