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802.11B and Amateur Networks

Ron (N6QL) on March 27, 2003
View comments about this article!

802.11B and Amateur Networks

This month there was an article in CQ called "IEE 802.11b: Friend or Foe?" as well there was an article in the February or January QST about the ARRL's initiative to "invent" an amateur 802.11b network.

I had a couple of comments to share with the purpose of raising awareness in the amateur community.

First, I found it a bit humorous that the ARRL positioned this as such a big project with all sorts of unknown issues and technology. The reality is there is little mystery here. It's quite simple to build a network of off-the-shelf 802.11b components that use amateur frequencies and conform to amateur part 97 rules. No special modifications are required - just configuring the equipment properly (including not using encryption). Virtually everything is available off-the-shelf although some equipment works better than others (just like all amateur gear!).

In reference to the comment in CQ about the amateurs in Livingston County MI possibly having the first amateur 802.11b network. This is quite incorrect and certainly not possible because I'm quite certain this title has already been claimed. I don't know who the first is but I can say that I have been running such a network since the late 90's first on the 900mhz band with FHSS equipment conforming to amateur FCC rules (this was not 802.11 though) and then when the FCC relaxed the spread spectrum rules on amateurs several years ago, on 2.4ghz with 802.11B DSSS radios. Prior to IRLP, I demonstrated digital voice repeater linking (similar to what IRLP is today) to the CalNet repeater group during one of their nets by linking my 1.2ghz repeater to their 70cm statewide system over a 10-mile 900mhz FHSS digital voice link using 200mw.

My 802.11b "amateur" network has been up for over 2 years. It covers a distance of approximately 15 miles using 100mw of power and wire mesh dish antennas gain. It is used to communicate both digital voice, control, and telemetry information to and from my 1.2ghz and 900mhz repeater system on a 2500 foot mountain site to my home QTU as well as to provide Internet and webcam services to my airplane hangar at the local airport - nearly 10 miles away. The system is legal as a part 15 system since it conforms to all rules in under that part however it is configured in such a way as to conform to amateur rules including IDing and frequency. This network provides 11mbit of data bandwidth 24/7 and rain or shine.

I don't know whether this is the first but it has been in operation LONG before the ARRL got interested.

I should also note that I got in touch with the ARRL people who where highlighted in a recent article in QST and on the ARRL website, told them of my work, and described in detail my system. They asked me many questions on how I did it etc. etc. and promised to include me in their project but then I never heard more from them.

On another note, I'm a bit concerned about the apparent lack of responsibility and arrogance on this project and some of the other 802.11b discussions (such as the CQ article). There is talk of running high power and the use of omni antennas. This will cause considerable interference to the many part 15 users - as well as other amateurs and only serves to raise the noise floor. First, this is not needed and under the FCC part 97 rules these systems should (and can) be operating at minimal power. I have done tests with 100mw and have achieved reliable communications over distances of 25 miles with careful attention to using low-loss cabling, quality receivers, and directional antennas (and still be legal for part 15 by the way).

This limit was not due to a limit of the radios but rather my time limitations to do longer range testing. Second, the attitude of "we are amateurs and part 15 users have no rights" as has been articulated by some involved in these projects is misguided. This type of inconsiderate "we own it" operation is likely to raise the ire of commercial part 15 equipment vendors and users who will rally against the amateur community under the banner of "benefiting the greater good".

I strongly suggest that any amateur who is interested in using 802.11b equipment for amateur use start doing so now but do so with responsibility. This is not that hard to do and I believe this is a straightforward effort for any amateur with even a small amount of UHF/microwave experience. It is quite easy to do and not nearly as complicated as outlined in the ARRL article.

73,
Ron Curry
N6QL

Member Comments:
This article has expired. No more comments may be added.
 
802.11B and Amateur Networks  
by N1AUP on March 27, 2003 Mail this to a friend!
I'm happy to discover that someone is running 802.11B over ham radio frequencies. IMHO, this technology has the potential to rescue ham radio from irrelevance in today's world of instant communication.

What if ham radio could provide a wireless internet that could provide computer to computer, voice and video data transmissions during times of emergency? What if a FEMA official could connect his personal laptop to a ham radio WAP, which linked him to other emergency personnel as easily as connecting to his cable modem? It’s more than likely that a serious disaster will shut down the real internet. Wouldn’t it be great if hams could provide a high performance alternative at no cost to the government? Just think of the possibilities! How could anyone justify taking away microwave spectrum space from us if hams provided the only backup to data communication?

