Joint routing and location-based service in VANETs

Nowadays Wireless Sensor Networks have attractedworldwide research and industrial interest, because theycan be applied in various areas. Geographic routingprotocols are very suitable to wireless sensor networksbecause they use location information when they need toroute packets. Obviously, location information ismaintained by Location-Based Services provided bynetwork nodes in a distributed way. The location basedservices can be classified into two classes: Flooding-Based and Rendez-vous-based location services.In this paper we choose to compare two hierarchicalrendez-vous location based-services, GLS (GridLocation Service) and HLS (Hierarchical LocationService) coupled to the GPSR routing protocol (GreedyPerimeter Stateless Routing).The simulations wereperformed using NS2 simulator for wireless sensornetworks to evaluate the performance and power of thetwo services in term of location overhead, the requesttravel time (RTT) and the query Success ratio (QSR).This work presents also the scalability performancestudy of both GLS and HLS, specifically, what happens ifthe number of nodes N increases. The study will focus onthree qualitative metrics: The location maintenance cost,the location query cost and the storage cost.

Geographic routing has been considered as an attractive approach for resource-constrained wireless sensor networks (WSNs) since it exploits local location information instead of global topology information to route data. However, this routing approach often suffers from the routing hole (i.e., an area free of nodes in the direction closer to destination) in various environments such as buildings and obstacles during data delivery, resulting in route failure. Currently, existing geographic routing protocols tend to walk along only one side of the routing holes to recover the route, thus achieving suboptimal network performance such as longer delivery delay and lower delivery ratio. Furthermore, these protocols cannot guarantee that all packets are delivered in an energy-efficient manner once encountering routing holes. In this paper, we focus on addressing these issues and propose an energy-aware dual-path geographic routing (EDGR) protocol for better route recovery from routing holes. EDGR adaptively utilizes the location information, residual energy, and the characteristics of energy consumption to make routing decisions, and dynamically exploits two node-disjoint anchor lists, passing through two sides of the routing holes, to shift routing path for load balance. Moreover, we extend EDGR into threedimensional (3D) sensor networks to provide energy-aware routing for routing hole detour. Simulation results demonstrate that EDGR exhibits higher energy efficiency, and has moderate performance improvements on network lifetime, packet delivery ratio, and delivery delay, compared to other geographic routing protocols in WSNs over a variety of communication scenarios passing through routing holes. The proposed EDGR is much applicable to resource-constrained WSNs with routing holes.

In this paper, we propose a combination of GPSR (Greedy Perimeter Stateless Routing) and Hierarchical Location Service (HLS). They used to be combined in the original work with a direct method, i.e. GPSR takes care of routing packets and HLS is called to get destination position when the target node position is unknown or is not fresh enough. When a destination is quite far away from the sender, the exact position of the target is first calculated. An extra overhead is generated from the sender to the receiver. Our aim in this paper, is to reduce this overhead. Then, when we send the packet to the former region where the destination was supposed to be. When the packet enters into the same region than the target, an HLS request is sent to determine the exact position of the destination. In order to implement this concept, we have proposed a patch over the NS-2 simulator which mixes both GPSR and HLS according to our proposal. We have conducted various simulations and we have varied the freshness of the destination location data. The obtained results are promising in terms of latency, packet delivery rate and overhead.

This chapter introduces geographic routing in vehicular ad hoc networks (VANETs). The aim of this chapter is to clarify the basic principle of geographic VANET routing protocols by stating their ideas. To this goal, we explain the common ideas behind the geographic routing protocols, and consider issues in applying those ideas to vehicular ad hoc networks. Then we summarize a wide variety of protocols; from ones in early design stages to understand the basic principle, to state-of-the-art ones to know recent research trends. After that, we give the detailed design of an example protocol to understand the design principle of VANET geographic routing protocols. Finally, we summarize the protocols introduced in this chapter and discuss future directions for possible research issues.

The most critical and important parameter to study is the Location Cache Maximum Age (LCMA). This parameter defines the maximum age at which location information is not considered fresh enough to be used when routing packets. Instead of this, a location request is launched to catch a more fresh location. In other words, it defines the freshness of the stored position in the location cache memory. In this paper, we propose a combination of GPSR (Greedy Perimeter Stateless Routing) and Location-based Services (Grid and Hierarchical Location Services (GLS/HLS)). In order to implement this concept, we have proposed a patch over the NS-2 simulator which mixes GPSR, GLS and HLS according to our proposal. We have conducted various simulations and we have varied the freshness of the destination location data. The obtained results are promising in terms of latency, packet delivery rate and overhead.

