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High-Speed Multimedia Hamming
Skuld-Chan writes "I noticed a few days ago that the ARRL (Amateur Radio Relay League) formed a working group to promote use of 802.11 protocols on the amateur radio bands."
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Houston Wireless User Group just discussed this as our presentation for last night's monthly meeting, oddly enough, complete with a very nice presentation by Erewhon.
What's your damage, Heather?
I was at the Houston Wireless Users Group (HWUG - http://www.houstonwireless.org/) meeting last night and this was our primary topic. One concern we had was stations supervised by licensed operators and classed under Part 97 communicating with Part 15 Unlicensed (eg Joe Sixpack WiFi APs) stations. I believe the consensus is that you're not supposed to communicate like that, but I don't think anyone has proposed effective access controls for it. Any suggestions?
funny munging
Actually, amateur radio operators are *licenced* users of the 2.4ghz spectrum that wifi uses. Wifi is a part 15 *unlicenced* user. Operating under part 15 means accepting any/all interference and causing none to licenced users. Hams have known this all along. Wifi users don't ask/don't tell.
Technically, yes. As a matter of regulatory policy, no. Right now encryption is prohibited unless the transmission involves authentication for control operations of another amateur radio station. Otherwise transmissions must not be obscured in an attempt to hide their meaning.
A spirited debate is ongoing at QRZ.com over this same topic.
The fact is that amateur radio is regulated not only by individual adminstrations i.e. FCC in the U.S.A., but also by ITU treaty regulations as well.
Commercial traffic that is a direct benefit to either of the parties conduction the contact are prohibited as is content of an obscene nature. In short, ham radio is not currently a legal way to provide "last mile" internet. You're still limited to 802.11A/B Part 15 devices for widespread unlicensed use.
"Insanity is doing the same thing over again expecting a different result."
What, exactly, would the FCC be looking for?
Of course, the fact that licensed amateurs aren't limited to the micro-power levels of Part 15 devices comes into play here.
Legally, licensed amateurs are required to use only the minimum power required to maintain communication... but the rules allow up to 1500 watts on most authorized bands (the hazards of 1500 watts at 2.4 GHz, particularly anywhere near the antenna, are left as an exercise for the reader).
Part 15 devices may not interfere with licensed operations, and must accept any interference caused by licensed operations.
The big advantage would be speed. Packet radio is slow. 1200baud is still the norm on the 2m band.
The bandwidth of 802.11b is too much to be run on any of the VHF bands, but 70cm (440MHz) or higher may be plausible. I envision the first efforts no on 2.4GHz involving a transverter (which would convert 2.4GHz down to something else for transmission, and back up for reception)
As for usage of the existing 2.4GHz band, I regret to inform the unlicensed users that radio amateurs had greater legal access to the band well before 802.11 came along. We have a secondary allocation to part of the band, and primary to another part. Unlicensed users, using the band under the part 15 rules, have no rights whatsoever. Even so, I see no reason why we need to go chasing each other around the bands, and I disagree with the point of view that was expressed in the ARRL article. You might, though, as a courtesy to us, pick a channel above 5, since only 1-5 can be used uner part 97... where they can be used with linear amplifiers quite legally (again, assuming the user is in posession of a license).
Regarding this system replacing the internet.... I am not certain that ham radio can do that. My main concern is the fact that we cannot carry messages for hire, nor can we carry any sort of commercial traffic (a single pop-up, spam, or ecommerce site would cause a legal problem). What will make things interesting is that it will be possible for someone with an unlicensed rig to communicate with someone using a high-powered licensed rig. This will mix up the rules a bit and I'm not sure what the end result will be....
www.wavefront-av.com
The posting shows the ARRL's name the "Amateur Radio Relay Legue," this isn't quite right. The ARRL is actually the American Radio Relay League, a National Association, primarily for Amateur Radio operators and interesed parties. It now has over 163,000 members and a staff of 120.
Trying is the First Step to Failing --Homer Simpson
Actually, you would be surprised what "their current gear" includes. Hams have been broadcasting and receiving SSTV (slow scan tv) for literally decades. Packet radio (which requires computers) for a very long time, have been doing homebrew GPS, Autopatch (radio to land-line) etc.
