Static routing

About: Static routing is a research topic. Over the lifetime, 25733 publications have been published within this topic receiving 576732 citations.

Optimal Routing in a Packet-Switched Computer Network

Abstract: The problem of finding optimal routes in a packet-switched computer network can be formulated as a nonlinear multicommodity flow problem.

Geometric spanners for routing in mobile networks

Abstract: We propose a new routing graph, the restricted Delaunay graph (RDG), for mobile ad hoc networks. Combined with a node clustering algorithm, the RDG can be used as an underlying graph for geographic routing protocols. This graph has the following attractive properties: 1) it is planar; 2) between any two graph nodes there exists a path whose length, whether measured in terms of topological or Euclidean distance, is only a constant times the minimum length possible; and 3) the graph can be maintained efficiently in a distributed manner when the nodes move around. Furthermore, each node only needs constant time to make routing decisions. We show by simulation that the RDG outperforms previously proposed routing graphs in the context of the Greedy perimeter stateless routing (GPSR) protocol. Finally, we investigate theoretical bounds on the quality of paths discovered using GPSR.

Predict and relay: an efficient routing in disruption-tolerant networks

Abstract: Routing is one of the most challenging open problems in disruption-tolerant networks (DTNs) because of the short-lived wireless connectivity environment. To deal with this issue, researchers have investigated routing based on the prediction of future contacts, taking advantage of nodes' mobility history. However, most of the previous work focused on the prediction of whether two nodes would have a contact, without considering the time of the contact. This paper proposes predict and relay (PER), an efficient routing algorithm for DTNs, where nodes determine the probability distribution of future contact times and choose a proper next hop in order to improve the end-to-end delivery probability. The algorithm is based on two observations: one is that nodes usually move around a set of well-visited landmark points instead of moving randomly; the other is that node mobility behavior is semi-deterministic and could be predicted once there is sufficient mobility history information. Specifically, our approach employs a time-homogeneous semi-markov process model that describes node mobility as transitions between landmarks. Landmark transition and sojourn time probability distributions are determined from nodes' mobility history. A simulation study shows that this approach improves the delivery ratio and also reduces the delivery latency compared to traditional DTN routing schemes.

Implementation experience with MANET routing protocols

Abstract: This paper outlines our experience with the implementation and deployment of two MANET routing protocols on a five node, four hop, network. The work was prompted by the lack of published results concerning the issues associated with the implementation of MANET routing protocols on actual wireless networks, as opposed to results of simulation experiments. We examined implementations of two distance vector MANET routing protocols and found a number of problems with both protocols during the course of our experiments. The most significant was that neither protocol could provide a stable route over any multi-hop network connection. The route discovery process of both protocols is fooled by the transient availability of network links to nodes that were more than one hop away. Packets transmitted over a fading channel cause the routing protocol to conclude incorrectly that there is a new one hop neighbor that could provide a lower metric (hop count) route to even more distant nodes. This can occur even when nodes are stationary, mobility resulted in even less route stability. We implemented a simple signal strength based neighbor selection procedure to test our assertion that fading channels and unreliable network links were the cause of the failure of the routing protocols. The result was that neighbor discovery and the filtering for neighbors with which nodes could communicate reliably enables the creation of reliable multihop routes. Based on our experiences, we outline several recommendations for future work in MANET research.

Spectrum Aware On-Demand Routing in Cognitive Radio Networks

Abstract: Routing in multi-hop cognitive radio net- works(CRN) should consider how to dynamically switch frequency band for either per flow throughput guarantee or global spectrum utilization. Previous research have offered both centralized and distributed solutions on combining the two, but since different nodes may sense different spectrum availability, efficiently sharing this information in the dynamic spectrum environment still remains challenging. In this paper, we propose an approach to reactively initiate route computing and frequency band selection. We further present a novel multi-flow multi-frequency scheduling scheme for single node to relief the multi-flow interference and frequent switching delay. We use cumulative delay along the path for evaluation, simulation results show that, comparing to other typical approaches, our protocol provides better adaptability to the dynamic spectrum and multi-flow environment, and incurs much lower cumulative delay.