Existing position-based unicast routing algorithms which forward packets in the geographic direction of the destination require that the forwarding node knows the positions of all neighbors in its transmission range. This information on direct neighbors is gained by observing beacon messages each node sends out periodically. Due to mobility, the information that a node receives about its neighb...

Sleep and wake-up scheduling of sensor nodes is an efficient solution to prolong the network lifetime. However, existing scheduling algorithms may significantly decrease the number of active nodes so that the network may be intermittently-connected. In such networks, traditional geographic routing protocols are inappropriate to obtain low latency routes due to route discovery and data forwardin...

Existing position-based unicast routing algorithms, where packets are forwarded in the geographic direction of the destination, require that the forwarding node knows the positions of all neighbors in its transmission range. This information on direct neighbors is gained by observing beacon messages each node sends out periodically. The transmission of beacons and the storage of neighbor inform...

The ability to discover services in Mobile Ad hoc Network (MANET) is a major prerequisite. Cluster basedcross layer intelligent service discovery for MANET (CBISD) is cluster based architecture, caching ofsemantic details of services and intelligent forwarding using network layer mechanisms. The cluster basedarchitecture using semantic knowledge provides scalability and accuracy. Also, the mini...

The obstacle avoidance problem in geographic forwarding is an important issue for location-based routing in wireless sensor networks. The presence of an obstacle leads to several geographic routing problems such as excessive energy consumption and data congestion. Obstacles are hard to avoid in realistic environments. To bypass obstacles, most routing protocols tend to forward packets along the...

The topology formed by vehicles changes quickly, which makes routing become instable. Geographic routing such as GPSR, compared with traditional routing, is more scalable and feasible. However, the commonly used greedy forwarding in geographic routing often fails, due to the urban topology in VANET is particular. Some improvements have been proposed, such as GROOV, which calculates the feasibil...

Most of the routing protocols proposed for ad-hoc networks and sensor networks are not designed with security as a goal. Hence, many routing protocols are vulnerable to an attack by an adversary who can disrupt the network or harness valuable information from the network. Routing Protocols for wireless sensor networks are classified into three types depending on their network structure as Flat ...

In this thesis we study two research aspects of geographical routing: efficient geographical addressing and a new routing scheme. In the first part we offer a novel geographical routing algorithm that relies on a well known data structure called Quadtree. Quadtree is an efficient method of mapping a twodimensional area by recursively partitioning it to disjoint squares. We present a greedy, gua...

in this paper by combining caching and replication techniques proposed a hybrid heuristic method based on the greedy algorithm to use the benefit of each other techniques. the algorithm in each interaction compares all the contents and one that made the best benefit value is selected for replication. the hybrid approach tested in a simulation environment and the results show that hybrid algorit...