Audiopedia

The Digital Living Network Alliance is an international, cross-industry collaboration of consumer electronics, computing industry and mobile device companies.

It allows devices that are certified as DLNA compatible to be accessed on a network by any other device on the network that can recognize it.  Each DLNA compatible device is able to announce its capabilities to any other device that asks for information and then allows itself to be controlled by the requesting device.

A DLNA compatible NAS (Network Attached Storage) device, for example, would allow any requesting device to access all the data stored on the storage device.  In a music server environment, a NAS with digital audio stored on it would stream any of that media to any DLNA compatible device requesting it.

The beauty of this system is that any DLNA compatible device can be used and accessed by any other DLNA compatible device.  The vast majority of NAS, routers, music servers and computers are all DLNA compatible.

Members of DLNA develop a concept of wired and wireless interoperable networks where digital content such as photos, music, and videos can be shared through consumer electronics (CE), personal computers (PCs), and mobile devices in and beyond the home. The organization delivers an interoperability framework and design guidelines. The framework definitions are accompanied by a certification and logo program to communicate the conformance and interoperability of compliant products to consumers.

DLNA was founded in 2003 and published its first set of Interoperability Guidelines in June 2004. The latest version of the DLNA Interoperability Guidelines, version 1.5, was published in March 2006 and then expanded in October 2006. The current guidelines expand the capabilities of the DLNA-defined network to include more device classes and functional capabilities—including printers, mobile devices, controllers, uploaders and downloaders. They also include specifications for digital rights management [1].

Certification

The certification and logo program to validate DLNA-compliant products was launched in September 2005, certified products are allowed to use the DLNA CERTIFIED logo. There are currently four DLNA-accredited testing laboratories covering the major geographic regions (U.S., Japan, Europe and Taiwan) which conduct the conformance and interoperability test suites for the certification. As a part of the program, Universal Plug and Play certification is required for products that can be tested for UIC certification. Similarly, for products that support a IEEE 802.11 wireless interface, Wi-Fi certification is required.

As of September 2008 more than 3000 DLNA CERTIFIED products from 36 manufacturers are registered, out of which about 900 are publicly listed on the DLNA website.

In addition to the DLNA Certification and Logo Program, the organization hosts technical conferences (plugfests) on a quarterly basis to provide its members with opportunities to test products with other companies’ products and prototypes in advance of their formal certification.

Members

As of 2008 the DLNA organization comprises of more than 200 Contributor Members and 26 Promoter Members:

Access, AMD, AWOX, Broadcom, Cisco, Comcast, DigiOn, HP, Huawei, IBM, Intel, Kenwood, Lenovo, LG Electronics, Macrovision, Microsoft, Motorola, Nokia, NXP, Panasonic, Philips, Pioneer, Samsung, Sharp, Sony and Toshiba.

Types of devices

There are three main roles for a DLNA devices and a given device may have one or many roles.

Digital Media Server

With this role a device has a store of content (such as video files) which it makes available for client devices to use, if those devices cannot use a particular format the server may be able to convert the file before sending.

Digital Media Player

With this role device can show content which it requests (or is sent) from the server, examples of these devices are Sony’s PlayStation 3, Microsoft’s Xbox 360 and some of Sony’s bravia range of televisions

Digital Media Controller

With this role a device can instruct other devices to do something, such as telling a server to play a video on a particular television or a photframe to send a photo to a printer[1]

Criticisms

The main criticism of the standard is not the standard itself but that it is a closed standard and as such the low-level details of how it works are not available without membership of the alliance which is relatively expensive from the perspective of a small company or hobbyist.