Multi-hop Wireless Routing Research Articles

Buffer occupancy and link state opportunistic routing for wireless mesh networks

Providing a high level of Quality of Service is essential for future wireless networks. This article presents a new multihop wireless routing protocol that opportunistically takes profit from variations of radio conditions in terms of path loss, shadowing and multipath fading to maximize the system capacity. However, guaranteeing high system capacity should not evade the packet delay minimization objective. Consequently, the best path should not only be considered as the path with best throughput but a combination of a good link throughput and, in addition, low router buffer occupancy load. Taking into account the available router buffer occupancy in its path selection, our proposal uses queuing theory information in order to also provide an efficient load balancing solution that adequately distributes the traffic load in the whole network. Exploiting this information, our solution dynamically adapts the selected path across time avoiding overexploited efficient links as well as low throughput link usage. This adaptation is performed considering each link state and the amount of channel information available. This improves the throughput and delay with only small marginal overhead cost. Our proposal applies to all wireless multihop networks, with increased benefit for extending cell coverage. We demonstrate through our simulation study that our solution raises the system capacity by more than 50% in several scenarii as well as reduces packet delays compared to state-of-the-art protocols such as Ad-hoc On-demand Distance Vector, Optimized Link State Routing and Link State Opportunistic Routing.

Link state opportunistic routing for multihop wireless networks

Enhancing the quality of service is the crucial issue of future wireless networks. In this paper, we propose a new multihop wireless routing protocol inspired by opportunistic resource allocation strategies that take into account the variability of the radio conditions due to path loss, shadowing and multipath fading. Thanks to this knowledge, our proposition dynamically adapts the selected path accross time. The adaptation is function of each link state and the amount of channel information available. This allows to improve system performance in terms of delay and throughput. This solution can be used in all multihop wireless contexts but can have a special interest in wireless coverage zone extension context. Simulation results will show that the proposed routing protocol greatly outperforms the other existing protocols such as ad-hoc on-demand distance vector, optimized link state routing and extremely opportunistic routing protocols reducing mean packet delays by more than 50% in several scenarii.

Energy Efficient Node Rank-Based Routing Algorithm in Mobile Ad-Hoc Networks

Mobile Ad-hoc Network (MANET) is an emerging technology, infrastructure less with self-organizing, selfhealing, multi-hop wireless routing networks in real time. In such networks, many routing problems arise due to complexity in the network mobility which results from difficulty in achieving energy efficient routing in the field of MANET. Due to the dynamic nature and the limited battery energy of the mobile nodes, the communication links between intermediate relay nodes may fail frequently, thus affecting the routing performance of the network and also the availability of the nodes. Though existing protocols are not concentrating about communication links and battery energy, node links are very important factor for improving quality of routing protocols because Node Rank helps us to determine whether the node is within transmission range or out of transmission range through considering residual energy of the node during the routing process. This paper proposes a novel Energy Efficient Node Rank-based Routing (EENRR algorithm which includes certain performance metrics such as control overhead and residual energy in order to improve the Packet Delivery Ratio (PDR), and Network Life Time (NLT) from its originally observed routing performance obtained through other existing protocols. Simulation results show that, when the number of nodes increases from 10 to 100 nodes, EENRR algorithm increases the average residual energy by 31.08% and 21.26% over the existing Dynamic Source Routing (DSR) and Energy Efficient Delay Time Routing (EEDTR) protocols, respectively. Similarly it increases the PDR by 45.38% and 28.3% over the existing DSR and EEDTR protocols respectively.

A generalized framework for disruption tolerant secure opportunistic routing during emergency situations using MANETs

Mobile ad-hoc networks (MANETs) play a constitutive role in the field of telecommunication. It enables communication between moving nodes by using auto-node configuration and multi hop wireless routing strategies. During disasters, the existing telecommunication structure is either completely destroyed or partially collapsed. Thus, it is very difficult to perform data communications during that period and also it takes more time to restore it to its original structure. The purpose of this research paper is to ensure reliable and secured communication using opportunistic routing between mobile nodes during such emergency situations. The existing methods of the disaster routing protocols do not guarantee reliable delivery of data in a secured manner and it assumes that the nodes are configured with a unique IP address before participating in the communication. This paper presents a novel framework disruption tolerant secure opportunistic routing (DTSOR) method that ensures secure communication between high mobility nodes. Cluster based address auto configuration mechanism and trace analysis are preferred methods used to select the optimal path for forwarding the packets. Selected path further ensures security using puzzle based data anonymization method. Performance analysis and simulation results shows that proposed framework outperforms the state of the art approaches in terms of the packet delivery ratio, network overhead and throughput.

