[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: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Theoretical TVWS coverage
I would imagine you will be able to have receive signals down to almost -95 or -98 dBm. Remember this should be relatively clean spectrum (and hopefully stay that way). According to Sascha the current white space devices that were in testing were supposed to receive signals 30 db below the signal required to receive a DTV signal. Thank You, Brian Webster -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Mike Hammett Sent: Wednesday, November 05, 2008 8:12 AM To: WISPA List 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: wireless@wispa.org 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: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Theoretical TVWS coverage
I chose -80 because in current operations, anything less isn't really utilizing the available spectrum. I try to engineer all of my links for full modulation. Anything less is a waste. I know -80 isn't full modulation, but it's not far away. Perhaps with more clean spectrum, receivers will be better, but the same was said about 3650 and that hasn't materialized. When browsing around on Channel Master's site that one of their DACs required -83 to -5 dBm with a SNR of 15 dB to operate. If TVWS devices are supposed to receive 30 dB below TV, then we should be able to receive signals that are -113 dBm. -- Mike Hammett Intelligent Computing Solutions http://www.ics-il.com -- From: "Brian Webster" <[EMAIL PROTECTED]> Sent: Wednesday, November 05, 2008 7:20 AM To: "WISPA General List" Subject: Re: [WISPA] Theoretical TVWS coverage > I would imagine you will be able to have receive signals down to > almost -95 > or -98 dBm. Remember this should be relatively clean spectrum (and > hopefully > stay that way). According to Sascha the current white space devices that > were in testing were supposed to receive signals 30 db below the signal > required to receive a DTV signal. > > > > Thank You, > Brian Webster > > > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Behalf Of Mike Hammett > Sent: Wednesday, November 05, 2008 8:12 AM > To: WISPA List > 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: wireless@wispa.org > > 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: wireless@wispa.org > > 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: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Theoretical TVWS coverage
Obviously we are still speculating here because the rules are certainly not clear. With technology development and the results I am hearing from those who are using WiMax equipment, I would say that -90 should be a safe signal level to use and still have good modulation rates. To assume TVWS will always get full modulation and then try to also claim that it is the most cost affective way to reach the low population density areas will be difficult. Site footprints have to be looked at lowest modulation rates because that RF signal is still out there. It is important to look at how far that signal will still be traveling even though you can't achieve full rates. The transmitted carrier will still be out there as part of the contour for your base and must be considered in the process of "registration". Your footprint will still be very large even though you don't prefer to operate at the slower rates, which for others would be "noise". To design a network with site footprints and spacing to achieve only full rates is an inefficient of spectrum because your undesired signal is still traveling a great distance preventing others from reusing that same spectrum. Thank You, Brian Webster -Original Message- From: Mike Hammett [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 05, 2008 8:29 AM To: [EMAIL PROTECTED]; WISPA General List Subject: Re: [WISPA] Theoretical TVWS coverage I chose -80 because in current operations, anything less isn't really utilizing the available spectrum. I try to engineer all of my links for full modulation. Anything less is a waste. I know -80 isn't full modulation, but it's not far away. Perhaps with more clean spectrum, receivers will be better, but the same was said about 3650 and that hasn't materialized. When browsing around on Channel Master's site that one of their DACs required -83 to -5 dBm with a SNR of 15 dB to operate. If TVWS devices are supposed to receive 30 dB below TV, then we should be able to receive signals that are -113 dBm. -- Mike Hammett Intelligent Computing Solutions http://www.ics-il.com -- From: "Brian Webster" <[EMAIL PROTECTED]> Sent: Wednesday, November 05, 2008 7:20 AM To: "WISPA General List" Subject: Re: [WISPA] Theoretical TVWS coverage > I would imagine you will be able to have receive signals down to > almost -95 > or -98 dBm. Remember this should be relatively clean spectrum (and > hopefully > stay that way). According to Sascha the current white space devices that > were in testing were supposed to receive signals 30 db below the signal > required to receive a DTV signal. > > > > Thank You, > Brian Webster > > > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Behalf Of Mike Hammett > Sent: Wednesday, November 05, 2008 8:12 AM > To: WISPA List > 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: wireless@wispa.org > > 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
