Showing papers on "Destination-Sequenced Distance Vector routing published in 2005"

Spray and wait: an efficient routing scheme for intermittently connected mobile networks

Abstract: Intermittently connected mobile networks are sparse wireless networks where most of the time there does not exist a complete path from the source to the destination. These networks fall into the general category of Delay Tolerant Networks. There are many real networks that follow this paradigm, for example, wildlife tracking sensor networks, military networks, inter-planetary networks, etc. In this context, conventional routing schemes would fail.To deal with such networks researchers have suggested to use flooding-based routing schemes. While flooding-based schemes have a high probability of delivery, they waste a lot of energy and suffer from severe contention, which can significantly degrade their performance. Furthermore, proposed efforts to significantly reduce the overhead of flooding-based schemes have often be plagued by large delays. With this in mind, we introduce a new routing scheme, called Spray and Wait, that "sprays" a number of copies into the network, and then "waits" till one of these nodes meets the destination.Using theory and simulations we show that Spray and Wait outperforms all existing schemes with respect to both average message delivery delay and number of transmissions per message delivered; its overall performance is close to the optimal scheme. Furthermore, it is highly scalable retaining good performance under a large range of scenarios, unlike other schemes. Finally, it is simple to implement and to optimize in order to achieve given performance goals in practice.

Ariadne: a secure on-demand routing protocol for ad hoc networks

Abstract: An ad hoc network is a group of wireless mobile computers (or nodes), in which individual nodes cooperate by forwarding packets for each other to allow nodes to communicate beyond direct wireless transmission range. Prior research in ad hoc networking has generally studied the routing problem in a non-adversarial setting, assuming a trusted environment. In this paper, we present attacks against routing in ad hoc networks, and we present the design and performance evaluation of a new secure on-demand ad hoc network routing protocol, called Ariadne. Ariadne prevents attackers or compromised nodes from tampering with uncompromised routes consisting of uncompromised nodes, and also prevents many types of Denial-of-Service attacks. In addition, Ariadne is efficient, using only highly efficient symmetric cryptographic primitives.

Joint mobility and routing for lifetime elongation in wireless sensor networks

Abstract: Although many energy efficient/conserving routing protocols have been proposed for wireless sensor networks, the concentration of data traffic towards a small number of base stations remains a major threat to the network lifetime. The main reason is that the sensor nodes located near a base station have to relay data for a large part of the network and thus deplete their batteries very quickly. The solution we propose in this paper suggests that the base station be mobile; in this way, the nodes located close to it change over time. Data collection protocols can then be optimized by taking both base station mobility and multi-hop routing into account. We first study the former, and conclude that the best mobility strategy consists in following the periphery of the network (we assume that the sensors are deployed within a circle). We then consider jointly mobility and routing algorithms in this case, and show that a better routing strategy uses a combination of round routes and short paths. We provide a detailed analytical model for each of our statements, and corroborate it with simulation results. We show that the obtained improvement in terms of network lifetime is in the order of 500%.

Geographic routing in city scenarios

Abstract: Position-based routing, as it is used by protocols like Greedy Perimeter Stateless Routing (GPSR) [5], is very well suited for highly dynamic environments such as inter-vehicle communication on highways. However, it has been discussed that radio obstacles [4], as they are found in urban areas, have a significant negative impact on the performance of position-based routing. In prior work [6] we presented a position-based approach which alleviates this problem and is able to find robust routes within city environments. It is related to the idea of position-based source routing as proposed in [1] for terminode routing. The algorithm needs global knowledge of the city topology as it is provided by a static street map. Given this information the sender determines the junctions that have to be traversed by the packet using the Dijkstra shortest path algorithm. Forwarding between junctions is then done in a position-based fashion. In this short paper we show how position-based routing can be aplied to a city scenario without assuming that nodes have access to a static street map and without using source routing.

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

Abstract: 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.

