Geographic routing

About: Geographic routing is a research topic. Over the lifetime, 11687 publications have been published within this topic receiving 302224 citations.

Location-Aided Opportunistic Forwarding in Multirate and Multihop Wireless Networks

Abstract: Routing in multihop wireless networks is challenging, mainly due to unreliable wireless links/channels. Geographic opportunistic routing (GOR) was proposed to cope with the unreliable transmissions by exploiting the broadcast nature of the wireless medium and the spatial diversity of the network topology. Previous studies on GOR have focused on networks with a single channel rate. The capability of supporting multiple channel rates, which is common in current wireless systems, has not carefully been studied for GOR. In this paper, we carry out a study on the impacts of multiple rates, as well as candidate selection, prioritization, and coordination, on the performance of GOR. We propose a new local metric, i.e., the opportunistic effective one-hop throughput (OEOT), to characterize the tradeoff between one-hop packet advancement and packet forwarding time. We further propose a local rate adaptation and candidate-selection algorithm to approach the optimum of this metric. The simulation results show that the multirate GOR (MGOR) incorporating the rate adaptation and candidate-selection algorithm achieves higher throughput and lower delay than the corresponding single-rate and multirate traditional geographic routing and single-rate opportunistic routing protocols.

Cluster-based routing protocols in wireless sensor networks: A survey

Abstract: Owing to the limited resources of the sensor nodes, designing energy-efficient routing mechanism to prolong the overall network lifetime becomes one of the most important technologies in wireless sensor networks (WSNs) As an active branch of routing technology, cluster-based routing protocols have proven to be effective in network topology management, energy minimization, data aggregation and so on In this paper, we present a survey of state-of-the-art routing techniques in WSNs We first outline the clustering architecture in WSNs, and classify the proposed approaches based on their objectives and design principles Furthermore, we highlight the challenges in clustering WSNs, including rotating the role of cluster heads, optimization of cluster size and communication mode, followed by a comprehensive survey of routing techniques Finally, the paper concludes with possible future research areas

Geographic Properties of Internet Routing

Abstract: In this paper, we study the geographic properties of Internet routing. Our work is distinguished from most previous studies of Internet routing in that we consider the geographic path traversed by packets, not just the network path. We examine several geographic properties including the circuitousness of Internet routes, how multiple ISPs along an end-to-end path share the burden of routing packets, and the geographic fault tolerance of ISP networks. We evaluate these properties using extensive network measurements gathered from a geographically diverse set of probe points. Our analysis shows that circuitousness of Internet paths depends on the geographic and network locations of the end-hosts, and tends to be greater when paths traverse multiple ISP. Using geographic information, we quantify the degree to which an ISP’s routing policy resembles hot-potato or cold-potato routing. We find evidence of certain tier-1 ISPs exhibiting hot-potato routing. Finally, based on network topology information gathered at CAIDA, we find that many tier-1 ISP networks may have poor tolerance to the failure of a single, critical geographic node, assuming the published topology information is reasonably complete.

A general theory for deadlock avoidance in wormhole-routed networks

Abstract: Most machines of the last generation of distributed memory parallel computers possess specific routers which are used to exchange messages between nonneighboring nodes in the network. Among the several technologies, wormhole routing is usually preferred because it allows low channel-setup time and reduces the dependency between latency and internode distance. However, wormhole routing is very susceptible to deadlock because messages are allowed to hold many resources while requesting others. Therefore, designing deadlock-free routing algorithms using few hardware facilities is a major problem for wormhole-routed networks. In this paper, we describe a general theoretical framework for the study of deadlock-free routing functions. We give a general definition of what can be a routing function. This definition captures many specific definitions of the literature (e.g., vertex dependent, input-dependent, source-dependent, path-dependent etc.). Using our definition, we give a necessary and sufficient condition which characterizes deadlock-free routing functions. Our theory embraces, at a high level, most of the theories related to deadlock avoidance in wormhole-routed networks previously derived in the literature. In particular, it applies not only to one-to-one routing, but also to one-to-many routing. The latter paradigm is used to solve the multicast problem with the path-based or tree-based facility.

Locating Nodes with EASE: Mobility Diffusion of Last Encounters in Ad Hoc Networks

Abstract: Routing in large-scale mobile ad hoc networks is challenging because all the nodes are potentially moving. Geographic routing can partially alleviate this problem, as nodes can make local routing decisions based solely on the destinations' geographic coordinates. However, geographic routing still requires an efficient {\em location service}, i.e., a distributed database recording the location of every destination node. Devising efficient, scalable, and robust location services has received considerable attention in recent years. The main purpose of this paper is to show that {\em node mobility} can be exploited to disseminate destination location information {\em without incurring any communication overhead}. We achieve this by letting each node maintain a local database of the time and location of its last encounter with every other node in the network. This database is consulted by packets to obtain estimates of their destination's current location. As a packet travels towards its destination, it is able to successively refine an estimate of the destination's precise location, because node mobility has ``diffused'' estimates of that location. We define and analyze a very simple algorithm called EASE (Exponential Age SEarch) and show that in a model where $N$ nodes perform independent random walks on a square lattice, the length of the routes computed by EASE are on the same order as the distance between the source and destination {\em even for very large $N$.} Therefore, without exchanging any explicit location information, the length of EASE routes are within a constant factor of routes obtained with perfect information. We discuss refinements of the EASE algorithm and evaluate it through extensive simulations. We discuss general conditions such that the mobility diffusion effect leads to efficient routes without an explicit location service. In practical settings, where these conditions may not always be met, we believe that the mobility diffusion effect can complement existing location services and enhance their robustness and scalability.