Why doesn't the AMA pursue new RC radios?

This past month a Jet Rally was cancelled early in the event when the discovered there was multi channel random radio interference. A very
expensive turbine went in and the suspect was interference. In the past two weeks a serious injury to a fellow flyer of a TOC quality gasser, with the carbon fiber prop doing severe damage to the individual. I posted here on this newsgroup a response to that serious injury, a dissertation on why were we still using the equivalent to reed radios, when much better technology was out there. Of couse I took the usual bloggs from people.
I'm starting to be concerned that with our sue happy society, consumer protectionism and government interference we could be one bad accident from loosing a hobby. There are accidents that can't be avoided, I'm not suggesting you can make our hobby bulletproof. And there are measures each of us should be doing such as preflights, routine maintenance, following safety codes, etc. Nothing can substitute for those.
BPL is getting a lot of press as a potential interference causing problem. Radio control cranes, high power beeper towers, as well as other sources generate pottential RF interference for our RC communications.
We even generate interference, most of it accidentally when somebody mistakenly turns on a transmitter on the same frequency. There have been incidents of malacious interference with people intentionally shooting someone down.
Were I am headed here, is that wireless technology for cell phones and computers have revolutionized the how devices communicate via wireless protocols. The wireless computer network (wifi) 802.11_ is generating a very high level of acceptance with Internet hot spots in cafe's, hotels, park, communities... That protocol is an error checking, error correcting protocol. By that I mean that errors are corrected in the background and the users don't notice. Wifi also is designed to have many simaltaneous users without ever having to worry what frequency they are on. The most popular wifi is 802.11b, and guess what folks it only utilizes 3 channels, and can move data at eleven million bits per second. And maybe more important the non recurring development costs of the components is all done, and they are dirt cheap.
Doing a little simple math on the amount of data an RC pcm transmitter sends, we could put over 1000 airplanes in the air simultaneously at one field utilizing this or similar technology. ( Of course we know we don't need 1000 airplanes flying at the same time, in fact you probably couldn't fit enough fields together with overflight borders and flyers to get a tenth of that. )
Imagine now -> no frequency board would be required, you would not have to order specific frequency transmitters or receivers. You could have have a dozen fields back to back to back, unlike the 3 mile shared frequency rule that now exists. And the potential that radio interference accidentally, intentionally, or from some other source becomes almost non existent. (nothing is 100%).
You would not need to transition over a period of time like we did going to gold stickered radios. But by going to a new portion of the frequency specrum, you could leave the existing RC channels alone to be used as is for many, many more years or forever. So nobody would need to buy new equipment until they wanted.
I'm not proposing we use the identical technology that wifi uses, primarily because it has range that is less than what we need. Typical wifi is only good for 300'. But there are elements that could be used, to lower costs.
The other point I might make is that wifi is in an area of the spectrum that the FCC doesn't regulate, it could be used now if the manufacturers so desired to put the equipment out.
Food for thought, maybe something people should start talking about.
Phil
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| That protocol is an error checking, error correcting protocol. By that | I mean that errors are corrected in the background and the users don't | notice. Wifi also is designed to have many simaltaneous users without | ever having to worry what frequency they are on. The most popular wifi | is 802.11b, and guess what folks it only utilizes 3 channels, and can | move data at eleven million bits per second.
Only three channels, huh? 1, 6 and 11, right? (Contrary to popular belief, while WiFi offers 11 channels, they overlap a lot, and there's only three completely seperate channels.)
Each 802.11b signal takes up about 30 mHz of bandwidth. In comparison, our part of the 72 mHz band is about 0.5 mHz, and each channel is only 10 kHz in size.
Also, WiFi rarely reaches the full 11 Mbit. 5.5 Mbit is much more likely -- the rest is lost to collisions and error correction.
| Doing a little simple math on the amount of data an RC pcm transmitter | sends, we could put over 1000 airplanes in the air simultaneously at one | field utilizing this or similar technology. ( Of course we know we | don't need 1000 airplanes flying at the same time, in fact you probably | couldn't fit enough fields together with overflight borders and flyers | to get a tenth of that. )
Your math is based upon us getting 30 mHz (or is it 90 mHz?) of bandwidth, something that will not happen. Bandwidth is gold, and while we might be able to get a little out of the FCC, we're not going to get Fort Knox.