I believe that we need to lay out a framework to design such a network topology, and need to implement this technology as soon as practically possible. We can’t let this opportunity get away.
 
RE: 802.11B and Amateur Networks  
by K0BG on March 27, 2003 Mail this to a friend!
I'm not surprised at the response (or lack of it) from the ARRL. It seems their growing size has stunted their ability to communicate effectively and exaserbated their lack understanding of their membership.

There will always be distractors to new technology and 802.11 is no exception. For those who think 802.11 is not amateur radio are only showing their lack of understanding as well.

My only concern is that the radio spectrum is finite and everyone it seems is looking for their personal chunk.

Alan, KØBG
 
RE: 802.11B and Amateur Networks  
by N2OBY on March 27, 2003 Mail this to a friend!
I totally agree that this could go a long way towards furthering our ability to help out when needed. However, unless he/she was a licensed amateur, I don't think that FEMA offical would be able to connect to the amateur network.

Ken N2OBY
 
RE: 802.11B and Amateur Networks  
by KA0MR on March 27, 2003 Mail this to a friend!
How is 802.11 Part 15 devices being used in the amateur service going to accomplish this??

There are many of us at 2.4 Ghz experimenting with weak signal propagation investgations for years. We have been here for years and suddenly with the 802.11 broadband device for sale now suddenly it's heaven sent.

This equipment to experiment has been here long before cheap piece of crap trashy RF spewing Part 15 was available. Why are you nowintrested in populating this band. Why haven't you went and invested in the clean equipment that's been around for so long. How is is going to save the band.

Just what we need Internet Nirvana in a band that requires clean signals to experiment with. Look at where the part 15 devices are assigned. Right where us experimenters have been for 30 + years.
Oh brother just what we need.
 
RE: 802.11B and Amateur Networks  
by W7STA on March 27, 2003 Mail this to a friend!
I thought the 802.11b article in QST was an April fools joke. Afterall, why bother to change one's SSID to their call sign and turn off WEP (for what ever that's worth!)? My wireless LAN at home is strictly run as Part 15, WiFi consumer grade products.
 
802.11B and Amateur Networks  
by WB8WKA on March 27, 2003 Mail this to a friend!
Ron:

I was running spread spectrum under part 97 in Farmington Michigan in 1995 (under the TAPR STA). My longest link was 12 miles. This was not reported in the ARRL article.

I'm trying to figure out why you are so upset.... that you where not mentioned in the article? I'm not upset that my Spread Spectrum network that predated the HSMM by 7 years was not mentioned. I do this for myself, not for fame and glory.

I had a chance to research this a little.... your postings on the ARRL 802.11b mailing list where very impressive. The vow you made on the HSMM reflector was not. (and yes, I took you very seriously)

I think it would be reckless for you to do this, regardless of your pesonal aminosity towards the ARRL for being overlooked. I myself have a mistrust of the ARRL but twice now I have been pleasently suprised by them, once yesterday and the other time when they formed the HSMM.

Point is, it is going to take time for any group to come around to a more modern way of thinking. The ARRL is not excluded from this. Like it or not, it is the only viable PAC amateurs have in Washington. To engage in wreckless behavior (or threaten to) will only harm amateur radio in the long run.

Please some back to the 802.11b mailing list and make your views heard, instead of putting the sour grapes here. I will support you and I'm sure most on the list will.

Best 73's,

Jeff wb8wka


 
RE: 802.11B and Amateur Networks  
by KT8K on March 27, 2003 Mail this to a friend!
It sounds like the barn door has been open for a while, as far as part 15 devices operating in our band, and I doubt there's any stopping it now. We should make the most of it however we can, and embracing and building on the best technology we can will let us rise above it with new inventions and practices, as hams always do.

