Hierarchical Routing Algorithm Research Articles

Efficient Routing on Large Road Networks Using Hierarchical Communities

Efficient routing is essential in everyday life. Although various hierarchical algorithms exist for computing shortest paths, their heavy precomputation/storage costs and/or query costs hinder their application to large road networks. By detecting a hierarchical community structure in road networks, we develop a community-based hierarchical graph model that supports efficient route computation on large road networks. We then propose a new hierarchical routing algorithm that can significantly reduce the search space over the conventional algorithms with acceptable loss of accuracy. Experimental results on a New York road network demonstrate the performance of the algorithm.

An Efficient Path Computation Approach for Road Networks Based on Hierarchical Communities

AbstractThe problem of efficient path computation arises in several applications such as intelligent transportation and network routing. Although various algorithms exist for computing shortest paths, their heavy precomputation/storage costs and/or query costs hinder their application to real-time routing. By detecting hierarchical community structure in road networks, we develop a community-based hierarchical graph model that supports efficient path computation on large road networks. We then propose a new hierarchical routing algorithm that can significantly reduce the search space over the conventional algorithms with acceptable loss of accuracy. Finally, we evaluate our approach experimentally using a large, real-world road network to show the gain in performance.

Energy and Throughput Optimized, Cluster Based Hierarchical Routing Algorithm for Heterogeneous Wireless Sensor Networks

We propose a novel cluster based distributed routing algorithm in a generalized form for heterogeneous wireless sensor networks. Heterogeneity with respect to number/types of communication interfaces, their data rates and that with respect to energy dissipation model have been exploited for energy and throughput efficiency. The algorithm makes routing assignment optimized for throughput and energy and has a complexity of N/K*logN+k2logk approximately, where N is the number of nodes and k is the number of kcluster heads. Performance experiments confirm the effectiveness of throughput and energy optimizations. The importance of choosing an optimal cluster radius has been shown. The energy consumption in the network scales up well with respect to the network size.

Load balancing-based hierarchical routing algorithm for wireless multimedia sensor networks

Wireless multimedia sensor networks (WMSNs) have the characteristics of the limited resources, the variable channel capacity, the dynamic links and the high data redundancy, which poses the great challenges to the quality of service (QoS) routing of WMSNs. Addressing these challenges, a load balancing-based hierarchical routing algorithm for WMSNs (LBHR) is proposed. Firstly, the network is divided by a novel clustering algorithm. Then the inter-cluster routing is built by the improved ant colony optimization algorithm to find a primary path and some backup paths. And the intra-cluster routing is built by the minimum spanning tree algorithm. The theoretical analysis and simulation experiments demonstrate that the LBHR has better scalability, adaptability, load balancing, higher transmission success rate and lower end-to-end delay compared with other routing algorithms. Thus, the LBHR can effectively prolong the network lifetime and guarantee the QoS of data transmission.

EBDHR: Energy Balancing and Dynamic Hierarchical Routing algorithm for wireless sensor networks

Due to energy resources constraint in wireless sensor networks, balancing energy consumption is very important in increasing the network life time. In this paper, the new hierarchical and dynamic routing algorithm is proposed to balance energy consumption among the nodes and to prevent from energy holing problem. Simulation results show that the proposed algorithm prolongs the network lifetime about 40% compared to the LEACH protocol.

Energy-Efficient Self-Organizing Routing for Wireless Mobile Networks

The instant deployment without relying on an existing infrastructure makes mobile ad hoc networks (MANET) a striking choice for many dynamic situations. An efficient MANET protocol may be applied to other important emerging wireless technologies, such as wireless mesh and sensor networks. This article proposes a hierarchical routing scheme that is scalable, energy efficient, and self-organizing. The new algorithm that is discussed in this article is the Dynamic Leader Set Generation (DLSG). This algorithm dynamically selects leader nodes based on traffic demand, locality, and residual energy level, and de-selects them based on residual energy. Therefore, energy consumption and traffic load are balanced throughout the network, and the network reorganizes itself around the dynamically selected leader nodes. Time, space, and message complexities are formally analyzed and implementation issues are also addressed. Incorporating the IEEE 802.11 medium access control mechanism and including the power saving mode, performance evaluation is carried out by simulating DLSG and four existing hierarchical routing algorithms. It shows that DLSG successfully extends network lifetime by 20 to 50% while achieving a comparable level of network performance.

