Globally Executable MHP
Encyclopedia
Globally Executable MHP (GEM) is a DVB specification of a Java
based middleware for TV broadcast receivers, IPTV
terminals and Blu-ray players. GEM is an ETSI standard ( ETSI TS 102 819, ETSI TS 102 728 ) and an ITU "Recommendation (ITU-T J.202). GEM defines a set of common functionalities which are independent from the signaling and protocols of a specific transmission network and enables to write interoperable Java applications for TV.
GEM is not intended to be directly implemented, but rather forms the basis for broader specifications targeting a particular network infrastructure (e.g. US cable) or class of device (e.g. Blu-ray Disc
players). GEM defines profiles for different device classes (targets) - these define the set of available features of GEM for this device class. Currently GEM defines targets (API profiles) for broadcast, packaged media (Blu-Ray) and IPTV. Combinations of these targets can be combined into a hybrid GEM platform, which enables to build devices with multiple network interfaces, such as a combined broadcast/IPTV set-top box.
-based application platform (a set of APIs), called MHP
, intended to support software applications running on digital television platforms. Such applications could include Electronic Program Guide
s (EPG's), interactivity, Video on Demand
(VOD), email through your television, etc. The MHP specification defines the download of MHP applications ("xlets") over transmission networks based on other DVB specifications (i.e. over-the-air or terrestrial networks using DVB-T
, satellite networks using DVB-S
, cable networks using DVB-C
). As other specification bodies such as CableLabs
and the Blu-ray Disc Association
chose to base their own DTV
software standards on MHP it became necessary to define a subset of MHP which removes the transmission-related elements of the MHP specification but retains the application API's, thus allowing broad content compatibility across a range of delivery platforms. Recently the DVB project made GEM the primary middleware specification and released a self-contained version of GEM in ETSI TS 102 728 .
As all these platforms are based on the common GEM-core, making it possible to write Java applications that will run interoperably on all these systems.
Java (programming language)
Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...
based middleware for TV broadcast receivers, IPTV
IPTV
Internet Protocol television is a system through which television services are delivered using the Internet protocol suite over a packet-switched network such as the Internet, instead of being delivered through traditional terrestrial, satellite signal, and cable television formats.IPTV services...
terminals and Blu-ray players. GEM is an ETSI standard ( ETSI TS 102 819, ETSI TS 102 728 ) and an ITU "Recommendation (ITU-T J.202). GEM defines a set of common functionalities which are independent from the signaling and protocols of a specific transmission network and enables to write interoperable Java applications for TV.
GEM is not intended to be directly implemented, but rather forms the basis for broader specifications targeting a particular network infrastructure (e.g. US cable) or class of device (e.g. Blu-ray Disc
Blu-ray Disc
Blu-ray Disc is an optical disc storage medium designed to supersede the DVD format. The plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs and CDs. Blu-ray Discs contain 25 GB per layer, with dual layer discs being the norm for feature-length video discs...
players). GEM defines profiles for different device classes (targets) - these define the set of available features of GEM for this device class. Currently GEM defines targets (API profiles) for broadcast, packaged media (Blu-Ray) and IPTV. Combinations of these targets can be combined into a hybrid GEM platform, which enables to build devices with multiple network interfaces, such as a combined broadcast/IPTV set-top box.
History
A few years ago, the DVB project started the development of a JavaJava (Sun)
Java refers to several computer software products and specifications from Sun Microsystems, a subsidiary of Oracle Corporation, that together provide a system for developing application software and deploying it in a cross-platform environment...
-based application platform (a set of APIs), called MHP
Multimedia Home Platform
Multimedia Home Platform is an open middleware system standard designed by the DVB project for interactive digital television. The MHP enables the reception and execution of interactive, Java-based applications on a TV-set. Interactive TV applications can be delivered over the broadcast channel,...
, intended to support software applications running on digital television platforms. Such applications could include Electronic Program Guide
Electronic program guide
Electronic program guides and interactive program guides provide users of television, radio, and other media applications with continuously updated menus displaying broadcast programming or scheduling information for current and upcoming programming...
s (EPG's), interactivity, Video on Demand
Video on demand
Video on Demand or Audio and Video On Demand are systems which allow users to select and watch/listen to video or audio content on demand...
(VOD), email through your television, etc. The MHP specification defines the download of MHP applications ("xlets") over transmission networks based on other DVB specifications (i.e. over-the-air or terrestrial networks using DVB-T
DVB-T
DVB-T is an abbreviation for Digital Video Broadcasting — Terrestrial; it is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television that was first published in 1997 and first broadcast in the UK in 1998...
, satellite networks using DVB-S
DVB-S
DVB-S is an abbreviation for Digital Video Broadcasting — Satellite; it is the original Digital Video Broadcasting forward error coding and demodulation standard for satellite television and dates from 1994, in its first release, while development lasted from 1993 to 1997...