Assuming that we only get 0.5 mHz of bandwidth, and that we lose 50% of the data to collisions and error correction, that greatly reduces the possible number of airplanes in the air. But it would still probably be at least 20, and when you went higher than that the only problem would be increased latency, not planes crashing left and right.
| Imagine now -> no frequency board would be required, you would not | have to order specific frequency transmitters or receivers. You | could have have a dozen fields back to back to back, unlike the 3 | mile shared frequency rule that now exists. And the potential that | radio interference accidentally, intentionally, or from some other | source becomes almost non existent. (nothing is 100%).
That is patently *incorrect*.
Ever tried to use WiFi with a microwave oven going? Or a 2.4 gHz non spread-spectrum phone? They don't play nice together.
Granted, spread spectrum/frequency hopping will handle interference better than our current system, but it can't ignore it entirely. | You would not need to transition over a period of time like we did going | to gold stickered radios. But by going to a new portion of the | frequency specrum, you could leave the existing RC channels alone to be | used as is for many, many more years or forever. So nobody would need | to buy new equipment until they wanted.
... except that this would require that the FCC give us a new frequency band. And let us keep the original one.
But spectrum is gold. Companies like Verizon are paying *billions* of dollars for spectrum. I wonder how much our 0.5 mHz of bandwidth -- under 100 mHz which makes it even more valuable -- is worth. Probably a lot.
Looks like 0.45 mHz of bandwidth (not sure what band) went for $395 million dollars in 1994. (http://www.cbo.gov/showdoc.cfm?index=9&sequence=3 ). Is our (current) spectrum really worth that much, or have I made a mistake here?
(And the figures get higher when we add in the 75 mHz ground band.)
| I'm not proposing we use the identical technology that wifi uses, | primarily because it has range that is less than what we need. Typical | wifi is only good for 300'. But there are elements that could be used, | to lower costs.
Oh, the technology in WiFi is fine. The reason the range is so limited is the limited power -- raise the limit to 1 or 2 watts, and we'd have as good or better range than we do with our current equipment.
But we wouldn't want to share our chunk of bandwidth with other unregulated bands like 900 mHz, 2.4 gHz, 5.8 gHz -- because other users of those bands could easily use up the entire band and leave us with nothing. You know those 108 Mbit cards? They get 108 Mbit by using the *entire* band. Which sounds wrong, but the rules do permit it.
| The other point I might make is that wifi is in an area of the spectrum | that the FCC doesn't regulate, it could be used now if the manufacturers | so desired to put the equipment out.
Two problems with this :
1) you really don't want to be where the FCC doesn't regulate. Because if you are, then what's to stop somebody else from setting up a new data link of some sort, using 1000 watts, right next door to your field, using the same unregulated frequencies?
2) the FCC regulates all the bands up to about 300 gHz. That's really too high for our uses -- in fact, that's where infrared begins. (Of course, a few people do control their planes via IR signals, but I digress.)
| Food for thought, maybe something people should start talking about.
Oh, people are already talking about it. In fact, people have already made such equipment using the 900 mHz and 2.4 gHz bands.
Spread spectrum is not the answer to all our interference problems. However, done properly, it would be the answer to our biggest issue: having to have each pilot have his own channel to fly, and all the effort spent in making sure that happens.
What I'd propose is this :
-- Ask the FCC for a new chunk of bandwidth. I'm guessing that 0.5 mHz would be just fine, but that math can be done.
The FCC may not be willing to give us the bandwidth, and I suspect that the AMA couldn't afford to buy it like a cell phone company would. But maybe we could get them to give it to us with the agreement that the FCC would take our current bands back in 2014?
(This would make much of our current equipment obsolete in 2014, which would make lots of people mad, but if it's what has to happen, I'd say it's worth it. It would be a hard sell for the AMA to the modeling community, however.)
-- Along with this chunk of bandwidth would come some specific regulations :
- Power permitted (hopefully 1-2 watts) - bandwidth permitted (hopefully enough for lots of channels on a single plane, and high resolution on those channels with low latency, and and some telemetry back, but not enough for things like video.) - R/C use *only*, and only for our spread spectrum system. (However, there would be no need for an air/ground split.)
