Routing In Multi-hop Wireless Networks Research Articles

Reclaiming the efficiency of opportunistic routing in wireless multi-hop networks

Opportunistic routing (OR) is an effective way to guarantee transmission reliability in wireless multi-hop networks. However, little research focuses on transmission efficiency. Thus, an analytical model based on open queuing network with Markov chains was proposed to evaluate the efficiency. By analyzing two typical ORs, we find duplicate transmission and collision avoidance overhead are the root reasons behind inefficiency. Therefore, a new scheme called dual priority cooperative opportunistic routing (DPCOR) was proposed. In DPCOR, forwarding candidates are configured with dual priority, which enables the network to classify forwarding candidates more effectively so as to reduce the back-off time and obtain more diversity gain. Theoretical analysis and simulation results show DPCOR achieves significant performance improvement with less time overhead compared with traditional routings and typical ORs.

Interference aware energy efficient multipath routing in multihop wireless networks

Energy efficiency is considered as an important design issue in multihop wireless networks as the nodes are battery limited. Energy efficiency can be achieved by establishing multiple paths. Multipath routing explores multiple disjoint paths between sources–sink pair in order to improve energy consumption at nodes and thus, provide robustness against possible node failure. However, it remains a challenging task in wireless networks due to associated interference. Reducing interference lowers the energy consumption, improving the network lifetime. This paper proposes an interference aware energy efficient multipath routing protocol for a given source-sink pair by a combined route construction and power allocation method. After finding k-minimum weight node disjoint paths on a weighted communication graph, iterative power allocation is performed on the derived paths considering signal to interference plus noise ratio (SINR) model. The power allocation method minimizes the interference experienced by each node at an acceptable level so that multiple transmissions can take place simultaneously. By alternatively invoking multipath route construction and power allocation method on a weighted communication graph, the proposed algorithm optimizes the assignment of transmission power and thereby minimizes the total energy consumption on k-node disjoint multipath. The simulation results show that the performance of the proposed scheme is better than existing multipath routing algorithms.

Scalable multi-hop routing in wireless networks

Infrastructure-less wireless multi-hop networks have long been proposed for natural disaster and warfare scenarios. However, the current demand of such networks has been towards social networking, gaming and ultimately, ubiquitous computing. In fact, the increasing number of users that own wireless capable devices is taking these networks to an entirely different scale. Existing routing protocols do not scale and do not consider the context wherein services operate. By presenting an alternative routing scheme that appropriately handles mobility of users among different contexts, large-scale clustered wireless networks are designed, using an efficient gateway selection with load-balancing capabilities. This approach uses a virtual hierarchy of clusters to explore the contextual-proximity of nodes, while reducing the total overhead of routing traffic even when compared with other cluster-based approaches. Moreover, it is capable of predicting gateway link disconnections, increasing the total amount of delivered data. The obtained results reveal that this routing scheme outperforms existing routing protocols regardless of the mobility pattern being used, being consistently lighter in overhead and delivering up to 50% more data traffic. These results motivate a new era of large-scale wireless multi-hop networks suitable for hand-held devices exchanging data amongst themselves.

Improving Energy Efficiency Using LEARN Algorithm for Wireless Sensor Networks

A number of energy-aware routing protocols were proposed to seek the energy efficiency of routes in Multihop wireless networks. Among them, several geographical localized routing protocols were proposed to help making smarter routing decision using only local information and reduce the routing overhead. However, all proposed localized routing methods cannot guarantee the energy efficiency of their routes. In this article, we first give a simple localized routing algorithm, called Localized Energy-Aware Restricted Neighbourhood routing (LEARN), which can guarantee the energy efficiency of its route if it can find the route successfully. The critical transmission radius in random networks which can guarantee that LEARN routing finds a route for any source and destination pairs asymptotically almost surely. So by using LEARN algorithm the energy efficient of the source and destination pair is thus may be maintained and the attacks occurs in the wireless network can also be reduced. One can also extend the proposed routing into three-dimensional (3D) networks and derive its critical transmission radius in 3D random networks.

