Given a network together with a set of connection requests, call admission control is the problem of deciding which calls to accept and which ones to reject in order to maximize the total profit of the accepted requests. We consider call admission control problems with advance reservations in star networks. For the most general variant we present a constant-factor approximation algorithm resolving an open problem due to Erlebach. Our method is randomized and achieves an approximation ratio of 1/18. It can be generalized to accommodate call alternatives, in which case the approximation ratio is 1/24. We show how our method can be derandomized. In addition we prove that call admission control in star networks is -hard even for very restricted variants of the problem.
|Title of host publication||Approximation and Online Algorithms (2nd International Workshop, WAOA 2004, Bergen, Norway, September 14-16, 2004, Revised Selected Papers)|
|Editors||G. Persiano, R. Solis-Oba|
|Place of Publication||Berlin|
|Publication status||Published - 2005|
|Name||Lecture Notes in Computer Science|