Buffer Management in Delay Tolerant Networks

Overview

Delay Tolerant Networks (DTNs) are characterized as sparsely connected, highly partitioned, and intermittently connected networks. In such networks, the end-to-end path between a given pair may never exist. In this project, we developed a suit of solutions to problems of resource allocation, packet scheduling, and buffering in DTNs. Particularly, we developed and evaluated a novel routing protocol called self adaptive routing protocol (SARP). The protocol is characterized by employing an efficient updating strategy for the stochastic information at each node. It can achieve minimum delay, high delivery ratio with less transmissions. Also, we developed two novel contention aware routing techniques, called self adaptive utility-based routing protocol (SAURP), and adaptive reinforcement-based routing protocol (ARBRP). The main feature of the introduced protocols is the strong capability in adaptation to the fluctuation of network status, traffic patterns/characteristics, and user behaviors. This is achieved by jointly considering node mobility statistics, congestion, and buffer occupancy, which are subsequently fused in a novel quality-metric (utility) function. We further implemented a novel message scheduling framework to enhance the performance of flooding and controlled flooding forwarding routing, in which additional buffer space and bandwidth overhead are needed in order to increase message delivery ratio and/or reduce message delivery delay. We also extend this concept to new message scheduling framework for utility-based forwarding routing. We develop buffer management policy based on the mechanism of the SAURP. The decision of forwarding or dropping the buffered messages is made based on the buffer occupancy status, the utility value of the messages, and the forwarding policy supported by SAURP mechanism, such that either the average delivery ratio or delivery delay can be optimized.

Funding

KAUST Baseline Funding

Team Members

• Dr. Ahmad Elwhishi, Electrical and Computer Engineering, University of Waterloo, Canada