Given a set of streams, with stream S_i a certain multimedia stream of a certain schema {X_i}, with X^m_i of a Micon type, that is T^m_i= Micon, and given a computational network that constitutes the query execution plan for a set of CQs and m-CQs, and this computational network is composed of both data processing operators (selection, projection, and join) and the special multimedia operators (fusion operator and transformation operator), it is required to compute a lower bound on the quality of service provided, measured by the average output rate R_i of each query.