Polynomial time algorithm for hop-constrained QoS routing

Design and performance analysis of an inductive QoS routing algorithm

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.

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

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.

A lot of work has been done on routing in MANETs. However, the proposed routing solutions deal only with the best effort data traffic. Connections with quality of service (QoS) requirements are not supported. The QoS routing has been receiving increasingly intensive attention in the wireline network domain. However, for MANETs are proposed only few QoS routing algorithms. For MANETs, approximated solutions and heuristic algorithms should be developed and QoS routing algorithms should be adaptive, flexible, and intelligent. In our previous work, we proposed a genetic algorithm (GA) based routing method for mobile ad-hoc networks (GAMAN). In this paper, we enhance the proposed algorithm by adding an effective topology extraction algorithm to reduce the search space of GAMAN. We call this algorithm E-GAMAN. The E-GAMAN uses two QoS parameters for routing. The performance evaluation via simulations shows that E-GAMAN has a good performance.

Mobile ad Hoc Networks (MANETs) are one of the most important technologies supporting Ubiquitous and Pervasive Computing (UPC). As many UPC applications pose Quality of Service (QoS) constraints, their implementation in MANETs becomes dependent on the MANET algorithms for QoS routing. In this paper Genetic Algorithms (GAs) for QoS routing in MANETs are considered. GAs can solve the NP search of QoS routes with multiple constraints, and then address the UPC QoS requirements. The focus is on tree-based GAs, which represent the set of paths from source to destination as a tree and encode them through the crossed junctions. They encode single paths in the chromosome. We investigate on the effects of binary encoding schema on tree-based GAs. To this purpose we design a GA with binary encoding that maps classes of paths in single chromosomes. These classes are both collectively exhaustive and mutually exclusive. The GA with binary encoding uses an adaptive mutation probability for deeper exploration of the search space, and local search on classes of paths. Simulation results compare the GA with binary encoding with two applications of GAMAN, the main existing tree-based GA. They show that the binary encoding allows the GA to converge faster although it introduces additional computational costs.

In providing new telecommunication services, the requisition for quality of network is more and more popular and sophisticated with high bandwidth, small value of delay time or packet loss etc. To assure the quality of network, the localized routing schemes have recently been researched as a promising alternative to the currently deployed global QoS routing schemes. Different from the traditional QoS routing algorithms which use global state information, the localized routing algorithms use local information collected from source node to make routing decisions. These localized routing algorithms can be solutions to meet the demand of telecom market in the near future. In this paper, we study and propose one model of localized QoS routing algorithm, which uses distributed routing type to route flows. We perform it with experiments, compare and realize the more considerable performance of this algorithm than other algorithms, which use the same conditions of simulation. From that, we imply that localized QoS routing algorithm using distributed routing works more effectively than other types of routing algorithm.

A wide range of services has been developed for Vehicular Ad hoc Networks (VANETs) ranging from safety to infotainment applications. An essential requirement for such services is that they are offered with Quality of Service (QoS) guarantees in terms of service reliability and availability. Searching for feasible routes subject to multiple QoS constraints is in general an NP-hard problem. Besides, routing reliability needs to be paid special attention as communication links frequently break in VANETs. In this paper, we propose employing the Situational Awareness (SA) concept and an Ant Colony System (ACS) based algorithm to develop a Situation- Aware Multi-constrained QoS (SAMQ) routing algorithm for VANETs. SAMQ aims to compute feasible routes between the communicating vehicles subject to multiple QoS constraints and pick the best computed route, if such a route exists. To mitigate the risks inherited from selecting the best computed route that may turn out to fail at any moment, SAMQ utilises the SA levels and ACS mechanisms to prepare certain countermeasures with the aim of assuring a reliable data transmission. Simulation results demonstrate that SAMQ is capable of achieving a reliable data transmission as compared to the existing QoS routing algorithms even when the network topology is highly dynamic.A wide range of services has been developed for Vehicular Ad hoc Networks (VANETs) ranging from safety to infotainment applications. An essential requirement for such services is that they are offered with Quality of Service (QoS) guarantees in terms of service reliability and availability. Searching for feasible routes subject to multiple QoS constraints is in general an NP-hard problem. Besides, routing reliability needs to be paid special attention as communication links frequently break in VANETs. In this paper, we propose employing the Situational Awareness (SA) concept and an Ant Colony System (ACS) based algorithm to develop a Situation- Aware Multi-constrained QoS (SAMQ) routing algorithm for VANETs. SAMQ aims to compute feasible routes between the communicating vehicles subject to multiple QoS constraints and pick the best computed route, if such a route exists. To mitigate the risks inherited from selecting the best computed route that may turn out to fail at any moment, SAMQ utilises the SA levels and ACS mechanisms to prepare certain countermeasures with the aim of assuring a reliable data transmission. Simulation results demonstrate that SAMQ is capable of achieving a reliable data transmission as compared to the existing QoS routing algorithms even when the network topology is highly dynamic.

