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Showing papers on "Optimized Link State Routing Protocol published in 2016"


Journal ArticleDOI
TL;DR: This paper surveys the work done toward all of the outstanding issues, relating to this new class of networks, so as to spur further research in these areas.
Abstract: Unmanned aerial vehicles (UAVs) have enormous potential in the public and civil domains. These are particularly useful in applications, where human lives would otherwise be endangered. Multi-UAV systems can collaboratively complete missions more efficiently and economically as compared to single UAV systems. However, there are many issues to be resolved before effective use of UAVs can be made to provide stable and reliable context-specific networks. Much of the work carried out in the areas of mobile ad hoc networks (MANETs), and vehicular ad hoc networks (VANETs) does not address the unique characteristics of the UAV networks. UAV networks may vary from slow dynamic to dynamic and have intermittent links and fluid topology. While it is believed that ad hoc mesh network would be most suitable for UAV networks yet the architecture of multi-UAV networks has been an understudied area. Software defined networking (SDN) could facilitate flexible deployment and management of new services and help reduce cost, increase security and availability in networks. Routing demands of UAV networks go beyond the needs of MANETS and VANETS. Protocols are required that would adapt to high mobility, dynamic topology, intermittent links, power constraints, and changing link quality. UAVs may fail and the network may get partitioned making delay and disruption tolerance an important design consideration. Limited life of the node and dynamicity of the network lead to the requirement of seamless handovers, where researchers are looking at the work done in the areas of MANETs and VANETs, but the jury is still out. As energy supply on UAVs is limited, protocols in various layers should contribute toward greening of the network. This paper surveys the work done toward all of these outstanding issues, relating to this new class of networks, so as to spur further research in these areas.

1,636 citations


Journal ArticleDOI
TL;DR: This paper proposes a new authentication protocol for VANETs in a decentralized group model by using a new group signature scheme that is featured with threshold authentication, efficient revocation, unforgeability, anonymity, and traceability.
Abstract: Vehicular ad hoc networks (VANETs) have recently received significant attention in improving traffic safety and efficiency. However, communication trust and user privacy still present practical concerns to the deployment of VANETs, as many existing authentication protocols for VANETs either suffer from the heavy workload of downloading the latest revocation list from a remote authority or cannot allow drivers on the road to decide the trustworthiness of a message when the authentication on messages is anonymous. In this paper, to cope with these challenging concerns, we propose a new authentication protocol for VANETs in a decentralized group model by using a new group signature scheme. With the assistance of the new group signature scheme, the proposed authentication protocol is featured with threshold authentication, efficient revocation, unforgeability, anonymity, and traceability. In addition, the assisting group signature scheme may also be of independent interest, as it is characterized by efficient traceability and message linkability at the same time. Extensive analyses indicate that our proposed threshold anonymous authentication protocol is secure, and the verification of messages among vehicles can be accelerated by using batch message processing techniques.

245 citations


Journal ArticleDOI
TL;DR: In this paper, the authors compare two routing algorithms for ad hoc networks: optimized link-state routing (OLSR) and predictive OLSR (P-OLSR), which takes advantage of the Global Positioning System (GPS) information available on board.
Abstract: This paper reports experimental results on self-organizing wireless networks carried by small flying robots. Flying ad hoc networks (FANETs) composed of small unmanned aerial vehicles (UAVs) are flexible, inexpensive, and fast to deploy. This makes them a very attractive technology for many civilian and military applications. Due to the high mobility of the nodes, maintaining a communication link between the UAVs is a challenging task. The topology of these networks is more dynamic than that of typical mobile ad hoc networks (MANETs) and of typical vehicle ad hoc networks. As a consequence, the existing routing protocols designed for MANETs partly fail in tracking network topology changes. In this paper, we compare two different routing algorithms for ad hoc networks: optimized link-state routing (OLSR) and predictive OLSR (P-OLSR). The latter is an OLSR extension that we designed for FANETs; it takes advantage of the Global Positioning System (GPS) information available on board. To the best of our knowledge, P-OLSR is currently the only FANET-specific routing technique that has an available Linux implementation. We present results obtained by both media-access-control (MAC) layer emulations and real-world experiments. In the experiments, we used a testbed composed of two autonomous fixed-wing UAVs and a node on the ground. Our experiments evaluate the link performance and the communication range, as well as the routing performance. Our emulation and experimental results show that P-OLSR significantly outperforms OLSR in routing in the presence of frequent network topology changes.

