FAA Plans to Change to Radios with 8.33 MHz spacing?

On Thursday, April 11, 2013 8:12:58 PM UTC-6, Bob Kuykendall wrote:
On Apr 11, 2:33*pm, "Paul Remde" wrote:

... *At a recent soaring

seminar someone stated that they thought the FAA was

going to require radios with the 8.33 MHz spacing starting in 2020.



I will be someewhat surprised if we get to 2020 and we are still using

what we think of today as "aircraft radios." I think that by then we

will find that the bandwidth dedicated to those old grampa boxes will

have been divided up and auctioned off, and we will be communicating

over a system based on mobile phone infrastructure.



If I'm wrong, I'll buy you a beer at the 2020 SSA convention. Offer

limited to the first 24 "I told ya sos."



Thanks, Bob K.

I've got a feeling you'll win that bet. By 2020, the 2 meter AM simplex air-band will be nearly 100 years old and very likely the last of its kind in use. It's way past its use-by date. There are better ways to communicate..

On Friday, April 12, 2013 5:06:53 AM UTC+2, Bill D wrote:
On Thursday, April 11, 2013 8:12:58 PM UTC-6, Bob Kuykendall wrote:

On Apr 11, 2:33*pm, "Paul Remde" wrote:



... *At a recent soaring



seminar someone stated that they thought the FAA was



going to require radios with the 8.33 MHz spacing starting in 2020.







I will be someewhat surprised if we get to 2020 and we are still using



what we think of today as "aircraft radios." I think that by then we



will find that the bandwidth dedicated to those old grampa boxes will



have been divided up and auctioned off, and we will be communicating



over a system based on mobile phone infrastructure.







If I'm wrong, I'll buy you a beer at the 2020 SSA convention. Offer



limited to the first 24 "I told ya sos."







Thanks, Bob K.



I've got a feeling you'll win that bet. By 2020, the 2 meter AM simplex air-band will be nearly 100 years old and very likely the last of its kind in use. It's way past its use-by date. There are better ways to communicate.

I got a feeling you guys will LOSE that bet. The installed base is too big, worldwide, and entrenched to change that quickly - so unless you want to limit yourself to a flarm-like comm system that only works with other similarly-equipped aircraft, and never plan to talk to ATC or other aircraft, you will be stuck with an antique VHF-AM radio.

Plus, good luck with a ground-based cellular comm system over the mid-Atlantic, or the Kalahari desert!

Not to say that a specialized, glider-only comm system couldn't be developed (again, along the FLARM model), but now bandwidth again becomes a problem..

Kirk
66

In article Bob Kuykendall writes:
On Apr 11, 2:33=A0pm, "Paul Remde" wrote:
... =A0At a recent soaring
seminar someone stated that they thought the FAA was
going to require radios with the 8.33 MHz spacing starting in 2020.

If they said that, they were confused. Especially since 123.3 and
123.5 are only 0.2 MHz apart. It's 8.33 kHz.

I see it as taking quite a while before it would become mandatory.
How long did it take to make the tighter frequency tolerances mandatory
when 720 channel radios became the norm? Quite a few years, as I recall.


I will be someewhat surprised if we get to 2020 and we are still using
what we think of today as "aircraft radios." I think that by then we
will find that the bandwidth dedicated to those old grampa boxes will
have been divided up and auctioned off, and we will be communicating
over a system based on mobile phone infrastructure.

This I don't believe. First off, auctioning off the bandwidth would
not work, since aviation is international, and includes those airliners
that come from other countries that are not into auctioning off spectrum.
A major change would involve international agreements and take some time.

Second, a mobile phone infrastructure system would be using ground
based cell towers (which are not reachable in much of the world, and
not even at an airstrip where I have flown). Also, cellular systems
work by frequency reuse, which requires the limited range of the cell
sites to the mobile phones to make reuse possible within a reasonable
distance. When you are at 10,000 feet, the horizon is about 120 miles
away, so those radio signals will go a long ways, and frequency reuse
becomes more difficult.

Third, there are folks who will reasonably not want their aircraft
communications to be dependent on ground based resources. Presently
even with no functioning ground resources for hundreds of miles, an
aircraft radio on the ground can communicate with one in the air.

Alan

Bob,

I don't believe that we switch to GSM or whatever.

1. For none of the digital communication techniques it was possible to
find a global frequency range.

2. The relative speed is too high. To my knowledge the highest speed to
which a digital communication system is certified is 500 km/h (310 mph).
This is GSM-R, Global System for Mobile Communications - Railway or
GSM-Railway, for details see Wikipedia.
500km/h would be good enough for us but not for others. We can forget it
in aviation thanks to Doppler effect.

Bear


On 12.04.2013 04:12, Bob Kuykendall wrote:
On Apr 11, 2:33 pm, "Paul Remde" wrote:
... At a recent soaring
seminar someone stated that they thought the FAA was
going to require radios with the 8.33 MHz spacing starting in 2020.

