Existing on-demand ad hoc network routing protocols continue
using a route until a link breaks. During the route reconstruction, packets can be dropped, which will cause significant throughput
degradation. In this thesis, we add a link breakage
prediction algorithm to one on-demand routing protocol: the Dynamic
Source Routing (DSR) protocol. The mobile node that implements the prediction
algorithm uses signal power strength from the received packets to predict the
link breakage time, and sends a warning to the source node of the packet if the
link is soon-to-be-broken. The source node can perform a pro-active route
rebuild to avoid disconnection. Experiments demonstrate that adding link
breakage prediction to DSR, even considering the increased number of control
messages (at most 33.5%), can significantly reduce the total number of dropped
data packets (at least 20%) due to link breakage by reducing the number of
broken links. We believe that TCP can potentially benefit well from the
pro-active route maintenance to increase throughput, which is
affected by broken links. We also propose a modification plan for AODV
and make recommendations about further improvement on DSR based on the link
breakage prediction.