Ideally, the protocol used would be a standard between all manufacturers, so everything works together.
The problems at this point are political, not technical. The FCC could make this happen very soon if they wanted to, or the AMA could start lobbying the FCC for something like this. I don't see anybody else as being able to make it happen.
The AMA would probably welcome a new bit of spectrum for this new system, but such spectrum would be hard to get. It would be much less willing to trade our current spectrum, but maybe it might think it's worth it.
It ought to be possible to make a spread spectrum system that co-exists with our current system, something that uses the channels not in use by traditional radios, but it would be tricky, and even if it did work perfectly (which is not certain), it would still be blamed for glitches and the like in traditional equipment users. Also, the current FCC regulations would not permit this, so they'd need to be changed.
--
Doug McLaren, snipped-for-privacy@frenzy.com
Captain Ahab just has to have his whale, didn't he?
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If terrorism escalates, and it most likely will, we will be lucky to be permitted to fly anything via R/C in the not to distant future. I am not optimistic at all in this regard.
Of course, one could argue that the terrorists will not bother utilizing commercially available R/C gear and use legal R/C frequencies. But that would be a sensible argument and anyone that has paid attention to the knee-jerk legislation that has been passed concerning firearms will know that legislators seldom rely upon logic and common sense.
Ed Cregger
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Doug, I oversimplfied that post intentionally. If you will reread the post you will see: | I'm not proposing we use the identical technology that wifi uses, | primarily because it has range that is less than what we need. Typical | wifi is only good for 300'. But there are elements that could be used, | to lower costs.
The elements I primarilary intended, such as frequency hopping, cdma or tdma (I suspect tdma would be more appropriate for RC use), error detection, and networking techniques. I would agree with most of your post, (except 802.11b is only 3 channels as I stated, the extra channels come in other 802.11 varients, but 802.11 b is the most prolific so far)
I used WiFi as an example!
Your proposal is very parallel to my thoughts, although I was still thinking open loop last night, telemetry or closing the loop would open up lots more portential. Without sitting down and designing a system, I'm not sure we couldn't utilize just a few of our current channels and improve the open loop controls of our RC equipment. I mean in practicality how many simultenous users do we need? At my field 6 would be fine, I'm sure there are other places that would need more.
I suspect that we could utilize a more sophicated modulation approach to get several users on one channel with our current narrow band channels. For example phone modems are using quadrature techniques to get much higher bit rates on approximately the same bandwith.
Without going into deep technical details, utilizing tdma, spread spectrum, error detection, and networking techniques we could see as I stated last night: | Imagine now -> no frequency board would be required, you would not | have to order specific frequency transmitters or receivers. You | could have have a dozen fields back to back to back, unlike the 3 | mile shared frequency rule that now exists. And the potential that | radio interference accidentally, intentionally, or from some other | source becomes almost non existent. (nothing is 100%).
And no I wouldn't really propose we use an unregulated frequency, my point was they are accomplishing a lot more data movement than we do or need on an unregulated frequency.
Yes there has been some talk, but we need to be talking a lot so the AMA hears.
Still, in closing there is much improvement that could be gained over our current radios. Actually there is much more we could do with our existing channels and radios to improve safety, which is still what concerns me..