Adaptive routing for intermittently connected mobile ad hoc networks

Abstract: The vast majority of mobile ad hoc networking research makes a very large assumption - that communication can only take place between nodes that are simultaneously accessible within the same connected cloud (i.e., that communication is synchronous). In reality, this assumption is likely to be a poor one, particularly for sparsely or irregularly populated environments. We present the context-aware routing (CAR) algorithm. CAR is a novel approach to the provision of asynchronous communication in partially-connected mobile ad hoc networks, based on the intelligent placement of messages. We discuss the details of the algorithm, and then present simulation results demonstrating that it is possible for nodes to exploit context information in making local decisions that lead to good delivery ratios and latencies with small overheads.

Beacon vector routing: scalable point-to-point routing in wireless sensornets

Abstract: We propose a practical and scalable technique for point-to-point routing in wireless sensornets. This method, called Beacon Vector Routing (BVR), assigns coordinates to nodes based on the vector of hop count distances to a small set of beacons, and then defines a distance metric on these coordinates. BVR routes packets greedily, forwarding to the next hop that is the closest (according to this beacon vector distance metric) to the destination. We evaluate this approach through a combination of high-level simulation to investigate scaling and design tradeoffs, and a prototype implementation over real testbeds as a necessary reality check.

Authenticated routing for ad hoc networks

Abstract: Initial work in ad hoc routing has considered only the problem of providing efficient mechanisms for finding paths in very dynamic networks, without considering security. Because of this, there are a number of attacks that can be used to manipulate the routing in an ad hoc network. In this paper, we describe these threats, specifically showing their effects on ad hoc on-demand distance vector and dynamic source routing. Our protocol, named authenticated routing for ad hoc networks (ARAN), uses public-key cryptographic mechanisms to defeat all identified attacks. We detail how ARAN can secure routing in environments where nodes are authorized to participate but untrusted to cooperate, as well as environments where participants do not need to be authorized to participate. Through both simulation and experimentation with our publicly available implementation, we characterize and evaluate ARAN and show that it is able to effectively and efficiently discover secure routes within an ad hoc network.

Practical routing in delay-tolerant networks

Abstract: Delay-tolerant networks (DTNs) have the potential to connect devices and areas of the world that are under-served by current networks. A critical challenge for DTNs is determining routes through the network without ever having an end-to-end connection, or even knowing which "routers" will be connected at any given time. Prior approaches have focused either on epidemic message replication or on knowledge of the connectivity schedule. The epidemic approach of replicating messages to all nodes is expensive and does not appear to scale well with increasing load. It can, however, operate without any prior network configuration. The alternatives, by requiring a priori connectivity knowledge, appear infeasible for a self-configuring network.In this paper we present a practical routing protocol that only uses observed information about the network. We designed a metric that estimates how long a message will have to wait before it can be transferred to the next hop. The topology is distributed using a link-state routing protocol, where the link-state packets are "flooded" using epidemic routing. The routing is recomputed when connections are established. Messages are exchanged if the topology suggests that a connected node is "closer" than the current node.We demonstrate through simulation that our protocol provides performance similar to that of schemes that have global knowledge of the network topology, yet without requiring that knowledge. Further, it requires a significantly smaller quantity of buffer, suggesting that our approach will scale with the number of messages in the network, where replication approaches may not.

Stability of end-to-end algorithms for joint routing and rate control

Abstract: Dynamic multi-path routing has the potential to improve the reliability and performance of a communication network, but carries a risk. Routing needs to respond quickly to achieve the potential benefits, but not so quickly that the network is destabilized. This paper studies how rapidly routing can respond, without compromising stability.We present a sufficient condition for the local stability of end-to-end algorithms for joint routing and rate control. The network model considered allows an arbitrary interconnection of sources and resources, and heterogeneous propagation delays. The sufficient condition we present is decentralized: the responsiveness of each route is restricted by the round-trip time of that route alone, and not by the round-trip times of other routes. Our results suggest that stable, scalable load-sharing across paths, based on end-to-end measurements, can be achieved on the same rapid time-scale as rate control, namely the time-scale of round-trip times.

