Multimedia Home Platform (DVB-MHP) 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 Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...

-based applications on a TV set. Interactive TV applications can be delivered over the broadcast channel, together with audio and video streams. These applications can be for example information services, games, interactive voting, e-mail, SMS or shopping. MHP applications can use an additional return channel that has to support IP.

Deployment

In May 2010 the largest deployments DVB-MHP are in Italy (

DVB-T DVB-T, short for Digital Video Broadcasting – Terrestrial, 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 Singapore in Fe ...

Korea Korea is a peninsular region in East Asia consisting of the Korean Peninsula, Jeju Island, and smaller islands. Since the end of World War II in 1945, it has been politically Division of Korea, divided at or near the 38th parallel north, 3 ...

( DVB-S), Belgium ( DVB-C) and

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, bordered by Lithuania and Russia to the northeast, Belarus and Ukrai ...

( DVB-S) with trials or small deployments in Germany, Spain, Austria,

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

Uruguay Uruguay, officially the Oriental Republic of Uruguay, is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast, while bordering the Río de la Plata to the south and the A ...

and Australia. MHP service was also offered in

Finland Finland, officially the Republic of Finland, is a Nordic country in Northern Europe. It borders Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland to the south, ...

by Finnish Broadcasting Corporation ( Yleisradio), but the service was shut down at the end of 2007 after technical failure. The shutdown wasn't ever officially announced. Ultimately the reason for the shutdown was that MHP never gained "critical mass". The main reasons for its lack of success in Finland were: 1) 50% of the Finnish households use the terrestrial network, where broadcasting of MHP applications can be really expensive, 2) TV broadcasters never told TV viewers about the MHP services—because the digitalization of the TV networks got extremely negative publicity in Finnish media, the broadcasters didn't want to upset their customers further if they had bought new expensive STBs which weren't capable of playing MHP apps, and 3) there were only a few MHP set-top boxes in the market—because Finland is such a small market, big manufacturers weren't interested in developing new MHP boxes just for Finland. MHP-capable STBs are no longer available in Finland. The U.S. cable industry has specified its own middleware system referred as OCAP, which is largely based on MHP. Currently, Belgium's largest cable provider Telenet is rolling out their DVB-MHP system, called DigiBox. Norway's upcoming terrestrial digital TV network NTV will also use the DVB-MHP standard. In late 2008 the Info+ channel in Greece (part of the ERT Digital platform) started broadcasting DVB-MHP info, however since standards have not been set as of February 2009 for digital television in Greece, most TV sets and DVB-T receivers sold in the country do not feature DVB-MHP.

Technology

The MHP specifies an extensive application execution environment for digital interactive TV, independent of the underlying, vendor-specific, hardware and software. This execution environment is based on the use of a

virtual machine In computing, a virtual machine (VM) is the virtualization or emulator, emulation of a computer system. Virtual machines are based on computer architectures and provide the functionality of a physical computer. Their implementations may involve ...

and the definition of generic APIs that provide access to the interactive digital TV terminal's typical resources and facilities. The interoperable MHP applications are running on top of these APIs. A so-called Navigator-application, which is part of the terminal software, allows the user the access to all MHP applications and other DVB services (like TV and radio). Sometimes Navigator can be also a Java program itself but that is not a requirement. The MHP is just a part of a family of specifications, which all base on the Globally Executable MHP (GEM)-Standard, which was defined to allow the worldwide adoption of MHP.

DVB-HTML

MHP applications come in two flavours. The first type are DVB-HTML applications. These are not very popular, partly because the specification for DVB-HTML was only completed with MHP 1.1, and partly because many broadcasters, box manufacturers and content developers find it too complex and difficult to implement. DVB-HTML applications are a set of

HTML Hypertext Markup Language (HTML) is the standard markup language for documents designed to be displayed in a web browser. It defines the content and structure of web content. It is often assisted by technologies such as Cascading Style Sheets ( ...

pages that are broadcast as part of a service. The spec is based around a modularized version of

XHTML Extensible HyperText Markup Language (XHTML) is part of the family of XML markup languages which mirrors or extends versions of the widely used HyperText Markup Language (HTML), the language in which Web pages are formulated. While HTML, pr ...

1.1, and also includes CSS 2.0, DOM 2.0, and

ECMAScript ECMAScript (; ES) is a standard for scripting languages, including JavaScript, JScript, and ActionScript. It is best known as a JavaScript standard intended to ensure the interoperability of web pages across different web browsers. It is stan ...

DVB-J

The second, and by far the most popular flavour is DVB-J ( DVB-Java) applications. These are written in

using the MHP

API An application programming interface (API) is a connection between computers or between computer programs. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how to build ...

set and consist of a set of

class Class, Classes, or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used d ...

files that are broadcast with a service. DVB-Java applications are known as " Xlets". These are a concept similar to applets for Web pages that has been introduced by Sun in the JavaTV specification. Like applets, the xlet interface allows an external source (the application manager in the case of an MHP receiver) to start and stop an application.DVB-J

Return channel

The MHP

set-top box A set-top box (STB), also known as a cable converter box, cable box, receiver, or simply box, and historically television decoder or a converter, is an information appliance device that generally contains a Tuner (radio)#Television, TV tuner inpu ...

es may provide a

backchannel Backchannel is the use of networked computers to maintain a real-time online conversation alongside the primary group activity or live spoken remarks. The term was coined from Backchannel (linguistics), the linguistics term to describe listeners' ...

for applications that wish to communicate with the outside world, for example a voting or shopping application. Typical upstream backchannels are phone line or

broadband In telecommunications, broadband or high speed is the wide-bandwidth (signal processing), bandwidth data transmission that exploits signals at a wide spread of frequencies or several different simultaneous frequencies, and is used in fast Inter ...

Internet connection (

ADSL Asymmetric digital subscriber line (ADSL) is a type of digital subscriber line (DSL) technology, a data communications technology that enables faster data transmission over Copper wire, copper telephone lines than a conventional voiceband modem ...

, or 56k in Italy, using a modem included in the set-top box). DVB-RCT (Return Channel Terrestrial) is a wireless technology utilizing the DVB infrastructure. It provides a VHF/UHF Wireless Return Channel back to the broadcaster for Interactive Terrestrial TV. It provides a data-rate of several kbit/s per user, for voting, polls, email, teleshopping, etc. If return channel is present it should provide IP with TLS support.

References

* Ulrich Reimers: DVB, The Family of International Standards for Digital Video Broadcasting, Second Edition, 2005, {{ISBN, 3-540-43545-X (chapter 14, MHP)

External links

MHP tutorialsMHP Knowledge DatabaseXleTView
an open source MHP emulator
Strategy & Technology MHP,OCAP and MHEG-5 solutionsAlticast SolutionsTV Without Borders
- MHP/OCAP Website from Steven Morris
dvb.org - DVB-RCT Return Channel TerrestrialInteractive TV ForumExploiting OSGi capabilities from MHP applicationstmira solutions
MH
broadcast server
and MH
iTV browser
and authoring tools.
Osmosys Open Standard solutionsOpenCaster free GPL licensed software for transport stream broadcastingFree practical MHP 1.1.2 Course in Spanish
MHP Interactive television Java virtual machine Digital Video Broadcasting software