Geographic routing protocols have been widely used in microsensor networks, however, they cannot directly apply to distributed mobile sensor systems as mobile sensors often do not know their neighbors' exact physical locations. In this paper we consider geographic routing in distributed sensor systems without location information. We address the problem by introducing a lightweight and distributed virtual coordinate assignment protocol. We focus on the effectiveness of routing algorithms for distributed data fusion in the system and provide a detailed analysis of several routing algorithms for a sensor system with group mobility. Our simulation results show that controlled data flows significantly increase the probability of relevant data being fused

Position-based routing protocols take advantage of location information to perform a stateless and efficient routing. To enable position-based routing, a node must be able to discover the location of the messages’ destination node. This task is typically accomplished by a location service. Recently, several location service protocols have been developed for ad hoc networks.In this paper we propose a novel location service called PHLS: Predictive Hierarchical Location Service. In PHLS, the entire network is partitioned into a hierarchy of smaller and smaller regions. For each node, one node in each-level region of the hierarchy is chosen as its local location server. When the network initializes or when a node attaches the network, nodes contact their local location server with their current location information (ie. position and velocity). Then, they only need to update their location server when they move away from their current region. Finally, nodes query their location servers and get the exact or predicted location of destination nodes.KeywordsMobile NodeLocation InformationDestination NodeLocation ServerPredictive SchemeThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

This paper fits into the continuous efforts of researchers to propose a routing protocol able to successfully deliver data at an affordable cost under the challenging networks that are Vehicular Delay Tolerant Networks. Through the literature, several routing protocols based on various approaches have been proposed. However, during the last decade, the geographical approach emerged as the most natural to apply, due mainly to the popularisation of embedded GPS navigation systems. Despite this, and the proposal of different geographic based routing protocols for VDTNs, researchers are still looking for an ideal one, because of hard assumptions, limited performances or small and idealistic evaluation scenarios compared to real word environments. In this paper, we propose GeoDTC, a new geographic routing protocol dedicated to VDTNs, based on two distinct metrics namely: Distance and Time; jointly to the recurrent use of Custody Transfer. We conduct an extensive study to compare our proposal against well-knows protocols namely: Epidemic, Direct Delivery, GeoSpray and Prophet, under realistic simulation environment and scenario by using the large-scale dataset TAPAS Cologne. Simulations results reveal better performances for our proposal. Moreover, they demonstrate the potential benefits of intensive usage of the Custody Transfer and the introduction of various mechanisms.

Location verification and trust management for resilient geographic routing

Using location information to help routing is often proposed as a means to achieve scalability in large mobile ad hoc networks(MANETs). One of the biggest challenge in geographic routing protocols is the design of scalable distributed location services that can locate the positions of mobile nodes. The accurate positioning of mobile nodes in MANETs is important to location service scheme since they are related to efficiency of routing protocols. We propose a grid-based predictive Location Service(GPLS) scheme. In proposed location service scheme GPLS, the network is partitioned into grids and grids are divided into groups by using a HASH function, which guarantees the uniform distribution of location servers of a node in the network. The proposed location service scheme GPLS provide accurate location query capability by means of location prediction of mobile nodes. The simulation results show that the location service scheme GPLS have better performance than CRLS and SLURP in query success ratio, query delay.

Several position-based routing protocols have been developed for mobile ad hoc networks. Many of these protocols assume that a location service is available which provides location information on the nodes in the network. This paper introduces a new schema in management of mobile nodes location in mobile ad hoc networks. Fuzzy logic optimization is applied to a better management of location update operation in hierarchical location services. Update management overhead is decreased without significant loss of query success probability. One-hop-chain-technique is used for Auto compensation. A new composed method can update mobile nodes location when the nodes cross a grid boundary. The proposed method uses a dynamic grid area that ?solves the ping-pong problem between grids. Simulation results show that these methods are effective. The algorithms are distributed and can keep scalability in the scenario of increasing nodes density?. The described solutions are not limited to a special network grid ordering, and can be used in every hierarchical ordering like GLS if the ordering can be mappable on these methods.

An energy-saving geographic routing is a crucial problem when trying to increase QoS and network life.In order for their adjacent neighbours to be able to reach effective routing performance, geographical routing nodes are necessary.However, the network's lifetime for efficient transmission has not been improved.In order to dynamically regulate the frequency of the position updates according to node movement dynamics, an updated position strategy for geographical routing is implemented.Various optimized geographical routing protocols have been designed to prevent interference between nodes, so that the data transmission did not improve easily.Nodes cannot easily save energy when transmitting data, which results in reduced network lifetime.On other hand, the reduction in the packet delivery ratio affects the overall throughput of the network.Anevolutionary technique based on geographical routing technology is introduced in this work to address the above limitations in current methods.To adopt evolutionary algorithms on Geographic Routing Protocol (GRP) to find optimal routing paths with reduced energy consumption and increased network lifetime.The work also carries out effective ways to avoid latency in delivering the packets from source to destination nodes.

