Hi Guys,
I am forwarding this email to the Eagle amsat list, which consists of just about everyone involved with our new satellite effort. Hopefully the right person will respond so we can work together on this issue.
73, Drew KO4MA Amsat-NA VP Operations LM 2332
----- Original Message ----- From: Paul Toth-NA4AR To: [email protected] Cc: Dave Anderson Sent: Saturday, November 04, 2006 5:53 PM Subject: 3.3 GHz ARBA Band Plan
Drew...
A new group call ARBA, the Amateur Radio Broadband Alliance, has formed in the ashes of ARRL's HSMM Working Group. Both Dave Anderson and I are part of ARBA.
One of the things we are working on is the development of a band plan for the 3.3 GHz to 3.5 GHz allocation. I know that AMSAT is planning something for Eagle that makes use of the 3.3GHz band. Would you please review the chart below and provide some input to allow this band plan to peacefully co-exut with whatever AMSAT is planning? Please feel free to share with others in the AMSAT leadership.
73 de Paul-NA4AR
ARBA BAND PLAN 3.3 GHZ - 3.5 GHz
3300-3310 3310-3330
3330-3340 3340-3350 3350-3370
3370-3380 3380-3390 3390-3410
3410-3420 3420-3430 3430-3450
3450-3460 3460-3470 3470-3490
3490-3500
Andrew Glasbrenner wrote:
One of the things we are working on is the development of a band plan for the 3.3 GHz to 3.5 GHz allocation. I know that AMSAT is planning something for Eagle that makes use of the 3.3GHz band. Would you please review the chart below and provide some input to allow this band plan to peacefully co-exut with whatever AMSAT is planning?
I would like to know what other uses are proposed for this band. Are they narrowband? Wideband? Digital or analog? Long range or short range? Etc.
This would be helpful in the design of modulation methods as well as bandwidths and frequency selection to minimize or eliminate mutual interference.
The biggest issue is power spectral density. An unmodulated carrier component often causes trouble because it's a spectral line with theoretically infinite power spectral density. On the commercial satellite bands, which historically were shared with terrestrial point-to-point links, the FCC imposes power spectral limits that effectively ban discrete carriers. We don't have those regulations on the ham bands, but we still want to avoid interference.
The usual fix is scrambling or spreading, but this increases complexity so we'd like to know if we have to do it.
Phil
Hi Phil,
Short range (~20 mile) point-to-point and point-to-multipoint high speed data is the primary purpose.
QPSK, 16QAM and 64QAM will be the modulations, depending on speed requirements.
Depending on speed required, it can very from 5mhz (12mb/sec) to 10mhz (24mb/sec) in micro channel mode.
The standard is 54mb/sec channel using 20mhz of spectrum.
Super channel usage at 108mb/sec is 40mhz of spectrum (bonds 2 20mhz channels together).
BTW, this follows the exact same specifications as the IEEE 802.11a modulation system which operates in the 5ghz part 15 UNNI spectrum.
The only change/addition is the ability to use micro sized channels, where as 802.11a does not permit this functionality.
Seeya, Dave KG4YZY www.aprsfl.net
>This would be helpful in the design of modulation methods >as well as bandwidths and frequency selection to minimize >or eliminate mutual interference. > >The biggest issue is power spectral density. An >unmodulated carrier component often causes trouble >because it's a spectral line with theoretically infinite >power spectral density. On the commercial satellite >bands, which historically were shared with terrestrial >point-to-point links, the FCC imposes power spectral >limits that effectively ban discrete carriers. We don't >have those regulations on the ham bands, but we still >want to avoid interference. > >The usual fix is scrambling or spreading, but this >increases complexity so we'd like to know if we have to do it.
participants (3)
-
Andrew Glasbrenner -
Dave Anderson -
Phil Karn