I will be someewhat surprised if we get to 2020 and we are still using
what we think of today as "aircraft radios." I think that by then we
will find that the bandwidth dedicated to those old grampa boxes will
have been divided up and auctioned off, and we will be communicating
over a system based on mobile phone infrastructure.

If I'm wrong, I'll buy you a beer at the 2020 SSA convention. Offer
limited to the first 24 "I told ya sos."

Thanks, Bob K.

On Saturday, April 13, 2013 12:26:36 PM UTC-6, Bear wrote:
Bob,



I don't believe that we switch to GSM or whatever.



1. For none of the digital communication techniques it was possible to

find a global frequency range.



2. The relative speed is too high. To my knowledge the highest speed to

which a digital communication system is certified is 500 km/h (310 mph).

This is GSM-R, Global System for Mobile Communications - Railway or

GSM-Railway, for details see Wikipedia.

500km/h would be good enough for us but not for others. We can forget it

in aviation thanks to Doppler effect.



Bear

So, how is digital communication with 17,000 mph satellites possible with Doppler effects?

Nobody suggested GSM as an alternative to a global aviation-specific digital communications protocol.

What is your proposal?


So, how is digital communication with 17,000 mph satellites possible with Doppler effects?

Nobody suggested GSM as an alternative to a global aviation-specific digital communications protocol.

The present 2-meter AM air-band "Party line" originated as a military system in the biplane era. Today's military has many highly secure digital communication nets used for airborne operations from close air support to drone attacks.

The DOD likes the idea of using COTS products so wherever possible, they push military technology into the commercial domain to spread R&D costs and reduce the price they pay per unit. That's where the air-band replacement will come from.

Why would the FAA and ICAO want to do this? Bandwidth. Digital communication uses spectrum far more efficiently and it eliminates channel clutter so pilots hear just what they need to hear.

On Saturday, April 13, 2013 2:13:33 PM UTC-6, Bear wrote:
What is your proposal?





So, how is digital communication with 17,000 mph satellites possible with Doppler effects?



Nobody suggested GSM as an alternative to a global aviation-specific digital communications protocol.

http://en.wikipedia.org/wiki/Orthogo...n_multiplexing

From wikipedia:

Summary of advantages
*High spectral efficiency as compared to other double sideband modulation schemes, spread spectrum, etc.
*Can easily adapt to severe channel conditions without complex time-domain equalization.
*Robust against narrow-band co-channel interference.
*Robust against intersymbol interference (ISI) and fading caused by multipath propagation.
*Efficient implementation using Fast Fourier Transform (FFT).
*Low sensitivity to time synchronization errors.
*Tuned sub-channel receiver filters are not required (unlike conventional FDM).
*Facilitates single frequency networks (SFNs); i.e., transmitter macrodiversity.


On Saturday, April 13, 2013 1:13:33 PM UTC-7, Bear wrote:
What is your proposal?





So, how is digital communication with 17,000 mph satellites possible with Doppler effects?



Nobody suggested GSM as an alternative to a global aviation-specific digital communications protocol.

The satellite ain't goin' 17,000 mph with respect to the ground station.
Doppler will be small with short transmissions.


"Bill D" wrote in message
...
On Saturday, April 13, 2013 12:26:36 PM UTC-6, Bear wrote:
Bob,



I don't believe that we switch to GSM or whatever.



1. For none of the digital communication techniques it was possible to

find a global frequency range.



2. The relative speed is too high. To my knowledge the highest speed to

which a digital communication system is certified is 500 km/h (310 mph).

This is GSM-R, Global System for Mobile Communications - Railway or

GSM-Railway, for details see Wikipedia.

500km/h would be good enough for us but not for others. We can forget it

in aviation thanks to Doppler effect.



Bear

So, how is digital communication with 17,000 mph satellites possible with
Doppler effects?

Nobody suggested GSM as an alternative to a global aviation-specific
digital communications protocol.

In article Bear writes:
Bob,

I don't believe that we switch to GSM or whatever.

1. For none of the digital communication techniques it was possible to
find a global frequency range.

Seems unlikely. Are you saying that there is no VHF or UHF band available
worldwide?


2. The relative speed is too high. To my knowledge the highest speed to
which a digital communication system is certified is 500 km/h (310 mph).
This is GSM-R, Global System for Mobile Communications - Railway or
GSM-Railway, for details see Wikipedia.
500km/h would be good enough for us but not for others. We can forget it
in aviation thanks to Doppler effect.

Bear

Hmmm. The prime communications channels with the space station are digital.

DirecTV and Dish Network are digital. The network feeds to your TV stations
are digital via satellite. The "cable channels" are fed digitally to your
cable companies.

GPS is digital. It seems to be popular in aircraft.

Alan