Multi-hop Wireless Ad-hoc Networks Research Articles

Exploring the effects of directional antennas on the secure connectivity and hop count of secure multi-hop ad-hoc wireless networks

Directional antennas can increase the received power in specific directions while reducing it in other directions. Utilizing this unique feature, we configure directional antennas at legitimate users to obtain twofold benefits for secure multi-hop ad-hoc wireless networks (AHWNs), i.e., enhancing the secure connectivity among legitimate users and lowering the hop count of the multi-hop paths. For the quantitative evaluation of these benefits, we first use a stochastic geometry graph to model the multi-hop AHWNs under the coexistence of eavesdroppers. Then, we introduce a simulation-based analysis method comprised of two algorithms: (a) the first algorithm provides the connectivity and the hop count of the shortest path between random source–destination pairs; (b) the second algorithm utilizes the results of the first one to return the average path connectivity, the probability mass function (pmf) of the hop count distribution, and the average hop count. This simulation-based analysis method helps to exhaustively study the behaviors of connectivity, hop count distribution, average hop count, and their mutual relationship in different scenarios. To the best of our knowledge, this paper is the first research work that studies the effects of directional antennas equipped at legitimate users on both secure connectivity and hop count of secure AHWNs in four combinations of two types of practical directional antennas, i.e., uniform circular array (UCA) antenna and uniform linear array (ULA) antennas, and two beamforming schemes, i.e., centralized and randomized beamforming. Moreover, comparisons with the case of using omnidirectional antennas are also provided. From the obtained simulation results, we demonstrate that using directional antennas does not always benefit the secure connectivity and hop count of secure AHWNs, i.e., only UCA-random gives higher secure connectivity and lower hop count than the omnidirectional antenna among four combinations of antenna type — beamforming scheme. Moreover, in the cases of high-density legitimate users and low-density eavesdroppers, lowering the average hop count is more remarkable than improving secure connectivity. The critical findings in this paper are valuable for deploying secure multi-hop AHWNs with directional antennas in practice.

Simulation based comparison of routing protocols in wireless multihop adhoc networks

Routing protocols are responsible for providing reliable communication between the source and destination nodes. The performance of these protocols in the ad hoc network family is influenced by several factors such as mobility model, traffic load, transmission range, and the number of mobile nodes which represents a great issue. Several simulation studies have explored routing protocol with performance parameters, but few relate to various protocols concerning routing and Quality of Service (QoS) metrics. This paper presents a simulation-based comparison of proactive, reactive, and multipath routing protocols in mobile ad hoc networks (MANETs). Specifically, the performance of AODV, DSDV, and AOMDV protocols are evaluated and analyzed in the presence of varying the number of mobile nodes, pause time, and traffic connection numbers. Moreover, Routing and QoS performance metrics such as normalized routing load, routing packet, packet delivery ratio, packet drop, end-to-end delay, and throughput are measured to conduct a performance comparison between three routing protocols. Simulation results indicate that AODV outperforms the DSDV and AOMDV protocols in most of the metrics. AOMDV is better than DSDV in terms of end-to-end delay. DSDV provides lower throughput performance results. Network topology parameters have a slight impact on AODV Performance.

Modeling and simulation of secure connectivity and hop count of multi-hop ad-hoc wireless networks with colluding and non-colluding eavesdroppers

Connectivity and hop count are two crucial attributes of dynamic wireless networks such as ad-hoc wireless networks (AHWNs). When the security issue is considered, establishing a secure multi-hop path in AHWNs is challenging because an intermediate node having a wireless link with previous nodes may not be secure to receive data from those nodes, and vice versa. In this paper, stochastic geometry graphs is used to model the AHWNs with eavesdroppers’ presence, then a simulation-based analysis method is proposed to investigate the characteristics of connectivity, hop count distribution, average hop count, and their relations in various scenarios. The proposed simulation-based analysis method consists of two algorithms. The first one finds all possible secure communication paths between two arbitrary legitimate users selected as source and destination and returns the shortest path’s hop count. This algorithm utilizes the random locations of legitimate users and eavesdroppers, the wireless channel condition, and the eavesdropper’s operating mode as input data. The second one provides the hop count distribution and the connection probability of the obtained multi-hop path of the first algorithm by averaging a huge number of network topology trials. So far, this paper is the first work that investigates both connectivity and hop count of security-aware multi-hop AHWNs. Moreover, these characteristics of multi-hop AHWNs with colluding eavesdroppers are compared with those of multi-hop AHWNs with non-colluding eavesdroppers and without eavesdroppers. Simulation results show that putting more legitimate users does not greatly improve the quality of the multi-hop path in the non-colluding case compared with that in colluding case. Furthermore, the shape parameter of Nakagami fading has a more substantial effect on the connectivity and hop count than the spread parameter. The results in this paper provide valuable insights in designing and evaluating security-aware multi-hop AHWNs.

