On the multiple TV channels on the same RF channel... I believe in that case, it's 1x HD or multiple SD. In the age of HD, you still only get 1 channel.
---------- Mike Hammett Intelligent Computing Solutions http://www.ics-il.com -------------------------------------------------- From: "Brian Webster" <[EMAIL PROTECTED]> Sent: Saturday, October 25, 2008 11:52 PM To: "WISPA General List" <[email protected]> Subject: Re: [WISPA] Whitespaces filing > Marlon, > This is probably one of your best filings to date. Nicely done and well > written. I have a few comments and/or suggestions in line. > > > > Thank You, > Brian Webster > www.wirelessmapping.com <http://www.wirelessmapping.com> > > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Behalf Of Marlon K. Schafer > Sent: Saturday, October 25, 2008 1:53 PM > To: WISPA General List > Subject: [WISPA] Whitespaces filing > > > Hi All, > > Here is my first draft of an FCC filing on the 04-186 white spaces issue. > To file your own comments go here: > http://fjallfoss.fcc.gov/prod/ecfs/upload_v2.cgi > > Enter 04-186 into the blue box. Follow the instructions. > > The main location for filing docs is: > http://www.fcc.gov/cgb/ecfs/ > > You can search for existing filings there. > > I'd love to have people's input on this filing. Any and all comments are > desired, pro or con. I'll try to file this late on Monday..... > > Dear Ms. Dortch, > > Odessa Office Equipment is one of the nations first WISP operators. We > started our ISP in the spring of 1997 and installed our first wireless > system in the winter of 1999/2000. We now cover parts of 4 counties in > eastern Washington state. The bulk of our coverage is in western Lincoln > and eastern Grant counties. Lincoln county has approximately 10,000 > citizens with Grant county coming in at about 40,000. These are also some > of the geographically largest counties in the state. We have roughly 6000 > square miles of coverage serviced by about 30 transmit sites, most with > multiple access points. > > Due to the low power restrictions in the 5.3 and 5.4 GHz bands we are not > able to use those bands to service customers in any meaningful fashion. > Almost all of our network has been built using WiFi based devices at 2.4 > GHz. This has been mainly due to cost and range considerations. However, > as you know the tragedy of the commons has created a huge problem in the > 2.4 > GHz band. When I first started operations there were a large number of > cell > phone and public safety backhaul systems in place. Mainly using Western > Multiplex (or the older Glenair gear) always on systems that typically > used > all or most of the band per link. Naturally most of those systems were > also > located on the higher ground that we also needed to use. > > Over the years we have gotten quite good at using coverage zone, antenna > polarity, and power level tuning to allow us to operate in that > environment. > But now, most of those systems have been replaced with licensed point to > point links. In their place we see a HUGE number of unlicensed devices. > In > my home town of Odessa a brief scan (about 60 seconds) for WiFI access > points done by only one of my AP's shows that it detects around 80 other > AP's. This may not seem like many, but please remember that Odessa is in > a > bowl, nothing is being detected from out of town and there are less than > 1000 people living here! In Ephrata, that same test, done from a distance > of about one mile and with a 45* sector netted 99 AP's in a one minute > scan! > > We are also seeing a significant problem with system to system > interference. > Or, self inflicted interference. Due to practical client per AP > limitations > and interference rejection we often have more than one AP per site. For > more info on this problem and how we try to deal with it please see: > http://www.wi-fiplanet.com/tutorials/article.php/3756431 > > As you can see, a better standard in an outdoor friendly band is > desperately > needed if we are to meet the next decade's needs in the broadband > industry. > As the only viable 3rd rail of broadband the FCC should insure that WISPs > can continue to service rural un or under served markets as well as force > competition in more dense markets. > > By and large I agree with WISPA's stance on Whitespaces. A licensed lite > approach brings several self evident advantages to the table. I fully > support the concept. Knowing that almost all WISPs are self funded and > often self staffed it's important that care be taken to insure that any > licensing mechanism is inexpensive in both dollars and time. > > I also agree that much higher power levels are needed today in much of the > country. If there are trees in the area it takes power to penetrate them > in > meaningful distances. In open ground long distances are needed (30 to 40 > mile cell sizes should be an option). In my area we have rolling hills, > tree lines as windbreaks and line of site in the 50 to 60 mile ranges. 