Air-Digital? Ever?

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SCPD

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Hello, I just came across some United traffic, it's been so long since I've listened to Aircraft :) Anyways, my question is, will the VHF high radio system ever move from AM analog to a digital format? It's been AM analog since the 1920's lol ok thanks!
 

SCPD

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It's been discussed a long time. But since the whole world aviation is AM I don't think it will happen very soon - if ever. :)
 

abear27

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Voice change would be very slow to implement... Lots of people nervous about the imact to life safety.

Having said that though, I've noticed digital data bursts from time to time on some of the corporate assigned frequencies. I wonder how well those have worked out?
 

kma371

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Having said that though, I've noticed digital data bursts from time to time on some of the corporate assigned frequencies. I wonder how well those have worked out?
If your talking about 128-132, those are ACARS messages, not voice traffic in a digital mode.
 

abear27

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Yes - Exactly what I was referring to. So it's not so inconceivable that digital voice data might also appear one day...
 

nd5y

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Several years ago the FAA was planning a next generation air traffic control system that included digital voice. I don't know what its current status is.
 

majoco

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Digital voice data? Do you mean digitalised voice?
Trouble with that is you need a very good signal unless there are very robust error correction routines. Light aircraft VFR at low altitudes often have scratchy voice but it's understandable which it wouldn't be if it was digitalised. How would it cope with two aircraft at once - total garble.
There is plenty of satellite based data going back and forth for the over-water routes, listen for an aircraft or controller on HF say "CPDLC" - Controller Pilot Data Link Communications on the Wiki - but they still reserve a normal HF voice backup.
 
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K9WG

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Yes - Exactly what I was referring to. So it's not so inconceivable that digital voice data might also appear one day...
I hope not, at least while I'm flying. Bad enough the local PD has to repeat things because "10-9, you transmissions went digital"...
 
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captaincraig44

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So long as there are humans flying the planes, and needing voice communication with the ground, there will be no digital voice comms in aviation. Additional frequencies are being made available to ease congestion and bleed over through use of 12.5 (US for now) and 8.333 (Europe) KHz channel spacing and radios that don't broadcast out of bandwidth for the smaller channel spacing. There is no conceivable benefit to going digital (especially considering the cost across the board to all users, which would be passed on to the end users ultimately ie you, the passengers on airlines and package shippers) with voice when there will be plenty of radio spectrum available with the smaller channel spacing.
 
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nd5y

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There is no 12.5 kHz channel spacing on VHF air band in the US.
Newer aircraft comm radios have selectable 25 or 8.33 kHz channels. Not 12.5 kHz.
Currently almost everything is 25 kHz spaced. 8.33 kHz spacing was recently allowed for non air traffic control use on certain frequencies.

At some point in the future aircraft communication will be probably digital. Here are some articles about it. Most of these are old and I don't know exactly what the current status is.
Next Generation Air-Ground Communication (NEXCOM)
VHF Data Link - Wikipedia, the free encyclopedia (scroll down to ICAO VDL Mode 3. This says the FAA abandonded it.)
Harris Corporation Presents VDL Mode 3 White Paper During Integrated Communications, Navigation and Surveillance Conference
 
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jaymatt1978

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I honestly don't think digital\ voice will ever be done in AM mode, i t would be totally useless because of the distortion.
 

immelmen

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At some point in the future aircraft communication will be probably digital. Here are some articles about it.
Yeah right, Just like pilots will be allowed adequate rest on overnights, the minimum qualification to be employed by an airline will be increased and pilots will be forced to retire before their age becomes a significant risk.

All of the above have laws mandating there implementation yet none of it has happened and none of it ever will. All three of my overnights this week barely left enough time for four hours in an actual bed trying to sleep in-between 12 hour duty days. real safe.

If airline management and lawmakers have such disregard for safety, the certainly don't care about pretty new digital communication systems so radio geeks can listen to them.(not an insult, Im a radio geek too)

The govt can propose and research it all they want, but when United, Delta, US air jetblue southwest and american all threaten to close there doors because TSO'd digital radios will break a budget that cant even afford enough pilots to staff the airline safely, the idea will be dead before it starts.

It will never happen. Not in any of our lifetimes.
 

majoco

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I really can't think of any good reason why there is a need for ordinary VHF com to go to digital - and it's not your gummint that would mandate the change - ICAO and the ITU would have to be convinced and that's a mighty big hurdle. How could you justify the expense of every aircraft in the world having to fit new radios and all the ATC towers in the world needing a refit too. Total cr@p.
 

nd5y

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I really can't think of any good reason why there is a need for ordinary VHF com to go to digital - and it's not your gummint that would mandate the change - ICAO and the ITU would have to be convinced and that's a mighty big hurdle. How could you justify the expense of every aircraft in the world having to fit new radios and all the ATC towers in the world needing a refit too. Total cr@p.
They are already implementing CPDLC in Europe to replace some voice communications.
EUROCONTROL - Welcome to Link 2000+ Programme Website
EUROCONTROL - Implementing Rule
 

majoco

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CPDLC is fine for what it does, but it doesn't have the immediacy of one-to-one voice radio as the signal goes up to a satellite, then down to the controller etc etc.
It was originally deployed in the South Pacific in the late 1990s and was later extended to the North Atlantic. FANS-1/A is an ACARS based service and, given its oceanic use, mainly uses satellite communications provided by the Inmarsat Data-2 (Classic Aero) service.
from the Wiki. So we have had CPDLC here for quite a while, ever since the 747-400 had FANS. But the pilot and the controller still have to type in the data for the preformed message. Fine for HF high level stuff, but no good for local control for an airport.

...and you still have to have an SSB HF service - you can't have CPDLC on it's own.
 
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