It is distressing, however, to sense another ARRL bureaucratic snafu developing. I have seen evidence of prior not-invented-here agendas in our national organization, and feel they hinder rather than help the hobby in these instances. I wish they would drop all pretense, and embrace hams and what hams do best: innovate and advance the hobby. Hams so very often surpass the best efforts of commercial ventures. I love it when they/we do that, and feel the ARRL should be trying to capitalize on it rather than seeming to protect commercial interests. I say to the ARRL: Please, let's lead by working together rather than getting tangled in politics and holding ourselves back.
Just my humble opinion - 73 de kt8k - Tim
 
802.11B and Amateur Networks  
by AB8LN on March 27, 2003 Mail this to a friend!
Dear Ron Curry,

As many users are pointing out, your emotional investment in the subject is tipping your hand. You are just crying because you are not the oldest and wisest amateur with knowledge of radio networking. Your caustic comments about gifted and knowledgable amateurs that are well respected, and at the top of their fields (WALT K5YFW) show that you must have an alternative agenda. You are an amateur yourself but seem to want to disband amateur radio altogether to be replaced by ISM band activities. What is your point to all this rambling. You know how to setup networks? No one else does. We should all look to you as the oracle on high California mountain?

Mark Williams AB8LN
 
FEMA  
by WA4MJF on March 27, 2003 Mail this to a friend!
Hi Ken,

FEMA actually has ham calls assigned
by NTIA. They are WF,NF,KF,AF- # -EMA.
For example, WGY912 in Berryville is
KF4EMA when on the ham bands. That call
had been assigned to a ham, but when those
callsign blocks were given to NTIA, the
FCC changed his.

Of course, NTIA has several blocks of ham
callsigns, but most are assigned to DOD,
such as the KG4xx callsigns at GITMO.

73 de Ronnie
 
802.11B and Amateur Networks  
by N9DG on March 27, 2003 Mail this to a friend!

It is really too bad that none of the existing gear for lower bands (HF - UHF) can take good advantage of this. This technology is a natural for building remote controlled HF stations. There is plenty of bandwidth and protocol robustness available in 802.11B to do it effectively. Now only if our lowly HF/VHF/UHF gear was designed around Ethernet standards for control and audio I/O (digital data transfer) we could really be doing some fun and innovative things with this (as I've ranted about here on eHam and elsewhere before!!).

Hey radio gear manufacturers will you now start thinking and listening??
 
802.11B and Amateur Networks  
by KC2JKD on March 28, 2003 Mail this to a friend!
I think there has been a misunderstanding somewhere along the line. I was a part 15er way before being an Amateur Radio operator and have been welcomed with open arms to the HSMM. As to the ARRL being slow and out of touch, the fact that they are looking into this at all is a huge step forward. Everything takes time and large organizations like the ARRL take time as well.
Incidentally, the HSMM is not only about 802.11b. The goal is to bring high-speed multi media capabilities to Amateur Radio. 802.11b is merely a starting point from which to leap off of. I encourage you to rejoin the list, as I will support you as well (as long as you are correct). No one is perfect.
-Derek, KC2JKD
www.nycwireless.net
 
RE: 802.11B and Amateur Networks  
by K8OCL on March 28, 2003 Mail this to a friend!
Excuse meeeee....as Chevy likes to say (HI), but I wrote Ron a very long reply, and he did not reply to me!

John Champa, K8OCL
ARRL Chairman
HSMM Working Group
 
RE: 802.11B and Amateur Networks  
by K8OCL on March 28, 2003 Mail this to a friend!
Ron is only writing about conventional WLANs. We are working towards mesh networking using 802.11 technology adapted to Part 97. Big difference.

John Champa, K8OCL
ARRL Chairman
HSMM Working Group
 
RE: 802.11B and Amateur Networks  
by K8OCL on March 28, 2003 Mail this to a friend!
We are trying to very inclusive, even going so far as to try to recruit technically oriented Part 15 users.

Most of us are engineers and technicians. We hate these arcane political, and nit picking legal debates on all the HSMM lists.

Let's just get out there and have some good times together experimenting on the air!

Vy 73,
John Champa, K8OCL
ARRL Chairman
HSMM Working Group
 
802.11B and Amateur Networks  
by W8UR on March 28, 2003 Mail this to a friend!
Ego and sour grapes. A PtP link is not a network. Large mesh dishes and 100 mW are not suited for ad hoc 802.11 networking.