Energy-balanced cooperative routing in multihop wireless networks

Cooperative communication (CC) allows multiple nodes to simultaneously transmit the same packet to the receiver so that the combined signal at the receiver can be correctly decoded. Since the CC can reduce the transmission power and extend the transmission coverage, it has been considered in minimum energy routing protocols to reduce the total energy consumption. However, previous research on cooperative routing only focuses on minimizing the total energy consumption from the source node to the destination node, which may lead to the unbalanced energy distribution among nodes. In this paper, we aim to study the impact of cooperative routing on balancing the energy distribution among nodes. By introducing a new routing scheme which carefully selects cooperative relay nodes and assigns their transmission power, our cooperative routing method can balance the remaining energy among neighboring nodes to maximize the lifetime of the network. Simulation results demonstrate that the proposed cooperative routing algorithm significantly balances the energy distribution and prolongs the lifetime of the network.

Interference-aware cooperative QoS routing in multi-hop wireless networks

Cooperative communication is a new physical technology, which has the potential to improve QoS support for multi-hop wireless network. Existing works did not consider the interference effect among links while designing cooperative QoS routing. To overcome this limitation, this paper targets at designing an interference-aware Cooperative QoS routing algorithm (CQ-routing) to satisfy users’ bandwidth requirement. We formulate the problem of finding cooperative routing path with maximum available bandwidth as an optimization problem, called Coop-routing problem. We prove that the Coop-routing problem is strong NP-hard. We propose both centralized and distributed algorithm to solve the Coop-routing problem. We prove that the centralized algorithm can achieve a constant approximation ratio. We evaluate the performance of these algorithms through simulations. The results show that CQ-routing algorithms can significantly improve the network performance in terms of available bandwidth and number of admitted flows.

Rate Allocation for Multipath Routing in Wireless Multihop Networks with Security Constraints Based on Erasure Channel Modeling

Multipath routing can offer various advantages for wireless multihop networks. Among those advantages, in this paper, we focus on an advantage of multipath routing for security using the notion of information-theoretic security. We formulate an optimization problem that maximizes the transmission rate from a source node to a destination node with information-theoretic security constraints to avoid eavesdropping that can be carried out at some nodes within a wireless multihop network. Binary erasure channel (BEC) modeling is employed to model wireless links that suffer from fading and interference. It is shown that the proposed throughput maximization problem is a linear optimization problem and the optimal rate allocation can be found by standard optimization techniques. We also study performance analysis including an asymptotic analysis to see whether or not multipath routing (with equal rate allocation) could be secure in terms of an information-theoretic security point of view. Through performance analysis, we can show that multipath routing can provide not only more secure routing against eavesdropping, but also a higher throughput as more multipaths are available.

Polynomial-Time Algorithms for Multirate Anypath Routing in Wireless Multihop Networks

In this paper, we present a new routing paradigm that generalizes opportunistic routing for wireless multihop networks. In multirate anypath routing, each node uses both a set of next-hops and a selected transmission rate to reach a destination. Using this rate, a packet is broadcast to the nodes in the set, and one of them forwards the packet on to the destination. To date, there is no theory capable of jointly optimizing both the set of next-hops and the transmission rate used by each node. We solve this by introducing two polynomial-time routing algorithms and provide the proof of their optimality. The proposed algorithms have roughly the same running time as regular shortest-path algorithms and are therefore suitable for deployment in routing protocols. We conducted measurements in an 802.11b testbed network, and our trace-driven analysis shows that multirate anypath routing is on average 80% better than 11-Mbps anypath routing, with a factor of 6.4 improvement in the best case. If the rate is fixed at 1 Mbps instead, performance improves by a factor of 5.4 on average.

