52 research outputs found

    Anchored Path Discovery in Terminode Routing

    Get PDF
    Terminode routing, defined for potentially very large mobile ad hoc networks, forwards packets along anchored paths. An anchored path is a list of fixed geographic points, called anchors. Given that geographic points do not move, the advantage to traditional routing paths is that an anchored path is alway

    Towards Mobile Ad-Hoc WANs: Terminodes

    Get PDF
    Terminodes are personal devices that provide functionality of both the terminals and the nodes of the network. A network of terminodes is an autonomous, fully self-organized, wireless network, independent of any infrastructure. It must be able to scale up to millions of units, without any fixed backbone or server. In this paper we present the main challenges and discuss the main technical directions

    A Self-Organising Distributed Location Server for Ad Hoc Networks

    Get PDF
    Wireless networks allow communication between multiple devices (nodes) without the use of wires. Range in such networks is often limited restricting the use of networks to small offices and homes; however, it is possible to use nodes to forward packets for others thereby extending the communication range of individual nodes. Networks employing such forwarding are called Multi-Hop Ad Hoc Networks (MANETS) Discovering routes in MANETS is a challenging task given that the topology is flat and node addresses reveal nothing about their place in the network. In addition, nodes may move or leave changing the network topology quickly. Existing approaches to discovering locations involve either broadcast dissemination or broadcast route discovery throughout the entire network. The reliance on the use of techniques that use broadcast schemes restricts the size of network that the techniques are applicable to. Routing in large scale ad hoc networks is therefore achieved by the use of geographical forwarding. Each node is required to know its location and that of its neighbours so that it may use this information for forward packets. The next hop chosen is the neighbour that is closest to the destination and a number of techniques are used to handle scenarios here the network has areas void of nodes. Use of such geographical routing techniques requires knowledge of the destination's location. This is provided by location servers and the literature proposes a number of methods of providing them. Unfortunately many of the schemes are limited by using a proportion of the network that increases with size, thereby immediately limiting the scalability. Only one technique is surveyed that provides high scalability but it has a number of limitations in terms of handling node mobility and failure. Ad hoc networks have limited capacity and so the inspiration for a technique to address these shortcomings comes from observations of nature. Birds and ants are able to organise themselves without direct communication through the observation of their environment and their peers. They provide an emergent intelligence based on individual actions rather than group collaboration. This thesis attempts to discover whether software agents can mimic this by creating a group of agents to store location information in a specific location. Instead of requiring central co-ordination, the agents observe one another and make individual decisions to create an emergent intelligence that causes them to resist mobility and node failures. The new technique is called a Self Organising Location Server (SOLS) and is compared against existing approaches to location servers. Most existing techniques do not scale well whereas SOLS uses a new idea of a home location. The use of this idea and the self organising behaviour of the agents that store the information results in significant benefits in performance. SOLS significantly out performs Terminode home region, the only other scalable approach surveyed. SOLS is able to tolerate much higher node failure rates than expected in likely implementations of large scale ad hoc networks. In addition, SOLS successfully mitigates node mobility which is likely to be encountered in an ad hoc network

    A Scalable Routing Method for Irregular Mobile Ad Hoc Networks

    Get PDF
    We designed the terminode routing protoc ol with the objective to scale in large mobile ad hoc networks where the topology, or node distribution, is irregular. Our routing protocol is a combination of two protocols: Terminode Local Routing (TLR - to reach a close destination) and Terminode Remot e Routing (TRR - to send data to remote destinations). TRR is the key element to achieve scalability and reduce dependence on intermediate systems. Termin-ode routing uses anchored paths, a list of geographic points - that are not affected by nodes mobili ty -, rather than conventional paths of nodes. Terminode routing is completed by a low-overhead distributed method for discovering of anchored paths, and by a method for handling the inaccuracy of the location information. The presented simu-lation result s confirm that terminode routing performs well in different sized networks. In smaller ad hoc networks performance of terminode routing is comparable to MANET routing protocols. In larger networks, where MANET-like routing protocols break, terminode routing performs well; moreover, in larger networks that are not uniformly populated with nodes, terminode routing outperforms the existing location-based routing protocols

