Date: Sun, 13 Apr 1997 13:08:13 -0500 (CDT) From: Jim Bryant <jbryant@argus> To: kgor@inetspace.com (Kent S. Gordon) Cc: freebsd-hackers@freebsd.org Subject: Re: question about X.25 drivers Message-ID: <199704131808.NAA06688@argus> In-Reply-To: <199704131555.KAA13761@chess.inetspace.com> from "Kent S. Gordon" at Apr 13, 97 10:55:58 am
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In reply: > From POPmail Sun Apr 13 12:40:10 1997 > X-POP3-Rcpt: jbryant@unix > Return-Path: kgor@chess.inetspace.com > Received: from chess.inetspace.com (chess.inetspace.com [206.50.163.14]) by unix.tfs.net (8.8.5/8.8.5) with ESMTP id KAA14847 for <jbryant@tfs.net>; Sun, 13 Apr 1997 10:50:47 -0500 > Received: (from kgor@localhost) by chess.inetspace.com (8.8.5/8.7.3) id KAA13761; Sun, 13 Apr 1997 10:55:58 -0500 (CDT) > Date: Sun, 13 Apr 1997 10:55:58 -0500 (CDT) > Message-Id: <199704131555.KAA13761@chess.inetspace.com> > From: "Kent S. Gordon" <kgor@inetspace.com> > To: jbryant@tfs.net > In-reply-to: <199704122243.RAA05171@argus> (message from Jim Bryant on Sat, 12 > Apr 1997 17:43:50 -0500 (CDT)) > Subject: Re: question about X.25 drivers > Mime-Version: 1.0 (generated by tm-edit 7.105) > Content-Type: text/plain; charset=US-ASCII > > > may be.. but there are many many many hams around the world > > using AX.25 for packet radio operation... i see uses for such a > > driver under FreeBSD... The newest Linux kernels have recently > > realized the numbers and have done such a driver... > What are the current requirement to operate packet radio equipment in > the US? Under FCC Part 15 rules, on approved equipment, such as the high speed stuff I mentioned, anyone can, unlicensed, and for any legal purpose. Since these Part 15 devices operate on a secodary basis, they must not interfere with, and must accept interference from the primary band users, and in the promising products, it is in the Amateur Radio bands. Keep in mind though that these are spread spectrum devices, and will accept a level of interference, and generally it merely raises the noise floor a little bit for other band users. > > with new spread-spectrum rules, hams in the us will soon be > > using off the shelf equipment for up to T1+ speeds... 115.2k/s > > is now possible using low-cost commercial equipment in the 33cm > > (902-928MHz) band... > Any idea of the expense of this equipment? What type of power/range > is this equipment? Under $500 for the above mentioned commercially made equipment... Part 15 limits these unlicensed devices to 1 watt output power. This is good for line of sight paths. Since the primary band user in these cases is Amateur Radio, the legal upper limit on power for a licensed Amateur with at least a Technician class license is 1500 Watts PEP. This power level can open up such possibilities as troposperic scattering, tropospheric ducting, and other esoteric long distance modes... But generally most people will be running 100 Watts or less, this is still essentially a line of sight band, and there are possible biological effects involved with running high power levels at these frequencies [ever put a frequency counter next to your microwave oven?]... One other thing to note would be that Amateur Radio licensees are prohibited from operating their equipment for for commercial gain. But then again, operating at the 1 Watt Part 15 level, using Part 15 approved equipment, you can do anything you want with it. > > I believe that 10Mbps is soon to be available in the C-Band > > (5.65-5.925GHz); see the FCC ruling for Apple Computers and > > their Part 15 devices in this band... See the FCC's Apple Computers ruling approving these devices for manufacture and sale... In the C-Band, Amateurs regularly get good quality [noise-quieting FM] voice contacts on line of sight paths of over 100 miles on just a few watts with a two foot dish... > Kent S. Gordon > Senior Software Engineer > INetSpace Co. > voice: (972)851-3494 fax:(972)702-0384 e-mail:kgor@inetspace.com Jim -- All opinions expressed are mine, if you | "I will not be pushed, stamped, think otherwise, then go jump into turbid | briefed, debriefed, indexed, or radioactive waters and yell WAHOO !!! | numbered!" - #1, "The Prisoner" jbryant@tfs.net - KC5VDJ 2-meter, 70cm - KPC-3 Plus packet capable
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