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Showing papers on "Geographic routing published in 2003"


Journal ArticleDOI
11 May 2003
TL;DR: This work proposes security goals for routing in sensor networks, shows how attacks against ad-hoc and peer-to-peer networks can be adapted into powerful attacks against sensors, and introduces two classes of novel attacks against sensor networks sinkholes and HELLO floods.
Abstract: We consider routing security in wireless sensor networks. Many sensor network routing protocols have been proposed, but none of them have been designed with security as a goal. We propose security goals for routing in sensor networks, show how attacks against ad-hoc and peer-to-peer networks can be adapted into powerful attacks against sensor networks, introduce two classes of novel attacks against sensor networks sinkholes and HELLO floods, and analyze the security of all the major sensor network routing protocols. We describe crippling attacks against all of them and suggest countermeasures and design considerations. This is the first such analysis of secure routing in sensor networks.

2,946 citations


Journal ArticleDOI
TL;DR: A probabilistic routing protocol for intermittently connected networks where there is no guarantee that a fully connected path between source and destination exist at any time, rendering traditional routing protocols unable to deliver messages between hosts.
Abstract: We consider the problem of routing in intermittently connected networks. In such networks there is no guarantee that a fully connected path between source and destination exist at any time, rendering traditional routing protocols unable to deliver messages between hosts. We propose a probabilistic routing protocol for such networks.

2,530 citations


Proceedings ArticleDOI
15 Sep 2003
TL;DR: A novel randomized network coding approach for robust, distributed transmission and compression of information in networks is presented, and its advantages over routing-based approaches are demonstrated.
Abstract: A novel randomized network coding approach for robust, distributed transmission and compression of information in networks is presented, and its advantages over routing-based approaches is demonstrated.

1,171 citations


Proceedings ArticleDOI
14 Sep 2003
TL;DR: This paper defines a scalable coordinate-based routing algorithm that does not rely on location information, and thus can be used in a wide variety of ad hoc and sensornet environments.
Abstract: For many years, scalable routing for wireless communication systems was a compelling but elusive goal. Recently, several routing algorithms that exploit geographic information (e.g. GPSR) have been proposed to achieve this goal. These algorithms refer to nodes by their location, not address, and use those coordinates to route greedily, when possible, towards the destination. However, there are many situations where location information is not available at the nodes, and so geographic methods cannot be used. In this paper we define a scalable coordinate-based routing algorithm that does not rely on location information, and thus can be used in a wide variety of ad hoc and sensornet environments.

898 citations


Proceedings ArticleDOI
13 Jul 2003
TL;DR: A new geometric routing algorithm is proposed which is outstandingly efficient on practical average-case networks, however is also in theory asymptotically worst-case optimal and the formerly necessary assumption that the distance between network nodes may not fall below a constant value is dropped.
Abstract: All too often a seemingly insurmountable divide between theory and practice can be witnessed. In this paper we try to contribute to narrowing this gap in the field of ad-hoc routing. In particular we consider two aspects: We propose a new geometric routing algorithm which is outstandingly efficient on practical average-case networks, however is also in theory asymptotically worst-case optimal. On the other hand we are able to drop the formerly necessary assumption that the distance between network nodes may not fall below a constant value, an assumption that cannot be maintained for practical networks. Abandoning this assumption we identify from a theoretical point of view two fundamentamentally different classes of cost metrics for routing in ad-hoc networks.

772 citations


Book ChapterDOI
12 Oct 2003
TL;DR: The issues of multipath routing in MANETs are examined to support application constraints such as reliability, load-balancing, energy-conservation, and Quality-of-Service (QoS).
Abstract: Mobile ad hoc networks (MANETs) consist of a collection of wireless mobile nodes which dynamically exchange data among themselves without the reliance on a fixed base station or a wired backbone network MANET nodes are typically distinguished by their limited power, processing, and memory resources as well as high degree of mobility In such networks, the wireless mobile nodes may dynamically enter the network as well as leave the network Due to the limited transmission range of wireless network nodes, multiple hops are usually needed for a node to exchange information with any other node in the network Thus routing is a crucial issue to the design of a MANET In this paper, we specifically examine the issues of multipath routing in MANETs Multipath routing allows the establishment of multiple paths between a single source and single destination node It is typically proposed in order to increase the reliability of data transmission (ie, fault tolerance) or to provide load balancing Load balancing is of especial importance in MANETs because of the limited bandwidth between the nodes We also discuss the application of multipath routing to support application constraints such as reliability, load-balancing, energy-conservation, and Quality-of-Service (QoS)

