Recommendation ITU-T J.298 describes the requirements and technical specifications of cable TV hybrid set-top-box that has the compatibility with terrestrial and satellite TV transport. The major purpose of the Recommendation is to specify a minimum and basic requirement for a hybrid STB, which meets the requirements for developing countries and regions .The hybrid set-top-box has full functionalities for traditional cable broadcasting services, at the same time, a satellite or a terrestrial broadcast receiving functions will also be implemented in the box so as the STB be able to receive satellite or terrestrial broadcast service. The basic functionalities for IP-based interactive video services is also required so as the STB be able to support the latest IP interactive services together with legacy DVB and ISDB-T services.