With the increasing availability of sophisticated mobile devices which include broadband Internet access services, cable operators, broadcasters and consumer electronics manufacturers have started taking advantage of this trend by providing connected devices which work as companion devices to enhance the TV watching experience. This technology creates several opportunities for players in all involved segments for delivering enriched and customized content and user experience. The integration of these companion mobile devices, also known as second screens with TV and cable STB platforms, support several scenarios based on content sharing, synchronization, user interaction and customized presentations. This integration also offers opportunities for the inclusion of intuitive and convenient user interfaces and additional areas for the presentation of information. This Recommendation defines high level requirements for the cable STB and mobile platforms involved in these scenarios. This Recommendation also describes some useful use cases to provide the ideas behind the requirements.