Phil
Doug McLaren wrote:

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<!doctype html public "-//w3c//dtd html 4.0 transitional//en"> <html> Doug, <br>&nbsp;I&nbsp; oversimplfied that post intentionally. <br>If you will reread the post you will see: <br><b><font size=+1>|</font> <u>I'm not proposing we use the identical technology that wifi uses,</u></b> <br>| primarily because it has range that is less than what we need.&nbsp; Typical <br>| wifi is only good for 300'.&nbsp; But there are elements that could be used, <br>| to lower costs. <p>The elements I primarilary intended, such as frequency hopping, cdma or tdma (I suspect tdma would be more appropriate for RC use), error detection,&nbsp; and networking techniques.&nbsp; I would agree with most of your post, (except 802.11b is only 3 channels as I stated, the extra channels come in other 802.11 varients, but 802.11 b is the most prolific so far) <p><b><u>I used WiFi as an example!</u></b> <p>Your proposal is very parallel to my thoughts, although I was still thinking open loop last night, telemetry or closing the loop would open up lots more portential.&nbsp; Without sitting down and designing a system, I'm not sure we couldn't utilize just a few of our current channels and improve the open loop controls of our RC equipment.&nbsp; I mean in practicality how many simultenous users do we need?&nbsp; At my field 6 would be fine, I'm sure there are other places that would need more. <p>I suspect that we could utilize a more sophicated modulation approach to get several users on one channel with our current narrow band channels.&nbsp; For example phone modems are using quadrature techniques to get much higher bit rates on approximately the same bandwith. <p>Without going into deep technical details, utilizing tdma, spread spectrum, error detection, and networking techniques we could see as I stated last night: <br>| Imagine now -> no frequency board would be required, you would not <br>| have to order specific frequency transmitters or receivers.&nbsp; You <br>| could have have a dozen fields back to back to back, unlike the 3 <br>| mile shared frequency rule that now exists.&nbsp; And the potential that <br>| radio interference accidentally, intentionally, or from some other <br>| source becomes almost non existent.&nbsp; (nothing is 100%). <p>And no I wouldn't really propose we use an unregulated frequency, my point was they are accomplishing a lot more data movement than we do or need on an unregulated frequency. <p>Yes there has been some talk, but we need to be talking a lot so the AMA hears. <p>Still, in closing there is much improvement that could be gained over our current radios.&nbsp; Actually there is much more we could do with our existing channels and radios to improve safety, which is still what concerns me.. <p>Phil <br>&nbsp; <br>&nbsp; <br>&nbsp; <p>Doug McLaren wrote:
<p>| That protocol is an error checking, error correcting protocol.&nbsp; By that <br>| I mean that errors are corrected in the background and the users don't <br>| notice.&nbsp; Wifi also is designed to have many simaltaneous users without <br>| ever having to worry what frequency they are on.&nbsp;&nbsp; The most popular wifi <br>| is 802.11b, and guess what folks it only utilizes 3 channels, and can <br>| move data at eleven million bits per second. <p>Only three channels, huh?&nbsp; 1, 6 and 11, right?&nbsp; (Contrary to popular <br>belief, while WiFi offers 11 channels, they overlap a lot, and there's <br>only three completely seperate channels.) <p>Each 802.11b signal takes up about 30 mHz of bandwidth.&nbsp; In <br>comparison, our part of the 72 mHz band is about 0.5 mHz, and each <br>channel is only 10 kHz in size. <p>Also, WiFi rarely reaches the full 11 Mbit.&nbsp; 5.5 Mbit is much more <br>likely -- the rest is lost to collisions and error correction. <p>| Doing a little simple math on the amount of data an RC pcm transmitter <br>| sends, we could put over 1000 airplanes in the air simultaneously at one <br>| field utilizing this or similar technology.&nbsp; ( Of course we know we <br>| don't need 1000 airplanes flying at the same time, in fact you probably <br>| couldn't fit enough fields together with overflight borders and flyers <br>| to get a tenth of that. ) <p>Your math is based upon us getting 30 mHz (or is it 90 mHz?) of <br>bandwidth, something that will not happen.&nbsp; Bandwidth is gold, and <br>while we might be able to get a little out of the FCC, we're not going <br>to get Fort Knox. <p>Assuming that we only get 0.5 mHz of bandwidth, and that we lose 50% <br>of the data to collisions and error correction, that greatly reduces <br>the possible number of airplanes in the air.&nbsp; But it would still <br>probably be at least 20, and when you went higher than that the only <br>problem would be increased latency, not planes crashing left and right. <p>| Imagine now -> no frequency board would be required, you would not <br>| have to order specific frequency transmitters or receivers.