Complex sentence: One or more PSs are joined together into a MPEG-2 TS (MPEG-2 Transport Stream); this is the basic digital stream which is being transmitted and received by home Set Top Boxes (STB).
Split into simpler sentences: One or more PSs are joined together into a MPEG-2 Transport Stream (TS). This is the basic digital stream which is being transmitted and received by home Set Top Boxes (STB).