242 citations


Journal ArticleDOI
TL;DR: It is observed that a hybrid routing protocol is the best choice for VANETs in both urban and highway environments, and the pros and cons for each routing protocol are presented.
Abstract: Position-based routing is considered to be a very promising routing strategy for communication within vehicular ad hoc networks (VANETs), due to the fact that vehicular nodes can obtain position information from onboard global positioning system receivers and acquire global road layout information from an onboard digital map. Position-based routing protocols, which are based mostly on greedy forwarding, are well-suited to the highly dynamic and rapid-changing network topology of VANETs. In this paper, we outline the background and the latest development in VANETs and survey the state-of-the-art routing protocols previously used in VANETs. We present the pros and cons for each routing protocol, and make a detailed comparison. We also discuss open issues, challenges and future research directions. It is observed that a hybrid routing protocol is the best choice for VANETs in both urban and highway environments.

240 citations


Journal ArticleDOI
TL;DR: It is argued that by carefully considering spatial reusability of the wireless communication media, one can tremendously improve the end-to-end throughput in multi-hop wireless networks and compare them with existing single-path routing and anypath routing protocols, respectively.
Abstract: In the problem of routing in multi-hop wireless networks, to achieve high end-to-end throughput, it is crucial to find the “best” path from the source node to the destination node. Although a large number of routing protocols have been proposed to find the path with minimum total transmission count/time for delivering a single packet, such transmission count/time minimizing protocols cannot be guaranteed to achieve maximum end-to-end throughput. In this paper, we argue that by carefully considering spatial reusability of the wireless communication media, we can tremendously improve the end-to-end throughput in multi-hop wireless networks. To support our argument, we propose spatial reusability-aware single-path routing (SASR) and anypath routing (SAAR) protocols, and compare them with existing single-path routing and anypath routing protocols, respectively. Our evaluation results show that our protocols significantly improve the end-to-end throughput compared with existing protocols. Specifically, for single-path routing, the median throughput gain is up to 60 percent, and for each source-destination pair, the throughput gain is as high as $5.3\times$ ; for anypath routing, the maximum per-flow throughput gain is 71.6 percent, while the median gain is up to 13.2 percent.

186 citations


Journal ArticleDOI
TL;DR: This paper articulate this problem and classify current routing protocols for WSNs into two categories according to their orientation toward either homogeneous or heterogeneous W SNs, further classified into static and mobile ones.
Abstract: Due to a battery constraint in wireless sensor networks (WSNs), prolonging their lifetime is important. Energy-efficient routing techniques for WSNs play a great role in doing so. In this paper, we articulate this problem and classify current routing protocols for WSNs into two categories according to their orientation toward either homogeneous or heterogeneous WSNs. They are further classified into static and mobile ones. We give an overview of these protocols in each category by summarizing their characteristics, limitations, and applications. Finally, some open issues in energy-efficient routing protocol design for WSNs are indicated.

148 citations


Journal ArticleDOI
TL;DR: The results show that the multihop routing in JCR may lead to the unbalanced CH selection, and the solution is provided to optimize the network lifetime by considering the gradient of one-hop neighbor nodes in the setting of backoff timer.
Abstract: For data collection in large-scale wireless sensor networks (WSNs), dynamic clustering provides a scalable and energy-efficient solution, which uses cluster head (CH) rotation and cluster range assignment algorithms to balance the energy consumption. Nevertheless, most existing works consider the clustering and routing as two isolated issues, which is harmful to the connectivity and energy efficiency of the network. In this paper, we provide a detailed analysis on the relations between clustering and routing, and then propose a joint clustering and routing (JCR) protocol for reliable and efficient data collection in large-scale WSN. JCR adopts the backoff timer and gradient routing to generate connected and efficient intercluster topology with the constraint of maximum transmission range. The relations between clustering and routing in JCR are further exploited by theoretical and numerical analyses. The results show that the multihop routing in JCR may lead to the unbalanced CH selection. Then, the solution is provided to optimize the network lifetime by considering the gradient of one-hop neighbor nodes in the setting of backoff timer. Theoretical analysis and simulation results prove the connectivity and efficiency of the network topology generated by JCR.

