A Development Framework for Extending VoIP Technologies to the Aviation Industry

ANOOP S BABUS7 CSENO : 06GECI

The great success of the aviation Industry is supported by user trust.

Security has the highest priority and that's why we are living in the safest era of the aviation history.

Only one flight in every 1.5 million had an accident in 2006, a 14% decrease compared to the previous year.

Still a single accident is covered by global news media leading to a possible user mistrust that is further enhanced if the cause is not timely determined.

FDR data could be stored on a terrestrial server.

Moreover, the audio stored on the Cockpit Voice Recorder could also be streamed to a terrestrial server.

A telecommunication system capable of recording the FDR data of every commercial flight in the World in a cost effective way.

1) Technical Feasibility

2) The system architecture profiting from the recent launches of INMARSAT 1-4 satellites offering mobile and global broadband access services.

3) The Flight Data Remote Protocol (FDRP)

4) Addresses security issues in several aspects.

5) Economic Feasibility

The FAA (Federal Aviation Administrations) regulations establishes the precise sample rate and quantization resolution with which each parameter is to be stored.

The maximum FDR data burst, occurring at a 64-second interval, is 980 bits.

The technical feasibility is easily established by simply dividing the system capacity of modern satellites (ie 450 Mb/s) by the bit rate required.

The maximum number of flights the network can serve if it were in an entirely dedicated network is about half a million flights in a single coverage area!

There are just only over 20,000 commercial jet planes in the World , so current satellite public services could be readily used to implement the BBolP system.

Digital FDR data is acquired by the black box through a Digital Flight Data Acquisition Unit (DFDAU).

FAA regulation concerning CVRs require four audio channels to be continuously recorded:

1)for the head set of the captain,

2)for that of the copilot,

3) for a third crew member,

4)the acoustic environment transduced at the cockpit-mounted area microphone.

Considering that the first three channels are dedicated to voice communications, the low bit rate G.729 codec could be used .

As for the the fourth channel, a wide-band codec, e.g. G.722.2 is used (having a better audio quality.

The BBolP Client - light embedded system.

If the added weight of a BBoIP client to a plane is much less than the passengers' weight standard deviation, no significant extra fuel will be spent.

The BBoIP Client is connected to the plane LAN through which traffic is routed toward the Satellite Gateway(GW).

The routing functions of the plane LAN should reserve enough bandwidth to avoid competition.

An event/transaction-processing platform is proposed for the BBolP Earth Station.

Once a session is initiated, the BBolP Client will periodically send the FDR/CVR data to the BBolP Earth Station.

In addition to the target application of fast flight data recovery after an accident, Accident Alert Systems, Information Services, and Pilot Training Assistance also be developed.

For minimizing overhead bandwidth usage, we specify a simple protocol that has SIP, TCP, and RTP characteristics.

It includes a procedure for data recovery during a connection failure.

(a) IP protocol stack with variable-length payload

(b) FDR/CVR data packet structure

(c) FDRP message packet structure.

Packet Data Structure

Threats accidental-satellite link failures

malicious-typical attacks on computer networks;such as -denial of service attacks, -corruption of data, -session hijack, -data theft, etc.

1) During an accidental satellite link failure, the FDRP previsions the buffering of data and its delayed transmission once the link is recovered.

2) A high level of rejection of unauthorized session or hijack attempts.

3) The FDRP protocol initially does not address confidentially of FDR data packets through encryption because the output data flow from the DFDAU is already encrypted.

If we divide the sum of the FDR and CVR transmission cost by the average number of passengers per flight, we get an increase of 21.4 cents per passenger per flight.

In terms of supporting the cost of satellite data transmission, the cost increase of a 120-minute flight makes the proposal economically "affordable".

Of course, a further step in the development process would include an analysis of hidden operational and development costs in parallel to prototype design.

The clustered architecture proposed for the Earth Station should solve scalability issues; so initial deployment could be done on a carrier-by-carrier or country-by-country basis.

Landing or taking-off under bad weather conditions could pose a serious drawback to the system if the satellite link fails.

The FDRP protocol could easily be extended to carry video channels if cameras are to be placed on the cockpit or elsewhere on the plane.

http://www.faa.gov/regulations_policies/faa_regulations

http://en.wikipedia.org/wiki/Voice_over_IP