Peripheral nodes and their effect in path planning in networks

We consider the problem of designing a path in a network that is as close as possible to most node locations in the network. In particular, we concern the case of designing mobile element tours in sensor networks, used to collect data from the network. The nodes that are not visited by the tour need to transmit their data using wireless multi-hop routing, which is expensive in terms of energy usage, and therefore limits the lifetime of the network. Nodes that happen to be placed in locations that are away from the central areas of the network can result in designing a tour that is skewed towards these 'out of the way' or peripheral nodes. In this work, we propose algorithmic solutions that aim to identify peripheral nodes in the network.We provide experimental evidence that the tour planning algorithms that consider peripheral nodes can significantly improve the solution.

AI-Augmented, Ripple-Diamond-Chain Shaped, Rateless Routing in Wireless Mesh Networks With Multibeam Directional Antennas

Use of multibeam directional antennas (MBDAs) allows a node to simultaneously communicate in multiple directions on its different beams, which can significantly improve the data throughput compared with omni-directional or single-beam directional antennas. However, conventional multihop wireless routing protocols cannot effectively exploit the benefits of MBDAs. In this paper, we present a novel routing scheme for a wireless mesh network (WMN) equipped with MBDAs, which has the following two features: 1) Ripple-Diamond-Chain (RDC) shaped routing: To exploit the multidirection transmission capability of MBDAs, we use rateless codes to obtain loss-resilient symbols for data packets, which can be simultaneously transmitted on multiple beams of a node. Then we use ripples to differentiate the nodes in each hop in the tree topology of WMN. While the symbols are dispatched on multiple beams of a main path node in one ripple, they converge into another main path node in the next ripple. The entire route thus looks like a diamond chain, which can exploit the MBDA benefits. 2) Artificial Intelligence (AI)-Augmented Path Selection : Our routing scheme is augmented by using two AI algorithms. The fuzzy logic is used to define a weighted link quality, in order to adapt to different quality-of-service requirements. The reinforcement learning is used to select the best main path based on the cumulative reward in all the links. In the simulations, we use the video as well as other time-sensitive traffic to evaluate efficiency of RDC routing, as well as intelligent path determination in WMN.

Information-centric content retrieval for delay-tolerant networks

The shift from host-centric to information-centric networking (ICN) promises seamless communication in mobile networks. However, most existing works either consider well-connected networks with high node density or introduce modifications to ICN message processing for delay-tolerant networking (DTN). In this work, we present agent-based content retrieval, which provides information-centric DTN support as an application module without modifications to ICN message processing. This enables flexible interoperability in changing environments. If no content source can be found via wireless multi-hop routing, requesters may exploit the mobility of neighbor nodes (called agents) by delegating content retrieval to them. Agents that receive a delegation and move closer to content sources can retrieve data and return it back to requesters. We show that agent-based content retrieval may be even more efficient in scenarios where multi-hop communication is possible. Furthermore, we show that broadcast communication may not be necessarily the best option since dynamic unicast requests have little overhead and can better exploit short contact times between nodes (no broadcast delays required for duplicate suppression).

New solution for the creation of MANETs based on personal devices

Mobile ad hoc networks (MANETs) enable communication between moving nodes through multi-hop wireless routes. There are protocols with special features that handle both auto-configuration and routing in these networks. Nevertheless, many of these auto-configuration protocols have not been truly implemented and in consequence, only exist a few available solutions for MANETs conformation. This article presents a new solution for this issue, mainly in cases where only personal devices are available. The core of the proposal is a new auto-configuration protocol, which allows dynamic allocation of unique IP addresses and accomplishes effective answers in front of issues like mergers and partitions of networks, and others. Finally, the results of simulations in OMNET++ and of tests of a pilot version based on Android mobile phones are shown.

