Supporting Protocols for Structuring and Intelligent Information Dissemination in Vehicular Ad Hoc Networks

The goal of this dissertation is the presentation of supporting protocols for structuring and intelligent data dissemination in vehicular ad hoc networks (VANETs). The protocols are intended to first introduce a structure in VANETs, and thus promote the spatial reuse of network resources. Segmenting a flat VANET in multiple cluster structures allows for more efficient use of the available bandwidth, which can effectively increase the capacity of the network. The cluster structures can also improve the scalability of the underlying communication protocols. The structuring and maintenance of the network introduces additional overhead. The aim is to provide a mechanism for creating stable cluster structures in VANETs, and to minimize this associated overhead. Further a hybrid overlay-based geocast protocol for VANETs is presented. The protocol utilizes a backbone overlay virtual infrastructure on top of the physical network to provide geocast support, which is crucial for intervehicle communications since many applications provide group-oriented and location-oriented services. The final contribution is a structureless information dissemination scheme which creates a layered view of road conditions with a diminishing resolution as the viewing distance increases. Namely, the scheme first provides a high-detail local view of a given vehicle\u27s neighbors and its immediate neighbors, which is further extended when information dissemination is employed. Each vehicle gets aggregated information for road conditions beyond this extended local view. The scheme allows for the preservation of unique reports within aggregated frames, such that safety critical notifications are kept in high detail, all for the benefit of the driver\u27s improved decision making during emergency scenarios

Multicast outing protocols and architectures in mobile ad-hoc wireless networks

The basic philosophy of personal communication services is to provide user-to-user, location independent communication services. The emerging group communication wireless applications, such as multipoint data dissemination and multiparty conferencing tools have made the design and development of efficient multicast techniques in mobile ad-hoc networking environments a necessity and not just a desire. Multicast protocols in mobile adhoc networks have been an area of active research for the past few years. In this dissertation, protocols and architectures for supporting multicast services are proposed, analyzed and evaluated in mobile ad-hoc wireless networks. In the first chapter, the activities and recent advances are summarized in this work-in-progress area by identifying the main issues and challenges that multicast protocols are facing in mobile ad-hoc networking environments and by surveying several existing multicasting protocols. a classification of the current multicast protocols is presented, the functionality of the individual existing protocols is discussed, and a qualitative comparison of their characteristics is provided according to several distinct features and performance parameters. In the second chapter, a novel mobility-based clustering strategy that facilitates the support of multicast routing and mobility management is presented in mobile ad-hoc networks. In the proposed structure, mobile nodes are organized into nonoverlapping clusters which have adaptive variable-sizes according to their respective mobility. The mobility-based clustering (MBC) approach which is proposed uses combination of both physical and logical partitions of the network (i.e. geographic proximity and functional relation between nodes, such as mobility pattern etc.). In the third chapter, an entropy-based modeling framework for supporting and evaluating the stability is proposed in mobile ad-hoc wireless networks. The basic motivations of the proposed modeling approach stem from the commonality observed in the location uncertainty in mobile ad-hoc wireless networks and the concept of entropy. In the fourth chapter, a Mobility-based Hybrid Multicast Routing (MHMR) protocol suitable for mobile ad-hoc networks is proposed. The MHMR uses the MBC algorithm as the underlying structure. The main features that the proposed protocol introduces are the following: a) mobility based clustering and group based hierarchical structure, in order to effectively support the stability and scalability, b) group based (limited) mesh structure and forwarding tree concepts, in order to support the robustness of the mesh topologies which provides limited redundancy and the efficiency of tree forwarding simultaneously, and c) combination of proactive and reactive concepts which provide the low route acquisition delay of proactive techniques and the low overhead of reactive methods. In the fifth chapter, an architecture for supporting geomulticast services with high message delivery accuracy is presented in mobile ad-hoc wireless networks. Geomulticast is a specialized location-dependent multicasting technique, where messages are multicast to some specific user groups within a specific zone. An analytical framework which is used to evaluate the various geomulticast architectures and protocols is also developed and presented. The last chapter concludes the dissertation

I-Min: An Intelligent Fermat Point Based Energy Efficient Geographic Packet Forwarding Technique for Wireless Sensor and Ad Hoc Networks