525 citations


Journal ArticleDOI
01 Nov 2003
TL;DR: A mechanism to perform position-based unicast forwarding without the help of beacons is proposed and results show that CBF significantly reduces the load on the wireless channel required to achieve a specific delivery rate compared to the load a beacon-based greedy forwarding strategy generates.
Abstract: Existing position-based unicast routing algorithms which forward packets in the geographic direction of the destination require that the forwarding node knows the positions of all neighbors in its transmission range. This information on direct neighbors is gained by observing beacon messages each node sends out periodically. Due to mobility, the information that a node receives about its neighbors becomes outdated, leading either to a significant decrease in the packet delivery rate or to a steep increase in load on the wireless channel as node mobility increases. In this paper, we propose a mechanism to perform position-based unicast forwarding without the help of beacons. In our contention-based forwarding scheme (CBF) the next hop is selected through a distributed contention process based on the actual positions of all current neighbors. For the contention process, CBF makes use of biased timers. To avoid packet duplication, the first node that is selected suppresses the selection of further nodes. We propose three suppression strategies which vary with respect to forwarding efficiency and suppression characteristics. We analyze the behavior of CBF with all three suppression strategies and compare it to an existing greedy position-based routing approach by means of simulation with ns-2. Our results show that CBF significantly reduces the load on the wireless channel required to achieve a specific delivery rate compared to the load a beacon-based greedy forwarding strategy generates.

481 citations


Journal ArticleDOI
01 Jan 2003
TL;DR: In this paper, the GPSR geographic routing algorithm and a new generation of efficient peer-to-peer lookup systems (such as Chord, CAN, Pastry, Tapestry, etc.).
Abstract: Sensornets are large-scale distributed sensing networks comprised of many small sensing devices equipped with memory, processors, and short-range wireless communication. Making effective use of sensornet data will require scalable, self-organizing, and energy-efficient data dissemination algorithms. Recent work has identified data-centric routing as one such method. In this paper we suggest that a companion method, data-centric storage, may also be a useful approach. While there are many ways to achieve data-centric storage, this paper proposes a mechanism that builds upon two recent advances; (1) the GPSR geographic routing algorithm and (2) a new generation of efficient peer-to-peer lookup systems (such as Chord, CAN, Pastry, Tapestry, etc.). We evaluate the performance of data-centric storage and two other dissemination approaches in several sensornet scenarios and identify the conditions under which the various approaches are preferable.

477 citations


Proceedings ArticleDOI
01 Jun 2003
TL;DR: Under standard mobility processes, the simulations show that route discovery cost can be decreased by an order of magnitude, a significant gain given thatroute discovery is a major source of routing overhead in ad hoc networks.
Abstract: We propose FResher Encounter SearcH (FRESH), a simple algorithm for efficient route discovery in mobile ad hoc networks. Nodes keep a record of their most recent encounter times with all other nodes. Instead of searching for the destination, the source node searches for any intermediate node that encountered the destination more recently than did the source node itself. The intermediate node then searches for a node that encountered the destination yet more recently, and the procedure iterates until the destination is reached. Therefore, FRESH replaces the single network-wide search of current proposals with a succession of smaller searches, resulting in a cheaper route discovery. Routes obtained are loop-free.The performance of such a scheme will depend on the nodes' mobility processes. Under standard mobility processes our simulations show that route discovery cost can be decreased by an order of magnitude, a significant gain given that route discovery is a major source of routing overhead in ad hoc networks.

