Distributed QoS routing with imprecise state information

Since the nodes in mobile ad hoc network act as a router and host, the routing protocol is the primary issue and has to be supported before any applications can be deployed for ad hoc wireless network. In recent years much work has been done on routing in ad hoc networks. But most of them couldn't provide the quality-of-service (QoS). Considering the characters of dynamic topology and the imprecise state information in mobile ad hoc network, we propose an extension QoS routing 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. The algorithm can tolerate a high degree of information imprecision by adding the fuzzy logic module which integrates the QoS requirements of application and the routing QoS parameters to determine the most qualified one in every node. This scheme considers not only the bandwidth and end-to-end delay of routing, but also the cost of the path. So it also may improve the network performance. On the other hand the merit of using fuzzy logic is that it can be implemented by hardware. This makes the realization of the scheme easier and faster. However our algorithm is based on DSR, the maximal hop count should be less than 10, i.e., the scale of mobile ad hoc network should not be very large.

Localised quality of service (QoS) routing has recently been proposed as a viable alternative approach to traditional QoS routing algorithms that use global state information. In this approach, problems associated with maintaining global state information are avoided by having the source nodes to infer the network QoS state based on flow blocking statistics collected locally, and perform flow routing using this localised view of the network QoS state. A credit based routing algorithm (CBR) which is a simple yet effective localised QoS routing algorithm is introduced. Its performance is compared against the localised proportional sticky routing (PSR) algorithm using different types of network topologies, QoS requirements and traffic patterns and under a wide range of traffic loads. Extensive simulations show that the algorithm outperforms the PSR scheme while maintaining the same level of adaptivity and stability. Its performance is also compared against the global widest-shortest path algorithm (WSP) and it is shown that CBR gives a comparable performance with better time complexity and very low communication overhead.

Due to mobility in wireless networks, the state information of all outgoing links (link delays, available resources and costs) of nodes is imprecise. Fuzzy logic has proven to be a powerful tool when dealing with imprecise information. The implemented distributed protocol incorporates fuzzy inference systems to guide the process of finding routes with sufficient resources to satisfy a certain delay and other requirements with least end-to-end cost in a dynamic network. Multi-path parallel search is used to increase the probability of finding a feasible path. When there are such multiple paths, the one with least cost is selected. Results show how this protocol can tolerate a high degree of information imprecision. Success ratios for delay resource constrained routing reach values over 92%.

Software-Defined Networking (SDN) is a new efficiently idea of programmable networks that separates the control plane from data plane of all network devices. Internet service provider is responsible for all the control decisions and communication among the forwarding elements from centralized controller. SDN provides the various optimized services. Quality of service (QoS) routing is a path computation method that is suitable for the different traffics generated by several applications, while utilization of network resources has increased. This agreement of service is defined by QoS requirements such as throughput, delay, jitter and packet loss etc. Multimedia applications often require assured from multi QoS constrained, causing the NP-complete problem which cannot be simply solved in polynomial time and high management complexity in the transition network. SDN is able to reduce complexity and it is used to efficiently implement traffic, hence SDN significantly values to development QoS routing. In this paper, we propose QoS routing algorithm called Quantized Level Balance (QLB) for SDN that considers one or many QoS parameters relating to the network application. To satisfy the requirements, QLB selects QoS parameters depending to the level of appropriate application service quality. We have replicated our algorithm on simulate topology with Scalable Video-streaming Evaluation Framework (SVEF). We measure the Peak Signal-to-Noise Ratio (PSNR) and Mean Opinion Score (MOS) of Scalable Video Coding (SVC) at the receiver. Our propose algorithm is improved than single-metric approach that may choose poor QoS parameter paths.

In this paper, a hop-by-hop Quality-of-Service (QoS) routing mechanism is proposed to maintain the routing performance in networks with imprecise link state information. The proposed mechanism, Normal- PI, applies statistical methods to compute two-sided simultaneous prediction intervals from sampled history of the available bandwidths. A QoS metric - statistical available bandwidth - is then generated from the prediction interval. This metric replaces the instantaneous available bandwidth in the ordinary widest-shortest path routing algorithm (WSR). Simulation results demonstrate that the Normal-PI achieves much less update message overhead compared to WSR without deteriorating the routing performance in terms of packet loss and link utilization.

Localized Quality of Service (QoS) routing has been recently proposed as a promising alternative to the currently deployed global routing schemes. In localized routing schemes, routing decisions are taken solely based on locally collected statistical information rather than global state information. This approach significantly reduces the overheads associated with maintaining global state information at each node, which in turn improves the overall routing performance. Routing with delay guarantee involves path-constrained requirements, which are harder and more complex to satisfy than routing with bandwidth guarantee, which involves only link-constrained requirements. In this paper we introduce a Localized Delay-Constrained QoS Routing algorithm (LDCR), which can guarantee the end-to-end delay requirements for network flows. The performance of the proposed algorithm is evaluated against the well-known global shortest path routing algorithm (Dijkstra) and against a modified delay-based version of the localized CBR. Simulation results have shown considerable performance improvement achieved by the proposed algorithm in terms of the overall network blocking probability.

Nowadays, more and more researchers are paying their attention to green routing. In this paper, we consider power consumption as a kind of QoS (quality of service) and apply a new learning-based approach for energy efficient transportation and QoS routing. Compared with traditional rule-based methods, the proposed method can learn additional information from the networks to improve routing performance, and have the flexibility to meet different QoS requirements. First, we propose a new identification of network nodes, namely node vectors, and a basic routing algorithm using node vectors is designed accordingly. Then, energy efficient transportation and QoS routing are proposed by adding QoS constraints into the routing decision. Link attributes such as power consumption, bandwidth and delay can be learned from these node vectors with neural networks. The learned link attributes together with the estimated distance can be used for routing decisions with QoS constraints. Simulation results show that the proposed method is reliable in routing tasks, and can achieve a remarkable performance when compared with the state-of-the-art work on the delay constrained least cost path (DCLC) problem.

