Finding Multiple New Optimal Locations in a Road Network

TL;DR

This paper addresses the complex problem of optimally placing multiple new servers in road networks, proposing efficient algorithms for small and large numbers of servers, and demonstrating improved results over existing methods.

Contribution

It introduces a novel algorithm for the NP-hard MinMax problem with multiple servers and an efficient approximation for large server counts.

Findings

The proposed algorithms outperform greedy methods in real road network experiments.

The algorithms are efficient when the number of new servers is small.

The 3-approximate algorithm provides a good balance between efficiency and solution quality.

Abstract

We study the problem of optimal location querying for location based services in road networks, which aims to find locations for new servers or facilities. The existing optimal solutions on this problem consider only the cases with one new server. When two or more new servers are to be set up, the problem with minmax cost criteria, MinMax, becomes NP-hard. In this work we identify some useful properties about the potential locations for the new servers, from which we derive a novel algorithm for MinMax, and show that it is efficient when the number of new servers is small. When the number of new servers is large, we propose an efficient 3-approximate algorithm. We verify with experiments on real road networks that our solutions are effective and attains significantly better result quality compared to the existing greedy algorithms.