MCR: MAC‐assisted congestion‐controlled routing for wireless multihop networks

AbstractTechniques for improving network congestion have been proposed in different fields. In recent years, the congestion control problems were studied to enhance the routing performance in wireless multihop networks (WMNs). In this paper, the network allocation vector (NAV) introduced by the contention‐based medium access control (MAC) protocols is utilized for the determination of the channel status around a wireless node (WN). A MAC‐assisted congestion‐controlled routing (MCR) algorithm is proposed to alleviate the network congestion problem by adopting the information from the MAC layer. The routing path is selected based on the congestion‐free probability along the path for transmitting the data packets. Moreover, the adaptive path‐switching scheme and the aggressive hop‐reduction (AHR) local repair mechanism further enhance the routing performance of the proposed MCR algorithm. The effectiveness of the MCR protocol is evaluated via both the analytical study and the simulation results. Without consuming excessive control packets for each WN, the MCR algorithm can achieve better performance when compared with other existing schemes, especially under the scenarios with network congestion. Copyright © 2010 John Wiley & Sons, Ltd.

Jamming aware routing for MHWN with dynamic measurement

Multi-hop wireless networks (MHWN) have emerged to be a promising cost effective paradigm for the next-generation wireless technology. However, the unique characteristics of nowadays MHWN, such as distributed and dynamic network architecture, broadcast nature of wireless medium and stringent resource constraints of wireless devices, makes it extremely attractive and vulnerable to malicious attacks. So how to ensure continuous network service becomes a critical problem especially in jammed situations. Although some research has been conducted on countering jamming attacks, few works consider jamming dynamics. In this paper, interference avoidance mechanisms are well concerned and a proactive multi-path routing mechanism based on measuring jamming dynamic is presented. In our proposed solutions, the novel mechanism defines a new metric for routing known as the degree of interference activity (IA) to represent the jamming dynamic on a node. A comprehensive simulation study is conducted to evaluate the performance of the proposed scheme. Performance results show that our solution outperforms existing ad hoc routing protocols in terms of packet delivery and average end-to-end delay in the presence of jammers.

Survey on Opportunistic Routing in Multihop Wireless Networks

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Energy-Efficient Localized Routing in Random Multihop Wireless Networks

A number of energy-aware routing protocols were proposed to seek the energy efficiency of routes in multihop wireless networks. Among them, several geographical localized routing protocols were proposed to help making smarter routing decision using only local information and reduce the routing overhead. However, all proposed localized routing methods cannot guarantee the energy efficiency of their routes. In this paper, we first give a simple localized routing algorithm, called Localized Energy-Aware Restricted Neighborhood routing (LEARN), which can guarantee the energy efficiency of its route if it can find the route successfully. We then theoretically study its critical transmission radius in random networks which can guarantee that LEARN routing finds a route for any source and destination pairs asymptotically almost surely. We also extend the proposed routing into three-dimensional (3D) networks and derive its critical transmission radius in 3D random networks. Simulation results confirm our theoretical analysis of LEARN routing and demonstrate its energy efficiency in large scale random networks.

Field Division Routing

Multihop communication objectives and constraints impose a set of challenging requirements that create difficult conditions for simultaneous optimization of features such as scalability and performance. Routing in wireless multihop networks represents a crucial component of the overall network efficacy because it is a lower layer that enables the actual functionality of networks. We have developed field division routing (FDR), a distributed and nonhierarchical routing protocol that aims to coordinated addressing of scalability, topology alternations, latency, throughput, energy efficiency, and local storage requirements. FDR is based upon two optimization mechanisms: a reactive and focused diffusion that collects only network topology information directly required formaking localized routing decisions, and a protocol for sharing routing information among neighboring nodes. Routing table initialization and maintenance are scalable in terms of both storage and overhead traffic necessary for building routing tables. FDR provides guaranteed connectivity while providing near-optimal all-node-pairs message delivery. The protocol is also power-efficient to a wide spectrum of topology changes that induce relatively few messages to update routing tables network wide. We analyzed the new routing protocol both theoretically and using simulation.

