Thanks for the explanation Jack, and thanks to others for their input. The radios I am finding are agile down to 5 MHz. So the example I used would put the center of a sub channel 1 device at 2407. If it is a 10MHz device, their very well could be spurious emissions below 2400, but not likely. With a 5 MHz channel size, the emissions should be well above the band edge.
I know there is a definition of frequency hopping devices, and of 802.11 specs. Just because there are 11 channels designated for the US, one doesn't have to comply with that particular channel spacing, as long as the device is not transmitting outside the band, either lower or upper, right? When the 802.11 devices first came out, we were able to "tune" them to use the amateur allocation at 2.4. We were able to build a wireless network for ham use on ham frequencies. And just as a point of reference, I DO NOT feel comfortable changing the country code on the interface to allow additional frequency agility. I might however try a 5 MHz channel setting at 2407 unless I'm told one must adhere to the US channel spacing. I would use a spectrum analyzer and look at the signal. Now where did my P3D stuff go anyway? Mike At 02:08 PM 9/9/2009, you wrote: >Be Careful!! Selecting another Country Code is unwise if you are >going to operate near the band edges because of "spurs" (spurious emissions). > >Here's an explanation. > >A 20-MHz (or 10 MHz or 5 MHz) channel is really more than 20 MHz (or >10 MHz or 5 MHz) wide when you consider that all of the 20 MHz (10, >5) energy does not remain within the channel. A little bit of it >"spills over" outside the channel. That spill-over can cause >interference to the legal users of the frequency space just below or >above the band. If they complain and the FCC investigates why you >are on center frequency that is too close to the edge of the band >with spurs spilling over outside the band then you are likely >looking at a pretty stiff fine. > >During the equipment certification process (anyone remember that?) >spurious emission levels are tested and verified to be below a level >that will cause an interference problem but if you select a non-US >country code and choose a center frequency too close to the band >edge with spurs extending outside the band at too high a level than >you will have no one to blame but yourself. > >So be careful. If you (Mike) select a 2406 center frequency with a >10-MHz wide channel, the signal doesn't necessarily remain "within >the definition of Channel 1". The only way to be sure that your >spurious emission levels are legal is to test that combination in a >lab and measure the spurious levels at each frequency. > >Your idea of using narrower channels is OK (although keep in mind >the throughput capacity of the narrower channels is less than a >standard-width channel) - just don't use a narrower channel that is >too near the edge of a band. How near is too near?? Lab testing is >the only way to find out. > >jack > > >Cameron Kilton wrote: >> >>I have you tried just setting your MT to a different country and see if >>it becomes available? I know brazil gives you access to above the 2462 >>limit which is nice because we can you much more above that in >>unlicensed spectrum. >> >>-Cameron >> >>-----Original Message----- >>From: <mailto:wireless-boun...@wispa.org>wireless-boun...@wispa.org >>[mailto:wireless-boun...@wispa.org] On >>Behalf Of Mike >>Sent: Wednesday, September 09, 2009 2:07 PM >>To: WISPA General List >>Subject: Re: [WISPA] 2.4 Frequency coordination >> >>And when I look at wireless info, I see this: >> >>2ghz-b-channels=2412:0,2417:0,2422:0,2427:0,2432:0,2437:0,2442:0,2447:0, >> 2452:0,2457:0,2462:0 >> >>So the Extended Frequency License will allow me to modify these? Any >>other way? I'd hate to have to buy an extra license for every CPE >>device. I would however buy one for the AP. It may steer me away >>from using MT for these customer sites IF I decide to try this. >> >>Mike >> >>******************************* >>Good idea, but it won't let me. I receive this message: >> >>message=bad band and/or channel, see 'wireless info' for supported >>channels;code=4 >> >>Apparently, it IS possible with the Wili cards, but still don't have >>a total answer to my query. Can anybody help a fellow WISPA member? >> >>Hasn't anybody thought about doing this or is doing this? You could >>squeeze a couple more sectors on a tower if this is possible. >> >>Mike >> >>At 08:36 AM 9/9/2009, you wrote: >> >>> >>>I believe you can but you'll need to use the CLI >>> >>>Int wireless set wlan1 frequency=2406 >>> >> >> >> >> >> >> >>> >>>On 9/9/09, Mike <mailto:m...