Maybe I should put a couple of pence into this for what ever it's worth For the last four years I have had my ISP hook up via 2.4 gHz A Cisco 350 system over a 15 mile connect at 100 mw. Weather has not been a factor. I use a 36 inch vertically polarized dish . 50 feet of LMR 400 coax to the Cisco transceiver. This is possible because the dish looks down a water shed where the fall off is equal to at least 3 feet per mile. That makes trees disappear so to speak. All of this might be a bit unusual , but it is possible.
I also use 2.4 gHz for Sat TV extention 3 systems using 433 mHz for data and control . My shack is a separate building 50 feet behind the house. The only interference I had on 2.4 gHz was when Santa provided a telephone remote that was a frequenncy hopper on 2.4 gHz. I gave that back to Santa and asked for 900 mHz spread spectrum unit No more interferrence.
And last, I live in a 150 person village 50 miles from all the big city interferrence I see referred to here on the BB
73's
Joe Murray K0VTY Amsat # 860 Area Coordinator for NE ============================== On Mon, 9 Oct 2006 00:47:25 +0100 (BST) Trevor m5aka@yahoo.co.uk writes:
I presume the eventual aim must be world-wide sales to achieve economies of scale. Quite frankly 10 km is a joke as you probably wouldn't even get that hilltop-to-hilltop. In a real-world environment a max range of 1 km would be more likely.
As I read the latest Ofcom Licence Excemption document it looks like these devices may be limited to 100 mW in the UK, see
http://www.ofcom.org.uk/consult/condocs/exemption/exemption.pdf
73 Trevor M5AKA
--- Roger Kolakowski rogerkola@aol.com wrote:
I googled the product with the "50" at the end of the part number
and
several sites came up with "claimed" ranges between 5 and 10
kilometers.
Because the product seems only to be available in the UK I didn't
convert it
to miles but I think it's 3-6 of them.
Roger WA1KAT
----- Original Message ----- From: "Trevor" m5aka@yahoo.co.uk To: "AMSAT BB" amsat-bb@amsat.org Sent: Sunday, October 08, 2006 4:03 PM Subject: [amsat-bb] Re: More Clutter on 2.4 GHz
--- Roger Kolakowski rogerkola@aol.com wrote:
And these radios have a range of 5 to 10 kilometers while you
get to
hold
them up against your head while transmitting!
I didn't see any range figures on the website, I'd have though a
max range
of 1
km (0.6 miles) is more likely.
73 Trevor M5AKA
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joseph Murray wrote:
Maybe I should put a couple of pence into this for what ever it's worth For the last four years I have had my ISP hook up via 2.4 gHz A Cisco 350 system over a 15 mile connect at 100 mw. Weather has not been a factor. I use a 36 inch vertically polarized dish . 50 feet of LMR 400 coax to the Cisco transceiver. This is possible because the dish looks down a water shed where the fall off is equal to at least 3 feet per mile. That makes trees disappear so to speak. All of this might be a bit unusual , but it is possible.
Also illegal. Check the FCC's ERP limits for point-to-point 802.11 and I believe you'll find that what your ISP did for you is breaking the law.
36" dish + 100 mW looks to me like it's way above the ISM band EIRP limits for unlicensed use, since the limit is 100mW EIRP.
(I seem to recall seeing that there was a higher limit for point-to-point, but a 36" dish is going to be enough gain it's going to blow that limit out of the water too.)
But since there's plenty of very public documentation of lots of people doing this, it's obvious the FCC simply doesn't give a damn, or they'd be hunting the web and mailing lists for all the people bragging about their link distances and mailing out Enforcement Action letters.
http://www.engadget.com/2005/07/31/unamplified-wifi-distance-record-set-at-1...
Consider your own setup there just more proof positive that (here in the U.S. at least) the 2.4 ISM band is just a free-for-all that the regulators really don't care about.
By the way, your ISP probably *could* have done that shot legally up at 5.8 GHz with Motorola Canopy or Trango Wireless gear. They get a limit of a full watt EIRP up there. Might have even gotten away with it at 5.3 GHz where they get a 200 mW EIRP limit.
Nate WY0X
At 03:11 AM 10/10/2006, Nate Duehr wrote:
Also illegal. Check the FCC's ERP limits for point-to-point 802.11 and I believe you'll find that what your ISP did for you is breaking the law.
36" dish + 100 mW looks to me like it's way above the ISM band EIRP limits for unlicensed use, since the limit is 100mW EIRP.
Hmm, I thought your base EIRP was 4W (same as it is here) for 2.4 GHz wifi (and probably other SS/high speed data networking), and that under US rules, you could increase that further on point to point links on a sliding scale (we can't, it's 4W for all antenna configurations here).
73 de VK3JED http://vkradio.com
participants (3)
-
joseph Murray -
Nate Duehr -
Tony Langdon