Quasi-Hierarchical Routing Algorithm for ZigBee/IEEE 802.15.4 Networks

ZigBee recently has been used a lot in wireless sensor networks because of its low power consumption and affordable chips. However, ZigBee's existing hierarchical routing algorithm has a disadvantage in that a node may communicate with a nearby node over several hops. In this letter we propose a Quasi-Hierarchical Routing (QHR) algorithm that can improve the ZigBee hierarchical routing method's inefficiency by using brief information on neighbors within radio range. The network simulation evaluates this QHR's performance by comparing it to other ZigBee routing schemes.

Route computation in large road networks: a hierarchical approach

The optimal route between a given origin and destination needs to be computed in a fast and efficient manner in dynamic route guidance systems. Conventional routing algorithms have been found to be inadequate when applied directly to large road networks. Algorithms based on the concept of hierarchical abstraction make use of the knowledge about the road network to reduce search and provide near-optimal solutions. A generic procedure is presented for organising a given road network as a multiple-layer hierarchy. An efficient hierarchical routing algorithm is proposed, which breaks down the route search into a number of individual searches in small sub-networks. The algorithm incorporates a heuristic layer-switching technique to improve its performance without compromising the accuracy. The hierarchical routing algorithm was tested on the road network of Singapore and the solutions were found to be comparable to the optimal least-cost paths.

Hierarchical Mathematic Model and Hierarchical Routing Algorithm

A hierarchical mathematic model of multi-layers satellite network is built in this paper. Based on the research of the mathematic model,a new hierarchical routing algorithm is proposed for multi-layers satellite network.The simulation results show that it has faster computing rate and has better performance in time delay.The routing performance of the multi-layers satellite network is effectively improved.

PERFORMANCE ANALYSIS AND IMPROVEMENT OF ZIGBEE ROUTING PROTOCOL

ZigBee is a recent wireless standard based on IEEE 802.15.4 for Personal Area Networks. Its use in Wireless Sensor Networks arouses many interests. In this paper, a performance analysis and an improvement of ZigBee routing protocol are carried out. ZigBee routing protocol uses a modified AODV by default and Hierarchical Tree Routing as last resort. Firstly, these two algorithms are compared in terms of delay performance and energy consumption. The results showed that Hierarchical Tree Routing provides shorter average end to end delay but performs poorly in terms of energy consumption. So for supporting real time communication, it is desirable to freely choose one or another according to the type of traffic (realtime and non real-time). Secondly, Hierarchical Tree Routing algorithm is slightly modified to provide shorter delays than the original one.

Heuristic techniques for accelerating hierarchical routing on road networks

The route computation module is one of the most important functional blocks in a dynamic route guidance system. Although various algorithms exist for finding the shortest path, their performance tends to deteriorate as the network size increases. We present an efficient hierarchical routing algorithm that finds a near-optimal route and evaluate it on a large city road network. Solutions provided by the hierarchical routing algorithm are compared with the optimal solutions to analyze and quantify the loss of accuracy. We propose a novel yet simple heuristic to substantially improve the performance of the hierarchical routing algorithm with acceptable loss of accuracy. A network pruning technique has been incorporated into the algorithm to reduce the search space and the correctness of the results is evaluated. The improved hierarchical routing algorithm that incorporates the heuristic techniques has been found to be over 50 times faster than a typical shortest path algorithm.

A QoS-based routing algorithm for PNNI ATM networks

Although the ATM Forum has proposed the Private Network–Network Interface (PNNI) specification to facilitate routing in ATM networks, path selection or routing algorithms that guarantee users' multiple Quality of Service (QoS) requirements remain an open issue since the PNNI protocol only provides a routing framework and does not standardize on a method of finding an appropriate path. In this paper, we propose a heuristic routing algorithm called the Backward Hierarchical Routing Algorithm (BHRA) for ATM networks, which is compliant with the PNNI protocol. BHRA uses an adaptive and iterative path search approach and takes advantage of the PNNI hierarchical network structure. It consists of three components: (1) a path selection algorithm, (2) a rerouting mechanism, and (3) inter-class resource sharing. The BHRA has been simulated using the BONeS network simulation tool and the simulation results show that call setup time is significantly reduced, and the computational overhead and call blocking probability are lower, compared to other PNNI routing algorithms. Network throughput is also improved by evenly distributing the traffic among several eligible paths. A multicast routing extension to BHRA is also presented.

QoS-based routing algorithms for ATM networks

This paper presents a planned routing algorithm (PRA) and a hierarchical routing algorithm (HRA) for ATM networks. The PRA can establish the multicast tree with the presence of bandwidth and delay constraints. The HRA can be compliant with the PNNI specification from the ATM Forum. It uses an adaptive and iterative path search approach and takes advantage of the PNNI hierarchical network structure to reduce path computation complexity and maximize network throughput. The performances of the PRA and HRA are evaluated by simulations. The simulation results show that the PRA can provide the best performance while the complexity is acceptable and the HRA can reduce processing time and improve network utilization, and both are suited for QoS requirements of ATM networks’ routing.