455 citations


Proceedings ArticleDOI
05 Nov 2003
TL;DR: The design of a distributed index for multi-dimensional data (or DIM) is described, which uses a novel geographic embedding of a classical index data structure, and is built upon the GPSR geographic routing algorithm.
Abstract: In many sensor networks, data or events are named by attributes. Many of these attributes have scalar values, so one natural way to query events of interest is to use a multi-dimensional range query. An example is: "List all events whose temperature lies between 50° and 60°, and whose light levels lie between 10 and 15." Such queries are useful for correlating events occurring within the network.In this paper, we describe the design of a distributed index that scalably supports multi-dimensional range queries. Our distributed index for multi-dimensional data (or DIM) uses a novel geographic embedding of a classical index data structure, and is built upon the GPSR geographic routing algorithm. Our analysis reveals that, under reasonable assumptions about query distributions, DIMs scale quite well with network size (both insertion and query costs scale as O(√N)). In detailed simulations, we show that in practice, the insertion and query costs of other alternatives are sometimes an order of magnitude more than the costs of DIMs, even for moderately sized network. Finally, experiments on a small scale testbed validate the feasibility of DIMs.

443 citations


Proceedings ArticleDOI
14 Sep 2003
TL;DR: The approach that is used is quite flexible and is a promising method to handle more sophisticated interference conditions, multiple channels, multiple antennas, and routing with diversity requirements.
Abstract: This paper considers the problem of determining the achievable rates in multi-hop wireless networks. We consider the problem of jointly routing the flows and scheduling transmissions to achieve a given rate vector. We develop tight necessary and sufficient conditions for the achievability of the rate vector. We develop efficient and easy to implement Fully Polynomial Time Approximation Schemes for solving the routing problem. The scheduling problem is a solved as a graph edge-coloring problem. We show that this approach guarantees that the solution obtained is within 67% of the optimal solution in the worst case and, in practice, is typically within about 80% of the optimal solution. The approach that we use is quite flexible and is a promising method to handle more sophisticated interference conditions, multiple channels, multiple antennas, and routing with diversity requirements.

Proceedings ArticleDOI
David Applegate1, Edith Cohen1
25 Aug 2003
TL;DR: It is possible to obtain a robust routing that guarantees a nearly optimal utilization with a fairly limited knowledge of the applicable traffic demands, according to a diverse collection of ISP networks.
Abstract: Intra-domain traffic engineering can significantly enhance the performance of large IP backbone networks. Two important components of traffic engineering are understanding the traffic demandsand configuring the routing protocols. These two components are inter-linked, as it is widely believed that an accurate view of traffic is important for optimizing the configuration of routing protocols and through that, the utilization of the network.This basic premise, however, never seems to have been quantified --How important is accurate knowledge of traffic demands for obtaining good utilization of the network? Since traffic demand values are dynamic and illusive, is it possible to obtain a routing that is "robust" to variations in demands? Armed with enhanced recent algorithmic tools we explore these questions on a diverse collection of ISP networks. We arrive at a surprising conclusion: it is possible to obtain a robust routing that guarantees a nearly optimal utilization with a fairly limited knowledge of the applicable traffic demands.

Proceedings ArticleDOI
19 Sep 2003
TL;DR: It is proved that in Quasi Unit Disk Graphs flooding is an asymptotically message-optimal routing technique, and the geometric routing algorithm being more efficient above all in dense networks, and classic geometric routing is possible with the same performance guarantees as for Unit Diskgraphs if d = 1/v2.
Abstract: In this paper we study a model for ad-hoc networks close enough to reality as to represent existing networks, being at the same time concise enough to promote strong theoretical results. The Quasi Unit Disk Graph model contains all edges shorter than a parameter d between 0 and 1 and no edges longer than 1.We show that .in comparison to the cost known on Unit Disk Graphs .the complexity results in this model contain the additional factor 1 /d2. We prove that in Quasi Unit Disk Graphs flooding is an asymptotically message-optimal routing technique, provide a geometric routing algorithm being more efficient above all in dense networks, and show that classic geometric routing is possible with the same performance guarantees as for Unit Disk Graphs if d = 1/v2.