Declarative routing: extensible routing with declarative queries

Abstract: The Internet's core routing infrastructure, while arguably robust and efficient, has proven to be difficult to evolve to accommodate the needs of new applications. Prior research on this problem has included new hard-coded routing protocols on the one hand, and fully extensible Active Networks on the other. In this paper, we explore a new point in this design space that aims to strike a better balance between the extensibility and robustness of a routing infrastructure. The basic idea of our solution, which we call declarative routing, is to express routing protocols using a database query language. We show that our query language is a natural fit for routing, and can express a variety of well-known routing protocols in a compact and clean fashion. We discuss the security of our proposal in terms of its computational expressive power and language design. Via simulation, and deployment on PlanetLab, we demonstrate that our system imposes no fundamental limits relative to traditional protocols, is amenable to query optimizations, and can sustain long-lived routes under network churn and congestion.

TWOACK: preventing selfishness in mobile ad hoc networks

Abstract: Mobile ad hoc networks (MANETs) operate on the basic underlying assumption that all participating nodes fully collaborate in self-organizing functions. However, performing network functions consumes energy and other resources. Therefore, some network nodes may decide against cooperating with others. Providing these selfish nodes, also termed misbehaving nodes, with an incentive to cooperate has been an active research area recently. In this paper, we propose two network-layer acknowledgment-based schemes, termed the TWOACK and the S-TWOACK schemes, which can be simply added-on to any source routing protocol. The TWOACK scheme detects such misbehaving nodes, and then seeks to alleviate the problem by notifying the routing protocol to avoid them in future routes. Details of the two schemes and our evaluation results based on simulations are presented in this paper. We have found that, in a network where up to 40% of the nodes may be misbehaving, the TWOACK scheme results in 20% improvement in packet delivery ratio, with a reasonable additional routing overhead.

DTN routing in a mobility pattern space

Abstract: Routing in delay tolerant networks (DTNs) benefits considerably if one can take advantage of knowledge concerning node mobility. The main contribution of this paper is the definition of a generic routing scheme for DTNs using a high-dimensional Euclidean space constructed upon nodes' mobility patterns. We call this the MobySpace. One way of representing nodes in this space is to give them coordinates that correspond to their probability of being found in each possible location. We present simulation results indicating that such a scheme can be beneficial in a scenario inspired by studies done on real mobility traces. This work should open the way to further use of the virtual space formalism in DTN routing.

New Heuristics for the Vehicle Routing Problem

Abstract: This chapter reviews some of the best metaheuristics proposed in recent years for the Vehicle Routing Problem. These are based on local search, on population search and on learning mechanisms. Comparative computational results are provided on a set of 34 benchmark instances.

A location-based routing method for mobile ad hoc networks

Abstract: Using location information to help routing is often proposed as a means to achieve scalability in large mobile ad hoc networks. However, location-based routing is difficult when there are holes in the network topology and nodes are mobile or frequently disconnected to save battery. Terminode routing, presented here, addresses these issues. It uses a combination of location-based routing (terminode remote routing, TRR), used when the destination is far, and link state-routing (terminode local routing, TLR), used when the destination is close. TRR uses anchored paths, a list of geographic points (not nodes) used as loose source routing information. Anchored paths are discovered and managed by sources, using one of two low overhead protocols: friend assisted path discovery and geographical map-based path discovery. Our simulation results show that terminode routing performs well in networks of various sizes. In smaller networks; the performance is comparable to MANET routing protocols. In larger networks that are not uniformly populated with nodes, terminode routing outperforms, existing location-based or MANET routing protocols.

Vehicle Routing Problem with Time Windows

Abstract: In this chapter we discuss the Vehicle Routing Problem with Time Windows in terms of its mathematical modeling, its structure and decomposition alternatives. We then present the master problem and the subproblem for the column generation approach, respectively. Next, we illustrate a branch-and-bound framework and address acceleration strategies used to increase the efficiency of branch-and-price methods. Then, we describe generalizations of the problem and report computational results for the classic Solomon test sets. Finally, we present our conclusions and discuss some open problems.