 
802.11B and Amateur Networks  
by K9COX on March 28, 2003 Mail this to a friend!
Ron, I agree with you completely. It is indeed extremely simple to install a wireless network from readily available standard components for whatever purpose one can imagine on amateur allocated frequencies. It is easy to add system components such as gain antennas to bring it into the realm of Part 97. That being said in your own words, what is the big deal?

Have fun with it!
73, Ross K9COX
 
RE: 802.11B and Amateur Networks  
by KB0KFX on March 28, 2003 Mail this to a friend!
Greetings all. I am usually not one to post my opinions, but I feel strongly for this topic.

Firstly, I would like to comment on the articles that were published in the two magazines mentioned. The editors of these magazines are always looking for new content to publish. All articles are submited by people who want their topic published. If it isn't brought forth, it does not come to their attention. That goes for most any publication.

It seems that there is a big polical rant and bitter feelings between different parties. As I recall, I am an amateur radio operator part of a large community of people who like to talk, voluteer, and further the radio art. The original article in the thread had some sort of purpose, but like others have said that it is more of a rant. Some people don't want to belong to an institution, fine. Like it or not, we are institutionalized. There is no reason to wage a personal attack against the ARRL or whomever it may be.

I have not been around as long as other people, but I am able to recognize the priorities of the hobby. To make it abuntantly clear, the ARRL is our savior of amateur radio in the United States. If you are not a member, seriously consider of becoming one. The ARRL is our future of the hobby to give organization, education, and focus on the future of the hobby. A big round of round of applause to all ARRL employees. Anyway, I don't want to drift astray to far.

Addressing the topic specifically, 802.11 is a great thing for amateur radio. If we pass up opportunities like this, too many heads are in the sand. If you have been paying attention, the ARRL is revamping their education and ham radio awareness strategies. Just think to yourself what interested you in amateur radio in the first place. Was it the new mode of SSB, FM repeaters, packet, APRS, or IRLP? Hams from all the generations have experienced these modes appearing in the hobby. Most of the advantages of 802.11b and high speed wireless networking are the obvious by utilizing them for emergency communications and all of its affiliations. This mode has major bonus points with giving the ability to service the public in a time of need. In my own opinion, this is part of what interests the ARRL so much.

From a more technical aspect, I think a major reason of why it has been getting so much attention lately is because of the availability of commerical gear at affordable prices. It is an easy way to get involved and utilize the higher frequency bands while on a budget. I don't see any affordable radio gear for the GHz bands on the same price line as a new HT. Most gear is homebrew or modified surplus. Everyone doesn't have that knowledge, access, or time to experiment in these frequency bands. I know some may argue differently, but it is the truth. Also, there has been much discussion between the Part 15 (unlicensed) and Part 97 (ham radio) rules. Since this is such a new "mode", most are being cautious of complying with Part 97 rules. For the most part the usage would be the same, but if we want to cash in on using a higher power, then the Part 97 rules come into play. Sure, the performance of a 100mW spread spectrum radio might be very good. But knowing full well of what amateurs do best, "we do it because we can". We are limited by a mere 100 watts on this band. hi hi. Ten miles for us is not enough. Licensed use (ham radio) is the primary user of this band, and Part 15 is a secondary service. We have many other allocations like this on the frequency bands. We have to peacefull coexist.

Well, I hope you can read into some of my points and thoughts. This is a quickly typed reply, but thought I would give some input. Good job to all those furthering the radio art and all who do good for the hobby. Keep it up. All views are on my own behalf and do not represent the ARRL, but am a proud member.

It seems the older we get, the more we become set in our ways and are more likely to rant and create resistance for no apparent reason. In any subject matter, try to understand all points of view.




 
RE: 802.11B and Amateur Networks  
by W4AN on March 29, 2003 Mail this to a friend!
Well, I'm putting this technology to work. I own an ISP company (that hosts this site) in Alpharetta Georgia. I have a cabin in north Georgia where my contest station is located. I have managed to span 50 miles on 2.4Ghz with 4 seperate hops to deliver T1-like speeds to the cabin. I'm then, operating my station remotely over an internet link using some new software a friend of mine wrote. The longest hop is 24 miles from Sawnee Mountain in Cumming Georgia to Burnt Mountain near Jasper Georgia. The link has been up almost a year with very few outages.

