OCAP, ACAP and ARIB
CableLabs and ATSC both took GEM as the basis for their own digital TV
standards (OCAP in the case of CableLabs, ACAP in the case of ATSC).
These both use elements from the full MHP specification as well as GEM.
The biggest difference is in the service information handling: both
OCAP and ACAP use ATSC service information, with OCAP systems also
using some cable-specific extensions. Other differences include the
replacement of the MHP 'navigator' with the 'monitor application',
which gives network operators a lot more control over the receiver, and
support for some different types of application such as stored
applications.