Qualitative Analysis of dual MAC in Multihop Adhoc Wireless Network

Multihop adhoc wireless networks offer great challenges for protocol designers. Stations in such networks are constrained by factors like low power, limited bandwidth, link errors and collisions. Changes are needed at various levels of the protocol stack, most importantly at the media access layer(MAC). This paper emphasizes in minimizing the collisions, and take care of the hidden and exposed problems in multihop wireless networks. The MAC with Distributed Coordination Function(DCF)does not scale well in such networks. We introduce Point Coordination Function(PCF)in the region of high traffic areas, and discuss its effect on network performance. To improve network scalability and throughput, we propose the design of dual MAC. This work discusses architecture and working of the dual MAC. Performance results of the network using MAC are presented, and compared with that of pure DCF operation.

Cross Layer Approach and ANFIS based Optimized Routing in Wireless Multi-Hop Ad Hoc Networks

Mobile ad hoc networks are non-dependent on any wired infrastructure and provide exceptional benefits during typical situations like conference, fair/exhibition, disaster recovery and emergency rescue operations. But these networks have to deal with several open issues, since they are battery operated and the dynamic topology can change due to mobility. Thus, multi-hop wireless ad hoc networking needs an energy efficient routing protocol that discovers/maintains routes to any other member node in the network, minimizing computation/communication overhead and battery power consumption. An adaptive neuro fuzzy inference system (ANFIS) based ad hoc routing approach has not been investigated before. In this paper, an ANFIS and cross layer approach-based energy efficient routing protocol for wireless multi-hop networks is proposed and its performance is compared with the Ad Hoc On-demand Distance Vector (AODV) Routing Protocol and fuzzy based AODV, using the network simulator ns2. Using remaining battery power, hop count and link stability as the input variables, the ANFIS module computes the optimum path cost, as the output. The proposed ANFIS based approach produces better results when compared using the metrics: average throughput, packet delivery ratio, average end-to-end delay in packet delivery between source and destination and average routing overhead.

A Study of Named Data Networking as Communication Protocol for Multi-hop Wireless Ad Hoc Network

Named Data Networking (NDN) has been repeatedly quoted in numerous past and existing literature reviews to have replaced Host Centric Networking (HCN) due to its ability to solve energy efficiency issues inherent in Multi-hop Wireless Ad-hoc Networks (WAHN). However, this claim is proven to be wholly unsubstantiated and is not justified by academic proof in said articles. Therefore, this study take the initiative to fill in this gap by presenting a comparative study of NDN based MWAHN and HCN based MWAHN through the use of real implementation by measuring two parameter metric that are related to energy efficiency, namely energy consumption and file transfer completion time. For this study, NDN-based MWAHN is compared with two type of actively developed HCN routing protocol implementation, namely Babeld and BMX6. The results obtained from this experiment is crucial for MWAHN researchers to gain better understanding of the real potential of the NDN based routing that can be used as a solution for energy consumption issues that exist in wireless multi-hop ad-hoc network.

An Upper Bound Capacity Algorithm for Multi-hop Wireless Ad Hoc Networks

The upper bound capacity based on the SINR model is a very important parameter when evaluating the performance of the multi-hop wireless ad hoc networks. In this paper, a new upper bound capacity algorithm is proposed. Firstly, we analyzed the classical physics SINR model over the Rayleigh fading channels to establish the relationship between density of nodes and path outage probability. Then, we developed the closed-form expression of the upper bound transmission capacity based on the Weber model for the random networks. Finally, we evaluated effects of parameters in the communication range, density, SINR threshold and fading factors, and consequently transmission capacity of the network by sensitivity analysis. The numerical simulation showed that the optimum density of nodes was existed to obtain the upper bound transmission capacity. The capacity increased firstly and then decreased over the density of nodes increasing. It affected by channel fading factor and communication range sensitively.