At any rate, I'm also in the process of delivering high speed Internet to people in north Georgia over these links. The folks currently have only dial-up connections with no real hope of DSL or cable. There are actually quite a few hams getting in to this business around the country, although I'm not sure it is a great business opportunity. I see lots of folks getting in, and then getting out.

73

Bill
 
RE: 802.11B and Amateur Networks  
by KA3JIJ on March 29, 2003 Mail this to a friend!
KB0KFX incorrectly states in his pose that "Licensed use (ham radio) is the primary user of this band, and Part 15 is a secondary service."

If you look at the Amateur band allocation at 2.4 gHz you will find that Amateurs have a primary allocation at 2390 to 2400 and 2402 to 2417 MHz. Both allocations contain insufficient contiguous spectrum to contain the spectrum assigned to an 802.11 carrier. The remainder of the band is allocated like this:
2390-2400 MHz Primary
2400-2402 Secondary
2402-2417 Primary
2417-2450 Co-Secondary
Given this hodge podge allocation, I don't think it's clear whose rights supercede in these bands, but it's certainly a question I'd like answered.
 
RE: 802.11B and Amateur Networks  
by KA8NCR on March 29, 2003 Mail this to a friend!

There's one issue that hasn't been touched upon by any party, organization or person that was "first to deploy this technology".

I am concerned about the coexistence of Part 15 devices with Part 97 devices. Namely, the very real potential of non-licensed people using Part-97 networks. Because amateurs can not employ WEP, SSL/TLS or any other form of encryption on their network, the only authentication seems to be by MAC address (nope, RADIUS won't work either). It doesn't take a genius to insert a MAC shim (most devices support this anyway) and sniff the network to find a permitted address.

Has anyone thought about the consequences of someone discovering a HSMM network and trying to share their collection of Heidi Klum semi-nude photographs? Granted, I think this contribution to amateur radio would be of great entertainment value, but that doesn't excuse the obvious license infractions.

Just voicing my concerns.
 
RE: 802.11B and Amateur Networks  
by WA4MJF on March 29, 2003 Mail this to a friend!
KA3JIJ, Part 15 devices must ALWAYS
accept interference from licensed services and
must NEVER interfere with licensed services.
Any interference must be corrected by the
Part 15 user.
I fail to see that there is any confusion!

73 de Ronnie
 
RE: 802.11B and Amateur Networks  
by KA3JIJ on March 29, 2003 Mail this to a friend!
WA4MJF, Thanks for the reply. I think my original message was poorly worded. I was not stating that Part 15 users might have any rights in the band. More clearly stated my question is: Given the majority of this band is allocated to Amateurs on a secondary basis, Who is the primary licensed user in the band that we as amateur users might have to be aware of?
 
RE: 802.11B and Amateur Networks  
by WA4MJF on March 29, 2003 Mail this to a friend!
As with most of our UHF, EHF and SHF bands,
it is the US Government. This is kinda of a
protection for us, as NTIA has not shown an
interest in givin' away their sat freqs, as they
have their other allocations.


They have given many of their HF and VHF allocations
to the FCC.


73 de Ronnie
 
802.11B and Amateur Networks  
by KB4IUJ on April 1, 2003 Mail this to a friend!
Does anyone have a setup online via a website, so we can have a look at your setup. I'm located in the middle of the country where my dial up speed is a blazing 24,000bps...56K is a dream.

My only hope is wifi !
 
RE: 802.11B and Amateur Networks  
by K8MZO on April 2, 2003 Mail this to a friend!
>WA4MJF, Thanks for the reply. I think my original >message was poorly worded. I was not stating that Part >15 users might have any rights in the band. More clearly >stated my question is: Given the majority of this band >is allocated to Amateurs on a secondary basis, Who is >the primary licensed user in the band that we as amateur >users might have to be aware of?

According to my chart from the NTIA those parts where hams have secondary allocation no service is specified as having primary allocation. There does exsist such situations.
 
RE: 802.11B and Amateur Networks  
by WA4MJF on April 2, 2003 Mail this to a friend!
Well, I've been retired for a while!

Two systems that the Army used back in my day
that are sure to be obsolete now, are the
AN/TRC-29 multichannel which had it's upper
limit frequencies in the 2.4 Gig range and
the AN/MPQ-10 Counter Battery Radar. This
was a neat machine that allowed us to watch
Charlie fire his mortars at us and tell us where
he was so we could shoot back. It operated
in the mid to high 2 Gig Range.