Performance comparison of scalable location services for geographic ad hoc routing

Abstract: Geographic routing protocols allow stateless routing in mobile ad hoc networks (MANETs) by taking advantage of the location information of mobile nodes and thus are highly scalable. A central challenge in geographic routing protocols is the design of scalable distributed location services that track mobile node locations. A number of location services have been proposed, but little is known about the relative performance of these location services. In this paper, we perform a detailed performance comparison of three rendezvous-based location services that cover a range of design choices: a quorum-based protocol (XYLS) which disseminates each node's location to O(/spl radic/N) nodes, a hierarchical protocol (GLS) which disseminates each node's location to O(logN) nodes, and a geographic hashing based protocol (GHLS) which disseminates each node's location to O(1) nodes. We present a quantitative model of protocol overheads for predicting the performance tradeoffs of the protocols for static networks. We then analyze the performance impact of mobility on these location services. Finally, we compare the performance of routing protocols equipped with the three location services with two topology-based routing protocols, AODV and DSR, for a wide range of network sizes. Our study demonstrates that when practical MANET sizes are considered, robustness to mobility and the constant factors matter more than the asymptotic costs of location service protocols. In particular, while GLS scales better asymptotically, GHLS is far simpler, transmits fewer control packets, and delivers more data packets than GLS when used with geographic routing in MANETs of sizes considered practical today and in the near future. Similarly, although XYLS scales worse asymptotically than GLS, it transmits fewer control packets and delivers more data packets than GLS in large mobile networks.

An Information Propagation Scheme for VANETs

Abstract: A goal in Vehicular Ad hoc Networks (VANETs) is to enable the dissemination of traffic and road conditions such as local congestion and surface ice as detected by independently moving vehicles. This activity known as Information Warning Functions is useful for vehicles on the highway and enables early reaction. This problem can be described as the direc- tional propagation of information originating from linearly- distributed mobile nodes on a rectilinear plane. By using limited-range packet radios and attribute-based routing, we are able to isolate vehicular from network traffic and permit directional propagation of messages outward from the point of origin. For example, it is desirable to propagate the occurrence of congestion created by an accident in both the forward and backward directions on a highway. We assume the use of multi-hop routing in clusters of connected vehicles to achieve a propagation rate that exceeds the speeds of individual carrier vehicles. We characterize the bounds of information propagation under various traffic patterns and describe a new technique and algorithm that can achieve these limits. We also show an implementation of the dissemination algorithm as a routing protocol using a combination of MANET (mobile ad hoc networking) and DTN (delay tolerant networking) methodologies.

Multicasting in delay tolerant networks: semantic models and routing algorithms

Abstract: Delay tolerant networks (DTNs) are a class of emerging networks that experience frequent and long-duration partitions. These networks have a variety of applications in situations such as crisis environments and deep-space communication. In this paper, we study the problem of multicasting in DTNs. Multicast supports the distribution of data to a group of users, a service needed for many potential DTN applications. While multicasting in the Internet and mobile ad hoc networks has been studied extensively, due to the unique characteristic of frequent partitioning in DTNs, multicasting in DTNs is a considerably different and challenging problem. It not only requires new definitions of multicast semantics but also brings new issues to the design of routing algorithms. In this paper, we propose new semantic models for DTN multicast and develop several multicast routing algorithms with different routing strategies. We present a framework to evaluate these algorithms in DTNs. To the best of our knowledge, this is the first study of multicasting in DTNs. Our objectives are to understand how routing performance is affected by the availability of knowledge about network topology and group membership and to guide the design of DTN routing protocols. Using ns simulations, we find that efficient multicast routing for DTNs can be constructed using only partial knowledge. In addition, accurate topology information is generally more important in routing than up-to-date membership information. We also find that routing algorithms that forward data along multiple paths achieve better delivery ratios, especially when available knowledge is limited.

Geometric spanners for routing in mobile networks

Abstract: We propose a new routing graph, the restricted Delaunay graph (RDG), for mobile ad hoc networks. Combined with a node clustering algorithm, the RDG can be used as an underlying graph for geographic routing protocols. This graph has the following attractive properties: 1) it is planar; 2) between any two graph nodes there exists a path whose length, whether measured in terms of topological or Euclidean distance, is only a constant times the minimum length possible; and 3) the graph can be maintained efficiently in a distributed manner when the nodes move around. Furthermore, each node only needs constant time to make routing decisions. We show by simulation that the RDG outperforms previously proposed routing graphs in the context of the Greedy perimeter stateless routing (GPSR) protocol. Finally, we investigate theoretical bounds on the quality of paths discovered using GPSR.