&nbsp; You <br>| could have have a dozen fields back to back to back, unlike the 3 <br>| mile shared frequency rule that now exists.&nbsp; And the potential that <br>| radio interference accidentally, intentionally, or from some other <br>| source becomes almost non existent.&nbsp; (nothing is 100%). <p>That is patently *incorrect*. <p>Ever tried to use WiFi with a microwave oven going?&nbsp; Or a 2.4 gHz non <br>spread-spectrum phone?&nbsp; They don't play nice together. <p>Granted, spread spectrum/frequency hopping will handle interference <br>better than our current system, but it can't ignore it entirely. <p>| You would not need to transition over a period of time like we did going <br>| to gold stickered radios.&nbsp; But by going to a new portion of the <br>| frequency specrum, you could leave the existing RC channels alone to be <br>| used as is for many, many more years or forever.&nbsp; So nobody would need <br>| to buy new equipment until they wanted. <p>... except that this would require that the FCC give us a new <br>frequency band.&nbsp; And let us keep the original one. <p>But spectrum is gold.&nbsp; Companies like Verizon are paying *billions* of <br>dollars for spectrum. I wonder how much our 0.5 mHz of bandwidth -- <br>under 100 mHz which makes it even more valuable -- is worth.&nbsp; Probably <br>a lot. <p>Looks like 0.45 mHz of bandwidth (not sure what band) went for $395 <br>million dollars in 1994. <br>(<a href="http://www.cbo.gov/showdoc.cfm?index=9&sequence=3 ">http://www.cbo.gov/showdoc.cfm?index=9&amp ;sequence=3</a>).&nbsp; Is our (current) <br>spectrum really worth that much, or have I made a mistake here? <p>(And the figures get higher when we add in the 75 mHz ground band.) <p>| I'm not proposing we use the identical technology that wifi uses, <br>| primarily because it has range that is less than what we need.&nbsp; Typical <br>| wifi is only good for 300'.&nbsp; But there are elements that could be used, <br>| to lower costs. <p>Oh, the technology in WiFi is fine.&nbsp; The reason the range is so <br>limited is the limited power -- raise the limit to 1 or 2 watts, and <br>we'd have as good or better range than we do with our current <br>equipment. <p>But we wouldn't want to share our chunk of bandwidth with other <br>unregulated bands like 900 mHz, 2.4 gHz, 5.8 gHz -- because other <br>users of those bands could easily use up the entire band and leave us <br>with nothing.&nbsp; You know those 108 Mbit cards?&nbsp; They get 108 Mbit by <br>using the *entire* band.&nbsp; Which sounds wrong, but the rules do permit <br>it. <p>| The other point I might make is that wifi is in an area of the spectrum <br>| that the FCC doesn't regulate, it could be used now if the manufacturers <br>| so desired to put the equipment out. <p>Two problems with this : <p>1) you really don't want to be where the FCC doesn't regulate. <br>Because if you are, then what's to stop somebody else from setting up <br>a new data link of some sort, using 1000 watts, right next door to <br>your field, using the same unregulated frequencies? <p>2) the FCC regulates all the bands up to about 300 gHz.&nbsp; That's really <br>too high for our uses -- in fact, that's where infrared begins.&nbsp; (Of <br>course, a few people do control their planes via IR signals, but I <br>digress.) <p>| Food for thought, maybe something people should start talking about. <p>Oh, people are already talking about it.&nbsp; In fact, people have already <br>made such equipment using the 900 mHz and 2.4 gHz bands. <p>Spread spectrum is not the answer to all our interference problems. <br>However, done properly, it would be the answer to our biggest issue: <br>having to have each pilot have his own channel to fly, and all the <br>effort spent in making sure that happens. <p>What I'd propose is this : <p>-- Ask the FCC for a new chunk of bandwidth.&nbsp; I'm guessing that 0.5 <br>mHz would be just fine, but that math can be done. <p>The FCC may not be willing to give us the bandwidth, and I suspect <br>that the AMA couldn't afford to buy it like a cell phone company <br>would.&nbsp; But maybe we could get them to give it to us with the <br>agreement that the FCC would take our current bands back in 2014? <p>(This would make much of our current equipment obsolete in 2014, which <br>would make lots of people mad, but if it's what has to happen, I'd say <br>it's worth it.&nbsp; It would be a hard sell for the AMA to the modeling <br>community, however.) <p>-- Along with this chunk of bandwidth would come some specific regulations : <p>&nbsp; - Power permitted (hopefully 1-2 watts) <br>&nbsp; - bandwidth permitted (hopefully enough for lots of channels on a <br>&nbsp;&nbsp;&nbsp; single plane, and high resolution on those channels with low latency, <br>&nbsp;&nbsp;&nbsp; and and some telemetry back, but not enough for things like video.) <br>&nbsp; - R/C use *only*, and only for our spread spectrum system. <br>&nbsp;&nbsp;&nbsp; (However, there would be no need for an air/ground split.) <p>Ideally, the protocol used would be a standard between all <br>manufacturers, so everything works together. <p>The problems at this point are political, not technical.