Proceedings ArticleDOI
05 Nov 2003
TL;DR: GEM (Graph EMbedding for sensor networks), an infrastructure for node-to-node routing and data-centric storage and information processing in sensor networks, is introduced and a concrete graph embedding method, VPCS (Virtual Polar Coordinate Space), is developed.
Abstract: The widespread deployment of sensor networks is on the horizon. One of the main challenges in sensor networks is to process and aggregate data in the network rather than wasting energy by sending large amounts of raw data to reply to a query. Some efficient data dissemination methods, particularly data-centric storage and information aggregation, rely on efficient routing from one node to another. In this paper we introduce GEM (Graph EMbedding for sensor networks), an infrastructure for node-to-node routing and data-centric storage and information processing in sensor networks. Unlike previous approaches, it does not depend on geographic information, and it works well even in the face of physical obstacles. In GEM, we construct a labeled graph that can be embedded in the original network topology in an efficient and distributed fashion. In that graph, each node is given a label that encodes its position in the original network topology. This allows messages to be efficiently routed through the network, while each node only needs to know the labels of its neighbors.To demonstrate how GEM can be applied, we have developed a concrete graph embedding method, VPCS (Virtual Polar Coordinate Space). In VPCS, we embed a ringed tree into the network topology, and label the nodes in such a manner as to create a virtual polar coordinate space. We have also developed VPCR, an efficient routing algorithm that uses VPCS. VPCR is the first algorithm for node-to-node routing that guarantees reachability, requires each node to keep state only about its immediate neighbors, and requires no geographic information. Our simulation results show that VPCR is robust on dynamic networks, works well in the face of voids and obstacles, and scales well with network size and density.

Proceedings ArticleDOI
25 Aug 2003
TL;DR: This paper uses a game-theoretic approach to investigate the performance of selfish routing in Internet-like environments based on realistic topologies and traffic demands in simulations and shows that in contrast to theoretical worst cases, selfish routing achieves close to optimal average latency in such environments.
Abstract: A recent trend in routing research is to avoid inefficiencies in network-level routing by allowing hosts to either choose routes themselves (e.g., source routing) or use overlay routing networks (e.g., Detour or RON). Such approaches result in selfish routing, because routing decisions are no longer based on system-wide criteria but are instead designed to optimize host-based or overlay-based metrics. A series of theoretical results showing that selfish routing can result in suboptimal system behavior have cast doubts on this approach. In this paper, we use a game-theoretic approach to investigate the performance of selfish routing in Internet-like environments. We focus on intra-domain network environments and use realistic topologies and traffic demands in our simulations. We show that in contrast to theoretical worst cases, selfish routing achieves close to optimal average latency in such environments. However, such performance benefit comes at the expense of significantly increased congestion on certain links. Moreover, the adaptive nature of selfish overlays can significantly reduce the effectiveness of traffic engineering by making network traffic less predictable.

Proceedings ArticleDOI
11 May 2003
TL;DR: The proposed routing algorithm, called Data Funneling, allows the network to considerably reduce the amount of energy spent on communication setup and control, an important concern in low data-rate communication.
Abstract: This paper considers the problem of minimizing the amount of communication needed to send readings from a set of sensors to a single destination in energy constrained wireless networks. Substantial gains can be obtained using packet aggregation techniques while routing. The proposed routing algorithm, called Data Funneling, allows the network to considerably reduce the amount of energy spent on communication setup and control, an important concern in low data-rate communication. This is achieved by sending only one data stream from a group of sensors to the destination instead of having an individual data stream from each sensor to the destination. Doing so also reduces the probability of packet collisions in the wireless medium because the same amount of information can be transmitted by having fewer nodes send longer packets. Additional gains can be realized by efficient compression of data. This is achieved by losslessly compressing the data by encoding information in the ordering of the sensors' packets. This "coding by ordering" scheme compresses data by suppressing certain readings and encoding their values in the ordering of the remaining packets. Using these techniques together can more than halve the energy spent in communication.