Routing in ad hoc networks: a case for long hops

Abstract: For multihop wireless networks, a fundamental question is whether it is advantageous to route over many short hops (short-hop routing) or over a smaller number of longer hops (long-hop routing). Short-hop routing has gained a lot of support, and its proponents mainly produce two arguments: reduced energy consumption and higher signal-to-interference ratios. Both arguments stem from a simplified analysis based on crude channel models that neglects delay, end-to-end reliability, bias power consumption, the impact of channel coding, mobility, and routing overhead. In this article we shed more light on these issues by listing 18 reasons why short-hop routing is not as beneficial as it seems to be. We also provide experimental evidence to support this claim. The conclusion is that for many networks, long-hop routing is in every aspect a very competitive strategy.

On-demand power management for ad hoc networks

Abstract: Battery power is an important resource in ad hoc networks. It has been observed that in ad hoc networks, energy consumption does not reflect the communication activities in the network. Many existing energy conservation protocols based on electing a routing backbone for global connectivity are oblivious to traffic characteristics. In this paper, we propose an extensible on-demand power management framework for ad hoc networks that adapts to traffic load. Nodes maintain soft-state timers that determine power management transitions. By monitoring routing control messages and data transmission, these timers are set and refreshed on-demand. Nodes that are not involved in data delivery may go to sleep as supported by the MAC protocol. This soft state is aggregated across multiple flows and its maintenance requires no additional out-of-band messages. We implement a prototype of our framework in the ns-2 simulator that uses the IEEE 802.11 MAC protocol. Simulation studies using our scheme with the Dynamic Source Routing protocol show a reduction in energy consumption near 50% when compared to a network without power management under both long-lived CBR traffic and on–off traffic loads, with comparable throughput and latency. Preliminary results also show that it outperforms existing routing backbone election approaches.

On routing in random Rayleigh fading networks

Abstract: This paper addresses the routing problem for large wireless networks of randomly distributed nodes with Rayleigh fading channels. First, we establish that the distances between neighboring nodes in a Poisson point process follow a generalized Rayleigh distribution. Based on this result, it is then shown that, given an end-to-end packet delivery probability (as a quality of service requirement), the energy benefits of routing over many short hops are significantly smaller than for deterministic network models that are based on the geometric disk abstraction. If the permissible delay for short-hop routing and long-hop routing is the same, it turns out that routing over fewer but longer hops may even outperform nearest-neighbor routing, in particular for high end-to-end delivery probabilities.

A quantitative trust establishment framework for reliable data packet delivery in MANETs

Abstract: In mobile ad hoc networks (MANETs), a source node must rely on other nodes to forward its packets on multi-hop routes to the destination. Secure and reliable handling of packets by the intermediate nodes is difficult to ensure in an ad hoc environment. We propose a trust establishment scheme for MANETs which aims to improve the reliability of packet forwarding over multi-hop routes in the presence of potentially malicious nodes. Each node forms an "opinion" about each of the other nodes based on both first and second-hand observation data collected from the network. The opinion metric can be incorporated into ad hoc routing protocols to achieve reliable packet delivery even when a portion of the network exhibits malicious behavior. We present numerical results which demonstrate the effectiveness of the proposed trust establishment scheme.