A reactive algorithm for deducing nodal forwarding behavior in a multihop ad-hoc wireless network in the presence of errors

novel algorithm is presented to deduce individual nodal forwarding behavior from standard end-to-end acknowledgments. The algorithm is based on a well-established mathematical method and is robust to network related errors and nodal behavior changes. The proposed solution was verified in a network simulation, during which it achieved sound results in a challenging multihop ad-hoc network environment.

Adaptive Transmission for Network-Coded All-to-All Broadcast in Multi-Hop Ad Hoc Wireless Networks

We describe and evaluate a new suite of protocols for the delivery of information from each node to every other node in a multi-hop ad hoc wireless network. The protocol suite is integrated with random linear network coding to mitigate the effects of packet losses due to noise and time-varying fading on the radio links. The suite includes a practical three-mode protocol for packet-by-packet selection of the channel code and modulation based on control information from statistics derived by the nodes themselves. Our performance metric is energy efficiency, and our emphasis is on robust performance in practical networks for which optimization is not feasible.

Significance of Wireless Multi-Hop AD-HOC Networks

International Journal of Computer Sciences and Engineering (A UGC Approved and indexed with DOI, ICI and Approved, DPI Digital Library) is one of the leading and growing open access, peer-reviewed, monthly, and scientific research journal for scientists, engineers, research scholars, and academicians, which gains a foothold in Asia and opens to the world, aims to publish original, theoretical and practical advances in Computer Science,Information Technology, Engineering (Software, Mechanical, Civil, Electronics & Electrical), and all interdisciplinary streams of Computing Sciences. It intends to disseminate original, scientific, theoretical or applied research in the field of Computer Sciences and allied fields. It provides a platform for publishing results and research with a strong empirical component. It aims to bridge the significant gap between research and practice by promoting the publication of original, novel, industry-relevant research.

Survey on Efficient Use of Spatial Reusability in Multhop Wireless Network

The present wireless routing protocols does not increase the end-to-end throughput by reducing the number of hops to deliver a single packet from a source to a destination node. To maintain the proper link among the nodes in multihop wireless ad-hoc networks, the medium access control (MAC) protocol plays a vital role. The spatial reuse and throughput of a multihop network is greatly affected in assessing the level of interference, channel sharing was not expeditiously utilized by the prevailing methodology of the IEEE 802.11.Routing protocols are generally depends on transmission cost, minimizing routing metrics. But they fail to give assurance for increasing end-to-end throughput. The existing protocols don't take spatial reusability of the remote correspondence media into account. This paper overviews numerous techniques to upgrade the effective channel use by enhancing the spatial reuse.

Diversity Backpressure Scheduling and Routing With Mutual Information Accumulation in Wireless Ad-Hoc Networks

We suggest and analyze algorithms for routing in multi-hop wireless ad-hoc networks that exploit mutual information accumulation as the physical layer transmission scheme, and are capable of routing multiple packet streams (commodities) when only the average channel state information is present and that only locally. The proposed algorithms are modifications of the Diversity Backpressure (DIVBAR) algorithm, under which the packet whose commodity has the largest "backpressure metric" is chosen to be transmitted and is forwarded through the link with the largest differential backlog (queue length). In contrast to traditional DIVBAR, each receiving node stores and accumulates the partially received packet in a separate "partial packet queue", thus increasing the probability of successful reception during a later possible retransmission. We present two variants of the algorithm: DIVBAR-RMIA, under which all the receiving nodes clear the received partial information of a packet once one or more receiving nodes firstly decode the packet; and DIVBAR-MIA, under which all the receiving nodes retain the partial information of a packet until the packet has reached its destination. We characterize the network capacity region with RMIA and prove that (under certain mild conditions) it is strictly larger than the network capacity region with the repetition (REP) transmission scheme that is used by the traditional DIVBAR. We also prove that DIVBAR-RMIA is throughput-optimum among the polices with RMIA, i.e., it achieves the network capacity region with RMIA, which in turn demonstrates that DIVBAR-RMIA outperforms traditional DIVBAR on the achievable throughput. Moreover, we prove that DIVBAR-MIA performs at least as well as DIVBAR-RMIA with respect to throughput. Simulations also confirm these results.

