Recommendation ITU-T J.1203 defines the detailed specification of a smart television operating system (TVOS) to enable integrated broadcast and broadband (IBB)-capable cable set-top box (STB) and TV to apply to broadcasting services and IP-based interactive services provided by cable television operators and third-party providers. By running the smart TV operating system, the IBB capable STB and TV will be able to provide subscribers with advanced and personalized services by downloading and installing advanced and personalized apps from cable operators' platforms and third-party platforms, which are interconnected with the related cable operators' platforms. Recommendation ITU-T J.1203 is developed in accordance with the requirements defined in [ITU-T J.1201] and based on the architecture defined in [ITU-T J.1202]. This Recommendation provides a specification for administrations and entities who intend to implement smart TV operating system.