March 16, 2007 – THE new World Airline Entertainment Association specification covering digital delivery of IFE content is in force following final approval by the WAEA board earlier this month. But the industry team responsible for its development is already gearing up for a second phase of work needed to complete standardisation all the way to the seat.

Now available on the WAEA Website, Specification 0403, entitled Digital Content Delivery Methodology for Airline In-Flight Entertainment Systems, is the result of several years of work by the Digital Content Management Working Group (DCMWG) under the chairmanship of Michael Childers (IMS), Julian Levin (Twentieth Century Fox Film/Fox In Flight) and Pierre Schuberth (Rockwell Collins).

It sets the standards for the various elements that go into the end-to-end delivery of digital content between provider and aircraft. These include codecs (the software used to compress the content for delivery over ground and aircraft networks to the screen), encryption for protection against piracy, digital rights management, minimum data rates and screen aspect ratios.

Despite early pressure to specify a single codec and standardise on fixed data rates, WAEA 0403 names MPEG-4 Part 2, MPEG-4 Part 10 and SMPTE VC-1 as acceptable codecs, and sets a minimum data rate of 1.0Mbit/sec and no maximum. The specification also embraces both the 4:3 and 16:9 aspect ratios, requiring that content be displayed without distortion in each case.

Although it represents a significant step in creating the long-awaited foundations for digital delivery, the new specification is in fact just the first phase of the DCMWG’s complete programme of work, covering delivery from the originator to the door of the aircraft. In Phase 2 the group will address the supply chain aboard the aircraft, addressing both wired and wireless distribution.

A team led by Michael Childers and two new co-chairs will define and pursue this phase. Issues to be tackled include the potentially thorny one of provision for encryption aboard the aircraft. The content providers want decryption keys to be specific to the aircraft, to the onboard server or even, in the case of handhelds, to individual devices. Some airlines, on the other hand, want the keys to be applicable to whole fleets.

Another question relates to responsibility for the management of decryption keys. Some airlines assume that they will be the key management authorities (KMAs), desiring to control the content while not wanting to take on the associated work. Some hardware providers expect that they will be the KMAs, administering keys on behalf of the airlines and content providers. But certain content providers have resisted that approach in the past and may seek to retain control for themselves.

In Phase 2 the group is also likely to consider an alternative scheme for wireless delivery inside the aircraft. Instead of streaming content from the head end to the seat as it is being consumed, an approach that requires a lot of wireless bandwidth, the content might instead be downloaded from the head end to hard discs in self-contained clients such as portables when no passengers are present on the aircraft. Encrypted content would reside on the hard disc of each client and be decrypted in playback. This would require less bandwidth between the head end and the user device, reducing the number of wireless access points and thus saving weight.