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" 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: wireless@wispa.org > > 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: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
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" 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" > 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: wireless@wispa.org >> >> 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: wireless@wispa.org > > 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: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Theoretical TVWS coverage
On Wed, Nov 05, 2008 at 06:50:45AM -0800, Marlon K. Schafer wrote: > 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. 2.4 is of limited use in scenes like this, where 90% of the houses are not visible from a hilltop or tower. http://www.f64.nu/albums2007/album114/DSC1595.jpg I don't need 50 miles. It would be overloaded in short order unless I charged by the byte like the cell companies. I want 2-6 miles and good woods penetration. I'm kinda pleased the have the new frequencies as unlicensed. Sure licensed lite would be nice, but unlicensed means inexpensive commodity equipment. That used to mean junk, but now, it's now there are diamonds in the rough developing for commodity based unlicensed equipment. > 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" > 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: wireless@wispa.org > > > > 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: wireless@wispa.org > > Subscribe/Unsubscribe: > http://lists.wispa.org/mailman/listinfo/wireless > > Archives: http://lists.wispa.org/pipermail/wireless/ -- /* Jason Philbrook | Midcoast Internet Solutions - Wireless and DSL KB1IOJ| Broadband Internet Access, Dialup, and Hosting http://f64.nu/ | for Midcoast Mainehttp://www.midcoast.com/ */ WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
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" 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" > 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" >> 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 >>> >>> >>> >>> ---
Re: [WISPA] Theoretical TVWS coverage
> I would say that -90 should be a safe signal > level to use and still have good modulation rates. I'm a little confused on that statement. With our Aperto live testing a few years back (pre-wimax), the best modulation we could get was qam16 at the -85 levels. And that was before considering the 25db SNR required above the noise. What good is sensitivity, if the noise ends up being higher than the sensitivity? Sure TV broadcasters shot for -120, but thats one direction broadcasting, with no expense cut for technology. Tom DeReggi RapidDSL & Wireless, Inc IntAirNet- Fixed Wireless Broadband - Original Message - From: "Brian Webster" <[EMAIL PROTECTED]> To: "Mike Hammett" <[EMAIL PROTECTED]>; "WISPA General List" Sent: Wednesday, November 05, 2008 8:46 AM Subject: Re: [WISPA] Theoretical TVWS coverage > > Obviously we are still speculating here because the rules are certainly > not > clear. With technology development and the results I am hearing from those > who are using WiMax equipment, I would say that -90 should be a safe > signal > level to use and still have good modulation rates. To assume TVWS will > always get full modulation and then try to also claim that it is the most > cost affective way to reach the low population density areas will be > difficult. Site footprints have to be looked at lowest modulation rates > because that RF signal is still out there. It is important to look at how > far that signal will still be traveling even though you can't achieve full > rates. The transmitted carrier will still be out there as part of the > contour for your base and must be considered in the process of > "registration". Your footprint will still be very large even though you > don't prefer to operate at the slower rates, which for others would be > "noise". > > To design a network with site footprints and spacing to achieve only full > rates is an inefficient of spectrum because your undesired signal is still > traveling a great distance preventing others from reusing that same > spectrum. > > > > Thank You, > Brian Webster > > > -----Original Message- > From: Mike Hammett [mailto:[EMAIL PROTECTED] > Sent: Wednesday, November 05, 2008 8:29 AM > To: [EMAIL PROTECTED]; WISPA General List > Subject: Re: [WISPA] Theoretical TVWS coverage > > > I chose -80 because in current operations, anything less isn't really > utilizing the available spectrum. I try to engineer all of my links for > full modulation. Anything less is a waste. I know -80 isn't full > modulation, but it's not far away. Perhaps with more clean spectrum, > receivers will be better, but the same was said about 3650 and that hasn't > materialized. > > When browsing around on Channel Master's site that one of their DACs > required -83 to -5 dBm with a SNR of 15 dB to operate. If TVWS devices > are > supposed to receive 30 dB below TV, then we should be able to receive > signals that are -113 dBm. > > > -- > Mike Hammett > Intelligent Computing Solutions > http://www.ics-il.com > > > > -- > From: "Brian Webster" <[EMAIL PROTECTED]> > Sent: Wednesday, November 05, 2008 7:20 AM > To: "WISPA General List" > Subject: Re: [WISPA] Theoretical TVWS coverage > >> I would imagine you will be able to have receive signals down to >> almost -95 >> or -98 dBm. Remember this should be relatively clean spectrum (and >> hopefully >> stay that way). According to Sascha the current white space devices that >> were in testing were supposed to receive signals 30 db below the signal >> required to receive a DTV signal. >> >> >> >> Thank You, >> Brian Webster >> >> >> -Original Message- >> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] >> Behalf Of Mike Hammett >> Sent: Wednesday, November 05, 2008 8:12 AM >> To: WISPA List >> 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