30 > to 40 mile line of site is commonplace. We have to reach out a LONG way > and > be able to plow through the windbreaks (sometimes several). We also have > to > have sufficient capacity on those long range networks to use them as feeds > to repeaters as we shoot down the canyons in our area. > > Personally, I'd like to see extremely rural areas allowed to use even more > than 20 watts of transmit power at the radio. I'd like to see a scale, > something like 200 miles from a top 50 MSO, 40 watts. Less than 200 miles > 20 watts. Maybe 10 or 20 miles would be 10 watts or less. > > I'd also like to see a geolocation and/or sensing mechanism put in place > under the rules. Set reasonably high standards of protection for the > broadcasters then let the manufacturers find ways to meet the standards. > Allow 20 watts for geolocation and 40 watts when sensing works the way > it's > supposed to. > > Whitespaces devices should not need to rely on "circles on a map" as these > never quite reflect the reality of coverage. Hills, buildings, noise > levels > etc. never show up. I know, we use that method for some of our marketing. > It's a good estimate, but signal checks are still the only really > effective > mechanism for finding coverage zones. > >>>>> The TV contours we are talking about protecting are not just simple > circles on a map. They are based on the FCC criteria (for which I can not > quote off the top of my head, but it is published) that the broadcasters > must submit which then defines that particular TV station contour. I have > attached a map image for the state of Washington showing all the combined > analog and digital TV contours for ALL channels on file with the FCC. Many > of them overlap and some look like circles because if you do an RF > propagation at some of these sites using 50,000 watts you will get pretty > close to a circle result. These contours are part of the criteria we are > proposing to use in the goelocation database. Those contours are already > defined by the FCC and we are obligated to protect those licensed users > for > that particular area. It's not a random choice and it's certainly not just > a > circle drawn on a map. This comes from years of already established RF > engineering principles and rules. Some of those defined by the > International > Telecommunications Union (ITU) and thus by treaty, the FCC and US > government > are obligated to obey. You can further drill down on this type of data by > channel. I also attached images showing only the UHF contours and one for > only channels 31 and 32. Keep in mind these images include the current > analog stations. Once they go off the air this picture will change a great > deal. The maps are just meant to illustrate that this is a much more > complex > process than just drawing circles on a map. This also should help > illustrate > exactly what the white space spectrum potential can be nationwide when > looked at channel by channel. > > The new devices should be held to a high standard for OOB emissions. I > think there should be two different standards. In one standard the > devices > aren't allowed to use the adjacent channels. But if a device is able to > limit it's OOB emissions sufficiently to protect the broadcasters the > adjacent channels should be allowed to be used. > > It's also time to start implementing some of the Spectrum Policy Task > Force's (SPTF) suggestions for improving the way spectrum is used. TV > broadcasting has remained basically static for what, 50+ years now? Same > channel sizes, same power output etc. With the change to DTV the > commission > should follow it's own advice and implement receiver standards instead of > only transmitter standards. Whitespaces devices AND TV sets/converters > should both be held to a minimum OOB rejection level of some kind. I > don't > know what the receive sensitivity is on the average TV set but based on > performance in my local area it's not very good these days. I think I've > run into less than 5 homes using over the air TV in the last 2 or 3 years. > When it became possible to get local channels via sat. signals everyone > moved to the better picture mechanisms that come with non broadcast > services. > >>>>> I don't know if you have tried off the air digital TV yet but you > should. First of all the current stations are running a fraction of their > concurrent analog station power levels. This is to protect adjacent market > analog stations on the same channels. Once February comes around they will > be turning those DTV stations up to maximum power. I have used a few > devices > with ATSC digital tuners in them and I can tell you there is one hell of a > difference in DTV over analog. It looks just like satellite quality when > it > works and if you compare it to the same analog broadcast, I have seen some > stations look perfect in DTV where I could hardly make out the picture in > analog mode. Another thing the DTV broadcasters have the option of doing > is > to multiplex up more than one programming channel on their broadcast in > digital. I have seen many stations run three or four separate channels on > their DTV carrier. That up to a 4 fold increase in spectrum efficiency. > You > may want to reconsider your point on that subject. > > The SPTF also suggested that we start looking at time sharing as well as > spectrum sharing. I'd suggest that all AP's be required to sync transmit > cycles with each other, much the way that the Motorola Canopy product > currently does in 5 GHz. A second should be carved up into x time slots. > As VoIP calls need delays of 200ms or less I'd suggest that a second be > cut > up into at least 50 time slots. 100, maybe even 500 would likely be even > better. Each AP would be allowed to use all time slots as long as it > didn't > need to share space with another system. When another system needed to > use > the same channel (lets say we're operating in an area that TV channels and > adjacent channels have only left 4 available channels) each AP would split > the available time slots. > > This would, for all practical purposes, eliminate base station to base > station catastrophic interference like that from the self inflicted > interference article mentioned above. It would also place some level of > pressure on the manufacturers to create devices able to push as much data > as > possible down the pipe in as short of a time as possible. > > All Whitespaces devices should act as an intelligent network. All CPE > devices should sense and report to the AP's. The AP's should sense and be > aware of other AP's in the area. The AP's should then use