128 citations


Journal ArticleDOI
TL;DR: A novel cluster-based routing protocol called ABC-SD that exploits the biologically inspired fast and efficient searching features of the Artificial Bee Colony metaheuristic to build low-power clusters and a realistic energy model is adopted in the considered network model.

125 citations


Journal ArticleDOI
TL;DR: The proposed protocol PDORP has the characteristics of both power efficient gathering sensor information system and DSR routing protocols, and hybridization of genetic algorithm and bacterial foraging optimization is applied to proposed routing protocol to identify energy efficient optimal paths.
Abstract: Energy consumption is one of the constraints in wireless sensor networks (WSNs). The routing protocols are the hot areas to address quality-of-service (QoS) related issues, viz., energy consumption, network lifetime, network scalability, and packet overhead. The key issue in WSN is that these networks suffer from the packet overhead, which is the root cause of more energy consumption and degrade the QoS in sensor networks. In WSN, there are several routing protocols, which are used to enhance the performance of the network. Out of those protocols, dynamic source routing (DSR) protocol is more suitable in terms of small energy density, but sometimes when the mode of a node changes from active to sleep, the efficiency decreases as the data packets need to wait at the initial point, where the packet has been sent and this increases the waiting time and end-to-end delay of the packets, which leads to increase in energy consumption. Our problem is to identify the dead nodes and to choose another suitable path so that the data transmission becomes smoother and less energy gets conserved. In order to resolve these issues, we propose directional transmission-based energy aware routing protocol named PDORP. The proposed protocol PDORP has the characteristics of both power efficient gathering sensor information system and DSR routing protocols. In addition, hybridization of genetic algorithm and bacterial foraging optimization is applied to proposed routing protocol to identify energy efficient optimal paths. The performance analysis, comparison through a hybridization approach of the proposed routing protocol, gives better result comprising less bit error rate, less delay, less energy consumption, and better throughput, which leads to better QoS and prolong the lifetime of the network. Moreover, the computation model is adopted to evaluate and compare the performance of the both routing protocols using soft computing techniques.

118 citations


Journal ArticleDOI
TL;DR: This paper builds a link model with a Wiener process to predict the probability of link availability, which considers the stable and unstable vehicle states according to the behavior of vehicles, and introduces a novel concept called the link correlation which represents the influence of different link combinations in network topology to transmit a packet with less network resource consumption and higher goodput.
Abstract: In urban vehicular ad hoc networks (VANETs), due to the high mobility and uneven distribution of vehicles, how to select an optimal relaying node in an intra-street and how to determine a street selection at the intersection are two challenging issues in designing an efficient routing protocol in complex urban environments. In this paper, we build a link model with a Wiener process to predict the probability of link availability, which considers the stable and unstable vehicle states according to the behavior of vehicles. We introduce a novel concept called the link correlation which represents the influence of different link combinations in network topology to transmit a packet with less network resource consumption and higher goodput. Based on this concept, we design an opportunistic routing metric called the expected transmission cost over a multi-hop path (ETCoP) implemented with our link model as the selection guidance of a relaying node in intra-streets. This metric can also provide assistance for the next street selection at an intersection. Finally, we propose a street-centric opportunistic routing protocol based on ETCoP for VANETs (SRPE). Simulation results show that our proposed SRPE outperforms the conventional protocols in terms of packet delivery ratio, average end-to-end delay, and network yield.

116 citations


Journal ArticleDOI
TL;DR: SCRP is a distributed routing protocol that computes E2ED for the entire routing path before sending data messages, and results show that SCRP outperforms some of the well-known protocols in literature.
Abstract: This paper addresses the issue of selecting routing paths with minimum end-to-end delay (E2ED) for nonsafety applications in urban vehicular ad hoc networks (VANETs). Most existing schemes aim at reducing E2ED via greedy-based techniques (i.e., shortest path, connectivity, or number of hops), which make them prone to the local maximum problem and to data congestion, leading to higher E2ED. As a solution, we propose SCRP, which is a distributed routing protocol that computes E2ED for the entire routing path before sending data messages. To do so, SCRP builds stable backbones on road segments and connects them at intersections via bridge nodes. These nodes assign weights to road segments based on the collected information of delay and connectivity. Routes with the lowest aggregated weights are selected to forward data packets. Simulation results show that SCRP outperforms some of the well-known protocols in literature.

