Originally Posted by
OZBUSDRIVER
Don't start this argument again, Leadsled. UAT , a MITRE invention, was a solution looking for a problem to cure. Bandwidth is the enemy. You need a hundred times more ground stations to supply that bandwidth. If you are out of range, you have no bandwidth and you will see nothing. 1090es talks to anything...even out of range of ground stations...Two 1090es equipped aircraft will still see each other 200nm west of Kickatinalong! If anyone wants actual wx in your cockpit in Oz...buy an app for your smartphone or tablet. Because the government..and the airlines...would NEVER allow that type of "investment" to give GA free bandwidth.
Oz,
Howe about you stick with the facts.
Folks,
The below in the interests of historical accuracy, no
"false history" please. The adoption of 1090ES as the international standard for ADS-B/C was and remains one of the most technologically regressive and short sighted moves in aviation since WWII. It has cost airlines unnecessary billions of dollars.
Naturally, Australia played a quite prominent role in "looking backwards", something at which, sadly, by international acclaim,we excel. We are stuck with 1090ES ADS-B, high cost of acquisition, high cost of fitting, and very limited in data transmission capability due being ancient technology in the broadband era.
Fact (1) ICAO ran a technical competition for a broadband system for future applications, the main ones, but not the only ones, being what we now call ADS-B/C Out, the other to transfer most ATC routine comms. from voice to the data-link.
Fact (2) There were two major competitors in the "final", VDL-4 (TDMA -- Ericsson patents ) and UAT (CDMA -- Qualcomm patents). Unfortunately, trans-Atlantic politics played a part, a re-run of the VOR/DME versus Decca fight several decades before.
Fact (3) The original "winner" was VDL-4 ---- votes at the UN/ICAO.
Fact (4) The first certified "ADS-B" into service ran on the VDL-4 system in Scandinavia.
Fact (5) ARINC/SITA has adopted VDL-2 as the replacement for VHF ACARS ---- so the great majority of airlines have had to fit a broadband transceiver, anyway, which ICAO originally intended to carry the ADS traffic. One for the price of two, so to speak, instead of two for the price of one.
Fact (6) The ground stations used by Airservices are the same ones FAA uses, except that the card slot for UAT is empty, from the ground station to aircraft, the range is the same, with only a minor difference in the frequencies meaning there is no difference in range -- it is line of sight.
Fact (7) From the ground receiver to the ATC computers it is a common signal format, regardless of whether the "air" part of the signal is 1090ES or UAT. Whoever told you bandwidth was a problem has sold you a furphy, and by the way, I have a big bridge in Sydney I can sell you cheap.
Fact (8) An unholy alliance, at the "last minute", proposed 1090ES as a "quick and cheap" solution to cash strapped US and IATA airlines, in a period when just about all US but Southwest were in/about to be/just emerged from Chapter 11 bankruptcy. It proved to be neither quick nor cheap, ask the airlines. QantasLink -8 conversion costs were in the order of twenty (20) times the CASA Cost/Benefit "estimate".
Fact (9) The channel congestion problems forecast by Mitre Corp. for 1090ES is now clearly a problem in the US, but such was the political pressure that a system that had not even been part of the ICAO technical competition was forceably accepted as an ICAO standard,
Fact (8) US domestic political pressure, given the dominance of US airlines/IATA and avionics manufactures, resulted in 1090ES, the clearly antiquated narrow band system was forceably adopted as the "International" standard, despite the fact that several VDL-4 system were up and running in Europe, a number of major US airports had adopted VDL-4 for tracking aircraft on the ground, and the US military, particularly the Marines, adopted VDL-4 for tracking aircraft on exercise ranges.
Fact (8) As FAA/ Mitre Corp. had done all the initial development based on UAT (CDMA), they stuck with UAT, and there are more GA aircraft on the N- register with UAT than 1090ES, the major reason UAT ADS-B is cheap is because of the size of the market, per unit many times the size of the airline market, and for several other reasons, cheap to produce ---- because the core transceiver is fundamentally the same as current mobile phones. The international market for non-airline 1090ES is sod all, by comparison.
Fact (9) UAT was not "invented" by Mitre Corp., if it was "invented" it was by Qualcomm in US for phones, and has become the basis of current generation mobile phones ---- CDMA.
Fact (10) All the early aviation development, including the Alaska and Ohio Valley trials were using equipment from Apollo Corp., later bought out by UPS -- United Parcel Service., which has something in the order of 500-600 freight aircraft.
Fact (11) A range of services are provided via UAT in USA, that can only be provided over a broadband data-link, it is a complete nonsense to suggest that a mobile phone is a substitute.
Fact (12) It is true that the FAA requires the transponder mode C to remain on UAT equipped aircraft, for TCAS availability/visibility to aircraft that do not have UAT, ie most airline aircraft.
TCAS DOES NOT require ADS-B/C in or out.
Fact (13) During the relevant period of time, for my sins, I held a number of technical appointments, and attended a number of conferences on the subject, supporting VDL-4, which I have long since realised was was an error, because many of us at the time did not understand the technical capabilities of CDMA versus TDMA , the history of mobile phones and the performance of FAA UAT data-links tell the story of why we were wrong, a case of 20/20 vision in hindsight.
And, folks, by the way, Mitre is not a commercial entity, it is a research and development organisation supported by FAA.
UAT is Universal Access Transceiver, which just about describes the intent of the original ICAO technical competition for a future (not the past) broadband service.
Tootle pip!!