A Deterministic Protocol for Permutation Routing in Dense Multi-Hop Sensor Networks

A large variety of permutation routing protocols in a single-hop Network are known in the literature. Since they are single hop, there is always a wireless link connecting two nodes. One way to solve this problem in a multiple hop environment is to partition nodes into clusters, where a node in each cluster called clusterhead is responsible for the routing service. In this paper, we propose a hybrid clustering mechanism to perform permutation routing in multi-hop ad hoc Networks. We first propose to partition the network in single-hop clusters also named cliques. Secondly, we run a local permutation routing to broadcast items to their local destinations in each clique. Next we partition the clusterheads of cliques with the hierarchical clustering technique. We show how the outgoing items can be routed to their destination cliques. We give an estimation of the number of broadcast rounds in the worse case. More precisely, we show that solving the permutation routing problem on a multi-hop sensor network need 2 (1 ) ( ) 2 max max (/ ) kO k HUB HUB np    k in the worse case. Where n is the number of the data items stored in the network, p is the number of sensors, |HUBmax| is the number of sensors in the clique of maximum size and k is the number of cliques after the first clustering. Finally, simulation results show that our algorithm performs better than the naive multiple gossiping. To the best of our knowledge, it is the first algorithm for permutation routing in multi-hop radio networks.

Optimal spectrum-efficient routing in multihop wireless networks

This paper addresses the problem of finding the route with maximum end-to-end spectral efficiency, under the constraint of equal bandwidth sharing, in multihop wireless networks. This problem has been addressed recently in the literature, and only exhaustive search with exponential computational complexity or suboptimal heuristics are known. This paper closes the algorithmic gap by introducing two algorithms that provide provably optimal solutions to the problem in polynomial-time. The proposed algorithms rely on the iterative use of a shortest path procedure. Our computational results further illustrate the efficiency of the proposed approach.

A general framework for efficient geographic routing in wireless networks

We propose a new link metric called normalized advance (NADV) for geographic routing in multihop wireless networks. NADV selects neighbors with the optimal trade-off between proximity and link cost. Coupled with the local next hop decision in geographic routing, NADV enables an adaptive and efficient cost-aware routing strategy. Depending on the objective or message priority, applications can use the NADV framework to minimize various types of link cost. We present efficient methods for link cost estimation and perform detailed experiments in simulated environments. Our results show that NADV outperforms current schemes in many aspects: for example, in high noise environments with frequent packet losses, the use of NADV leads to 81% higher delivery ratio. When compared to centralized routing under certain settings, geographic routing using NADV finds paths whose cost is close to the optimum. We also conducted experiments in Emulab testbed and the results demonstrate that our proposed approach performs well in practice.

On Multipath Routing in Multihop Wireless Networks: Security, Performance, and Their Tradeoff

Routing amid malicious attackers in multihop wireless networks with unreliable links is a challenging task. In this paper, we address the fundamental problem of how to choose secure and reliable paths in such environments. We formulate the multipath routing problem as optimization problems and propose algorithms with polynomial complexity to solve them. Game theory is employed to solve and analyze the formulated multipath routing problem. We first propose the multipath routing solution minimizing the worst-case security risk (i.e., the percentage of packets captured by attackers in the worst case). While the obtained solution provides the most security routes, it may perform poorly given the unreliability of wireless links. Hence we then investigate the multipath routing solution maximizing the worst-case packet delivery ratio. As a natural extension, to achieve a tradeoff between the routing security and performance, we derive the multipath routing protocol maximizing the worst-case packet delivery ratio while limiting the worst-case security risk under given threshold. As another contribution, we establish the relationship between the worst-case security risk and packet delivery ratio, which gives the theoretical limit on the security-performance tradeoff of node-disjoint multipath routing in multihop wireless networks.