About the only "new" equipment needed would be a 802.11 compilant transciver, which is nothing more than a radio that can transmit and receive at a given frequency (and a bit-o software), when you get right down to it.
-73-
"If, therefore, any be unhappy, let him remember that he is unhappy by reason of himself alone."
~Epictetus
Is there much a determined radio amateur couldn't jam?
It rarely happens on purpose. Causing intentional harmful interference is a big no-no in amateur radio. It's against the spirit of the hobby, and quite illegal in most places. Among other things, the amateur radio rules require a specific receiving party; you can't just transmit garbage for no reason.
That said, part 15 devices must accept harmful interference from properly licensed non-15 devices. If a receiver can't handle a nearby signal from a device operated legally under part 97 (with proper identification, power output, receiving end, etc), too bad. Get a better receiver or petition the FCC to open up more frequency space to unlicensed low-power devices. I think that's the real solution.
-John, KG4RUO
Except part 97 does not permit broadcasting. :) Seriously, I see almost no potential for using 802.11b in any normal way on the ham bands. The story says they hope this will encourage existing part 15 users to get amateur licenses and operate under part 97. I just can't see any practical motivation for this.
Remember, ham comminications must not be encrypted. They must not be commercial. (This means no ads, no non-ham commerce, basically no websurfing.) They must not be broadcast. (Not really a problem, not much different from packet radio this way.) Each transmitter must identify itself. (I suppose using the ham callsign as the SSID would work for that.)
Sure, hams can have fun playing with 802.11b under part 97, but because of the content restrictions it's in NO WAY any replacement for the people operating under part 15. Seriously, how useful is a network connection that is not allowed to be secure or be used for commercial traffic.? Yes, it has potential for ham-related events, contests, and emergencies. But I don't see anything else.
One peeve of mine is that hams have become followers and are no longer leaders in radio technology. There was a time when hams did things first, and commercial radio products and services grew from those efforts. Technology has mostly become too complex for the single hobbyist to provide a substantial development contribution. Now the ham community mostly waits for commercial technologies to become old and inexpensive, then adapts them for their own purposes while adding little or nothing new. A large part of the reason hams are allocated valuable spectrum is for innovation, but in the past decade I've seen only regurgitation. I would love to use my ham license to do something I couldn't do more cheaply and effectively on the commercial bands. 802.11b under part 97 is another example of less functionality for more effort.
I'm not saying it's not worth doing, just that it's only useful to the hobbyist who wants to play and do a thing because it can be done. I'm saying it's not useful to anybody who wants to operate a real and practical wireless network.
In the hours/days after the WTC attacks, most of the cellular phone infrastructure in lower Manhattan was dead, not simply overloaded. During that period ham communications aided many agencies begin the rescue efforts, including fire, police and the Red Cross. Most of these agencies' radio equipment operated on non-compatible frequencies, so even though their radios were working, they could not talk to other groups. Many hams volunteered as "shadows" who stayed with officials of the various agencies, allowing them to talk with other officials via ham frequencies. This lack of interagency communications still exists today, although the problem is being addressed at the local, state and federal levels.
George/W2GEK
Look at all the happy creatures dancing on the lawn...
Communication for media sources is incidental and usually prohibited.
The communication that Hams in ARES and RACES (look 'em up) was for the EMERGENCY WORKERS and GOVERNMENT, plus support systems like Salvation Army (see SAREX) and Red Cross.
We act as an auxilliary communications system. When the hospital needs supplies, for instance, and can't get through on the phone, it will be Ham operators who get that message through.
You don't get it--all of the "modern" communicatiosn methods are easily disabled or overloaded. Even trunked police radio systems are vulnerable--but Hams with HT's and training can provide the backup that we need.
Hams saved lives, people. Many of us are in this hobby primarily for public service--so that we're ready to help when the time (9/11, OK City, natural disasters, disaster weather) comes. We spend our own money and our own time to equip and prepare our emergency forces--it's an all volunteer system.
You may someday owe your life to the actions of a Ham.
Jim
kc0lpv