Communication among isolated networks (clusters) in delay tolerant networks (DTNs) can be supported by a message ferry, which collects bundles from clusters and delivers them to a sink node. When there are lots of distant static clusters, multiple message ferries and sink nodes will be required. In this paper, we aim to make groups, each of which consists of physically close clusters, a sink node, and a message ferry. Our objective is minimizing the overall mean delivery delay of bundles in consideration of both the offered load of clusters and distances between clusters and their sink nodes. Based on existing work, we first model this problem as a nonlinear integer programming. Using a commercial nonlinear solver, we obtain a quasi-optimal grouping. Through numerical evaluations, we show the fundamental characteristics of grouping, the impact of location limitation of base clusters, and the relationship between delivery delay and the number of base clusters.
Masahiro Sasabe, K. Habibul Kabir, Tetsuya Takine, Nonlinear Integer Programming Formulation for Quasi-Optimal Grouping of Clusters in Ferry-Assisted DTNs, IEICE Transactions on Communications, E96-B(8), pp.2076-2083, August 2013.
@article{sasabe13NonlinearIntegerProgramming,
author = "Sasabe, Masahiro and Kabir, K. Habibul and Takine, Tetsuya",
title = "Nonlinear {{Integer Programming Formulation}} for {{Quasi-Optimal Grouping}} of {{Clusters}} in {{Ferry-Assisted DTNs}}",
year = "2013",
month = "August",
journal = "IEICE Transactions on Communications",
volume = "E96-B",
number = "8",
pages = "2076--2083",
doi = "10.1587/transcom.E96.B.2076"
}