&nbsp; The FCC <br>could make this happen very soon if they wanted to, or the AMA could <br>start lobbying the FCC for something like this.&nbsp; I don't see anybody <br>else as being able to make it happen. <p>The AMA would probably welcome a new bit of spectrum for this new <br>system, but such spectrum would be hard to get.&nbsp; It would be much less <br>willing to trade our current spectrum, but maybe it might think it's <br>worth it. <p>It ought to be possible to make a spread spectrum system that <br>co-exists with our current system, something that uses the channels <br>not in use by traditional radios, but it would be tricky, and even if <br>it did work perfectly (which is not certain), it would still be blamed <br>for glitches and the like in traditional equipment users.&nbsp; Also, the <br>current FCC regulations would not permit this, so they'd need to be <br>changed. <p>--
<br>Captain Ahab just has to have his whale, didn't he?</blockquote> </html>
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I have been convinced that in the last 10 or 12 years there has existed an OFF THE SHELF solution to our interference problems that seemed to spin around the SS concept. Note I did not say SS, but SS concept. Once I saw that, I began speaking openly for movement in that direction as a major safety issue. Recently there has been a major injury and in the past a death in England that were directly attributed to radio problems. Some of those kinds of incidents could have been prevented with better systems design.
From all the flack and negative comments I have received over the last 8 or 9 years on the subject of better radio systems, it is clear that there are some who will stand in the way of progress for the simple satisfaction of stopping something from happening. It also seems to be clear that the radio makers could care less as the market just does not want to support the mental effort to design better systems, or so some say. The bottom line appears to have been "Hand us a set in concrete solution and move aside while we consider it" Call that my bad attitude #659.
To me this appears to be a major public safety issue. Why don't you (Phil) and Doug McLaren form an Ad Hoc committee and put together something (in writing) that will work and present the solution to the public, here, and the AMA. It is clear to me that both of you [Phil and Doug] and some other modelers around - here and elsewhere on the net, have the intelligence, competence, and experience to accomplish the systems design task in relatively short order.
wrote: | That protocol is an error checking, error correcting protocol. By that | I mean that errors are corrected in the background and the users don't | notice. Wifi also is designed to have many simaltaneous users without | ever having to worry what frequency they are on. The most popular wifi | is 802.11b, and guess what folks it only utilizes 3 channels, and can | move data at eleven million bits per second. Only three channels, huh? 1, 6 and 11, right? (Contrary to popular belief, while WiFi offers 11 channels, they overlap a lot, and there's only three completely seperate channels.) Each 802.11b signal takes up about 30 mHz of bandwidth. In comparison, our part of the 72 mHz band is about 0.5 mHz, and each channel is only 10 kHz in size. Also, WiFi rarely reaches the full 11 Mbit. 5.5 Mbit is much more likely -- the rest is lost to collisions and error correction. | Doing a little simple math on the amount of data an RC pcm transmitter | sends, we could put over 1000 airplanes in the air simultaneously at one | field utilizing this or similar technology. ( Of course we know we | don't need 1000 airplanes flying at the same time, in fact you probably | couldn't fit enough fields together with overflight borders and flyers | to get a tenth of that. ) Your math is based upon us getting 30 mHz (or is it 90 mHz?) of bandwidth, something that will not happen. Bandwidth is gold, and while we might be able to get a little out of the FCC, we're not going to get Fort Knox. Assuming that we only get 0.5 mHz of bandwidth, and that we lose 50% of the data to collisions and error correction, that greatly reduces the possible number of airplanes in the air. But it would still probably be at least 20, and when you went higher than that the only problem would be increased latency, not planes crashing left and right. | Imagine now -> no frequency board would be required, you would not | have to order specific frequency transmitters or receivers. You | could have have a dozen fields back to back to back, unlike the 3 | mile shared frequency rule that now exists. And the potential that | radio interference accidentally, intentionally, or from some other | source becomes almost non existent. (nothing is 100%). That is patently *incorrect*. Ever tried to use WiFi with a microwave oven going? Or a 2.4 gHz non spread-spectrum phone? They