Journal ArticleDOI
TL;DR: An optimizing strategy to balance the latency requirement and the cost on cellular networks is presented, in which vehicles are encouraged to send the SDN control requests through the cellular networks by rebating network bandwidth.
Abstract: The vehicle ad hoc network (VANET) is an emerging network technology that is expected to be cost-effective and adaptable, making it ideal to provide network connection service to drivers and passengers on today's roads. In the next generation of VANETs with fifth-generation (5G) networks, software-defined networking (SDN) technology will play a very important role in network management. However, for infotainment applications, high latency in VANET communication imposes a great challenge for network management, whereas direct communication through the cellular networks brings high cost. In this paper, we present an optimizing strategy to balance the latency requirement and the cost on cellular networks, in which we encourage vehicles to send the SDN control requests through the cellular networks by rebating network bandwidth. Furthermore, we model the interaction of the controller and vehicles as a two-stage Stackelberg game and analyze the game equilibrium. From the experimental results, the optimal rebating strategy provides smaller latency than other control plane structures.

Journal ArticleDOI
01 Aug 2016-Optik
TL;DR: In this work, an attempt is carried out to assess the diverse hierarchical routing protocols, developed from LEACH and is extended to other presented routing protocols like TEEN, APTEEN, and PEGASIS.

Journal ArticleDOI
TL;DR: This paper proposes a novel energy-efficient region-based routing protocol (ER-RPL), which achieves energy- efficient data delivery without compromising reliability and the key of energy saving.
Abstract: Routing plays an important role in the overall architecture of the Internet of Things. IETF has standardized the RPL routing protocol to provide the interoperability for low-power and lossy networks (LLNs). LLNs cover a wide scope of applications, such as building automation, industrial control, healthcare, and so on. LLNs applications require reliable and energy-efficient routing support. Point-to-point (P2P) communication is a fundamental requirement of many LLNs applications. However, traditional routing protocols usually propagate throughout the whole network to discover a reliable P2P route, which requires large amount energy consumption. Again, it is challenging to achieve both reliability and energy-efficiency simultaneously, especially for LLNs. In this paper, we propose a novel energy-efficient region-based routing protocol (ER-RPL), which achieves energy-efficient data delivery without compromising reliability. In contrast of traditional routing protocols where all nodes are required for route discovery, the proposed scheme only requires a subset of nodes to do the job, which is the key of energy saving. Our theoretical analysis and extensive simulation studies demonstrate that ER-RPL has a great performance superiority over two conventional benchmark protocols, i.e., RPL and P2P-RPL.

Journal ArticleDOI
TL;DR: This work proposes classifying candidate set selection procedures into sender-side, receiver- side, and hybrid approaches, and candidate coordination procedures into timer-based and control-packet-based approaches and argues that those characteristics should be considered during the design of opportunistic routing protocols for different scenarios in underwater sensor networks.
Abstract: The unique characteristics of the underwater acoustic channel impose many challenges that limit the utilization of underwater sensor networks. In this context, opportunistic routing, which has been extensively investigated in terrestrial wireless ad hoc network scenarios, has greater potential for mitigating drawbacks from underwater acoustic communication and improving network performance. In this work, we discuss the two main building blocks for the design of opportunistic routing protocols for underwater sensor networks: candidate set selection and candidate coordination procedures. We propose classifying candidate set selection procedures into sender-side, receiver-side, and hybrid approaches, and candidate coordination procedures into timer-based and control-packet-based approaches. Based on this classification, we discuss particular characteristics of each approach and how they relate to underwater acoustic communication. Furthermore, we argue that those characteristics should be considered during the design of opportunistic routing protocols for different scenarios in underwater sensor networks.

Journal ArticleDOI
TL;DR: This paper 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 noncolluding eavesdroppers and derives accurate approximations of the SCP.
Abstract: 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 noncolluding 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.