the information > that they've gained to automatically set channels, power levels, time > slots > etc. on the fly and without operator intervention. > > All Whitespaces AP's should also issue owner contact information as well. > WiFi systems will tell scanners what channel they are on, what their name > is, MAC address, IP address etc. I think these new devices should NOT > have > the option of hiding. They should tell anyone that has the right tools to > look, what channels they are on and who owns them as well as how to > contact > that owner (via phone and/or email address). > > ATPC (automatic transmit power control) should also be built into > Whitespaces devices down to the transmission level. With base stations > dictating who will transmit at what time it should be reasonable to expect > the AP and client to only transmit at the power levels needed to maintain > stable connections based on receive signal levels at each device. With > ATPC > we should be able to run our systems at 5 to 10 dB of fade margin and > still > maintain great links. Time slot mechanisms that prevent system to system > competition for broadcast times would also help to limit the amount of > fade > margin that's needed. > > WISPA's proposal to give first in rights to those that build first is a > bad > idea. It effectively gives large companies or well funded venture firms a > nearly exclusive hold on the most lucrative markets. That will also > effectively stifle innovation and competition in a few short years. The > time slot mechanism allows for competition while also protecting existing > investments. I say this as the operator that was first in in most of my > current markets. On one hand I'd love to have been able to keep others > out > of my areas, as a successful entrepreneur I understand the value of > consumer > choice. > >>>>> WISPA's proposal does not give anyone first in rights. We were very > careful in our wording to not take that position and the use it or lose it > clause was put in there to try and minimize the spectrum campers from > doing > what you express (it has always been a concern of mine as well and that > point was always made clear to the committee). Nowhere does it state there > are first in rights. We have proposed that there are requirements for > notification of a new site to anyone else on that frequency registered in > the database and that there is record of such notification so that there > is > ample time for both parties to work out their technical details to avoid > interference to each other. After the 30 days they are still able to > construct even if there is no response from the other operators. If there > are interference issues the documentation will help the FCC deal with the > problem. This is one of those times when two operators could do things > like > share their time slot information to best occupy the spectrum. We did not > try and nail down the full technical details given the time constraints, > but > we felt the language was such that it would allow those details to be > worked > out later as part of any final order issued by the FCC. > > I've got very mixed opinions on personal portable devices and WLANs. I > don't think that the propagation properties of sub 1 GHz bands make for a > particularly good home or business LAN mechanism. If low powered 2.4 GHz > devices will travel through walls and trees and still create interference > within the band at distances far greater than they are said to go, how bad > will the tragedy of the commons become for Whitespaces devices? Plus > there > is already a LOT of spectrum available for WLANs. In fact there is a 5.1 > GHz indoor ONLY band that should maybe be tweaked to encourage more > utilization. > > If personal portable devices are to be allowed they should only be allowed > to link with registered base stations. This would help to avoid the > tragedy > of the commons while also giving the benefits of mass market production > economies of scale. Personal portable devices could also then be > reasonably > allowed to use much higher power levels and have far greater ranges than > have been suggested thus far. MAN and public safety networks would then > become a practical reality. > > The Commission should also take this opportunity to set new max channel > size > limits on systems. We should not ever have devices that transmit on large > channel sizes even when they have no payload to deliver. Again, this > should > be used as a chance to design mechanisms intended to drive innovation and > efficiencies into the available spectrum. > > In a nutshell Whitespaces devices should: > Allow for either or both geolocation and sensing. > Not allow for personal portable or indoor only networks. > Set high standards of incumbent protection but not disallow any unused > spectrum. > Set receiver standards. > Allow for market innovation by setting standards based almost > exclusively on device emissions rather than defining how that's > accomplished. > Protect any existing operator be that a broadcaster or a network > operator. > Foster innovation in spectral efficiencies. > Set max channel size limits. > > These suggestions, if properly implemented would strongly protect the > current licensed users as well as encourage tremendous new opportunities. > And, by using ATPC and time sharing we'd also protect any new networks > from > predatory products. > > Thank you for your consideration, > Marlon K. Schafer > (509) 988-0260 cell > Owner, Odessa Office Equipment > Founding board member, WISPA > FCC Committee member, WISPA > Former FCC Committee chairman, WISPA > > > > > ---------------------------------------------------------------------------- > ---- > 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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