An Adaptive Threshold Method to Address Routing Issues in Delay-Tolerant Networks.
wireless environments face long delays and intermittent connectivity anomalies. A
promising solution is delay-tolerant networks, but these networks have inherent issues
with routing. Popular mobile ad hoc routing protocols such as AODV and OSPF rely on the
existence of an end-to-end path. These protocols first establish a path before traffic
is sent. A delay-tolerant network, ... read morehowever, is characterized by intermittent
connectivity and consequently for these types of networks, traditional routing protocols
fail. This thesis presents an adaptive threshold routing algorithm with the intent of
improving upon the traditional threshold method. An adaptive algorithm is an ideal
approach for dynamic, challenged, network environments. It takes into account changes in
the network structure and adjusts the algorithm parameters to optimize performance in
terms of reducing network load, lowering the delivery rate of packets, and maximizing
packet throughput. In order to analyze the performance of the adaptive threshold
algorithm, both the threshold method and the adaptive threshold method are implemented
in a discrete event simulator called OMNET++. Simulations are run to analyze the
performance of both of these algorithms in varying network topologies and the results
are compared. Experimental results show that as the network topology changes, the
adaptive threshold method not only maintains a high throughput while lowering the
network load, it also outperforms the threshold method by reducing the average packet
Thesis (M.S.)--Tufts University, 2011.
Submitted to the Dept. of Electrical Engineering.
Advisor: Chorng Chang.
Committee: Chorng Chang, Mohammed Afsar, and Ethan Danahy.
Keyword: Electrical Engineering.read less