don't play nice together. Granted, spread spectrum/frequency hopping will handle interference better than our current system, but it can't ignore it entirely. | You would not need to transition over a period of time like we did going | to gold stickered radios. But by going to a new portion of the | frequency specrum, you could leave the existing RC channels alone to be | used as is for many, many more years or forever. So nobody would need | to buy new equipment until they wanted. ... except that this would require that the FCC give us a new frequency band. And let us keep the original one. But spectrum is gold. Companies like Verizon are paying *billions* of dollars for spectrum. I wonder how much our 0.5 mHz of bandwidth -- under 100 mHz which makes it even more valuable -- is worth. Probably a lot. Looks like 0.45 mHz of bandwidth (not sure what band) went for $395 million dollars in 1994. (http://www.cbo.gov/showdoc.cfm?index=9&sequence=3 ). Is our (current) spectrum really worth that much, or have I made a mistake here? (And the figures get higher when we add in the 75 mHz ground band.) | I'm not proposing we use the identical technology that wifi uses, | primarily because it has range that is less than what we need. Typical | wifi is only good for 300'. But there are elements that could be used, | to lower costs. Oh, the technology in WiFi is fine. The reason the range is so limited is the limited power -- raise the limit to 1 or 2 watts, and we'd have as good or better range than we do with our current equipment. But we wouldn't want to share our chunk of bandwidth with other unregulated bands like 900 mHz, 2.4 gHz, 5.8 gHz -- because other users of those bands could easily use up the entire band and leave us with nothing. You know those 108 Mbit cards? They get 108 Mbit by using the *entire* band. Which sounds wrong, but the rules do permit it. | The other point I might make is that wifi is in an area of the spectrum | that the FCC doesn't regulate, it could be used now if the manufacturers | so desired to put the equipment out. Two problems with this : 1) you really don't want to be where the FCC doesn't regulate. Because if you are, then what's to stop somebody else from setting up a new data link of some sort, using 1000 watts, right next door to your field, using the same unregulated frequencies? 2) the FCC regulates all the bands up to about 300 gHz. That's really too high for our uses -- in fact, that's where infrared begins. (Of course, a few people do control their planes via IR signals, but I digress.) | Food for thought, maybe something people should start talking about. Oh, people are already talking about it. In fact, people have already made such equipment using the 900 mHz and 2.4 gHz bands. Spread spectrum is not the answer to all our interference problems. However, done properly, it would be the answer to our biggest issue: having to have each pilot have his own channel to fly, and all the effort spent in making sure that happens. What I'd propose is this : -- Ask the FCC for a new chunk of bandwidth. I'm guessing that 0.5 mHz would be just fine, but that math can be done. The FCC may not be willing to give us the bandwidth, and I suspect that the AMA couldn't afford to buy it like a cell phone company would. But maybe we could get them to give it to us with the agreement that the FCC would take our current bands back in 2014? (This would make much of our current equipment obsolete in 2014, which would make lots of people mad, but if it's what has to happen, I'd say it's worth it. It would be a hard sell for the AMA to the modeling community, however.) -- Along with this chunk of bandwidth would come some specific regulations : - Power permitted (hopefully 1-2 watts) - bandwidth permitted (hopefully enough for lots of channels on a single plane, and high resolution on those channels with low latency, and and some telemetry back, but not enough for things like video.) - R/C use *only*, and only for our spread spectrum system. (However, there would be no need for an air/ground split.) Ideally, the protocol used would be a standard between all manufacturers, so everything works together. The problems at this point are political, not technical. The FCC could make this happen very soon if they wanted to, or the AMA could start lobbying the FCC for something like this. I don't see anybody else as being able to make it happen. The AMA would probably welcome a new bit of spectrum for this new system, but such spectrum would be hard to get. It would be much less willing to trade our current spectrum, but maybe it might think it's worth it. It ought to be possible to make a spread spectrum system that co-exists with our current system, something that uses the channels not in use by traditional radios, but it would be tricky, and even if it did work perfectly (which is not certain), it would still be blamed for glitches and the like in traditional equipment users. Also, the current FCC regulations would not permit this, so they'd need to be changed.