A cross-layer protocol for exploiting cooperative diversity in multi-hop wireless ad hoc networks

Cooperative communication has emerged to reap the benefits of spatial diversity. To fully exploit cooperative diversity, we propose a medium access control and routing enabled cross-layer cooperative transmission (MACR-CCT) protocol for improving the performance in multi-hop wireless ad hoc networks (MWAN). Different from previous cooperative protocols that determine a receiver in one hop according to a non-cooperative routing protocol first and then select a cooperative relay, MACR-CCT selects the cooperative relay together with the receiver in one hop to exploit fully cooperative diversity, so that the receiver is selected for higher cooperative gain and closer distance to destination, and the relay is selected to achieve the better throughput performance while considering transmission error. Furthermore, considering that there are multiple source---destination pairs in MWAN, MACR-CCT takes interference mitigation into account to further improve network throughput when selecting the cooperative relay. Besides, we propose a theoretical model to analyze the throughput performance. Finally, we take advantage of simulation results to validate the effectiveness of our analytical model and show that our proposed MACR-CCT protocol can significantly outperform existing packet transmission mechanisms in terms of throughput and delay under the multi-hop multi-flow network scenario.

Secure Routing in Multihop Wireless Ad-Hoc Networks With Decode-and-Forward Relaying

In this paper, we study the problem of secure routing in a multihop wireless ad-hoc network in the presence of randomly distributed eavesdroppers. Specifically, the locations of the eavesdroppers are modeled as a homogeneous Poisson point process (PPP) and the source-destination pair is assisted by intermediate relays using the decode-and-forward (DF) strategy. We analytically characterize the physical layer security performance of any chosen multihop path using the end-to-end secure connection probability (SCP) for both colluding and non-colluding eavesdroppers. To facilitate finding an efficient solution to secure routing, we derive accurate approximations of the SCP. Based on the SCP approximations, we study the secure routing problem which is defined as finding the multihop path having the highest SCP. A revised Bellman-Ford algorithm is adopted to find the optimal path in a distributed manner. Simulation results demonstrate that the proposed secure routing scheme achieves nearly the same performance as exhaustive search.

Sparse Vehicular Sensor Networks for Traffic Dynamics Reconstruction

In this paper, we propose the use of an ad-hoc wireless network formed by a fraction of the passing vehicles (sensor vehicles) to periodically recover their positions and speeds. A static roadside unit (RSU) gathers data from passing sensor vehicles. Finally, the speed/position information or space-time velocity (STV) field is then reconstructed in a data fusion center with simple interpolation techniques. We use widely accepted theoretical traffic models (i.e., car-following, multilane, and overtake-enabled models) to replicate the nonlinear characteristics of the STV field in representative situations (congested, free, and transitional traffic). To obtain realistic packet losses, we simulate the multihop ad-hoc wireless network with an IEEE 802.11p PHY layer. We conclude that: 1) for relevant configurations of both sensor vehicle and RSU densities, the wireless multihop channel performance does not critically affect the STV reconstruction error, 2) the system performance is marginally affected by transmission errors for realistic traffic conditions, 3) the STV field can be recovered with minimal mean absolute error for a very small fraction of sensor vehicles (FSV) ≈ 9%, and 4) for that FSV value, the probability that at least one sensor vehicle transits the spatiotemporal regions that contribute the most to reduce the STV reconstruction error sharply tends to 1. Thus, a random and sparse selection of wireless sensor vehicles, in realistic traffic conditions, is sufficient to get an accurate reconstruction of the STV field.

