Rethinking the Embedded IFE
One of the most exciting changes to the traditional IFE architecture is the move from head-end centric to seat-centric, to help deliver the innovative and robust experience to the passenger. Instead of storing the bulk content (video/audio) in the head end server, content is replicated at each individual seat display unit (SDU). This helps deliver a better user experience since Audio-Video on Demand (AVOD) HD content is served with extremely low latency and no jitter, with no effect of cabin network congestion if it occurs.
The storage of content at the seat produces various benefits:
- It allows the traditional moving map experience to become richer and user-interactive. Rather than have the moving map generated and streamed from the server, the map database is stored in the SDU and displayed based on the airplane flight coordinates sent by the server. This allows the passenger to interact with the map system, much like using interactive maps on the ground, e.g. zooming, POI, etc.
- It allows pre-recorded messages, safety videos, etc. to be stored at the SDU in different languages, with different language subtitles. Pre-Recorded Announcements and Music (PRAMs) are thus displayed in a language of the passenger’s choosing.
- The seat-centric architecture also eliminates one of the key problems with the head-end centric architecture: single point media storage failure. Since the content is replicated, any media storage failure at a SDU is localized. The SDU seamlessly fetches content from the neighboring SDU, again ensuring that the user experience is unaffected.
- For the airline, the seat-centric architecture eliminates the need for redundant, expensive and heavy media servers at the head end and a high capacity expensive cabin network to ensure low latency, no congestion and minimal jitter when streaming AVOD HD video in real time to all passengers simultaneously. This leads to savings in space, weight, cost, wiring, power, cooling and integration effort.
At the heart of a seat centric architecture, is the concept of a “Smart SDU”. The smart SDU, much like a smart phone or a smart TV, has a high resolution, capacitive touch screen, supporting touch gestures and icon driven interface, ability to play all formats of audio/video, with hardware decoding. It has a USB interface to allow the passenger to connect his own Personal Electronic Device (PED), and supporting a wealth of third party apps, from existing app stores.
Besides providing smartphone like features to passengers, the smart SDU also provides commercial benefits to the airlines. Being based on standard mobile or tablet chipsets and platforms, perhaps using an existing Android port, reduces the NRE as well as maintenance cost for the SDU, while creating a device that delays obsolescence for few years. A slimmed down smart SDU based on mobile/tablet platforms also allows easier integration into the seat, and immensely saves on power and TCO.
Wireless IFEC & BYO-IFE
Wireless technologies, notably Wi-Fi has been in use in aircraft cabins for many years, starting with Connexion. In recent times, it has found widespread acceptance for internet services within the aircraft cabin for passengers. Wireless networking can also be used in place of the wired network for the IFE system, either embedded or handheld. Using wireless in place of the wired network has some great advantages for the airline: weight saving due to elimination of cabling, and hence saving in fuel costs; simpler installation and maintenance.
It is not possible to use a wireless system to stream HD video to a large number of seats simultaneously. Using 802.11n, a single access point may be able to support no more than 20 simultaneous passengers watching full-HD video content (6 Mbps CBR), and in a wide body with close to 300 seats, a streaming wireless IFE solution may not be feasible. It is of course possible to have a wireless streaming solution with SD content, or with lower bitrate for HD content, or with fewer seats (e.g. single-aisle aircraft).
A more efficient solution is to use the wireless network with the seatcentric architecture for loading/refreshing of the bulk content to the SDUs. Current content is accessed by the passenger from the local store, while the content for the next refresh cycle is downloaded in the background using the wireless link. This scheme uses the wireless bandwidth as available, without relying on the wireless network to deliver a low latency, jitter free video streaming experience to the passenger.
Using an all wireless network for an embedded IFE is problematic since current regulations prohibit the use of wireless during take-off and landing. An embedded IFE system needs to interrupt the playing content to display announcements made by the flight crew, and play safety videos. During take-off and landing, without a network link to control the behavior of the SDUs, the SDUs would mandatorily need to be inaccessible to the passenger. A possible option is to use a wired network in addition to the wireless, e.g. power line communication, but that would largely defeat the intent of having an all wireless network. Wireless networking really comes into its own when coupled with handheld devices: carrier-owned, or brought on board by the user, i.e. PEDs. As noted earlier, handheld devices cannot be currently used during take-off and landing, and hence the user experience suffers since the IFE is available only during level flight.
Delivering an IFE experience on PEDs, i.e. Bring Your Own IFE or BYOIFE, is truly a disruption of the current IFE models. It relies on equipment brought on board by the passenger at no cost to the airline, and is usually a generation ahead of the installed, embedded IFE. It is available to the passenger at no cost to the airline, and can serve to keep the passenger entertained when there is no installed IFE in the aircraft.
Wireless IFE will serve as a complement to existing embedded IFE systems in the long-haul market, while it may be the perfect solution for the short-haul market which usually has no entertainment options.