Tour and path planning methods for efficient data gathering using mobile elements

We consider a well-established model of data gathering in wireless sensor networks WSNs that combines mobile elements visiting some of the nodes, and wireless communication from the rest. Since wireless communication impacts the life-time of the network, there is a need to design the mobile element path so that the required communication is minimised, while the path length is bounded in length. Based on the required structure of the tour we investigate two variations of this problem. First, we consider mobile element tours that start and end at a predefined sink. Then we consider the unrestricted case, where the path is not required to return to the predefined sink node. We propose new algorithms that alternate between the path design and the multi-hop wireless communication routes, and iteratively improve the out-come of each phase. We compare the resulting performance of our algorithms with the best known comparable schemes in the literature.

Peripheral nodes and their effect in path planning in networks

We consider the problem of designing a path in a network that is as close as possible to most node locations in the network. In particular, we concern the case of designing mobile element tours in sensor networks, used to collect data from the network. The nodes that are not visited by the tour need to transmit their data using wireless multi-hop routing, which is expensive in terms of energy usage, and therefore limits the lifetime of the network. Nodes that happen to be placed in locations that are away from the central areas of the network can result in designing a tour that is skewed towards these 'out of the way' or peripheral nodes. In this work, we propose algorithmic solutions that aim to identify peripheral nodes in the network.We provide experimental evidence that the tour planning algorithms that consider peripheral nodes can significantly improve the solution.

A Real-Time Vibration Frequency Measurement System of Bridge Pier

This study developed a real-time remote monitoring system (RTRMS) to receive the vibration frequency of bridge pier. The system included a front station and a middle station. A multi-hop wireless routing is employed to transmit the data from the front to the middle station. The front station includes a receiver equipped to receive the vibration frequency, and a wireless sensor network to transmit the data. The middle station is designed by an embedded system for storing the data. The pressure test shows that the loss rate of received data is less than 0.6%. The consuming power of one day is 3 ampere hours in the front station and 30 ampere hours in the middle station if the 12 voltage battery is used.

하이브리드 WMN을 위한 가상 도메인 기반의 반응형 라우팅 프로토콜

본논문은하이브리드WMN의계층구조메시를고려한무선다중홉라우팅프로토콜에대하여제안한다. 다양한 무선 응용서비스의 가능성을 가진 WMN은 오랜 연구에도 불구하고 실제 사용을 위해서는 아직 해결되어야 할 과제들이 많이 남아있다. 특히 라우팅 프로토콜 부문은 MANET을 위해 설계된 프로토콜을 적용하면 하이브리드 WMN에서는 라우팅 효율이 떨어지는 문제를 우선적으로 해결하여야 한다. 라우팅 성능향상을 위해서는 우수한 경로구성 프로토콜과 경로 메트릭이 필요하다. 하지만 최근의 연구는 교차 계층 설계에 의한 경로 메트릭에 집중되어 있다. 따라서 본 논문은 하이브리드 WMN에서의 라우팅 성능향상을 위해 필요하지만 연구가 부족한 경로구성 프로토콜을 제안하는 것이 목적이다. 본 논문에서 제안한 라우팅 프로토콜은 하이브리드 WMN을 가상의 도메인으로 노드들을 그룹화하고 전송경로 구성을 도메인 기반으로 수행하도록 설계된 reactive 방식이다. 제안한 프로토콜의 성능분석을 위한 시뮬레이션 결과 경로결정 평균 지연시간이 대표적인 reactive 방식인 AODV에 비해 43% 단축되었다. This paper propose a new wireless multi-hop routing protocol that takes the hierarchical mesh of the hybrid WMN into account. WMN that is possible to provide various applications of wireless networks still has many open issues that should be solved despite the studies carried out over a decade. Especially, in routing protocol area, a problem degrading the routing efficiency by applying one of the routing protocols, which are designed for the MANET, to the hybrid WMN be solved above all. For the improvement of the routing performance, both good routing protocol and metric are essential. However, the recent studies are only concentrated in routing metric by use of the cross-layer design. Therefore, this paper is dedicated to the routing protocol that is essential for the performance of the routing but needed more studies. The proposed protocol in this paper is reactive, and designed to reorganize the hybrid WMN with several pseudo domains, and carry out domain-based route decision. By the simulation result for the performance analysis of the proposed protocol, the average delay for the route decision was decreased by 43% compared to AODV that is the typical reactive protocol.

