Editing Multimedia Home Platform

{{Short description|Standard for interactive digital television}}
'''Multimedia Home Platform''' ('''DVB-MHP''') is an open [[middleware]] system [[standardization|standard]] designed by the [[Digital Video Broadcasting|DVB]] project for [[Interactive television|interactive digital television]]. The MHP enables the reception and execution of interactive, [[Java (programming language)|Java]]-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 [[Internet Protocol|IP]].

== Deployment ==
In May 2010 the largest deployments DVB-MHP are in Italy ([[DVB-T]]), [[Korea]] ([[DVB-S]]), Belgium ([[DVB-C]]) and [[Poland]] ([[DVB-S]]) with trials or small deployments in Germany, Spain, Austria, [[Colombia]], [[Uruguay]] and Australia.

MHP service was also offered in [[Finland]] by Finnish Broadcasting Corporation ([[Yle|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".<ref>{{cite web |url=http://www.talouselama.fi/kolumni/article168212.ece |title=Sinullekin oma tv-kanava - Talouselämä |accessdate=2009-07-08 |url-status=dead |archiveurl=https://web.archive.org/web/20090415022546/http://www.talouselama.fi/kolumni/article168212.ece |archivedate=2009-04-15 }} Talouselämä 1.2.2008, Petteri Järvisen kolumni Sinullekin oma tv-kanava</ref> 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 [[OpenCable Application Platform|OCAP]], which is largely based on MHP.
Currently{{when|date=December 2022}}, Belgium's largest cable provider [[Telenet (Belgium)|Telenet]] is rolling out their DVB-MHP system, called DigiBox. Norway's upcoming terrestrial digital TV network [[Norges televisjon|NTV]] will also use the DVB-MHP standard.<ref>[http://www.mhp.org Official website for DVB-MHP and DVB-GEM - Open Middleware for Interactive TV] {{webarchive|url=https://web.archive.org/web/20060421101018/http://www.mhp.org/ |date=2006-04-21 }}</ref> In late 2008 the Info+ channel in Greece (part of the [[ERT Digital]] platform) started broadcasting DVB-MHP info,<ref>[http://www.ertdigital.gr/info/vasi.html info+ ΜΙΑ ΤΕΡΑΣΤΙΑ ΒΑΣΗ ΔΕΔΟΜΕΝΩΝ ΜΕ ΤΟ ΠΑΤΗΜΑ ΕΝΟΣ ΠΛΗΚΤΡΟΥ] {{webarchive|url=https://web.archive.org/web/20090325200931/http://www.ertdigital.gr/info/vasi.html |date=2009-03-25 }} (in greek)</ref> 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.<ref>[http://www.fullhd.gr/index.php/pro/2008-03-05-02-33-57/568-ert-info ERT Info+] FullHD.gr (in greek)</ref>

== Technology ==
[[Image:MHP-software stack english.png|frame|right|MHP software stack]]
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 [[Java platform|Java]] [[virtual machine]] and the definition of generic APIs that provide access to the interactive digital TV [[Computer terminal|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 ==
{{main|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]] pages that are broadcast as part of a service. The spec is based around a modularized version of [[XHTML]] 1.1, and also includes [[Cascading Style Sheets|CSS]] 2.0, [[Document Object Model|DOM]] 2.0, and [[ECMAScript]].

== DVB-J ==
The second, and by far the most popular flavour is [[DVB-J]] ([[DVB-Java]]) applications. These are written in [[Java (programming language)|Java]] using the MHP [[API]] set and consist of a set of [[class (computer science)|class]] files that are broadcast with a service. DVB-Java applications are known as "[[Xlet]]s". 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.<ref>[http://mhpkdbwiki.s3.uni-due.de/mhpkdbwiki/index.php/DVB-J DVB-J] {{webarchive|url=https://web.archive.org/web/20101203024308/http://mhpkdbwiki.s3.uni-due.de/mhpkdbwiki/index.php/DVB-J |date=2010-12-03 }}</ref>

== Return channel ==
The MHP [[set-top box]]es may provide a [[backchannel]] 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]] Internet connection ([[Asymmetric Digital Subscriber Line|ADSL]], 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 [[Internet Protocol|IP]] with [[Transport Layer Security|TLS]] support.

== See also ==
* [[MHEG-5]]
* [[Hybrid Broadcast Broadband TV]] (HbbTV), an alternative technology used for interactive television services via broadcasting and broadband communication media in some European countries.
* [[BD-J]]
* [[Interactive television]]
* [[IP over DVB]]
* [[OSGi]]
* [[Datacasting]]
* [[Telesoftware]] The invention upon which MHP is based.

== References ==
{{reflist}}
* 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 ==
*[http://www.mhp-interactive.org/ MHP tutorials]
*[https://web.archive.org/web/20060207234749/http://www.mhp-knowledgebase.org/ MHP Knowledge Database]
*[https://web.archive.org/web/20081225013011/http://www.xletview.org/ XleTView] an open source MHP emulator
*[http://www.s-and-t.com Strategy & Technology MHP,OCAP and MHEG-5 solutions]
*[https://archive.today/20130410125026/http://www.alticast.com/index.php/solutions/tv-experience/altiplatform Alticast Solutions]
*[http://mhp-interactive.org/ TV Without Borders] - MHP/OCAP Website from Steven Morris
*[http://www.dvb.org/(RoxenUserID=5fac63d0cfe60e3c5b157acb99095c88)/technology/fact_sheets/WP03_RCT.pdf dvb.org - DVB-RCT Return Channel Terrestrial]
*[https://web.archive.org/web/20130611014343/http://interactivetvforum.org/ Interactive TV Forum]
*[https://www.jvrb.org/past-issues/4.2007/1110 Exploiting OSGi capabilities from MHP applications]
*[http://www.tmira.com/ tmira solutions] MHP [https://web.archive.org/web/20090511114848/http://www.tmira.com/en/products/tmbroadcast broadcast server] and MHP [https://web.archive.org/web/20090721000504/http://www.tmira.com/en/products/tmplayer iTV browser] and authoring tools.
*[http://www.osmosys.tv Osmosys Open Standard solutions]
*[https://web.archive.org/web/20100406064824/http://www.avalpa.com/the-key-values/15-free-software/33-opencaster OpenCaster free GPL licensed software for transport stream broadcasting]
*[https://web.archive.org/web/20100129100828/http://www.code4tv.com/c/tutorialmhp112 Free practical MHP 1.1.2 Course in Spanish]

[[Category:Digital Video Broadcasting|MHP]]
[[Category:Interactive television]]
[[Category:Java virtual machine]]
[[Category:Digital Video Broadcasting software]]