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 always ”valid”. In order to forward packets along anchored paths, the source needs to acquire them by means of path discovery methods. We present two of such methods: Friend Assisted Path Discovery assumes a common protocol in all nodes and a high collaboration among nodes for providing paths. It is a social oriented path discovery scheme. Geographic Maps-based Path Discovery needs to have or to build a summarized view of the network topology, but does not require explicit collaboration of nodes for acquiring path. The two schemes are complementary and can coexist.

In this paper we present a Location Aided Knowledge Extraction Routing (LAKER) protocol for MANETs, which utilizes a combination of caching strategy in Dynamic Source Routing (DSR) and limited flooding area in Location Aided Routing (LAR) protocol. The key novelty of LAKER is that it can gradually discover knowledge of topological characteristics such as population density distribution of the network. This knowledge can be organized in the form of a set of guiding_routes, which includes a chain of important positions between a pair of source and destination locations. The guiding_route information is learned during the route discovery phase, and it can be used to guide future route discovery process in a more efficient manner. LAKER is especially suitable for mobility models where nodes are not uniformly distributed. LAKER can exploit the topological characteristics in these models and limit the search space in route discovery process in a more refined granularity. Simulations results show that LAKER outperforms LAR and DSR in term of routing overhead, saving up to 30% broadcast routing messages compared to the LAR approach.

Using location information to help routing is often proposed as a means to achieve scalability in large mobile ad-hoc networks. However, location based routing is difficult when there are holes in the network topology and nodes are mobile. Terminode routing, presented here, addresses these issues. It uses a combination of location based routing (Terminode Remote Routing, TRR), used when the destination is far, and link state routing (Terminode Local Routing, TLR), used when the destination is close. TRR uses anchored paths, a list of geographic points (not nodes) used as loose source routing information. Anchored paths are discovered and managed by sources, using one of two low overhead protocols: Friend Assisted Path Discovery and Geographical Map-based Path Discovery. Our simulation results show that terminode routing performs well in networks of various sizes. In smaller networks, the performance is comparable to MANET routing protocols. In larger networks that are not uniformly populated with nodes, terminode routing outperforms existing location-based or MANET routing protocols.

We designed the terminode routing protocol 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 Remote Routing (TRR- to send data to remote destinations). TRR is the key element to achieve scalability and reduce dependence on intermediate systems. Terminode routing uses anchored paths, a list of geographic points- that are not affected by nodes mobility-, 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 simulation results 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 MANETlike 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.

Abstract: Routing in infrastructure less vehicular ad hoc networks is challenging because of the dynamic network, predictable topology, high speed of nodes, and predictable mobility patterns. This paper presents an enhanced routing protocol specifically designed for city environments. It uses vehicular speed and directional density for dynamic junction selection. Simulation results exhibit increased packet delivery ratio while decreased end-to-end delay when compared with state of the art protocols.