you'll find is that most of the more sensitive facilities would rather not have
transmitters of any kind anywhere near them--even their own.
At some facilities, the vehicular traffic within the facility is *all* diesel, to
eliminate ignition noise--which is particularly bothersome for pulsar
observations at 74 and 150mhz.
Given that cognitive radios will have a plenitude of tiny silicon microchip brains, they
can (at least as a starting point), avoid the ITU-agreed radio astronomy frequencies, listed
here:
Specific Protected radio astronomy frequencies:
- 13.36-13.41 MHz
- 25.55-25.67 MHz
- 38.0-38.25 MHz
- 73-74.6 MHz
- 406.1-410 MHz
- 1400-1427 MHz [Hydrogen Line at 1420.406 MHz]
- Radio Astronomy on a secondary basis 1610-1626.5 MHz
- 1660.5-1668.4 MHz [Hydroxyl Spectral Line 1665 and 1667 MHz]
- Radio Astronomy on a secondary basis 1718.8-1722.2 MHz
- 2690-2700 MHz
- 4825-4865, 4950-4990 MHz
- Formaldehyde Line 14,470-14,500 MHz
- 31.2-31.3, 36.43-36.5, 42.5-43.5, 48.94-49.04 GHz
- 97.88-98.08, 140.69-140.98, 142-149 GHz
- 262.24-262.76, 265-275 GHz
John Gilmore wrote:
This msg is about "Cognitive" radios, not just software-defined radios. Cognitive radios make major adjustments in their transmission and reception behavior, based on observing the local radio environment.
Cornell makes some good points. There are small areas of the spectrum where NOBODY can transmit, so that passive receivers such as radiotelescopes can receive.
I've been advocating for defining a simple scheme for "posting" frequency bands with machine-readable signs (like the "No Hunting" signs found on trees and fences). It would have to be simple enough that every cognitive radio transmitter could implement it, listening to learn the rules of the neighborhood before transmitting. The radio astronomers could "fence off" their frequencies and physical locations by occasionally transmitting these "No Trespassing" signs on a nearby coordinating frequency. Anyone interested?
John
Date: Tue, 22 Feb 2005 08:03:02 -0800 From: Seth David Schoen <[EMAIL PROTECTED]> To: John Gilmore <[EMAIL PROTECTED]>
John Gilmore writes:
[Have we talked recently to folks at FCC about this? Let's check in and
see what we can learn. ...
This is presumably going to be a rule in ET Docket 03-108.
There's some continuing ex parte activity there.
Here's a reply comment critical of us and PK from the radio astronomers at Cornell.
http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?native_or_pdf=pdf&id_document=6516210510
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