As I said I'm know all that stufff is obsolete,
so maybe NTIA doesn't have any users there any
more.

Any how it is good that NTIA still hangs on to them.

73 de Ronnie

 
RE: 802.11B and Amateur Networks  
by VE3TOS on April 3, 2003 Mail this to a friend!
What are the address for the two mailing lists? The one from arrl and hsmm? I can't seem to find them.


Thanks
 
RE: 802.11B and Amateur Networks  
by WA7NWP on April 3, 2003 Mail this to a friend!
> Given the majority of this band is allocated to Amateurs on a secondary basis, Who is the primary licensed user in the band that we as amateur users might have to be aware of?

---

We're playing second fiddle to a kitchen appliance - the microwave oven.
 
RE: 802.11B and Amateur Networks  
by WA7NWP on April 3, 2003 Mail this to a friend!
> What are the address for the two mailing lists? The one from arrl and hsmm? I can't seem to find them.

1. At TAPR: http://www.tapr.org/cgi-bin/lyris.pl?enter=ham-80211&text_mode=0

2. HSMM - see the Contacts page at www.arrl.org/hsmm - http://www.arrl.org/hsmm/contact.html
 
RE: 802.11B and Amateur Networks  
by VE3TOS on April 3, 2003 Mail this to a friend!
Thanks!
 
802.11b mini tutorial  
by N6QL on April 5, 2003 Mail this to a friend!
Here is an attempt at a mini 802.11b tutorial to help frame some of the issues in my original article. This may not be a perfect explaination and some industry experts may find some things wrong with it but it's a reasonable summary I believe.

Let's simplify the discussion and break it down into sections. First, let's define the devices used in 802.11b based communications then let's discuss how the writers of the specification intended them to operate, then we can discuss using 802.11b in a wide area network environment vs what it was originally architected for (local area networking).

Let's define the devices first...

Bridge - Bridges are not defined in the 802.11b spec however many manufacturers have designed a bridge "feature" into their AP's. In simple terms bridges are special access points that allow all traffic to pass transparently between the radio port and the wired port or, in some cases, in the radio port and back out the radio port (like a repeater). A bridge doesn't modify or route the information it simply sends whatever comes in one port (either the radio port or the wired port back out the other port with no changes.

Bridges are usually used to connect two networks together in a point-to-point arrangement although some bridges support point to multi-point configurations where one bridge is designated as a central master bridge which communicates to multiple slave bridges. In this configuration the master bridge not only bridges between it's own radio port and wired port but also behaves as a repeater by repeating everything it receives back out the radio port. Cisco recommends not using more than 4 or 5 slave bridges in this environment since the repeater action severely limits throughput due to all traffic being re-transmitted to all other bridges (they need not all hear each other - they need only hear the master). Some bridges (the good ones) can do limited routing via MAC and IP filtering which can help limit the forwarding of unwanted traffic in this situation as well as in the normal bridge configuration. The bridge protocol is not specified in the 802.11b spec and is proprietary to each vendor therefore bridges from different vendors will not talk to each other!

Access Point - These devices are designed to be centrally located among a group of clients and provide a "bridge" for a small number of these clients to a wired network. They are designed to support a hub and spoke type of network. Although the specification supports up to 255 clients per AP, (I think that's the max - I could be mistaken) the number is limited in practice by throughput considerations and is usually capped by the network designer/admin at 5-20 depending on throughput requirements, network topology and link speed capability. In an "Infrastructure mode" environment (defined below) most AP's also act as a very basic router deciding whether to route traffic from clients to the wired ethernet port or repeat the traffic back out the radio port to another client. AP's can only communicate with clients and cannot communicate with other AP's via the radio port unless they have bridging capability and it is enabled. Of course in this case they become a bridge as described above. Some AP's can operate both as a bridge and a normal AP at the same time (Cisco's for example)

Client (also called "wireless stations") - Clients are typically PC cards plugged into a notebook computer, or PCI cards plugged into a desktop machine. There are also client devices that interface via USB or via an ethernet cable. The radios are the same as all other devices except the control firmware identifies these devices as clients and they run the client specific side of the 802.11b protocol. In "Infrastructure mode" (the most common configuration), a client can only communicate with an AP and not other clietns. It can, however, communicate directly with other clients if both clients are configured in "adhoc" mode. As I'll explain below, this mode isn't desirable for most environments. I won't go into the protocol details but clients are essentally slaves to AP's and behave as such.