--
Doug McLaren, snipped-for-privacy@frenzy.com
Captain Ahab just has to have his whale, didn't he?
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I created a Yahoo group here, I'll see if we can get something going:
http://groups.yahoo.com/group/RCradios /
Phil
Six_O'Clock_High wrote:

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Phil wrote:

Oh goody, another yahoo group :-)
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Have you bothered to send this to AMA to see what they say?

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No just trying to get people thinking, but am considering sending something to the AMA.
"C.O.Jones" wrote:

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Here is a long post, but, very much to the point of your message.
http://www.rcuniverse.com/forum/fb.asp?m !44882&tostyle=tm

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The AMA can't pursue new radios. That is up to the RCMA and the users! The AMA can lobby for the frequency use when the RCMA decides to make the stuff.
-- Paul McIntosh http://www.rc-bearings.com

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Paul, I'm curious, why can't the AMA call a meeting of RC radio Manufacturers and challenge them to put together an interoprability plan, and a specification for safer more immune radios systems? I would agree they can't force any manufacturer to do something or attend. But I do think they could show some leadership to the future.
Phil
Paul McIntosh wrote:

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The US is only one market for radios. Does anyone know about RF control in other counrties? mk

past
for
a
hotels,
that
wifi
one
probably
have
going
be
Typical
used,
spectrum
manufacturers
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Phil,
Do you know that they haven't aready done that? I don't and I am sure that the RCMA must either be working feverishly on this or there is some other technical or bureaucratic reason they can't right now.
If there ain't no money in it, they won't bother.
-- Paul McIntosh http://www.rc-bearings.com

past
for
a
hotels,
that
wifi
one
probably
have
going
be
Typical
used,
spectrum
manufacturers
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the
very
gasser,
radios,
usual
consumer
accident
I'm
and
wireless
generating
don't
without
can
important
and
transmitter
flyers
have
need
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Phil:
You make some interesting points, but with regards to the AMA: The AMA has zero influence on the mfrs. The AMA has no regulatory power, their sole existence is based on their abililty to find an insurance company willing to underwrite the risk of modeling - but only for those who want to be "members".
So the first question is whether you want public recognition by the AMA that the current technology is contributing to accidents - keeping in mind that there is NO evidence to support that it is, or that changing the technology will have an impact. What would happen? Well, for one, your AMA dues would probably increase. Insurance companies don't care whether or not cars are safe - they simply adjust their rates based on perceived risk. And if the AMA steps forward and says the risk has increased - you know the rest. Are you willing to pay $100 a year to the AMA? So the AMA will be the last "person" to make a public position on the safety of radios because it makes no sense for them to do so. (We won't even get into the impact on magazine advertising revenues if they piss off Horizon or Hobbico) The AMA has no data, no position of expertise, and no incentive.
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zero
existence
underwrite
that
Not contributing to them Paul. Simply not preventing them. And it should be recognized that the current technology is not very current. So maybe truely current technology can be incorporated to really make our radios RFI free.
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Hi Phil
Actually, the AMA has a committee in place.
Frequency Advisory Council (1/89): Airtronic; FMA DIRECT; Fred Marks (MD); Futaba; Hitec RCD; Horizon; Novak Electronics; Adnan Kahn/Bob Novak; Kraft Midwest Products, Inc.; Peter Waters (MI); Bryan Shaw; Dave Poole; and Rick Matte.
Unfortunately, the committee is somewhat less than helpful at times. About two years ago, the members of the committee claimed that the Rx's they are building are capable of 2 mile separation between clubs. The EC prepared the necessary changes to the Safety Code and asked the committee for documentation. There was no response. At Toledo, a year ago, the manufacturers were asked to meet, since most would be there already, and supply the documentation. No show. It seems the liability of making such information available outweighs the obvious benefits to the AMA membership.
I wish you luck in your quest.

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