Abstract
The information brokerage and the geographic routing are two important applications in mobile ad hoc networks (MANETs). In this thesis, we investigate some problems of the information brokerage without the assistance of Global Positioning System (GPS) and the routing with the assistance of GPS separately. In the first part of this thesis, we study the GPS-free information brokerage problem. In the past, many information brokerage schemes achieve low data retrieval latency using the double-ruling technique. However, these schemes require static nodes or GPS support. To apply the double-ruling technique without the assistance of GPS in MANATs, we propose a zero-knowledge double-ruling-based GPS-free information brokerage scheme (MobiMark). Simulations show that MobiMark achieves good performance in terms of data retrieval rate and data retrieval latency. In the second part of this thesis, we study the geographic routing problem. To employ the geographic routing, two neighboring nodes need to exchange the location information with each other periodically. In MANETs, however, a packet transmitted between two neighboring nodes may be lost due to the out-of-date location information, resulting in demanding extra energy to retransmit the packet. By considering the out-of-date neighboring location information, we propose two methods capable of augmenting geographic routing protocols to reduce energy consumption in MANETs. Simulations show that geographic routing protocols augmented with our methods can significantly reduce the energy consumption while preserving the high packet delivery rate.