The integrated digital home, thanks to DLNA - find out here what DLNA means for you and your TV-viewing habits.

In many top-range TVs, DLNA is now standard - for example, in the Philips Cinema 21:9.

The TV and PC were once bitter enemies, at least from the industry's point of view - until as recently a few years ago, Intel and Microsoft enjoyed regular squabbles with the consumer-electronics industry. Bill Gates even went so far as to claim that PCs would always be superior to TVs. But consumers still faced the question: Computer or TV?

Nowadays, the answer is increasingly becoming: "both". The PC now makes an excellent video source-device for the living-room screen - and, conversely, customers can also receive TV programs on their PCs. The devices no longer compete, and, instead, form a powerful team.

Home-networking begins with one simple question: How can I get the content I have on my PC onto the TV or stereo system? That's obvious, you might say - just put it on a disk, card, or memory stick and hook it up to the device of your choice. Or - and this is the much more elegant solution - use DLNA to access files directly across the network, and save yourself the trip.

DLNA is an abbreviation for "Digital Living Network Alliance", an international union of manufacturers of computers, consumer-electronics, and mobile telephones. DLNA aims to allow enjoyment of digital media such as photos, music, and movies throughout the home - and to make this as straightforward and convenient as possible.

From the car to the PC and even the TV: DLNA hopes to network all the electronics in your home.

Having lain dormant for five years, the DLNA standard finally made its breakthrough in 2008. In order to define a universal networking standard, the alliance drew on many elements of the PC world.

• the network protocols 802.3i/u and 802.11a/b/g/n, known as LAN and WLAN, for transmission via Ethernet cable or wireless,
• the internet protocol IPv4,
• the transfer protocols http 1.0 and 1.1,
• the basic specification for Universal Plug and Play (UPnP Device Architecture 1.0),
• the UPnP extension AV 1.0, a protocol for audiovisual content,
• the JPEG, PCM, and MPEG-2 standards for still pictures, audio, and video.

What here sounds awfully technical, and theoretical, brings concrete, highly practical effects in real life: You can, for example, quickly look at photos from a digital camera on the big, living-room screen. Or listen to music from your laptop on the stereo system. Or use your mobile phone as a remote control via WLAN - the list just keeps on going.

Depending on its categorization, there are different things that a DLNA device must be able to do. For home use, devices are split into servers (Digital Media Server, DMS), players (DMP), renderers (DMR), controllers (DMC), and printers, as well as the category "Media Interoperability Unit" (MIU). Players and renderers count as receivers, whereas the server is responsible for delivering the content.

A controller supervises and directs the entire system, telling the player, for example, which content is available. The Media Interoperability Unit (MIU), on the other hand, is responsible for converting incompatible formats into a form that all participating devices understand, so that the digital family is pulling in unison.

Network hard disks make excellent DLNA servers - but they'll need to carry the DLNA logo in order for the communication to work properly.

DLNA assigns more categories to mobile devices - an "uploader" (M-DMU), for example. Uploaders include mobile phones that make content available to the server over the network. Other than that, mobile devices have similar classifications to those described above, though the areas of use vary - from mini players for watching on-the-go, to multimedia fun for the car.

PCs can also work as a DLNA server - but only if they're running special software such as Twonky Vision.

The network alliance's regulations distribute the burden and tasks relatively uniformly to all participating devices, though the server carries the most "responsibility": It has to convert files into a format that the playback end of the chain also understands. This is no problem for still images and music - a JPEG, for example, is pretty quick to convert. It gets harder, however, with videos in MPEG-2 format, since the server must unpack an MPEG-4 file, for example, and then produce a new data stream - and it has to do this all in real time, during playback.

On the other end, the receivers have to decode constantly, and must detect the resolution, bit rate, and frame rate in each case. For this reason, the DLNA standard is still largely confined to expensive, top-range TVs with built-in HD tuners. Given the wide variety of profiles, resolutions, and tools present in the video standards, playing back files across a network often remains a game of luck - despite all efforts to make the system compatible.

Those that fancy trying their luck anyway, and that already have a home network, should keep a keen eye out for the DLNA logo when buying a new TV. Those that are happy instead just to check info on the Internet - during ad breaks, for example - can look out for an Internet-ready TV: More and more manufacturers are integrating this lesser technology into their devices. In fact, alongside energy-saving, this is the big TV-trend of 2009.