In multi-hop wireless networks, we often encounter a situation where there are some candidate paths between source node S and destination node D, and have to choose a path from the candidates. Although ordinary routing protocols select paths with minimum hops, QoS (quality of service) routing protocols evaluate paths using measures of QoS, such as expected transmission count (ETX). In multi-hop wireless networks with QoS routing, it is an important issue to identify and characterize the best path from the viewpoint of network design. To do this, we proposed an approximate method to theoretically compute minimum route ETX in static one-dimensional random multi-hop wireless networks, and we theoretically identified the best path and gave an exact formula to compute minimum route ETX in static lattice multi-hop wireless networks. In this paper, we propose a new approximate method to theoretically analyze minimum route ETX in a two-dimensional random network. In this method, we extend the approximate method proposed to be used for two-dimensional random networks. We show this approximate method well describes minimum route ETX by comparing the numerical results of the theoretical methods and simulation results.

Indirect distance measuring is a way with high performance vs. price ratio, but more work should be done to improve the measuring precision. Derived from the behavior characteristics of the wireless sensor networks based on minimum hop count routing, a distance estimating algorithm based on the minimum hop count and the routing redundancies was presented. Compared with the DV-hop algorithm, the measuring precision is improved largely by use of the routing redundancies. The analysis and simulation validate that the method is quite effective in the wireless sensor networks deployed with dense nodes.

Proactive routing protocols for mobile ad hoc networks (MANETs) follow on Optimum Routing Approach (ORA) to choose and use the optimal route at any time instant. On the other hand, on-demand routing protocols for MANETs have been traditionally designed using the Least Overhead Routing Approach (LORA) wherein a route determined using broadcast flooding-based route discovery is used as long as exists. With LROA, a route determined to be the best optimal route based on a particular route selection metric, may later become sub-optimal, and could be still used, if exists. In this paper, we evaluate the impact of the ORA and LORA strategies on minimum hop routing. Our hypothesis is that the LORA strategy could yield routes with a larger time-averaged hop count when compared to the minimum hop count of routes determined using the ORA strategy. We evaluate the two routing strategies under diverse conditions of network density, node mobility and mobility models such as the Random Waypoint model, City Section model and the Manhattan model. Simulation results illustrate that the hop count of routes maintained according to the LORA strategy is at most 12% greater than that incurred with the ORA strategy. The Random Waypoint model under the LORA strategy incurs the lowest hop count per path and the largest increase in hop count vis-à-vis the ORA strategy; on the other hand, the Manhattan model incurs a larger hop count per path and the smallest increase in hop count.KeywordsOptimum Routing Approach (ORA)Least Overhead Routing Approach (LORA)Mobility ModelHop CountMobile Ad hoc Networks

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.

Energy is a critical resource in wireless sensor networks (WSNs). To make the best use of the severely limited resource, in this paper, proposes minimum-hop layer model and ER-MHL protocol. The model layers the network based on the minimum hops to sink node. And the neighbors are classed as paternal nodes, brother nodes and son nodes. In ER-MHL, event packets are forwarded among paternal nodes in paths that ensure the paths to have the minimum hops and the maximum residual energy. The results of analysis and experiments show minimum-hop layer model and ER-MHL routing protocol have outstanding performance in packets delay, dissipated energy and lifetime of network.

Network planning of multi-layer heterogeneous mobile networks with complex topology is an important task. In this paper the spectral and energy efficiency of integrated LTE/Wi-Fi technologies for 5G are improved. A method of adaptive formation of the structure of radio access level (RAL) with the provision of the required quality of service (QoS) and the possibility of broadband data transmission is proposed. The Voronoi tessellation is used for designing the RAL of 5G mobile networks for the placement of base stations, which allowed optimum delimiting the coverage area for each base station and provide users the cell interface services. To minimize interference there was proposed a method of dynamic frequency reuse for different sizes of Voronoi cells. Modelling shows the developed method is effective both at low and at high network load, however, at high load there is a slightly smaller gain in energy efficiency than at low load.

We consider the problem of quality of service (QoS) routing in multi-hop wireless networks where data are transmitted from a source node to a destination node via multiple hops. The routing component of a QoS-routing algorithm essentially involves the link and path metric calculation which depends on many factors such as the physical and link layer designs of the underlying wireless network, transmission errors due to channel fading and interference, etc. The task of link metric calculation basically requires us to solve a tandem queueing problem which is the focus of this paper. We present a unified tandem queue framework which is applicable for many different physical layer designs. We present both exact and approximated decomposition approaches. Using the queueing framework, we can derive different performance measures, namely, end-to-end loss rate, end-to-end average delay, and end-to-end delay distribution. The proposed decomposition approach is validated and some interesting insights into the system performance are highlighted. We then present how to use the decomposition queueing approach to calculate the link metric and incorporate this into the route discovery process of the QoS routing algorithm. The extension of the queueing and QoS routing framework to wireless networks with class-based queueing for QoS differentiation is also presented.