Now let's discuss the 802.11b specification for a moment and what it was designed to do in simplistic terms. The 802.11b specification was designed to enable local area networking of wireless devices with "wired equivalency" via two operating modes - ad hoc and enterprise.

Ad-hoc mode (sometimes called "peer-to-peer mode"
This mode of operation allows any radio to talk to any other radio as long as they have an adequate signal to hear each other. There is no requirement for an AP although one may be used if it can be configured as a client. This mode is the closest equivalent to amateur packet radio where all radios are on the same frequency and every radio hears every other radio that is within range. This mode is designed for very small networks with just a few clients where it is guaranteed they can all hear each other. It is susceptable to "hidden transmitter" problems to a certain extent but the impact is merely a performance degration rather than bringing down the entire network as with amateur packet radio. The 802.11b protocol includes a CTS/RTS (clear to send/ready to send) capability that minimizes this problem. Of course the more "hidden transmitters" there are in a given network the more degradation there will be due to the extra CTS/RTS traffic.

Adhoc mode is VERY inefficient for more than a few stations and through-put and range are limited because all stations hear all traffic (just like amateur packet radio). The 802.11b specification says this mode was provided in the specification primarily to enable a handful of clients that are in close proximity (i.e. within the same room or
building) and that have no need to connect to a wired network, to quickly connect to each other and form a small "adhoc" network.

Infrastructure mode (sometimes called "enterprise mode")
This mode specifies a central "Access Point" and numerous clients in a hub and spoke arrangement. All traffic is routed through the AP. Clients can only communicate to other clients via the AP and not directly to each other. In larger networks the AP is commonly attached to a wired network. This might be directly to the wired Internet, or a private wired interconnect (or backbone) which connects servers, wired clients and other AP's together. This is the mode that is most commonly used because it provides for higher security and more efficient use of the available bandwidth and higher throughput than an adhoc network.

Now let's explore why 802.11b isn't well suited for implementing wide area networks except in certain configurations as part of a more complex solution likely using multiple technologies and network topologies.

802.11b was architected to allow network managers to set up WLANs (wireless local area networks) with relatively broad coverage (100's of feet to a couple of thousand feet) by creating a series of overlapping 802.11b cells throughout a building or across a campus. These cells are designed to have a relatively short range of a couple of hundred feet so as not to interfere with more distant cells which may be using a channel that has frequencies with overlap. Cell to cell communications was originally intended to be via a wired network (hence the reason why bridges were not part of the specification).

802.11b was never designed to be a "city-wide" (or state-wide, or country wide) networking solution with high level, high powered access points on omni-directional antennas covering miles. Here is why:

802.11b based networks were intended to be the wireless equivalent of a LOCAL area network (LAN) where relatively small groups of clients
(workgroups) needed access to the local wired network. It was never intended and nor do the protocols effectively support WIDE area network
(WAN) capability (like GSM for example) with many clients spread over a broad geographic area (miles vs a few hundred feet). Nor does the 802.11b contain protocols to deal effectively with AP's that have overlapping RF coverage areas.

The 802.11b protocol depends on the concept of "channel reuse" to prevent collisions and ensure useful and successful networks. There are only 14 channels specified in 802.11 DSSS and amateurs can only use six. Out of the 14 there are only three channels that do not overlap. It is important that each access point be geograhpically located and the setup on an 802.11 DSSS channel so that it does not overlap with the channels used by neighboring access points. Otherwise, they will collide with each other and reduce throughput. Because nearly all channels overlap, this is only possible if the devices have limited range. Devices in range of one another WILL cause interference to one another EVEN IF ON DIFFERENT CHANNELS unless they can be set on non-overlapping channels. Collisions will lower the total available bandwidth FOR EVERYONE. If the access points are high level or run higher power than the 802.11b architects and the FCC intended, one can easily see an environment where there are numerous AP's and clients in a given geographical area throughput will slow to a crawl. With only three overlapping channels it's pretty obvious it doesn't take many stations to reach saturation.

