Abstract:
Delay-Tolerant Networks (DTNs) are target environments suffering from instability or no
complete path between source and destination nodes. The contact duration between pairs of
network nodes is limited due to node movement and limited range of peer-to-peer wireless
communication. The pairs of node takes a long time to contact again in sparse delay-tolerant
networks, which is longer than contact duration. Therefore limited contact duration needs more
consideration to design buffer management forwarding policy. Several work has been done in the
design of forwarding algorithms, but little work has focused on studying forwarding under the
presence of limited contact duration. The pairs of network nodes require waiting till they come
into communication range again when do not finish exchanging the message during the contact
time. Consequently, the message which is started to transmit may drop when expired before the
nodes contact again and destination node waits till to receive complete message. Also, receiver
node drops a complete message to create space for incoming partial message items upon buffer
overflow. To solve the raised problem, we proposed a novel contact duration aware buffer
management forwarding policy. Since all intended buffered messages may not be exchanged
between nodes within a single contact duration, our proposed scheme select and forward only
complete transmit messages.
To evaluate the performance of proposed work we have used Opportunistic Network Environment
(ONE) network simulator. The proposed algorithm is integrated with the MaxProp routing protocol
buffer management forwarding policy and they were analyzed on two different metrics namely
bundle delivery probability and average delivery delay. Also, we considered number of node,
buffer size and simulation time to test performance of proposed work. Consequently, across all the
experiments the simulation results obtained in this thesis show that our proposed algorithm
outperforms than existing forwarding policy.