Location-based service (LBS) is a kind of mobile valueadded services in mobile communication systems. The development of mobile positioning techniques promotes application of LBS. This paper presents a type of architecture of LBS. In this architecture, TDOA positioning modules are appended into the mobile basestations in order to implement LBS. LBS gateway and application platform are two vital parts in this architecture. LBS gateway modules are added into MSC of the mobile communication networks. LBS application platform is similar to a mobile location server. TDOA positioning modules deal with rough location testing and simple data computing. LBS gateway is a comprehensive management device which processes location information related to the mobile users. LBS application platform incepts location information processed in LBS gateway, cooperates with the mobile terminal and sends location information to the mobile users by proper data format. LBS application platform is developed based on ArcIMS map server which provides a lot of APIs. The application programming flowchart for LBS is implemented in detail in this paper. The real testing in the mobile communication systems shows that the proposed LBS can provide exact location services for mobile users.

네트워크 중심전의 실현을 위해 여러 체계들이 개발되고 있다. 그중에서 무인 항공기 체계는 군사적인 응용에서 가장 주목을 받고 있다. 일반적으로 무인 항공기들은 임의로 애드혹 네트워크를 형성할 수 있을 뿐만 아니라 소스 노드와 목적지 노드사이의 홉수도 많이 줄일 수 있다. 하지만 무인 항공기 네트워크 환경은 높은 이동성, 높은 데이터 전송률, 실시간 서비스를 제공해야 하는 특성이 있다. 이러한 무인 항공기 네트워크의 요구사항에 동적으로 적응할 수 있는 멀티홉 라우팅 프로토콜의 설계가 요구되고 있다. 본 논문에서는 소스 노드와 목적지 노드 사이의 제일 짧은 지리적 거리를 사용하여 효율적이고 신뢰적인 전송을 하는 Geographic Routing Protocol의 성능을 분석한다. Geographic Routing Protocol은 비디오 서비스를 제공하는 시나리오에서 TDMA 모델을 사용하여 시뮬레이션을 수행하여 평가하였다. 시뮬레이션 결과 Geographic Routing Protocol은 기존의 MANET 라우팅 프로토콜보다 패킷 수신율, 종단간 지연, 라우팅 트래픽 발생량 등 면에서 더 좋은 성능을 보였다. Many systems are developing for the realization of NCW(Network Centric Warfare). UAV(Unmanned Aerial Vehicle) Network is attracting attention in a lot of military applications. In general, UAVs have the potential to create an ad-hoc network and greatly reduce the hops from source to destination. However, UAV networks exhibit unique properties such as high mobility, high data rate, and real time service. The routing protocols are required to design the multi-hop routing protocols that can dynamically adapt to the requirements of UAV network. In this paper we analyse Geographic Routing Protocol is based on geographical distance between source and destination for efficient and reliable transmission. Geographic Routing Protocol is evaluated in video service scenarios with TDMA model in our simulation. The simulation results show that the performance of Geographic Routing Protocol is better than the MANET Routing Protocol in terms of packet received ratio, end to end delay, and routing traffic sent.

SummaryUnmanned aerial vehicles (UAVs) have become widespread because of their involvement in a variety of applications. The task of designing the energy‐efficient routing between UAVs has been considered a matter of great interest due to the inherent challenges of controlling the dynamics exhibited by UAVs. Energy limitations are considered the main limitations of UAVs. This research paper proposes a novel routing protocol, adaptive ranking and mobile sink (MS)‐enabled energy‐efficient geographic routing (ARMS‐EGR) for flying ad hoc networks. In ARMS‐EGR, the whole network is partitioned into cells. The cell contains cell members (CM) and cell heads (CHs). The CH works as a cluster head. Additionally, two MSs have been used to collect data captured by CM. Multihop communication on the network leads to an increase in traffic and consumes the energy of the UAVs located near the base station (BS). MSs are used for power distribution and load balancing across the network. Adaptive ranking of forwarder UAVs and CHs is performed during intracell and intercell multihop communication, respectively, using adaptive ranking. A cell with one‐hop communication can directly send packets to the MS, but the ARMS‐EGR routing protocol has been proposed for multihop communication. The proposed approach is simulated in NS‐2.35 software. The results show that end‐to‐end latency and power consumption during packet transmission are greatly minimized. ARMS‐EGR also demonstrates improvements in message success rates, number of alive nodes, and packet delivery ratio, making ARMS‐EGR particularly suitable for flying ad hoc networks (FANETs).