In this paper, we extend the previously presented QoS routing scheme called pre-computation based selective probing (PCSP) to the practical environment where the state information available for the routing decision is not precise. This extended PCSP algorithm pre-computes the QoS variations as well as the cost and QoS metrics of the least-cost and best-quality paths, taking into account the impreciseness of state information. The pre-computed information enables to strictly limit the set of neighbor nodes involved in the probing process, thereby reducing the message complexity without sacrificing cost optimality. This extended PCSP scheme encompasses the original PCSP scheme as a special case where the variation of state information reduces to zero. Computer simulation reveals that the extended PCSP scheme maintains low message complexity and high success ratio with guaranteed optimal search.

Implementing the dynamic couple of searching paths and resource allocation becomes increasingly important in the research of Quality of Service (QoS) routing. In this paper, we formulate the problem of dynamic QoS routing with resource allocation based on Worst-case Fair Weighted Fair Queuing (WF2Q) packet scheduling style. We propose an algorithm using the proved results -- the optimal path resource allocation algorithm (OPRA2), which can allow intelligent choice of the maximized reliability and minimized delay path according to the types of applications and adapt QoS parameters and allocated resources related to WF2Q in process of routing. It can find an optimal path which satisfies different QoS requirements and compute the amount of bandwidth and buffer resources needed at each node. We provide the simulation results to illustrate the effect of buffers and bandwidths according to the values of control parameters.

Recent studies provide evidence that Quality of Service (QoS) routing can provide increased network utilization compared to routing that is not sensitive to QoS requirements of traffic. However, there are still strong concerns about the increased cost of QoS routing, both in terms of more complex and frequent computations and increased routing protocol overhead. The main goals of this paper are to study these two cost components, and propose solutions that achieve good routing performance with reduced processing cost. First, we identify the parameters that determine the protocol traffic overhead, namely (a) policy for triggering updates, (b) sensitivity of this policy, and (c) clamp down timers that limit the rate of updates. Using simulation, we study the relative significance of these factors and investigate the relationship between routing performance and the amount of update traffic. In addition, we explore a range of design options to reduce the processing cost of QoS routing algorithms, and study their effect on routing performance. Based on the conclusions of these studies, we develop extensions to the basic QoS routing, that can achieve good routing performance with limited update generation rates. The paper also addresses the impact on the results of a number of secondary factors such as topology, high level admission control, and characteristics of network traffic.

The scheme of Quality of Service (QoS) routing algorithms based on local state information has recently been proposed as an alternative approach to the traditional QoS routing algorithms. By implementing this localized QoS routing algorithm, each source node predetermines and maintains a set of candidate paths for each destination. These sets of paths will help the source node to decide the most appropriate path for a connection request. Hence, it helps to avoid the problems associated with the maintenance of the global network state information. In this paper, we propose a new and effective localized QoS routing algorithm, compare its performance with those of other localized algorithms and a traditional QoS routing algorithm under the same type of network topology, QoS requirements and traffic patterns. The simulations results show that our proposed algorithm can perform better than other routing algorithms. DOI: 10.32913/rd-ict.vol3.no14.258

QoS routing in GMPLS-capable integrated IP/WDM networks with router cost constraints

With the Development of mobile ad hoc network (MANET), Quality of Service (QoS) routing and power-aware routing become more and more important. In the past, QoS guarantee and power control issues were treated separately. In this paper, we propose a novel on-demand QoS routing protocol, PMQR (power-aware multi-path QoS routing) in TDMA-based MANETs. Our protocol combines QoS routing and power-aware routing, which can provide QoS guarantee and achieve energy conservation by taking into account both the transmission power and the remaining energy at the intermediate nodes between a source and a destination. PMQR also can establish multiple paths, even for a single call, when the route search cannot find a path that meets the QoS requirements. Simulation results show that PMQR has good network performance and balances the energy consumption of mobile hosts.

Quality of service (QoS) routing between domains is indispensable for deploying QoS in the Internet. State aggregation is a technique that makes QoS routing scalable to large networks. As the impreciseness in the advertised aggregate adversely affects the performance of the QoS routing process, it is important to investigate the accuracies of various aggregation schemes. In this paper, we study the efficacy of a new bandwidth aggregation scheme, and compare our scheme's performance with that of the existing schemes. Our analytical and experimental studies show that for active networks, the proposed aggregation scheme is more accurate, and gives a better routing performance than the current schemes.

In Mobile Ad-Hoc Networks (MANET), the increasing demand for multimedia application is more challenging and the existing routing protocols are not adequate owing to the complex design requirements of Quality of Service (QoS) routing. This paper proposes a stateless position-based solution for QoS routing issues and offers an efficient end-to-end communication guarantee. The proposed Stateless QoS (SQoS) routing protocol is based on adaptive compass greedy routing to determine a qualified path which satisfies the QoS requirements and the void handling scheme overcomes the local maximum issue. In addition, the SQoS routing utilises the node overhearing capacity to obtain the link quality measurement to provide a guarantee for efficient end-to-end transmission through the identification of high-quality links for multimedia streams. The performance of the proposed SQoS routing protocol is compared with existing QoS-GPSR. Finally, the performance evaluation proves that the SQoS routing protocols outperform the existing protocols.