Re: [WISPA] Theoretical TVWS coverage
That's my point, the noise will be much lower in these bands if things are deployed in a sane way. Wimax gear has receive sensitivity in the -93 to -98 range and from the reports I have heard, works very well at those levels. While a WISP may be trying to set a network up for max modulation, the FCC will look at the contour a whitespace station creates in a much different way. It will be based on the RF energy it creates, not the signal margin above the receiver threshold needed to achieve the better modulation rate. If you map a realistic footprint based on a signal level down as low as -98, that might be closer to the contour they will create in their geolocation database. This contour will be the one they use to see if you will encroach on any TV contour or other protected/semi protected users of the spectrum. The WISP operator will not get to determine the contour limits based on their own desired modulation rate. I was saying that you should be able to use the -90 number in your mapping to get a more realistic sense of where the signal will be going and what size polygon you might have to deal with as you register it in a geolocation database. Remember, even though you may not agree that a particular signal level is adequate for your purposes at a certain level, the signal that still remains on the air at the lower levels, will be an interfering/undesired signal to all other systems. The FCC is charged with managing the total signal emitted, it's affects over distance, and the other users of the spectrum. They have the big picture to look at, while as a WISP it can be easy to overlook those other factors. I am not sure what the signal level will be that the FCC determines must be protected for TV receivers, but whatever that number is you would be wise to do RF plots that show signal down to that level. It may not be useable as a data network but it will certainly be able to bother TV reception at that level. WISP use of whitespaces will be a secondary use to LICENSED users of the band. And homeowners with off air TV reception will be considered licensed in this case. That is a different mindset from what most are used to. It will create the need for different thinking when planning a network. This is not bad news, just a new and different way to think about your RF planning. Thank You, Brian Webster -Original Message- From: Tom DeReggi [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 05, 2008 3:41 PM To: [EMAIL PROTECTED]; WISPA General List Subject: Re: [WISPA] Theoretical TVWS coverage > I would say that -90 should be a safe signal > level to use and still have good modulation rates. I'm a little confused on that statement. With our Aperto live testing a few years back (pre-wimax), the best modulation we could get was qam16 at the -85 levels. And that was before considering the 25db SNR required above the noise. What good is sensitivity, if the noise ends up being higher than the sensitivity? Sure TV broadcasters shot for -120, but thats one direction broadcasting, with no expense cut for technology. Tom DeReggi RapidDSL & Wireless, Inc IntAirNet- Fixed Wireless Broadband - Original Message - From: "Brian Webster" <[EMAIL PROTECTED]> To: "Mike Hammett" <[EMAIL PROTECTED]>; "WISPA General List" Sent: Wednesday, November 05, 2008 8:46 AM Subject: Re: [WISPA] Theoretical TVWS coverage > > Obviously we are still speculating here because the rules are certainly > not > clear. With technology development and the results I am hearing from those > who are using WiMax equipment, I would say that -90 should be a safe > signal > level to use and still have good modulation rates. To assume TVWS will > always get full modulation and then try to also claim that it is the most > cost affective way to reach the low population density areas will be > difficult. Site footprints have to be looked at lowest modulation rates > because that RF signal is still out there. It is important to look at how > far that signal will still be traveling even though you can't achieve full > rates. The transmitted carrier will still be out there as part of the > contour for your base and must be considered in the process of > "registration". Your footprint will still be very large even though you > don't prefer to operate at the slower rates, which for others would be > "noise". > > To design a network with site footprints and spacing to achieve only full > rates is an inefficient of spectrum because your undesired signal is still > traveling a great distance preventing others from reusing that same > spectrum. > > > > Thank You, > Brian Webster > > > -Original Message----- > From: Mike Hammett [mailto:[EMAIL PROTECTED] > Sent: Wednesday, November 05, 2008 8:29 AM > To: [EMAIL PROTECTED]; WISPA