An algebraic theory of dynamic network routing

Abstract: We develop a non-classic algebraic theory for the purpose of investigating the convergence properties of dynamic routing protocols. The algebraic theory can be regarded as a generalization of shortest-path routing, where the new concept of free cycle generalizes that of a positive-length cycle. A primary result then states that routing protocols always converge, though not necessarily onto optimal paths, in networks where all cycles are free. Monotonicity and isotonicity are two algebraic properties that strengthen convergence results. Monotonicity implies protocol convergence in every network, and isotonicity assures convergence onto optimal paths. A great many applications arise as particular instances of the algebraic theory. In intra-domain routing, we show that routing protocols can be made to converge to shortest and widest paths, for example, but that the composite metric of Internet Gateway Routing Protocol (IGRP) does not lead to optimal paths. The more interesting applications, however, relate to inter-domain routing and its Border Gateway Protocol (BGP), where the algebraic framework provides a mathematical template for the specification, design, and verification of routing policies. We formulate existing guidelines for inter-domain routing in algebraic terms, propose new guidelines contemplating backup relationships between domains, and derive a sufficient condition for signaling correctness of internal-BGP.

BeeAdHoc: an energy efficient routing algorithm for mobile ad hoc networks inspired by bee behavior

Abstract: In this paper we present BeeAdHoc, a new routing algorithm for energy efficient routing in mobile ad hoc networks. The algorithm is inspired by the foraging principles of honey bees. The algorithm mainly utilizes two types of agents, scouts and foragers, for doing routing in mobile ad hoc networks. BeeAdHoc is a reactive source routing algorithm and it consumes less energy as compared to existing state-of-the-art routing algorithms because it utilizes less control packets to do routing. The results of our extensive simulation experiments show that BeeAdHoc consumes significantly less energy as compared to DSR, AODV, and DSDV, which are state-of-the-art routing algorithms, without making any compromise on traditional performance metrics (packet delivery ratio, delay and throughput).

A unified approach to constrained mapping and routing on network-on-chip architectures

Abstract: One of the key steps in Network-on-Chip (NoC) based design is spatial mapping of cores and routing of the communication between those cores. Known solutions to the mapping and routing problem first map cores onto a topology and then route communication, using separated and possibly conflicting objective functions. In this paper we present a unified single-objective algorithm, called Unified MApping, Routing and Slot allocation (UMARS). As the main contribution we show how to couple path selection, mapping of cores and TDMA time-slot allocation such that the network required to meet the constraints of the application is minimized. The time-complexity of UMARS is low and experimental results indicate a run-time only 20% higher than that of path selection alone. We apply the algorithm to an MPEG decoder System-on-Chip (SoC), reducing area by 33%, power by 35% and worst-case latency by a factor four over a traditional multi-step approach.

Near-Optimal Worst-Case Throughput Routing for Two-Dimensional Mesh Networks

Abstract: Minimizing latency and maximizing throughput are important goals in the design of routing algorithms for interconnection networks. Ideally, we would like a routing algorithm to (a) route packets using the minimal number of hops to reduce latency and preserve communication locality, (b) deliver good worst-case and average-case throughput and (c) enable low-complexity (and hence, low latency) router implementation. In this paper, we focus on routing algorithms for an important class of interconnection networks: two dimensional (2D) mesh networks. Existing routing algorithms for mesh networks fail to satisfy one or more of design goals mentioned above. Variously, the routing algorithms suffer from poor worst case throughput (ROMM [13], DOR [23]), poor latency due to increased packet hops (VALIANT [31]) or increased latency due to hardware complexity (minimaladaptive [7, 30]). The major contribution of this paper is the design of an oblivious routing algorithm - O1TURN - with provable near-optimal worst-case throughput, good average-case throughput, low design complexity and minimal number of network hops for 2D-mesh networks, thus satisfying all the stated design goals. O1TURN offers optimal worst-case throughput when the network radix (k in a kxk network) is even. When the network radix is odd, O1TURN is within a 1/k2 factor of optimal worst-case throughput. O1TURN achieves superior or comparable average-case throughput with global traffic as well as local traffic. For example, O1TURN achieves 18.8%, 0.7% and 13.6% higher average-case throughput than DOR, ROMM and VALIANT routing, respectively when averaged over one million random traffic patterns on an 8x8 network. Finally, we demonstrate that O1TURN is well suited for a partitioned router implementation that is of similar delay complexity as a simple dimension-ordered router. Our implementation incurs a marginal increase in switch arbitration delay that is completely hidden in pipelined routers as it is not on the clock-critical path.