Journal ArticleDOI
TL;DR: An efficient and practical pseudonymous authentication protocol with conditional privacy preservation that protects a user's privacy until the user honestly follows the protocol and the results show the feasibility of the protocol in terms of end-to-end delay and packet delivery ratio.
Abstract: Vehicular ad hoc network (VANET) is a technology that enables smart vehicles to communicate with each other and form a mobile network VANET facilitates users with improved traffic efficiency and safety Authenticated communication becomes one of the prime requirements of VANET However, authentication may reveal a user’s personal information such as identity or location, and therefore, the privacy of an honest user must be protected This paper proposes an efficient and practical pseudonymous authentication protocol with conditional privacy preservation Our protocol proposes a hierarchy of pseudonyms based on the time period of their usage We propose the idea of primary pseudonyms with relatively longer time periods that are used to communicate with semi-trusted authorities and secondary pseudonyms with a smaller life time that are used to communicate with other vehicles Most of the current pseudonym-based approaches are based on certificate revocation list (CRL) that causes significant communication and storage overhead or group-based approaches that are computationally expensive and suffer from group-management issues These schemes also suffer from trust issues related to certification authority Our protocol only expects an honest-but-curious behavior from otherwise fully trusted authorities Our proposed protocol protects a user’s privacy until the user honestly follows the protocol In case of a malicious activity, the true identity of the user is revealed to the appropriate authorities Our protocol does not require maintaining a CRL and the inherent mechanism assures the receiver that the message and corresponding pseudonym are safe and authentic We thoroughly examined our protocol to show its resilience against various attacks and provide computational as well as communicational overhead analysis to show its efficiency and robustness Furthermore, we simulated our protocol in order to analyze the network performance and the results show the feasibility of our proposed protocol in terms of end-to-end delay and packet delivery ratio

Proceedings ArticleDOI
01 Jan 2016
TL;DR: These routing protocols are studied in depth and simulated using NS-2 and the impact of network size, packet delivery ratio, average delay and average throughput will be presented.
Abstract: Communication among the wireless links between mobile nodes is become popular research area because of its simplicity of deployment and mobility. Collection of all mobile nodes through which all wireless links are connected called as Mobile Ad hoc Network (MANET). MANET network gets too much attraction of researchers due to its mobility, reliability, self-repairing, dynamic infrastructure and independent with the help of center administration. Despite of numerous advantages it has many problems like synchronization, routing protocol, delay and shortest path. Many routing protocols have been proposed like OLSR, DSDV, DSR, AODV and TORA so far to improve the routing performance therefore these routing protocols are studied in depth and simulated using NS-2. The simulation and comparison results will briefly present the impact of network size, packet delivery ratio, average delay and average throughput.

Journal ArticleDOI
TL;DR: A novel trust management system to secure the data plane of ad-hoc networks and defend against increasing attacks to trust management systems is proposed by integrating it into the optimized link state routing (OLSR) protocol.
Abstract: The rapidly developing ad-hoc network technology has a wide range of applications, such as vehicular ad-hoc networks (VANETs), wireless sensor networks (WSNs), and emergency and military communications. Due to the characteristics such as openness and dynamic topology, ad-hoc networks suffer from various attacks in the data plane. Even worse, some attacks can subvert or bypass the frequently used identity-based security mechanisms. To secure the data plane of ad-hoc networks, we propose a novel trust management system. In the system, fuzzy logic is employed to formulate imprecise empirical knowledge, which is used to evaluate the path trust value. Together with fuzzy logic, graph theory is adopted to build a novel trust model for calculating the node trust value. To defend against increasing attacks to trust management systems, such as slandering and harboring, we propose a filtering algorithm. An efficient trustworthiness decay method is also designed to resolve the conflict about the decaying historical trust value in a trust-based routing decision. Additionally, we present a feasible trust factor collection approach to assure that the trust management system is compatible with other security primitives, such as encryption and encapsulation. Finally, we implement the proposed trust management system by integrating it into the optimized link state routing (OLSR) protocol. Simulation results show that the proposed trust management system works well in detecting and resisting data-plane attacks.

