Minimum-total-length covering in general solid grid graphs

Determine the minimum-total-length set of length-constrained tours covering a general solid grid graph, where each tour starts and ends at a common base station.

Background

The paper studies the minimum-total-length covering problem for rectangular grid graphs using tours that start and end at a corner base station and satisfy a length bound. The authors place this problem in the broader setting of solid grid graphs, meaning grid graphs without holes, and state that the corresponding optimization problem remains unresolved in general. The rectangular corner-base-station case addressed by the paper is presented as a tractable special case of this broader open problem.