Proceedings ArticleDOI
09 Jul 2003
TL;DR: A new algorithm for routing of messages in ad-hoc networks where the nodes are energy-constrained achieves a logarithmic competitive ratio and performs better than previously proposed algorithms for other suggested metrics such as network lifetime maximization.
Abstract: A new algorithm for routing of messages in ad-hoc networks where the nodes are energy-constrained is presented. The routing objective is to maximize the total number of messages that can be successfully sent over the network without knowing any information regarding future message arrivals or message generation rates. From a theoretical perspective, we show that if admission control of messages is permitted, then the worst-case performance of our algorithm is within a factor of O(log(network size)) of the best achievable solution. In other words, our algorithm achieves a logarithmic competitive ratio. Our approach provides sound theoretical backing for several observations that have been made by previous researchers. From a practical perspective, we show by extensive simulations that the performance of the algorithm is very good even in the absence of admission control (the admission control being necessary only to prove the competitive ratio result), and that it also performs better than previously proposed algorithms for other suggested metrics such as network lifetime maximization. Our algorithm uses a single shortest path computation, and is amenable to efficient implementation. We also evaluate by simulations the performance impact of inexact knowledge of residual battery energy, and the impact of energy drain due to dissemination of residual energy information.

Proceedings ArticleDOI
19 Dec 2003
TL;DR: In this paper, a spatially aware packet routing approach is proposed to predict permanent topology holes caused by spatial constraints and avoid them beforehand, which can be used in combination with any existing geographic forwarding protocol as an extension.
Abstract: Inter-vehicle communication can become an important building block for ITS telematics applications like safety and warning functions. Mobile ad hoc networks (MANETs) can serve as a local wireless network for exchanging information between cars for cooperative driver assistance applications. For the routing of data packets in such large-scale MANETs consisting of vehicles on the road, geographic multi-hop packet forwarding is a promising approach. However, a main drawback is that it performs poorly in networks with many topology holes. In this paper, we propose a spatially aware packet routing approach to predict permanent topology holes caused by spatial constraints and avoid them beforehand. This approach is generic and can be used in combination with any existing geographic forwarding protocol as an extension. Our simulations demonstrate that spatial awareness can significantly improve geographic forwarding performance in situations with many permanent topology holes, like in dynamic vehicle networks.

Proceedings ArticleDOI
20 Mar 2003
TL;DR: In this article, the authors proposed a new multipath routing algorithm that enables the trade-off between the amount of traffic and the reliability of WSNs, where the data packet is split in k subpackets (k = number of disjoined paths from source to destination) and only E/sub k/subpackets are necessary to rebuild the original data packet.
Abstract: In wireless sensor networks (WSN) data produced by one or more sources usually has to be routed through several intermediate nodes to reach the destination. Problems arise when intermediate nodes to reach the destination. Problems arise when intermediate nodes fail to forward the incoming messages. The reliability of the system can be increased by providing several paths from source to destination and sending the same packet through each of them (the algorithm is known as multipath routing). Using this technique, the traffic increases significantly. In this paper, we analyze a new mechanism that enables the trade-off between the amount of traffic and the reliability. The data packet is split in k subpackets (k = number of disjoined paths from source to destination). If only E/sub k/ subpackets (E/sub k/ < k) are necessary to rebuild the original data packet (condition obtained by adding redundancy to each subpacket), then the trade-off between traffic and reliability can be controlled.

Journal ArticleDOI
Jian-Qiang Hu1
TL;DR: An integer linear programming formulation is developed and it is shown through numerical results that it is a very viable method to solve the diverse routing problem for most optical networks found in many applications which typically have no more than a few hundred nodes and fiber spans.
Abstract: We study the diverse routing problem in optical mesh networks. We use a general framework based on shared risk link groups to model the problem. We prove that the diverse routing problem is indeed NP-complete, a result that has been conjectured by several researchers previously. In fact, we show that even the fiber-span-disjoint paths problem, a special case of the diverse routing problem, is also NP-complete. We then develop an integer linear programming formulation and show through numerical results that it is a very viable method to solve the diverse routing problem for most optical networks found in many applications which typically have no more than a few hundred nodes and fiber spans.