혼합형 무선 메시 네트워크를 위한 AODV 개선 연구

By the enormous increase in mobile nodes and diverse service requests on wireless networks, wireless mesh network(WMN) takes an interest as the solution for such requests. However, lots of issues which should be solved to deploy WMN are still remained. In the network layer, the performance improvement of routing protocols is the major issue of nowadays researches. WMN can be easily deployed by use of protocols for mobile ad-hoc networks(MANET) because it is much similar with MANET in multi-hop wireless routing and which node plays as host and router concurrently. Unfortunately, most routing protocols for MANET have drawbacks such as large traffic overhead and long delay time for route discovery due to the network extension. They are major factors of performance degradation of WMN and most researches are focused on them. In this paper, domain-based AODV which is amended AODV to be applied in hybrid WMN is proposed. The proposed scheme divides a hybrid WMN as several domains and performs route discovery by header layer domain. Therefore it can reduce the distance for route discovery as much as average hop count between domain header and member nodes. From the simulation, domain-based AODV was showed slowly increasing delay time due to the network extension.

A Joint Approach to Routing Metrics and Rate Adaptation in Wireless Mesh Networks

This paper presents MARA, a joint mechanism for automatic rate selection and route quality evaluation in wireless mesh networks. This mechanism targets at avoiding the problems of lack of synchronization between metric and rate selection decisions and inaccurate link quality estimates, common to main existing proposals of multihop wireless routing metrics and automatic rate adaptation. In this proposal, the statistics collected by the routing protocol are used by the rate adaptation algorithm to compute the best rate for each wireless link. This coordinated decision aims at providing better routing and rate choices. In addition to the basic MARA algorithm, two variations are proposed: MARA-P and MARA-RP. The first considers the size of each packet in the transmission rate decision. The second variation considers the packet size also for the routing choices. For evaluation purposes, experiments were conducted on both real and simulated environments. In these experiments, MARA was compared to a number of rate adaptation algorithms and routing metrics. Results from both environments indicate that MARA may lead to an overall network performance improvement.

Max Weight Learning Algorithms for Scheduling in Unknown Environments

We consider a discrete time queueing system where a controller makes a 2-stage decision every slot. The decision at the first stage reveals a hidden source of randomness with a control-dependent (but unknown) probability distribution. The decision at the second stage generates an attribute vector that depends on this revealed randomness. The goal is to stabilize all queues and optimize a utility function of time average attributes, subject to an additional set of time average constraints. This setting fits a wide class of stochastic optimization problems, including multi-user wireless scheduling with dynamic channel measurement decisions, and wireless multi-hop routing with multi-receiver diversity and opportunistic routing decisions. We develop a simple max-weight algorithm that learns efficient behavior by averaging functionals of previous outcomes.

Eliminating Duplicate Forwarding in Wireless Opportunistic Routing

Opportunistic routing is a wireless multi-hop routing approach that allows each packet to be relayed through any node that overhears the transmission. In this letter, we propose a method for avoiding duplicate forwarding in opportunistic routing. The proposed technique enables forwarding nodes to control relaying at their neighbors on a per-packet basis using a small amount of information piggybacked on packets. Our simulation results show that DFOR achieves higher throughput than existing relevant protocols by reducing unnecessary transmissions.

Path approximation for multi-hop wireless routing under application-based accuracy constraints

