## Abstract

The paper concerns a new variant of the hierarchical facility location problem on metric powers (HFL_{β} [h]), which is a multi-level uncapacitated facility location problem defined as follows. The input consists of a set F of locations that may open a facility, subsets D_{1}, D_{2}, ..., D_{h - 1} of locations that may open an intermediate transmission station and a set D_{h} of locations of clients. Each client in D_{h} must be serviced by an open transmission station in D_{h - 1} and every open transmission station in D_{l} must be serviced by an open transmission station on the next lower level, D_{l - 1}. An open transmission station on the first level, D_{1} must be serviced by an open facility. The cost of assigning a station j on level l ≥ 1 to a station i on level l - 1 is c_{i j}. For i ∈ F, the cost of opening a facility at location i is f_{i} ≥ 0. It is required to find a feasible assignment that minimizes the total cost. A constant ratio approximation algorithm is established for this problem. This algorithm is then used to develop constant ratio approximation algorithms for the bounded depth Steiner tree problem and the bounded hop strong-connectivity range assignment problem.

Original language | English |
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Pages (from-to) | 341-362 |

Number of pages | 22 |

Journal | Journal of Discrete Algorithms |

Volume | 7 |

Issue number | 3 |

DOIs | |

State | Published - Sep 2009 |

Externally published | Yes |

## Keywords

- Approximation algorithms
- Facility location
- Range assignment
- Steiner trees
- Wireless networks