Proceedings ArticleDOI
03 Apr 2016
TL;DR: Through vehicle-to-UAV (V2U) communication, the overall connectivity between vehicles is improved and therefore the routing process is efficiently improved.
Abstract: It is a challenging task to develop an efficient routing solution for a reliable data delivery in urban vehicular environments. Indeed, it is difficult to find a shortest end-to-end connected path especially in urban city given the mobility pattern of the vehicles and the various obstructions to a clear transmission such as buildings. To overcome these difficulties, we investigate how unmanned aerial vehicles (UAVs) can assist vehicles on the ground in relaying in urban areas. In this paper, we propose UVAR (UAV-Assisted VANET Routing Protocol), a new routing technique for Vehicular Ad hoc Networks (VANets). This protocol is based on the use of the traffic density and the knowledge of vehicular connectivity in the streets. With this approach UAVs collect information about the traffic density on the ground and the state of vehicles connectivity, and exchange them with vehicles through Hello messages. These information allow UAV to place themselves so as to allow relaying data when connectivity between sole vehicles on the ground is not possible. Through vehicle-to-UAV (V2U) communication, the overall connectivity between vehicles is improved and therefore the routing process is efficiently improved. The performance of the proposed protocol is evaluated and the results to different scenarios are discussed.

Journal ArticleDOI
TL;DR: This article has elaborated the basic concept of Opportunistic routing, different areas in which it has been claimed to be beneficial, some protocols their metrics and their drawbacks.

Proceedings ArticleDOI
14 Mar 2016
TL;DR: The general principle of swarm intelligence is discussed and the research efforts on these SI based protocols according to various promising meta-heuristics are surveyed, pointing out the fundamental issues and potential future directions.
Abstract: Swarm Intelligence techniques have been widely used in the science and engineer domains such as Mobile Ad Hoc Networks (MANETs) and Wireless Sensor Networks (WSNs). It is a relatively novel and promising field, focusing on the adaptation of collective behaviors of various natural creatures like ants, fish, birds, and honey bees, and a large number of routing protocols for WSNs have been developed according to the inspiration from the foraging behaviors of these species. In this paper, we first discuss the general principle of swarm intelligence and survey the research efforts on these SI based protocols according to various promising meta-heuristics. In the second part of the paper, we present the properties of termite colony optimization and fission-fusion social structure based spider monkey optimization based clustering in WSNs. Last, we conclude the paper with a comparative analysis, pointing out the fundamental issues and potential future directions.


Journal ArticleDOI
TL;DR: This paper surveys and discusses different metaheuristics applied to solve the routing problem within VANET, and technical challenges and future trends are treated and presented.
Abstract: Vehicular $ad~ hoc$ network (VANET) is a set of vehicles trying to exchange security and comfort data even if they are not directly within radio range of each other. As VANET presented several challenges, the various contributions defined are not efficient to provide reliable services. Consequently, several researches and projects have been launched to develop an intelligent transportation system that guarantees both safety and comfort for users. Although the use of metaheuristics seems to be the most convenient to overcome these issues, actually, to the best of our knowledge, there are no studies addressing the uses of those approaches in VANET. This paper surveys and discusses different metaheuristics applied to solve the routing problem within VANET. Furthermore, technical challenges and future trends are treated and presented.

Journal ArticleDOI
TL;DR: This paper presents an efficient protocol for fast dissemination of authenticated messages in VANETs that ensures the anonymity of the senders and also provides mechanism for law enforcement agencies to trace the messages to their senders, when necessary.

Journal ArticleDOI
TL;DR: An interference aware metric with a prediction algorithm is proposed in order to reduce the level of interference between each pair of nodes at the MAC and routing layer in multi-radio vehicular networks, and significant performance improvements were obtained.
Abstract: Vehicular ad hoc networks (VANETs) represent a particular mobile technology that permits communication between vehicles, offering security and comfort. Nowadays, distributed mobile wireless computing is becoming a very important communication paradigm, due to its flexibility to adapt to different mobile applications. In this work, an interference aware metric is proposed in order to reduce the level of interference between each pair of nodes at the MAC and routing layer. In particular, this metric with a prediction algorithm is proposed to work in a cross-layered MAC and an on-demand routing scheme in multi-radio vehicular networks, wherein each node is equipped with two multi-channel radio interfaces. The proposed metric is based on the maximization of the average signal-to-interference ratio (SIR) level of the connection between source and destination. In order to relieve the effects of the co-channel interference perceived by mobile nodes, transmission channels are switched on a basis of a periodical SIR evaluation. Our solution has been integrated with an on-demand routing scheme but it can be applied to other routing strategies. Three on-demand interference aware routing schemes integrating IEEE 802.11p Multi-channel MAC have been tested to assess the benefits of the novel metric applied to a vehicular context. NS-3 has been used for implementing and testing the proposed idea, and significant performance improvements were obtained: in particular, the proposed policy has resulted in an enhancement of network performance in terms of throughput and packet delivery ratio.