Provisioning of rich routing building blocks to mobile ad hoc networking applications has been of high interest. Several MANET applications need flexibility in describing paths their traffic will follow. To accommodate this need, previous work has proposed several viable routing schemes such as Dynamic Source Routing (DSR) and Trajectory-Based Routing (TBR). However, tradeoffs involved in the interaction of these routing schemes and the application-specific requirements have not been explored. Especially, techniques to help the application to do the right routing choices are much needed. In this paper, we consider techniques that minimize routing protocol state costs under application-based constraints. We study the constraint of “accuracy” of the application’s desired route, as this constraint provides a range of choices to the applications. As a crucial part of this concept, we investigate the tradeoff between the size of packet headers (needed to store end-to-end paths) and the network state (needed to store routing tables). We, then, apply the concept to the case of TBR with application-based accuracy constraints in obeying a given trajectory. We begin with simple discrete models to clarify the tradeoff between the packet header size and the network state. We show that the problem of accurate approximation of a trajectory (a.k.a. an application-specific end-to-end path) with the objective of minimizing the cost incurred due to header size and network state is difficult to solve optimally. We design an exhaustive search method as well as a genetic algorithm to find the optimum solution. We also develop heuristics solving this problem with smaller computational complexity and illustrate their performance. Finally, we explore ways of customizing our trajectory approximation framework for power-scarce or memory-scarce networking scenarios.

Stability routing with constrained path length for improved routability in dynamic MANETs

Quality of service (QoS) routing is known to be an NP-hard problem in case of two or more additive constraints, and several exact algorithms and heuristics have been proposed to address this issue. In this paper, we consider a particular two-constrained quality of service routing problem maximizing path stability with a limited path length in the quest of improving routability in dynamic multi-hop mobile wireless ad hoc networks. First, we propose a novel exact algorithm to solve the optimal weight-constrained path problem. We instantiate our algorithm to solve the most stable path not exceeding a certain number of hops, in polynomial time. This algorithm is then applied to the practical case of proactive routing in dynamic multi-hop wireless ad hoc networks. In these networks, an adequate compromise between route stability and its length in hops is essential for appropriately mitigating the impact of the network dynamics on the validity of established routes. Secondly, we set up a common framework for the comparison between three families of proactive routing: the shortest path-based routing, the most stable path-based routing and our proposed most stable constrained path routing. We show then through extensive simulations that routing based on our proposed algorithm selects appropriate stable paths yielding a very high routability with an average path length just above that of the shortest paths.

Testbed results of an opportunistic routing for multi-robot wireless networks

Opportunistic routing is a candidate for multihop wireless routing where the network topology and radio channels vary rapidly. However, there are not many opportunistic routing algorithms that can be implemented in a real multihop wireless network while exploiting the node mobility. It motivates us to implement an opportunistic routing, random basketball routing (BR), in a real multi-robot network to see if it can enhance the capacity of the multihop network as mobility increases. For implementation purposes, we added some features, such as destination RSSI measuring, a loop-free procedure and distributed relay probability updating, to the original BR. We carried out the experiments on a real multi-robot network and compared BR with AODV combined with CSMA/CA (routing + MAC protocol). We considered both static and dynamic scenarios. Our experiments are encouraging in that BR outperforms AODV + CSMA/CA, particularly in dynamic cases; the throughput of BR is 6.6 times higher than that of AODV + CSMA/CA. BR with dynamic networks shows 1.4 times higher throughput performance than BR with static networks. We investigate the performance of BR in the large-scale network using NS-2 simulation. We verify the effect of node density, speed, destination beacon signal and loop-free procedure. According to the large-scale simulation, the end-to-end throughput grows with the node speed.

Availability and End-to-end Reliability in Low Duty Cycle MultihopWireless Sensor Networks

A wireless sensor network (WSN) is an ad-hoc technology that may even consist of thousands of nodes, which necessitates autonomic, self-organizing and multihop operations. A typical WSN node is battery powered, which makes the network lifetime the primary concern. The highest energy efficiency is achieved with low duty cycle operation, however, this alone is not enough. WSNs are deployed for different uses, each requiring acceptable Quality of Service (QoS). Due to the unique characteristics of WSNs, such as dynamic wireless multihop routing and resource constraints, the legacy QoS metrics are not feasible as such. We give a new definition to measure and implement QoS in low duty cycle WSNs, namely availability and reliability. Then, we analyze the effect of duty cycling for reaching the availability and reliability. The results are obtained by simulations with ZigBee and proprietary TUTWSN protocols. Based on the results, we also propose a data forwarding algorithm suitable for resource constrained WSNs that guarantees end-to-end reliability while adding a small overhead that is relative to the packet error rate (PER). The forwarding algorithm guarantees reliability up to 30% PER.