During the route discovery process, each node receiving the route request packet (RReq) will retransmit it exactly once. A distant neighbor may accidentally receive/loose the only RReq and use it to announce a new route, although that link is inferior/superior for route reply packets (RRep) or actual message routing. Overall, the constructed route may be far from the optimal. All existing route discovery schemes (including DSR/AODV) apply retransmission during route discovery exactly once (1R). Based on a realistic physical layer model, we propose two new route discovery schemes: n-retransmission (nR, retransmitting exactly n times) and n-retransmission c-reception (ncRR), retransmitting until we either reach a total of n own retransmissions or c copies from neighbors are heard. We compare our two new scheme with the traditional one, under otherwise identical conditions (same metric, same packet reception probability on each link) and the same choices about possibly retransmitting again upon discovering a better route (R+) or discarding it (R1), generating route reply packet for every received RRep (B*), or for first and better discovered routes only (B2), and retransmitting RRep exactly once (A1), up to a maximum of three times (A3), or optimally u times decided by link quality (Au). Experimental results show that the proposed ncRR scheme (for n=2 and c=3 or c=4) achieves the best tradeoff between quality of route, success rate and message overhead in the route discovery process, followed by the nR scheme, and both of them are superior to the existing traditional schemes.

During the route discovery process, each node receiving the route request packet (RReq) will retransmit it exactly once. A distant neighbor may accidentally receive/loose the only RReq and use it to announce a new route, although that link is inferior/superior for route reply packets (RRep) or actual message routing. Overall, the constructed route may be far from the optimal. All existing route discovery schemes (including DSR/AODV) apply retransmission during route discovery exactly once (1R). Based on a realistic physical layer model, we propose two new route discovery schemes: n-retransmission (nR, retransmitting exactly n times) and n-retransmission c-reception (ncRR), retransmitting until we either reach a total of n own retransmissions or c copies from neighbors are heard. We compare our two new scheme with the traditional one, under otherwise identical conditions (same metric, same packet reception probability on each link) and the same choices about possibly retransmitting again upon discovering a better route (R+) or discarding it (R1), generating route reply packet for every received RRep (B*), or for first and better discovered routes only (B2), and retransmitting RRep exactly once (A1), up to a maximum of three times (A3), or optimally u times decided by link quality (Au). Experimental results show that the proposed ncRR scheme (for n=2 and c=3 or c=4) achieves the best tradeoff between quality of route, success rate and message overhead in the route discovery process, followed by the nR scheme, and both of them are superior to the existing traditional schemes.

Title: Transshipment Terminal – A study of environmental effects from the introduction of a transshipment terminal and a route planning system in the municipality of Kalmar Examiner: Andersson, Petra Key words: Transshipment terminal, route planning, environmental impact Purpose: The study aims to examine how a transshipment terminal and a route planning system may have implications for the municipality of Kalmar from environmental concerns. Methodology: The thesis is a case study on the municipality of Kalmar. A positivistic -and an objectivistic approach have been used. The strategic approach that was used was quantitative. Theoretical perspectives: The thesis has mainly been based on theories of transshipment terminal, route planning and environmental impact, but also other relevant theories have been used. Emperical foundation: Empirical data has gathered through interviews with the municipality of Kalmar and its suppliers and from data that was obtained from them. The information has then been analyzed using the theoretical framework. Conclusions: By imposing a transshipment terminal and route planning for the municipality of Kalmar, the number of transports, transport distance and carbon dioxide emissions can be reduced. transshipment terminal can be analyzed, and how suppliers can change their routes when a transshipment terminal is inmplemented. Also where the transshipment terminal should be placed can be another subject to study. Suggestions for further research: The authors suggest that a deeper study of the total costs of

In mobile IP, a triangular routing problem usually leads to additional delays and non-seamless handoff, which causes the loss of a large amount of in-fly packets. In this thesis we propose an adaptive route optimization scheme that considers the seamless handoff and mobility rate. The proposed scheme adopts the mobile routing table scheme and includes an efficient cost function. The cost function is a trade-off between network bandwidth utilized by the routing path, signaling messages and processing loads of agents. The primary idea is to adaptively determine when to perform route optimization. The effect of the mobility rate and the cell sojourn time of a mobile node are studied. Both new call and handoff call are considered in the cost calculation. Simulation result shows that the proposed scheme can effectively reduce the total cost composed of link and signaling costs.

Effective routing is critical in mobile ad hoc networks (MANETs). In recent years, many hierarchical routing protocols have been proposed to build a backbone structure for supporting MANET routing, especially for large scalability. The clustering approach is seen as the first step in providing a flat network with a hierarchical architecture. The clusterheads become the backbone nodes (BNs), which use greater power to transmit packets, forming the backbone network. Backbone network routing can reduce the number of data-packet forwarding hops throughout the entire network. However, previous protocols have focused on clustering schemes. Fault tolerance in a backbone structure has not been considered. In this paper, we propose a backup routing scheme that can repair broken links locally without activating a route re-discovery procedure. The backup route is piggybacked in the data packet header to achieve the most durable route. The proposed method can improve the packet delivery ratio and reduce control overhead, compared to general hierarchical routing protocols.

The Camino Francés, a 780km pilgrimage in Northern Spain, has been traveled by millions of pilgrims over the last 800 years. In recent decades the route has been increasingly threatened by insensitive development and infrastructure. Surprisingly little research has been conducted on the nature and ecology of pilgrims’ experiences and the landscape necessary to support the roughly 170,000 people that walk the Camino each year. Adapting methods from recreation and leisure science, this autoethnographic research explored the influence of the environment on my pilgrimage experience as I walked for five weeks in the Fall of 2011. Analysis used a variety of qualitative techniques in creating my own narrative. My research suggests that the landscape is essential to a positive and meaningful pilgrimage experience. Future planning and design efforts for this UNESCO route should incorporate the influence of the landscape on the experience of pilgrimage.

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During the route discovery process, each node receiving the route request packet (RReq) will retransmit it exactly once. A distant neighbor may accidentally receive/loose the only RReq and use it to announce a new route, although that link is inferior/superior for route reply packets (RRep) or actual message routing. Overall, the constructed route may be far from the optimal. All existing route discovery schemes (including DSR/AODV) apply retransmission during route discovery exactly once (1R). Based on a realistic physical layer model, we propose two new route discovery schemes: n-retransmission (nR, retransmitting exactly n times) and n-retransmission c-reception (ncRR), retransmitting until we either reach a total of n own retransmissions or c copies from neighbors are heard. We compare our two new scheme with the traditional one, under otherwise identical conditions (same metric, same packet reception probability on each link) and the same choices about possibly retransmitting again upon discovering a better route (R+) or discarding it (R1), generating route reply packet for every received RRep (B*), or for first and better discovered routes only (B2), and retransmitting RRep exactly once (A1), up to a maximum of three times (A3), or optimally u times decided by link quality (Au). Experimental results show that the proposed ncRR scheme (for n=2 and c=3 or c=4) achieves the best tradeoff between quality of route, success rate and message overhead in the route discovery process, followed by the nR scheme, and both of them are superior to the existing traditional schemes.

Thèses (M.Sc.)--Université de Sherbrooke (Canada), 2004. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.

Thèse doct.-ing.--Paris VI, 1972. / Bibliogr. p. 285-287. Résumé en anglais, allemand, espagnol et russe.