@aweiowa.com><m...@aweiowa.com> wrote: >>> >>>> >>>>I have some questions on the frequency agility of Mikrotik >>>> >> >>equipment, >> >>>> >>>>FCC regs, and frequency coordination. >>>> >>>>There are 3 non-overlapping channels at 2.4G; 1, 6 and 11. That >>>>makes an assumption we are using 20MHz channel size. >>>> >>>>Some of the newer radios can run 10MHz and 5MHz channel sizes. >>>> >>>>Using the RouterOS interface, the only choice for channel selection >>>>is the center frequency of each of the 11 channels available in the >>>>US. So, the only choice, say for channel 1 is 2412MHz. When using >>>>20MHz channel size, the RF will occupy 2401 to 2423 according to FCC >>>>rules, on channel 1. >>>> >>>>If I want to deploy a device capable of running 10MHz channel width, >>>>is there a way to set the channel frequency to say 2406? The signal >>>>would occupy 2401 to 2411, and still be within the definition of >>>> >> >>channel 1. >> >>>> >>>>Would a Mikrotik Extended Frequency License allow this frequency >>>>agility? Would every CPE connected to such an AP also be required >>>> >> >>to >> >>>> >>>>have the license? Is this within FCC rules? >>>> >>>>Are any of you doing this? If so, what equipment are you using? >>>> >>>>Thanks! Mike >>>> >>>> >>>> >>>> >>>> >>>> >> >>------------------------------------------------------------------------ >>-------- >> >>>> >>>>WISPA Wants You! Join today! >>>><http://signup.wispa.org/>http://signup.wispa.org/ >>>> >>>> >> >>------------------------------------------------------------------------ >>-------- >> >>>> >>>>WISPA Wireless List: <mailto:wireless@wispa.org>wireless@wispa.org >>>> >>>>Subscribe/Unsubscribe: >>>><http://lists.wispa.org/mailman/listinfo/wireless>http://lists.wispa.org/mailman/listinfo/wireless >>>> >>>>Archives: >>>><http://lists.wispa.org/pipermail/wireless/>http://lists.wispa.org/pipermail/wireless/ >>>> >>>> >>> >>> >>>-- >>>Josh Luthman >>>Office: 937-552-2340 >>>Direct: 937-552-2343 >>>1100 Wayne St >>>Suite 1337 >>>Troy, OH 45373 >>> >>>"When you have eliminated the impossible, that which remains, however >>>improbable, must be the truth." >>>--- Sir Arthur Conan Doyle >>> >>> >>>----------------------------------------------------------------------- >>> >> >>--------- >> >>> >>>WISPA Wants You! Join today! >>><http://signup.wispa.org/>http://signup.wispa.org/ >>>----------------------------------------------------------------------- >>> >> >>--------- >> >>> >>>WISPA Wireless List: <mailto:wireless@wispa.org>wireless@wispa.org >>> >>>Subscribe/Unsubscribe: >>><http://lists.wispa.org/mailman/listinfo/wireless>http://lists.wispa.org/mailman/listinfo/wireless >>> >>>Archives: >>><http://lists.wispa.org/pipermail/wireless/>http://lists.wispa.org/pipermail/wireless/ >>> >> >> >> >> >> >>------------------------------------------------------------------------ >>-------- >>WISPA Wants You! Join today! >><http://signup.wispa.org/>http://signup.wispa.org/ >>------------------------------------------------------------------------ >>-------- >> >>WISPA Wireless List: <mailto:wireless@wispa.org>wireless@wispa.org >> >>Subscribe/Unsubscribe: >><http://lists.wispa.org/mailman/listinfo/wireless>http://lists.wispa.org/mailman/listinfo/wireless >> >>Archives: >><http://lists.wispa.org/pipermail/wireless/>http://lists.wispa.org/pipermail/wireless/ >> >> >> >>-------------------------------------------------------------------------------- >>WISPA Wants You! Join today! >><http://signup.wispa.org/>http://signup.wispa.org/ >>-------------------------------------------------------------------------------- >> >>WISPA Wireless List: <mailto:wireless@wispa.org>wireless@wispa.org >> >>Subscribe/Unsubscribe: >><http://lists.wispa.org/mailman/listinfo/wireless>http://lists.wispa.org/mailman/listinfo/wireless >> >>Archives: >><http://lists.wispa.org/pipermail/wireless/>http://lists.wispa.org/pipermail/wireless/ >> >> >> > > >-- >Jack Unger - President, Ask-Wi.Com, Inc. >Author - "Deploying License-Free Wireless WANs" >Serving the Broadband Wireless Industry Since 1993 ><http://www.ask-wi.com>www.ask-wi.com 818-227-4220 ><mailto:jun...@ask-wi.com>jun...@ask-wi.com > > > > > > > >-------------------------------------------------------------------------------- >WISPA Wants You! 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