Patent
24 Dec 2003
TL;DR: In this article, a wireless data communication system includes a number of mobile data terminals organized into one more peer groups forming a dynamic mesh-like network, each terminal includes a transceiver to permit the direct exchange of wireless messages containing routing information including a destination address with any other terminal within range, and a processor programmed to prepare outgoing messages and extract the routing information contained within the wireless messages.
Abstract: A wireless data communication system includes a number of mobile data terminals organized into one more peer groups forming a dynamic mesh-like network. Each terminal includes a transceiver to permit the direct exchange of wireless messages containing routing information including a destination address with any other terminal within range, and a processor programmed to prepare outgoing messages and extract the routing information contained within the wireless messages. When the routing information contains an identification code of the receiving terminal, it either presents a received message for local processing in the receiving terminal if the received message is addressed thereto or forwards the received message to another terminal identified in the extracted routing information.

Proceedings ArticleDOI
30 Jun 2003
TL;DR: A general algorithm is proposed, in which message is forwarded to exactly those neighbors, which may be best choices for a possible position of destination (using the appropriate criterion), in which memoryless and past traffic memorization variants of each scheme are proposed.
Abstract: A broad variety of location dependent services will become feasible in the near future due to the use of the Global Positioning System (GPS), which provides location information (latitude, longitude and possibly height) and global timing to mobile users. Routing is a problem of sending a message from a source to a destination. Geocasting is a problem of sending a message to all nodes located within a region (e.g. circle or square). Recently, several localized GPS based routing and geocasting protocols for a mobile ad hoc network were reported in literature. In directional (DIR) routing and geocasting methods, node A (the source or intermediate node) transmits a message m to all neighbors located between the two tangents from A to the region that could contain the destination. It was shown that memoryless directional methods might create loops in routing process. In two other proposed methods (proven to be loop-free), geographic distance (GEDIR) or most forward progress within radius (MFR) routing, node A forwards the message to its neighbor who is closest to destination, or has greatest progress towards destination (respectively). In this paper, we propose a general algorithm (based on a unified framework for both routing and geocasting problems), in which message is forwarded to exactly those neighbors, which may be best choices for a possible position of destination (using the appropriate criterion). We then propose and discuss new V-GEDIR and CH-MFR methods and define R-DIR, modified version of existing directional methods. In V-GEDIR method, these neighbors are determined by intersecting the Voronoi diagram of neighbors with the circle (or rectangle) of possible positions of destination, while the portion of the complex hull of neighboring node is analogously used in the CH-MFR method. Routing and geocasting algorithms differ only inside the circle/rectangle. We propose memoryless and past traffic memorization variants of each scheme. The proposed methods may be also used for the destination search phase allowing the application of different routing schemes after the exact destination of position is discovered. Memoryless V-GEDIR and CH-MFR algorithms are loop-free, and have smaller flooding rate (with similar success rate) compared to directional method. Simulations involving the proposed and some known algorithms are in progress and confirm our expectations.

Proceedings ArticleDOI
09 Jul 2003
TL;DR: This paper defines and analyzes a very simple algorithm called EASE (exponential age search) and shows that in a model where N nodes perform independent random walks on a square lattice, the length of the routes computed by EASE are on the same order as the distance between the source and destination even for very large N.
Abstract: Routing in large-scale mobile ad hoc networks is challenging because all the nodes are potentially moving. Geographic routing can partially alleviate this problem, as nodes can make local routing decisions based solely on the destinations' geographic coordinates. However, geographic routing still requires an efficient location service, i.e., a distributed database recording the location of every destination node. Devising efficient, scalable, and robust location services has received considerable attention in recent years. The main purpose of this paper is to show that node mobility can be exploited to disseminate destination location information without incurring any communication overhead. We achieve this by letting each node maintain a local database of the time and location of its last encounter with every other node in the network. This database is consulted by packets to obtain estimates of their destination's current location. As a packet travels towards its destination, it is able to successively refine an estimate of the destination's precise location, because node mobility has "diffused" estimates of that location. We define and analyze a very simple algorithm called EASE (exponential age search) and show that in a model where N nodes perform independent random walks on a square lattice, the length of the routes computed by EASE are on the same order as the distance between the source and destination even for very large N. Therefore, without exchanging any explicit location information, the length of EASE routes are within a constant factor of routes obtained with perfect information. We discuss refinements of the EASE algorithm and evaluate it through extensive simulations. We discuss general conditions such that the mobility diffusion effect leads to efficient routes without an explicit location service. In practical settings, where these conditions may not always be met, we believe that the mobility diffusion effect can complement existing location services and enhance their robustness and scalability.