Energy consumption and delay incurred in packet delivery are the two important metrics for measuring the performance of geographic routing protocols for Wireless Adhoc and Sensor Networks (WASN). A protocol capable of ensuring both lesser energy consumption and experiencing lesser delay in packet delivery is thus suitable for networks which are delay sensitive and energy hungry at the same time. Thus a smart packet forwarding technique addressing both the issues is thus the one looked for by any geographic routing protocol. In the present paper we have proposed a Fermat point based forwarding technique which reduces the delay experienced during packet delivery as well as the energy consumed for transmission and reception of data packets.Comment: 11 Page

Geocasting and Multicasting Routing Operation in Mobile Ad Hoc Network

Abstract: The paper considers, the different multicasting routing protocols in wireless mobile Ad hoc network (MANET).An Ad hoc network is composed of mobile nodes without the presence of a wired support infrastructure .In this environment routing/multicasting protocols are faced with the challenge of producing multihop router under host mobility and band constraints. Various approaches and routing protocol have been proposed to address Ad hoc networking problems and multiple standardization effort within the Internet Engineering Task Force, along with academic and industrial research projects. In recent year, a number of new multicast protocols of different styles have been proposed for Ad hoc networks. Geocast Adaptive Mesh Environment for Routing [GAMER] is one which provides geocast communication in an Ad hoc network and it adapts to the correct network environment by dynamically changing the density of the mesh. Forwarding Group Multicast Protocol [FGMP] is based on the forward group concept and it dynamically refreshes the forward group member using a procedure to On-Demand routing. The relative strengths, weakness and applicability of each multicast protocol to diverse situations have considered and analyzed. Index Terms: FGMP Protocol, GAMER Protocol, MANETs, multicast, routing. An Ad hoc networks [1] [2] , is a dynamically reconfigurable wireless network with no fixed infrastructure (or) central administration. Due to the limited radio propagation range of wireless devices, routers are often "multihop". Applications such as disaster recovery, crowd control, search, rescue and automated battlefields are typical examples of where Ad hoc networks are deployed. Nodes in these networks more arbitrary thus network topology changes frequently and unpredictably. Moreover, bandwidth and battery power are limited. These constraints, in combination with the dynamic network topology make routing and multicasting in Ad hoc networks extremely challenging. Various multicast protocols have been newly proposed to perform multicasting in Ad hoc network. However, no operation study between them has yet been performed. The comparative analysis of Ad hoc unicast routing protocols has been reported. This paper gives a comparison study of two protocols with different characteristics: GAMER [3] and FGMP The rest of the paper is organized as follows. Section I presents an overview of the multicast protocols. The section II discusses the future enhancements, and concluding remarks are made in section III.

Integrate Airtime Metric and Geocast over P2P-Based VoD Streaming Cache

[[abstract]]Peer-to-peer based systems have been widely proposed to provide the Video-on-Demand (VoD) service on the Internet in recent years.With the development of mobile networks, we proposed a suitable VoD system for mobile networks, in which peers are classified into groups and the backbone networks are established so that peers in the same group can share and transmit the streaming videos through the backbone networks. Further, mobile nodes that are not located at the backbone networks can receive the streaming videos through the Wireless Mesh Networks (WMNs). Through our path selection mechanism, peers can route faster and the system will be load-balancing. By considering the influence of the locality to mobile nodes, we delimit the new range of WMNs. In addition, according to the Airtime metric proposed in IEEE 802.11s, the Airtime cost of every mesh loop is calculated and the optimal path thus can be figured out.[[notice]]補正完畢[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙

Dynamic Time-Stable Geocast Routing in Vehicular Ad Hoc Networks

Vehicular ad hoc networks (VANETs) have emerged as an area of interest for both industry and research scholars because they have become an essential part of intelligent transportation systems (ITSs). Many applications in VANET require sending a message to certain or all vehicles within a region, called geocast. Sometimes geocast requires that the message be kept alive within the region for a period of time. This time-stable geocast has a vital role in some ITS applications, particularly commercial applications. This study presents a novel time-stable geocast protocol that works well even in too sparse networks. Moreover, since commercial applications sometimes make it necessary to change the duration of the stable message within the region, the dynamic nature of a geocast protocol should allow this time to be extended, reduced, or canceled without any additional cost. Therefore, we call it a dynamic time-stable geocast, DTSG, protocol. It works in two phases (the pre-stable period and the stable period), and the simulation results show that it works well in its performance metrics (delivery ratio and network cost). In addition, these results validate the protocol prediction of its performance metrics. Moreover, with the informed time of zero, all the intended vehicles will be informed as soon as they enter the region. The fact that the protocol is independent of the networks’ density, the vehicles’ speed, and the vehicles’ broadcasting range, makes it more robust than others that fail in sparse networks or in high-speed nodes