    Self Organized Terminode Routing

    Get PDF
    We consider the problem of routing in a wide area mobile ad-hoc network called Terminode Network. Routing in such a network is designed with the following objectives. Firstly, it should scale well in terms of the number of nodes and geographical coverage, secondly, routing should have scalable mechanisms that cope with the dynamicity in the network due to mobility, and thirdly nodes need to be highly collaborative and redundant, but, most of all, cannot use complex algorithms or protocols. Our routing scheme is a combination of two protocols called Terminode Local Routing (TLR) and Terminode Remote Routing TRR). TLR is used to route packets to close destinations. TRR is used to route to remote destinations and is composed of the following elements: Anchored Geodesic Packet Forwarding (AGPF), Friend Assisted Path Discovery (FAPD), multipath routing and path maintenance. The combination of TLR and TRR has the following features: (1) it is highly scalable because every node relies only on itself and a small number of other nodes for packet forwarding; (2) it acts and reacts well to the dynamicity of the network because multipath routing is considered as a rule; and (3) it can be implemented and run in very simple devices because the algorithms and protocols are very simple and based on high collaboration. We have performed simulations of the TLR and TRR protocols in GloMoSim. The simulation results demonstrate that the routing protocol is able to deliver over 80% of user data in a large, highly mobile simulation environment whereas Dynamic Source Routing(DSR) achieves less than 10%

    The Terminodes Project: Towards Mobile Ad-Hoc WANs

    Get PDF
    The Terminode project follows a system approach to investigate wide area, large, totally wireless networks that we call mobile ad-hoc wide area networks. A network of terminodes is an autonomous, self-operated, wireless multimedia network, independent of any infrastructure. In this paper we present the main challenges and certain initial technical directions

    Self Organized Terminode Routing - Version 2

    Get PDF
    We consider the problem of routing in a wide area mobile ad hoc network called Terminode Network. Routing in this network is designed with the following objectives. First, it should scale well in terms of the number of nodes and geographical coverage; second, routing should have scalable mechanisms that cope with the dynamicity in the network due to mobility; and third, nodes need to be highly collaborative and redundant, but, most of all, cannot use complex algorithms or protocols. Our routing scheme is a combination of two protocols called Terminode Local Routing (TLR) and Terminode Remote Routing (TRR). TLR is used to route packets to close destinations. TRR is used to route to remote destinations and is composed of the following elements: Geodesic Packet Forwarding (GPF), Anchored Geodesic Packet Forwarding (AGPF), Friend Assisted Path Discovery (FAPD), multipath routing and path maintenance. The combination of TLR and TRR has the following features: (1) it is highly scalable because every node relies only on itself and a small number of other nodes for packet forwarding; (2) it acts and reacts well to the dynamicity of the network because as a rule multipath routing is considered; and (3) it can be implemented and run in very simple devices because the algorithms and protocols are very simple and based on high collaboration. We performed simulations of the TLR and TRR protocols using the GloMoSim simulator. The simulation results for a large, highly mobile ad-hoc environment demonstrate benefits of the combination of TLR and TRR over an existing protocol that uses geographical information for packet forwarding

    Enabling cost aware routing with auctions in wireless ad-hoc networks

    Get PDF
    Battery power is a precious resource in wireless ad-hoc networks, and most routing protocols that have been proposed so far do not generate cost efficient routes. In this thesis, a novel auction-based cost-aware routing scheme, called CARA, is presented. CARA is designed as an extension of the MAC layer, and is shown to improve the cost efficiency of existing ad-hoc routing protocols through dynamic power control, while introducing only minimal additional overhead. The MAC layer at each node is given the capability to run local sealed-bid second-price auctions for the user data packets that need to be transmitted, and to determine any neighbor nodes that reduce the transmission cost to the next hop identified by the network layer. Existing network layer routing protocols are utilized with no changes or impact on their operation. Selforganized networks, where nodes are greedy and selfish, are being supported through the proposed auction-based framework

    VANET: Performance Comparison of BNGF Method in Different Vehicular Traffic Scenarios

    Get PDF
    A Vehicular Ad hoc Network (VANET) is a wireless ad hoc network that is formed between vehicles on an on demand basis. A lot of research work around the world is being conducted to design the routing protocols for VANETs. In this paper, we examine the significance Greedy Forwarding with Border Node based approach for VANETs to optimize path length between vehicles in different traffic scenarios. This protocol is called Border Node Greedy Forwarding (BNGF) since it uses border nodes with Greedy Forwarding. We categorize BNGF as BNGF-H for highway and BNGF-C for city traffic scenarios. We have simulated this protocol using NS-2 simulator and calculated the performance in terms of end-to-end delay and packet delivery ratio. We compare both the methods for highway and city traffic scenarios. The result clearly show that the end-to-end delay for BNGF-C is significantly lower and packet delivery ratio is higher than BNGF-H
    • …
    corecore