Patent
31 Jul 2003
TL;DR: In this paper, the source node discovers routing to the destination node, ranks the discovered routes according to at least one link metric, and distributes message data to destination node the routes based on the ranking.
Abstract: A mobile ad-hoc network includes a plurality of intermediate mobile nodes (2, 3, 5) between the source node (1) and the destination node (4), and a plurality of wireless communication links connecting the nodes. The source node discovers routing to the destination node, ranks the discovered routes according to at least one link metric, and distributes message data to the destination node the routes based on the ranking. The link metric may include a measurement of link delay, link capacity, link available capacity, and/or link reliability.

Proceedings ArticleDOI
01 May 2003
TL;DR: A load-balanced adaptive routing algorithm for torus networks, GOAL - Globally Oblivious Adaptive Locally - that provides high throughput on adversarial traffic patterns, matching or exceeding fully randomized routing and exceeding the worst-case performance of Chaos, RLB, and minimal routing by more than 40%.
Abstract: We introduce a load-balanced adaptive routing algorithm for torus networks, GOAL - Globally Oblivious Adaptive Locally - that provides high throughput on adversarial traffic patterns, matching or exceeding fully randomized routing and exceeding the worst-case performance of Chaos [2], RLB [14], and minimal routing [8] by more than 40%. GOAL also preserves locality to provide up to 4.6× the throughput of fully randomized routing [19] on local traffic. GOAL achieves global load balance by randomly choosing the direction to route in each dimension. Local load balance is then achieved by routing in the selected directions adaptively. We compare the throughput, latency, stability and hot-spot performance of GOAL to six previously published routing algorithms on six specific traffic patterns and 1,000 randomly generated permutations.

Proceedings ArticleDOI
01 Dec 2003
TL;DR: A node-centric algorithm that constructs a load-balanced tree in sensor networks of asymmetric architecture is designed and it is found that the algorithm achieves routing trees that are more effectively balanced than the routing based on breadth-first search (BFS) and shortest-path obtained by Dijkstra's algorithm.
Abstract: By spreading the workload across a sensor network, load balancing reduces hot spots in the sensor network and increases the energy lifetime of the sensor network. In this paper, we design a node-centric algorithm that constructs a load-balanced tree in sensor networks of asymmetric architecture. We utilize a Chebyshev Sum metric to evaluate via simulation the balance of the routing trees produced by our algorithm. We find that our algorithm achieves routing trees that are more effectively balanced than the routing based on breadth-first search (BFS) and shortest-path obtained by Dijkstra's algorithm.