Journal ArticleDOI
01 Jul 2016
TL;DR: This paper compares the performance for Normal, Uniform, Exponential and Weibull distributions of mesh clients by sending multiple constant bit rate flows in the network and shows that for HWM protocol the throughput of Uniform distribution is higher than other distributions, however, for OLSR protocol,The throughput of Exponential distribution is better than other distribution.
Abstract: Wireless mesh networks (WMNs) are attracting a lot of attention from wireless network researchers. Node placement problems have been investigated for a long time in the optimization field due to numerous applications in location science. In our previous work, we evaluated WMN-GA system which is based on genetic algorithms (GAs) to find an optimal location assignment for mesh routers. In this paper, we evaluate the performance of four different distributions of mesh clients for two WMN architectures considering throughput, delay and energy metrics. For simulations, we used ns-3, optimized link state routing (OLSR) and hybrid wireless mesh protocols (HWMP). We compare the performance for Normal, Uniform, Exponential and Weibull distributions of mesh clients by sending multiple constant bit rate flows in the network. The simulation results show that for HWM protocol the throughput of Uniform distribution is higher than other distributions. However, for OLSR protocol, the throughput of Exponential distribution is better than other distributions. For both protocols, the delay and remaining energy are better for Weibull distribution.

Journal ArticleDOI
TL;DR: This paper abstracts the MT model reflecting the dynamic routing-related characteristics in practical urban scenarios along streets, including the effect of mobility of vehicles, signal fading, wireless channel contention, and existing data traffic, and proposes a novel street-centric routing protocol based on MT (SRPMT) along the streets for VANETs.
Abstract: In a vehicular ad hoc network (VANET), high mobility and uneven distribution of vehicles are important factors affecting the performance of routing protocols. The high mobility may cause frequent changes of network topology, whereas the uneven distribution of vehicles may lead to routing failures due to network partition; even high density of vehicles may cause severe wireless channel contentions in an urban environment. In this paper, we propose a novel concept called the microtopology (MT), which consists of vehicles and wireless links among vehicles along a street as a basic component of routing paths and even the entire network topology. We abstract the MT model reflecting the dynamic routing-related characteristics in practical urban scenarios along streets, including the effect of mobility of vehicles, signal fading, wireless channel contention, and existing data traffic. We first analyze the endside-to-endside routing performance in an MT as a basis of routing decision. Then, we propose a novel street-centric routing protocol based on MT (SRPMT) along the streets for VANETs. Simulation results show that our proposed SRPMT protocol achieves higher data delivery rate and shorter average end-to-end delay compared with the performance of greedy perimeter stateless routing (GPSR) and greedy traffic-aware routing (GyTAR).

Journal ArticleDOI
TL;DR: SDN Partitioning as mentioned in this paper partitions the topology into sub-domains with SDN-enabled border nodes, such that OSPF's routing updates have to traverse SDN border nodes to reach neighboring subdomains.
Abstract: Hybrid IP networks that use both control paradigms - distributed and centralized - promise the best of two worlds: programmability and agility of SDN, and reliability and fault tolerance of distributed routing protocols like OSPF. The common approaches follow a division of labor concept, where SDN controls prioritized traffic and OSPF assures care-free operation of best effort traffic. We propose SDN Partitioning, which establishes centralized control over the distributed routing protocol by partitioning the topology into sub-domains with SDN-enabled border nodes, such that OSPF's routing updates have to traverse SDN border nodes to reach neighboring sub-domains. This allows the central controller to modify how sub-domains view one another, which in turn allows to steer inter-sub-domain traffic. The degree of dynamic control against simplicity of OSPF can be trade off by adjusting the size of the sub-domains. This paper explains the technical requirements, presents a novel scheme for balanced topology partitioning, and provides the models for common network management tasks. Our performance evaluation shows that - already in its minimum configuration with two sub-domains - SDN Partitioning provides significant improvements in all respects compared to legacy routing protocols, whereas smaller sub-domains provide network control capabilities comparable to full SDN deployment.

Journal ArticleDOI
TL;DR: AODV and DSDV protocols are analyzed in terms of routing overhead, packet delivery ratio, throughput and end to end delay and the modification in A ODV is given which helps to improve the performance of AODV in presence of black hole attack.