A joint management of radio resources in heterogeneous networks is considered to raise efficiency. In this paper we focus on joint schemes for admission control and access technology selection using vertical handoff. We study a system where both streaming and elastic traffic are supported, and two radio access technologies covering the same areas are available: TDMA and WCDMA. Optimal solutions for different optimization criteria which can be expressed in terms of blocking probabilities and throughput are found and properly described, and a new heuristic policy is proposed. Finally, in order to provide some understanding of the cost of a single vertical handoff, a new optimization criteria is defined where its cost is found in relation to that of voice and data blocking.