Journal ArticleDOI
TL;DR: It is shown that an aggregate information scenario which uses only aggregated and not per-path information provides sufficient information for a suitably developed algorithm to be able to perform almost as well as the complete information scenario.
Abstract: This paper presents new algorithms for dynamic routing of restorable bandwidth-guaranteed paths. We assume that connection requests one-by-one and have to be routed with no a priori knowledge of future arrivals. In order to guarantee restorability, in addition to determining an active path to route each request, an alternate link (node) disjoint backup (restoration) path has to be determined for the request at the time of connection initiation. This joint on-line routing problem is becoming particularly important in optical networks and in multiprotocol label switching (MPLS)-based networks due to the trend in backbone networks toward dynamic provisioning of bandwidth-guaranteed or wavelength paths. A straightforward solution for the restoration problem is to find two disjoint paths. However, this results in excessive resource usage. Given a restoration objective, such as protection against single-link failures, backup path bandwidth usage can be reduced by judicious sharing of backup paths amongst certain active paths while still maintaining restorability. The best sharing performance is achieved if the routing of every path in progress in the network is known to the routing algorithm at the time of a new path setup. We give an integer programming formulation for this problem which is new. Complete path routing knowledge is a reasonable assumption for a centralized routing algorithm. However, it is not often desirable, particularly when distributed routing is preferred. We show that an aggregate information scenario which uses only aggregated and not per-path information provides sufficient information for a suitably developed algorithm to be able to perform almost as well as the complete information scenario. Disseminating this aggregate information is feasible using proposed traffic engineering extensions to routing protocols. We formulate the dynamic restorable bandwidth routing problem in this aggregate information scenario and develop efficient routing algorithms. We show that the performance of our aggregate information-based algorithm is close to the complete information bound.

Proceedings ArticleDOI
25 Aug 2003
TL;DR: This work presents a routing paradigm called PBR that utilizes steepest gradient search methods to route data packets and shows that the family of PBR schemes are loop free, and that the standard shortest path routing algorithms are a special case of the PBR paradigm.
Abstract: We present a routing paradigm called PBR that utilizes steepest gradient search methods to route data packets. More specifically, the PBR paradigm assigns scalar potentials to network elements and forwards packets in the direction of maximum positive force. We show that the family of PBR schemes are loop free and that the standard shortest path routing algorithms are a special case of the PBR paradigm. We then show how to design a potential function that accounts for traffic conditions at a node. The resulting routing algorithm routes around congested areas while preserving the key desirable properties of IP routing mechanisms including hop-by-hop routing, local route computations and statistical multiplexing. Our simulations using the ns simulator indicate that the traffic aware routing algorithm shows significant improvements in end-to-end delay and jitter when compared to standard shortest path routing algorithms. The simulations also indicate that our algorithm does not incur too much control overheads and is fairly stable even when traffic conditions are dynamic.

Proceedings ArticleDOI
02 Apr 2003
TL;DR: Simulation results shows that irrespective of the routing protocol used, this approach improves the lifetime of the system and Load balanced clustering increases the system stability and improves the communication between different nodes in the system.
Abstract: Wireless sensor networks have received increasing attention in recent few years. In many military and civil applications of sensor networks, sensors are constrained in onboard energy supply and are left unattended. Energy, size and cost constraints of such sensors limit the communication range. Therefore, multi-hop wireless connectivity is required to forward data on their behalf to a remote command site. In this paper, we investigate the performance of an algorithm to network these sensors into well defined clusters with less-energy-constrained gateway nodes acting as clusterheads as well as to balance the load among these gateways. Load balanced clustering increases the system stability and improves the communication between different nodes in the system. To evaluate the efficiency of this approach, we studied the performance of sensor networks by applying various different routing protocols. Simulation results shows that irrespective of the routing protocol used, this approach improves the lifetime of the system.

Journal ArticleDOI
11 May 2003
TL;DR: This work proposes Local Positioning System (LPS), a method that makes use of local node capabilities-angle of arrival, range estimations, compasses and accelerometers, in order to internally position only the groups of nodes involved in particular conversations.
Abstract: Position centric approaches, such as Cartesian routing, geographic routing, and the recently proposed trajectory based forwarding (TBF), address scalability issues in large ad hoc networks by using Euclidean space as a complementary name space. These approaches require. that nodes know their position in a common coordinate system. While a GPS receiver in each node would be ideal, in many cases an approximation algorithm is necessary for networks with only a few GPS enabled nodes. These algorithms however require collaboration of large portions of the network, thus imposing an overhead for nodes which do not need positioning, or are mobile. We propose Local Positioning System (LPS), a method that makes use of local node capabilities-angle of arrival, range estimations, compasses and accelerometers, in order to internally position only the groups of nodes involved in particular conversations. Localized positioning enables position centric uses, like discovery, flooding and routing in networks where global positioning is not available.