scope:

The present document defines the GEM platform based on MHP [1]. GEM is applicable for specifications and standards based on the MHP APIs, content formats, and semantic guarantees.

The present document is firstly intended to be used by entities writing terminal specifications and/or standards based on MHP. Secondly it is intended for developers of applications that use the GEM functionality and APIs. The GEM specification aims to ensure interoperability between GEM applications and different implementations of platforms supporting GEM applications. This includes interoperability across different middleware specifications, e.g. MHP, OCAP 1.0 [3], and ARIB AE [5]. Implementers should consult the publisher of specifications which reference GEM regarding conformance.

NOTE: The present document defines the interfaces visible to applications. Application developers should not assume that any related interface is available unless it is specifically listed. Terminal standards or implementations may have other interfaces present.

One of the primary goals of the present document is to minimize the number of divergences between MHP and GEM terminal specifications, wherever practical. Divergence is defined in clause 3.1. Where divergences are inescapable, the present document serves as a place to document and control the permitted divergences, so that they will be predictable to terminal manufacturers, broadcasters, and application authors.