We propose a range-free localization algorithm for a wireless ad-hoc network utilizing the hopcount metric's ability to indicate proximity to anchors (i.e., nodes with known positions). In traditional sense, hop-count generally means the number of intermediate routers a datagram has to go through between its source and the destination node. We analytically show that hop-count could be used to indicate proximity relative to an anchor node. Our proposed algorithm is computationally feasible for resource constrained wireless ad-hoc nodes, and gives reasonable accuracy. We perform both real experiments and simulations to evaluate the algorithm's performance. Experimental results show that our algorithm outperforms similar proximity based algorithms utilizing Received Signal Strength (RSS) and Expected Transmission Count (ETX). We also analyze the impact of various parameters like the number of anchor nodes, placements of anchor nodes and varying transmission powers of the nodes on the hop-count based localization algorithm's performance through simulation.

In Mobile Ad hoc Network (MANET), Disruption Tolerant Networking (DTN) mechanisms can be used to cope with MANET disruptions as well as to improve the outcomes of bulk data dissemination in disrupted MANETs. We are interested in an emergency communication scenario where multiple OLSR-driven MANET partitions are deployed by different emergency responder teams to gather situational information. When two (or more) of such emergency responder teams reconvene for situational updates, there are strong demands to effectively disseminate and synchronize bulk data files (e.g. situational photos and revised maps) stored in the two previously separate MANET partitions in a newly joined MANET partition. Traditional multicast data dissemination in MANET is, however, very bandwidth consuming and does not suite our situation.We have conducted our research in two parts. First, we devise a novel approach that identifies the best emerging link among the newly formed MANET links [16]. Second, which is this work, we adopt and test the Random Linear Network Coding (RLNC) technique to facilitate the synchronization of bulk data files from two previously separate MANET partitions via such best emerging link. We evaluate our system through a real-world test bed. We call our approach DTNC-CAST which reflects the many-tomany bulk data file dissemination in a Network-Coded DTN-like manner for OLSR MANETs.