http://www.shephard.co.uk/inflight/Default.aspx?Action=-1000945703&ID=c3150e68-6fc5-4de8-86d8-aa2736029264

January 29, 2007 – THE new World Airline Entertainment Association (WAEA) specification covering digital delivery of IFE content has passed two key milestones and is on course for ratification in the next few weeks. 

WAEA 0403, entitled Digital Content Delivery Methodology for Airline In-Flight Entertainment Systems, was adopted last week by the association’s Digital Content Management Working Group (DCMWG) and then by the larger WAEA Technology Committee. It will go before the WAEA board in March for final ratification.

The specification 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.

The new specification represents 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, covering both wired and wireless distribution.   

Current co-chair Michael Childers of handheld IFE provider IMS is now seeking new co-chairs and volunteers to 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 assume that they will be the KMAs, administering keys on behalf of the airlines and content providers. But some 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.
 
This approach is already being studied by California-based IMS, which is working with at least two customers on integrating portable devices into the seat without permanently attaching them. American Airlines’ Boeing 767-300 business-class seat is an example, with the device sliding into a holder on the seatback. Other airlines will take a similar approach, but using a swing arm stored in the armrest to hold the device. These solutions are expected to be more secure and to weigh much less than head-end streaming to the client.