, cable networks using DVB-C
DVB-C
DVB-C stands for Digital Video Broadcasting - Cable and it is the DVB European consortium standard for the broadcast transmission of digital television over cable...
). As other specification bodies such as CableLabs
CableLabs
Founded in 1988 by cable television operating companies, Cable Television Laboratories, Inc. is a not-for-profit research and development consortium that has cable operators as its members. System operators from around the world are eligible to be members. Members dues are based on revenue...
and the Blu-ray Disc Association
Blu-ray Disc Association
The Blu-ray Disc Association is the industry consortium that develops and licenses Blu-ray Disc technology and is responsible for establishing format standards and promoting business opportunities for Blu-ray Disc...
chose to base their own DTV
Digital television
Digital television is the transmission of audio and video by digital signals, in contrast to the analog signals used by analog TV...
software standards on MHP it became necessary to define a subset of MHP which removes the transmission-related elements of the MHP specification but retains the application API's, thus allowing broad content compatibility across a range of delivery platforms. Recently the DVB project made GEM the primary middleware specification and released a self-contained version of GEM in ETSI TS 102 728 .
Platforms
At the time of writing, the following platforms are defined, which base on/extend GEM:- the Multimedia Home PlatformMultimedia Home PlatformMultimedia Home Platform is an open middleware system standard designed by the DVB project for interactive digital television. The MHP enables the reception and execution of interactive, Java-based applications on a TV-set. Interactive TV applications can be delivered over the broadcast channel,...
(MHP), the open, multi-platform middleware specification developed by the DVB project, - the OpenCable Application PlatformOpenCable Application PlatformThe OpenCable Application Platform, or OCAP, is an operating system layer designed for consumer electronics that connect to a cable television system, the Java-based middleware portion of the platform. Unlike operating systems on a personal computer, the cable company controls what OCAP programs...
(OCAP / tru2wayTru2WayTru2way is a brand name for interactive digital cable services delivered over the cable video network, for example interactive program guides, interactive ads, games, chat, web browsing, and t-commerce. The brand also appears as “'” and is used to market cable services, applications, and devices...
), which is an Interactive televisionInteractive televisionInteractive television describes a number of techniques that allow viewers to interact with television content as they view it.- Definitions :...
(iTV) middleware software layer for US cable, - the Advanced Common Application PlatformAdvanced Common Application PlatformThe Advanced Common Application Platform is intended to provide television consumers with advanced interactive services and offer content providers, broadcasters, cable and satellite operators, and consumer electronics manufacturers the technical details necessary to develop interoperable services...
(ACAP) from North America’s ATSCATSCATSC standards are a set of standards developed by the Advanced Television Systems Committee for digital television transmission over terrestrial, cable, and satellite networks....
, - GEM-IPTV, a version of GEM developed by DVB intended for telco-based networks,
- the ARIB B.23 specification from Japan's ARIBAribArib is a town in northern Algeria....
, - the PAE specification in the Open IPTV Forum,
- BD-JBD-JBD-J, or Blu-ray Disc Java, is a specification supporting Java ME Xlets for advanced content on Blu-ray Disc and the Packaged Media profile of Globally Executable MHP .BD-J allows bonus content on Blu-ray Disc titles to be far more sophisticated than bonus content provided by standard DVD,...
the Java-platform for the Blu-ray discBlu-ray DiscBlu-ray Disc is an optical disc storage medium designed to supersede the DVD format. The plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs and CDs. Blu-ray Discs contain 25 GB per layer, with dual layer discs being the norm for feature-length video discs...
As all these platforms are based on the common GEM-core, making it possible to write Java applications that will run interoperably on all these systems.
See also
- Digital Video Broadcasting
- Hybrid Broadcast Broadband TVHybrid Broadcast Broadband TVHybrid Broadcast Broadband TV is both an industry standard and promotional initiative for hybrid digital TV to harmonise the broadcast, IPTV, and broadband delivery of entertainment to the end consumer through connected TVs and set-top boxes...
- 10-foot user interface10-foot user interfaceIn computing a 10-foot user interface is a software GUI designed for display on a large television with interaction using a regular television-style remote control."10 foot" refers to the fact that the GUI's...
- Enhanced TVEnhanced TVEnhanced TV is one example of interactive TV. It is used in particular in reference to Two-Screen Solutions TV + PC services. Generally users of these ETV services have their TV and computer in the same room, and navigate their web browser to a particular program-specific Web site that is...
- Interactive televisionInteractive televisionInteractive television describes a number of techniques that allow viewers to interact with television content as they view it.- Definitions :...
- Over-the-top contentOver-the-top contentIn the fields of broadcasting and content delivery, over-the-top content means on-line delivery of video and audio without the Internet service provider being involved in the control or distribution of the content itself...