Yep. Thats why many folks use a lower gain for their sectors and omnis. ----- Original Message ----- From: "Marlon K. Schafer" <[EMAIL PROTECTED]> To: "WISPA General List" <[email protected]> Sent: Wednesday, November 05, 2008 8:26 PM Subject: Re: [WISPA] Theoretical TVWS coverage
> 16dB by 120* won't have much of a vertical pattern will it? I'd guess > less > than 10*. > marlon > > ----- Original Message ----- > From: "Chuck McCown" <[EMAIL PROTECTED]> > To: "WISPA General List" <[email protected]> > Sent: Wednesday, November 05, 2008 10:43 AM > Subject: Re: [WISPA] Theoretical TVWS coverage > > >> No but they will be about 20 feet high for an H pol 600 MHz slotted >> waveguide 16 dBi 120 degree sector. >> >> ----- Original Message ----- >> From: "Mike Hammett" <[EMAIL PROTECTED]> >> To: "WISPA General List" <[email protected]> >> Sent: Wednesday, November 05, 2008 8:36 AM >> Subject: Re: [WISPA] Theoretical TVWS coverage >> >> >>>I could see 16 dB sectors. Of course they will be large, but that's what >>>it >>> takes at these frequencies. We'll have antennas the same size as the >>> broadcast TV antennas are now (I've seen some over 40' tall). Hopefully >>> a >>> manufacturer can work something out with regards to not having to have >>> 4x >>> 40' sectors on a tower to provide the needed coverage... that could >>> result >>> in some tasty rates. >>> >>> I don't think the number of wifi devices we see is a useful argument. >>> Their >>> response is 3.65 and 5.4 GHz... plenty of new space and no wifi >>> devices. >>> We need to stress the penetration abilities and the need for copious >>> amounts >>> of spectrum that has these penetration abilities. I believe these lower >>> frequencies will help fill in coverage gaps within any given range. We >>> may >>> not have any more range with TVWS vs. existing bands with equal EIRP >>> because >>> of smaller antenna requirements, but buildings and trees no longer make >>> that >>> coverage spotty. >>> >>> >>> ---------- >>> Mike Hammett >>> Intelligent Computing Solutions >>> http://www.ics-il.com >>> >>> >>> >>> -------------------------------------------------- >>> From: "Marlon K. Schafer" <[EMAIL PROTECTED]> >>> Sent: Wednesday, November 05, 2008 8:50 AM >>> To: "WISPA General List" <[email protected]> >>> Subject: Re: [WISPA] Theoretical TVWS coverage >>> >>>> Hmmm >>>> >>>> Just for fun I ran the numbers at 600mhz. >>>> >>>> 20 dB tx from the radio, 16dB tx antenna (probably not at all >>>> reasonable >>>> due >>>> to size and small 50ish* coverage) to a 10 dB cpe antenna. -80 at 50 >>>> miles! >>>> >>>> Same thing with an 8dB (say omni) would be 20 miles at -80. >>>> >>>> The sad part though? We can do that with today's wifi gear! 20 miles >>>> is >>>> pretty easy in the open. >>>> >>>> Now lets run this at the WISPA 20 WATT level. That's 43dB eirp. >>>> >>>> So, 35dB tx power and 8dB omni to 10dB cpe antenna. I get -80 at 100 >>>> miles! >>>> Now we're talkin! >>>> >>>> The next question that has to be answered. What is the receive signal >>>> of >>>> the average TV set these days? What does it need to be able to pick up >>>> a >>>> signal? We need to know that number if we're to come up with a non >>>> interfering OOB level that we can suggest to the FCC. >>>> >>>> This is why people need to join wispa. We have to fight this fight. >>>> They >>>> are still looking at what to do with us it sounds like. We have to be >>>> ready >>>> to go back there again. We need to show them pictures of our areas, >>>> demographics, screen shots of all of the wifi devices we pick up at our >>>> ap's. etc. etc. etc. >>>> >>>> Pretty cool. >>>> marlon >>>> >>>> ----- Original Message ----- >>>> From: "Mike Hammett" <[EMAIL PROTECTED]> >>>> To: "WISPA List" <[email protected]> >>>> Sent: Wednesday, November 05, 2008 5:12 AM >>>> Subject: [WISPA] Theoretical TVWS coverage >>>> >>>> >>>>> Based on TV antenna, it looks like the largest gain CPE will be around >>>>> 10 >>>>> dB for all but the lowest of frequencies. >>>>> >>>>> I just ran a Radio Mobile coverage area using a guesstimate at a white >>>>> spaces system... EIRP of 20 dBm, 16 dBi sector, 10 dBi CPE, -80 dBm >>>>> minimum allowed receive. The range wasn't much more than 2 miles in >>>>> flat >>>>> country land. >>>>> >>>>> With those same measurements with a 36 dBm EIRP, we have 10 miles, but >>>>> terrain comes more into play here. >>>>> >>>>> For the extreme rural areas, this is where tower height comes into >>>>> play. >>>>> For everyone else, this is your foliage beater. In these areas we >>>>> still >>>>> need small cells for bandwidth capacity and interference rejection. >>>>> >>>>> Remember, the only signal levels mentioned were 40 mw for personal >>>>> portable devices. Anything else is just speculation at this point. >>>>> They >>>>> may very well give fixed stations 4 W as they do in all other >>>>> unlicensed >>>>> bands. >>>>> >>>>> >>>>> ---------- >>>>> Mike Hammett >>>>> Intelligent Computing Solutions >>>>> http://www.ics-il.com >>>>> >>>>> >>>>> >>>>> -------------------------------------------------------------------------------- >>>>> WISPA Wants You! Join today! >>>>> http://signup.wispa.org/ >>>>> -------------------------------------------------------------------------------- >>>>> >>>>> WISPA Wireless List: [email protected] >>>>> >>>>> Subscribe/Unsubscribe: >>>>> http://lists.wispa.org/mailman/listinfo/wireless >>>>> >>>>> Archives: http://lists.wispa.org/pipermail/wireless/ >>>> >>>> >>>> >>>> -------------------------------------------------------------------------------- >>>> WISPA Wants You! Join today! >>>> http://signup.wispa.org/ >>>> -------------------------------------------------------------------------------- >>>> >>>> WISPA Wireless List: [email protected] >>>> >>>> Subscribe/Unsubscribe: >>>> http://lists.wispa.org/mailman/listinfo/wireless >>>> >>>> Archives: http://lists.wispa.org/pipermail/wireless/ >>>> >>> >>> >>> -------------------------------------------------------------------------------- >>> WISPA Wants You! Join today! >>> http://signup.wispa.org/ >>> -------------------------------------------------------------------------------- >>> >>> WISPA Wireless List: [email protected] >>> >>> Subscribe/Unsubscribe: >>> http://lists.wispa.org/mailman/listinfo/wireless >>> >>> Archives: http://lists.wispa.org/pipermail/wireless/ >>> >> >> >> >> -------------------------------------------------------------------------------- >> WISPA Wants You! Join today! >> http://signup.wispa.org/ >> -------------------------------------------------------------------------------- >> >> WISPA Wireless List: [email protected] >> >> Subscribe/Unsubscribe: >> http://lists.wispa.org/mailman/listinfo/wireless >> >> Archives: http://lists.wispa.org/pipermail/wireless/ > > > > -------------------------------------------------------------------------------- > WISPA Wants You! Join today! > http://signup.wispa.org/ > -------------------------------------------------------------------------------- > > WISPA Wireless List: [email protected] > > Subscribe/Unsubscribe: > http://lists.wispa.org/mailman/listinfo/wireless > > Archives: http://lists.wispa.org/pipermail/wireless/ > -------------------------------------------------------------------------------- WISPA Wants You! 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