MHP, or the Multimedia
Home Platform, and GEM, or Globally Executable
MHP, are two related sets of Java™ based open
middleware specifications developed by the DVB
Project. MHP was designed to work across all DVB transmission
technologies whereas GEM is a platform-indepedent environment
that can be adopted across a range of delivery systems including
packaged media. GEM is thus a common core engine on which
interactive applications can run; implementing GEM requires
the definition of how those applications actually connect
with that core.
Both MHP and GEM are published as open
standards by ETSI, the European
Telecommunications Standards Institute.
The use of an open middleware standard
for interactive television creates a situation where receiver
manufacturers can target multiple markets, rather than developing
products to the specification of a particular broadcaster
or operator. Applications based on MHP or GEM can be developed
by multiple service providers, enabling a horizontal market.
For a short overview of either MHP or
GEM you can download the following Fact Sheets:
MHP Fact Sheet
GEM Fact Sheet
Three different versions of MHP are currently
published by ETSI, with revisions of each published from time
to time. The graphic below outlines the elements contained
in each MHP version.
the menu to the right to find more information on the individual
GEM has now been adopted by a number of
other organisations including CableLabs, the ATSC, ARIB and
the Blu-ray Disc Association. GEM currently defines three
different "targets" designed for the different deployment
scenarios: a "broadcast target"
for broadcast TV using cable, terrestrial or satellite; an
"IPTV target" for IPTV based set-top
boxes; and a "packaged media target"
for use in disc-based services. All of these targets share
a common application model and a common set of core classes.
The graphic below shows how the different GEM based specifications
The broadcast target is available since
GEM 1.0.x and evolved in GEM1.1
and GEM 1.2.
- OpenCable Application Platform, developed by CableLabs
in collaboration with the DVB Project; now being deployed
under the brand tru2way™
- Advanced Common Application
Platform, closely related to OCAP and developed by the
ATSC for the US terrestrial
B.23 - developed by ARIB,
the Japanese TV standards body, as an Application Execution
Engine Platform for Digital Broadcasting, based on GEM
The IPTV target was introduced in GEM
- formally a subset of the MHP 1.2
specification which includes IPTV support
The packaged media target is defined since
GEM 1.0.x .
- Blu-ray Disc Java is the interactive platform supporting
advanced content for Blu-ray
information on deployments in the NewsBlog