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" 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" > 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" >> 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" >>> 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 i
Re: [WISPA] Theoretical TVWS coverage
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" 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" > 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" >> 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" >>> 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" >>>> Sent: Wednesday, November 05, 2008 5:12 AM >>>> Subject:
Re: [WISPA] Theoretical TVWS coverage
Oh, I don't argue against the fact that there is signal present and can interfere with other systems beyond what I consider usable. I was just saying I don't think we're going to be able to efficiently have systems that go 50 miles. -- Mike Hammett Intelligent Computing Solutions http://www.ics-il.com -- From: "Brian Webster" <[EMAIL PROTECTED]> Sent: Wednesday, November 05, 2008 3:20 PM To: "Tom DeReggi" <[EMAIL PROTECTED]>; "WISPA General List" Subject: Re: [WISPA] Theoretical TVWS coverage > That's my point, the noise will be much lower in these bands if things are > deployed in a sane way. Wimax gear has receive sensitivity in the -93 > to -98 > range and from the reports I have heard, works very well at those levels. > While a WISP may be trying to set a network up for max modulation, the FCC > will look at the contour a whitespace station creates in a much different > way. It will be based on the RF energy it creates, not the signal margin > above the receiver threshold needed to achieve the better modulation rate. > If you map a realistic footprint based on a signal level down as low > as -98, that might be closer to the contour they will create in their > geolocation database. This contour will be the one they use to see if you > will encroach on any TV contour or other protected/semi protected users of > the spectrum. The WISP operator will not get to determine the contour > limits > based on their own desired modulation rate. I was saying that you should > be > able to use the -90 number in your mapping to get a more realistic sense > of > where the signal will be going and what size polygon you might have to > deal > with as you register it in a geolocation database. > > Remember, even though you may not agree that a particular signal level is > adequate for your purposes at a certain level, the signal that still > remains > on the air at the lower levels, will be an interfering/undesired signal to > all other systems. The FCC is charged with managing the total signal > emitted, it's affects over distance, and the other users of the spectrum. > They have the big picture to look at, while as a WISP it can be easy to > overlook those other factors. I am not sure what the signal level will be > that the FCC determines must be protected for TV receivers, but whatever > that number is you would be wise to do RF plots that show signal down to > that level. It may not be useable as a data network but it will certainly > be > able to bother TV reception at that level. WISP use of whitespaces will be > a > secondary use to LICENSED users of the band. And homeowners with off air > TV > reception will be considered licensed in this case. That is a different > mindset from what most are used to. It will create the need for different > thinking when planning a network. This is not bad news, just a new and > different way to think about your RF planning. > > > > Thank You, > Brian Webster > > > > > > -Original Message- > From: Tom DeReggi [mailto:[EMAIL PROTECTED] > Sent: Wednesday, November 05, 2008 3:41 PM > To: [EMAIL PROTECTED]; WISPA General List > Subject: Re: [WISPA] Theoretical TVWS coverage > > >> I would say that -90 should be a safe signal >> level to use and still have good modulation rates. > > I'm a little confused on that statement. > > With our Aperto live testing a few years back (pre-wimax), the best > modulation we could get was qam16 at the -85 levels. > And that was before considering the 25db SNR required above the noise. > What > good is sensitivity, if the noise ends up being higher than the > sensitivity? > > Sure TV broadcasters shot for -120, but thats one direction broadcasting, > with no expense cut for technology. > > Tom DeReggi > RapidDSL & Wireless, Inc > IntAirNet- Fixed Wireless Broadband > > > - Original Message - > From: "Brian Webster" <[EMAIL PROTECTED]> > To: "Mike Hammett" <[EMAIL PROTECTED]>; "WISPA General List" > > Sent: Wednesday, November 05, 2008 8:46 AM > Subject: Re: [WISPA] Theoretical TVWS coverage > > >> >> Obviously we are still speculating here because the rules are certainly >> not >> clear. With technology development and the results I am hearing from >> those >> who are using WiMax equipment, I would say that -90 should be a safe >> signal >> level to use and still have good modulation rates. To assume TVWS will >> always get full modulation and then try to also claim that it is the most >> cost affective way t
