In this paper we propose a mathematical model for the dimensioning of a 3G multimedia network and design a Tabu Search heuristic to solve it. The model is an anticipative one in which we assume that we know a priori the traffic over the planning period, and the dimensioning is consequently defined with a kind of best possible call admission control procedure. Due to the potentially large number of sessions and periods, solving the mathematical program can be done only for small size instances, so a heuristic approach is required for solving larger instances. Experimental results are provided for some multi-service multi-period problems.