Distributed formation of degree constrained minimum routing cost tree in wireless ad-hoc networks

During several decades, there have been many researches on approximation algorithms for constructing minimum routing cost tree (MRCT) that minimizes the sum of routing cost of all pairs in a tree topology. Existing algorithms have been mainly studied in the field of graph theory, thus it is difficult to apply them to multi-hop wireless ad-hoc networks due to the theoretical and centralized methodology. In addition, wireless ad-hoc network protocols restrict the maximum degree, which is the maximum number of children a parent may have, in order to prevent excessive concentration of traffic. However, this limitation has not been considered by any existing algorithms. In this paper, we define the degree constrained MRCT (DC-MRCT) problem and extract the characteristics of DC-MRCT by analyzing all possible tree topologies for the given number of nodes. Based on these characteristics that DC-MRCT has the minimum sum of tree level and the maximum square sum of subtree sizes, we propose a distributed DC-MRCT Formation (DC-MRCTF) algorithm that can be applicable to any type of wireless ad-hoc network protocols working on tree topology. Performance evaluation shows that DC-MRCTF gives noticeable benefit for up to 80% of individual communication pair compared with the representative tree formation algorithm in ZigBee as well as significantly reduces the sum of routing cost of all pairs regardless of network density.

On cooperative transmission range extension in multi-hop wireless ad-hoc and sensor networks: A review

Range extension is a promising feature offered by cooperative transmission (CT), also known as virtual multiple-input–single-output (VMISO). Many authors have considered how the diversity and array gains from CT may benefit a wireless multi-hop network, when the gains are used for increasing link reliability and reducing transmit power. However, relatively less attention has been given to the benefits of CT range extension and few testbed implementations of CT have been demonstrated. In this paper, we focus on how CT range extension can impact the lower three layers, especially medium access control (MAC) and routing for ad hoc and sensor multi-hop networks (AHSMNs). We assume cooperators decode and forward the packets. Various analytical models, performance analyses, and experimental results using software-defined radios in an indoor office environment are discussed. For wireless sensor networks (WSNs), we review CT range extension at the network layer, to eliminate the energy hole that forms around sink nodes in non-CT networks, and we review cooperator selection and duty cycle scheduling algorithms at Layer 2, to maximize the lifetime of a multi-hop WSN. For ad hoc networks, we emphasize a family of lightweight broadcasting and unicasting protocols based on a simple form of CT called the opportunistic large array (OLA). Experimental results, including OLA-based unicast routing and diversity order effects in two-hop CT networks, are discussed.

Energy Aware Forwarding in Content Centric Based Multihop Wireless Ad Hoc Networks

Energy Aware Forwarding in Content Centric Based Multihop Wireless Ad Hoc Networks

Performance Analysis of Statistical QoS Routing Schemes for Multihop Wireless Ad Hoc Networks

The quality of service (QoS) standard in Mobile Ad-hoc Networks (MANET's) is much more challenging compared to the wired networks. In the last decade there was a lot of attention in the area of integration of QoS standard in MANET protocols. QoS-based routing protocols are integral part of any QoS solution, because their function is to check whether the nodes in the network are able to provide services to network applications. These protocols play a key role in controlling the information received and delivered from data transfer sessions. The purpose of this paper is to study and review the QoS routing schemes designed for IEEE 802.11 standard in Multihop Ad-hoc networks. Moreover, the paper simulates a routing scheme and shows results for an effective end-to-end communication.

E-BEB: Enhanced Binary Exponential Backoff Algorithm for Multi-hop Wireless Ad-hoc Networks

Binary exponential backoff algorithm is the de-facto medium access control protocol for wireless local area networks, and it has been employed as the standard contention resolution algorithm in multi-hop wireless ad-hoc networks. However, this algorithm does not function well in multi-hop wireless environments due to its several performance issues and technical limitations. In this paper, we propose a simple, efficient, priority provision, and well performed contention resolution algorithm called enhanced binary exponential backoff (E-BEB) algorithm for impartial channel access in multi-hop wireless ad-hoc networks. We also provide a simple and accurate analytical model to study the system saturation throughput of the proposed scheme. Simulations are conducted to evaluate the performance of E-BEB algorithm. The results show that the E-BEB algorithm can alleviate the fairness problem and support multimedia transmission in multi-hop wireless environments.