Virtual Topology Based Routing Protocol for Multihop Dynamic Wireless Networks

In this paper, a new hierarchical multihop routing algorithm and its performance evaluation is presented for fully dynamic wireless networks. The routing algorithm operates on a virtual topology ob...

A loop-free routing protocol for large-scale internets using distance vectors

The loop-free path-finding algorithm (LPA) has been shown to maintain loop-free routing tables and to obtain correct routing tables after topological and link-cost changes faster and with less processing and communication overhead than link-state algorithms and prior loop-free routing algorithms based on vectors of distances. The limitation of LPA and prior routing algorithms based on routing trees has been the fact that, because LPA operates by communicating shortest-path routing trees incrementally among neighbor nodes, it forces routers to maintain more ‘host routes’ than would be needed in a traditional distance vector algorithm. Maintaining such information incurs additional storage overhead and may not be feasible in some cases (e.g. due to subnetting). To remedy this, and to provide a scalable Internet routing solution, we propose a new hierarchical routing algorithm that combines LPA with the area-based hierarchical routing scheme first proposed by McQuillan for distance-vector algorithms. The new algorithm, which we call the hierarchical information path-based routing (HIPR) algorithm, accommodates an arbitrary number of aggregation levels and can be viewed as a distributed version of Dijkstra's algorithm running over a hierarchical graph. HIPR is verified to be loop-free and correct. Simulations are used to show that HIPR is much more efficient than OSPF in terms of speed, communication and processing overhead required to converge to correct routing tables. HIPR constitutes the basis for future Internet routing protocols that are as simple as RIPv2, but with no looping and better performance than protocols based on link-states.

An overview of quality of service routing for next-generation high-speed networks: problems and solutions

The upcoming gigabit-per-second high-speed networks are expected to support a wide range of communication-intensive real-time multimedia applications. The requirement for timely delivery of digitized audio-visual information raises new challenges for next-generation integrated services broadband networks. One of the key issues is QoS routing. It selects network routes with sufficient resources for the requested QoS parameters. The goal of routing solutions is twofold: (1) satisfying the QoS requirements for every admitted connection, and (2) achieving global efficiency in resource utilization. Many unicast/multicast QoS routing algorithms have been published, and they work with a variety of QoS requirements and resource constraints. Overall, they can be partitioned into three broad classes: (1) source routing, (2) distributed routing, and (3) hierarchical routing algorithms. We give an overview of the QoS routing problem as well as the existing solutions. We present the strengths and weaknesses of different routing strategies, and outline the challenges. We also discuss the basic algorithms in each class, classify and compare them, and point out possible future directions in the QoS routing area.

Hybrid routing

A general-purpose routing algorithm for very-large-scale integrated (VLSI) circuits and printed circuit board (PCB) designs is proposed. Ideas behind the maze-running algorithm and the hierarchical routing algorithm are combined into a powerful algorithm called hybrid routing. The new algorithm demonstrates a speed compatible to a hierarchical router and produces routings with quality equivalent to that obtained by a maze router. Hybrid routing is based on the maze-running method with a third search dimension added. The extra search space is built by recursively constructing a hierarchy of coarser grid meshes. By means of a parameter-controlled expansion into the coarser meshes, the hybrid router is able to find the preferred search region very quickly and will not miss local information as a hierarchical router does. A user-given parameter can turn the algorithm into a pure maze router, a pure hierarchical router, or a wide spectrum of hybrid routers with different speed/quality characteristics between the extremes. The algorithm has been implemented and integrated into a global router that can handle large-scale routing, such as that encountered in the sea-of-gates layout. >

A hardware accelerator for hierarchical VLSI routing

Wire routing is a cpu-bound task in the physical design of VLSI circuits. In the recent past, there has been a widespread interest in speeding up routing algorithms through the use of parallel processing techniques. In this paper we are concerned with the hardware acceleration of a hierarchical routing algorithm, known as the cut-and-paste routing algorithm. This approach for routing is relatively new, and is based on the powerful divide-and-conquer strategy. The area of the chip is recursively divided into smaller and smaller regions, until the routing problem within a region can be handled by a simple optimal router. Then the adjacent regions are successively pasted together to obtain the routing of the entire chip. We identify the inherent parallelism in the algorithm, and show that a parallel router based on the reduced array architecture can be developed for its efficient execution. The advantages of using the reduced array include a reduction in processor count, improved processor utilization, and ease of VLSI implementation.