Location-Aided Opportunistic Forwarding in Multirate and Multihop Wireless Networks

Routing in multihop wireless networks is challenging, mainly due to unreliable wireless links/channels. Geographic opportunistic routing (GOR) was proposed to cope with the unreliable transmissions by exploiting the broadcast nature of the wireless medium and the spatial diversity of the network topology. Previous studies on GOR have focused on networks with a single channel rate. The capability of supporting multiple channel rates, which is common in current wireless systems, has not carefully been studied for GOR. In this paper, we carry out a study on the impacts of multiple rates, as well as candidate selection, prioritization, and coordination, on the performance of GOR. We propose a new local metric, i.e., the opportunistic effective one-hop throughput (OEOT), to characterize the tradeoff between one-hop packet advancement and packet forwarding time. We further propose a local rate adaptation and candidate-selection algorithm to approach the optimum of this metric. The simulation results show that the multirate GOR (MGOR) incorporating the rate adaptation and candidate-selection algorithm achieves higher throughput and lower delay than the corresponding single-rate and multirate traditional geographic routing and single-rate opportunistic routing protocols.

Orthogonal Rendezvous Routing Protocol for Wireless Mesh Networks

Routing in multi-hop wireless networks involves the indirection from a persistent name (or ID) to a locator. Concepts such as coordinate space embedding help reduce the number and dynamism complexity of bindings and state needed for this indirection. Routing protocols which do not use such concepts often tend to flood packets during route discovery or dissemination, and hence have limited scalability. In this paper, we introduce Orthogonal Rendezvous Routing Protocol (ORRP) for meshed wireless networks. ORRP is a lightweight-but-scalable routing protocol utilizing directional communications (such as directional antennas or free-space-optical transceivers) to relax information requirements such as coordinate space embedding and node localization. The ORRP source and ORRP destination send route discovery and route dissemination packets respectively in locally-chosen orthogonal directions. Connectivity happens when these paths intersect (i.e., rendezvous). We show that ORRP achieves connectivity with high probability even in sparse networks with voids. ORRP scales well without imposing DHT-like graph structures (eg: trees, rings, torus etc). The total state information required is O(N <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3/2</sup> ) for N-node networks, and the state is uniformly distributed. ORRP does not resort to flooding either in route discovery or dissemination. The price paid by ORRP is suboptimality in terms of path stretch compared to the shortest path; however we characterize the average penalty and find that it is not severe.

Optimal Distributed Stochastic Routing Algorithms for Wireless Multihop Networks

A novel framework was introduced recently for stochastic routing in wireless multihop networks, whereby each node selects a neighbor to forward a packet according to a probability distribution. Generalizing (deterministic) shortest path routing, stochastic routing offers greater flexibility that matches the random nature of wireless links. Consider the pairwise reliability matrix R, whose (i, j)-th entry Rij represents the probability that a packet transmitted from the j-th user Uj is correctly received by the i-th user Ui. Using R to capture physical layer aspects of the wireless medium, several rate-oriented stochastic routing formulations can be reduced to centrally solvable convex optimization problems. The present paper, introduces distributed algorithms that find optimal routing probabilities without the burden of collecting R at a central node and then percolating the resulting routing probabilities through network nodes. The resultant schemes are distributed in the sense that: (i) terminal Uj has access only to the j-th row and column of R; and (ii) Uj interchanges variables only with those single-hop neighbors having positive probability of decoding its packets. The distributed algorithms are built by recasting the optimization problems and applying dual decomposition techniques. Since iterates obtained via dual decomposition do not always converge to centralized optimal routing probabilities, two known regularization approaches are further invoked, namely the method of multipliers (MoM) and the alternating-direction MoM. Convergence to the optimal routing matrix is then guaranteed under mild conditions. Many rate-oriented optimality criteria of practical interest can be addressed by the distributed framework, including maximization of: (i) the minimum rate; (ii) a weighted sum of rates; (iii) the product of rates; and (iv) the source's rate in a relay network. Robustness of the distributed algorithms is tested with respect to topological changes, communication errors and node mobility.