In a normal 802.11b network, it is a challenge to ensure that AP's do not overlap but because each AP's range is only a couple of hundred feet it is possible. However, in the kinds of networks that some amateurs are hoping to deploy with high power levels and high-gain omni antennas, the range of their AP's will be miles. In an urban environment there will most certainly be many, perhaps hundreds, or even thousands, of low-level part 15 users happily running their 60-100mw AP's in their home or business environments. Once the amateurs in the area start broadcasting with their 500mw - 10w APs the non amateur AP's will start having collisions with the high powered amateur equipment. Some of this will undoubtably interfere with the amateurs but it will be the part 15 users that will get really clobbered by the high power levels the amateurs are running. The part 15 users will see reduced throughput and performance. It is also important to note that this is really quite EASY to trace since most AP's and clients can be set to identify all stations they are receiving (or being interfered by). In a high density city environment literally thousands of users will be able to see the SSID's and node descriptions of those interfering with them.

This is the similar problem to that which amateur packet radio networks in areas which contain many stations have today. It's made much worse by the fact that 802.11b channels overlap, there are only a small number to choose from, and the fact that there are already millions of non-ham users using 802.11b based hardware for business and personal use.

802.11b was just not designed for "cells" to have ranges measured in miles. We (hams) need to consider and define better ways to achieve some of our goals. Simply trying to replicate our packet radio topologies or the simple hub/spoke topologies that the 802.11b architects specified for the relatively short range radios they had in mind will not work effectively. Mesh networks of 802.11b nodes is also not likely the answer either because it suffers from the same issues described above with regards to the many radios necessary to achieve the overlapping "mesh". Point-to-point links with highly directional antenna overcome some of the issues (not all) and are useful for connecting strings of stations to gether but they don't address the "dreams" of many amateurs of setting up their own "Internet broadcasting stations". We need to have some serious dialog to determine responsible and effective solutions and recommendations to deal with this.

Hope this helps.

Ron Curry N6QL
 
802.11B and Amateur Networks  
by WA2JJH on September 9, 2004 Mail this to a friend!
I do own a 2.4 gig 1 watt TX and RX. It sits in my closet.

All laptops have 802.11B. Some have a,c and G band too.

I use wireless laptops all day, every day.
My 2.4 GIG homebrew video/audio TX just gathers dust!
Cost me $500 to build 5 years ago!

2.4 gig wireless cards cost maybe $60bux now.

Who knew?!
 
RE: 802.11B and Amateur Networks  
by WA6BFH on March 17, 2005 Mail this to a friend!
The military has the primary allocation use in most of “our” UHF and SHF spectrum; we are secondary.

Also, I’m not sure that any such usage would stand analysis for coordination in Amateur applications. Noise floor would have to be assessed for any given ‘community service area’, and the intended coverage within that area.
 
RE: 802.11B and Amateur Networks  
by K3ROJ on June 3, 2005 Mail this to a friend!
I have recently been experimenting with FM ATV on the 2.4 GHz band using gear sold by a amateur radio dealer in California. To obtain good quality video for a typical 10 mile path it is necessary to run about 1 watt or so. When first starting to receive another amateur station there was terrible interference from at least two 802.11b units in my neighborhood. I was told to leave my transmitter on for long periods and to transmit indentification on the video to make it legal and by doing this for several days the interference went away. I later heard that the 802.11b units were taken out of service since they couldn't be depended upon and the networks were hardwired with CAT5. That proves that most wireless lans are not needed and people should use wired hookups to prevent interference with amateur service.
 
RE: 802.11B and Amateur Networks  
by KB7YOU on June 25, 2005 Mail this to a friend!
K3ROJ Wrote "When first starting to receive another amateur station there was terrible interference from at least two 802.11b units in my neighborhood. I was told to leave my transmitter on for long periods and to transmit indentification on the video to make it legal"

In other words, instead of being a good neighbor and a good ham you left your ATV transmitter on for no valid reason and jammed your neighbors.

Shared means shared. We do not have any god given right to sole use in the shared parts of the 2.4 GHz band.

How come you did not make any effort to help your neighbors select a different channel for their wireless network. Or better yet, how come you did not select a different frequency for your ATV BROADCAST. Yes, that�s what you did, you broadcasted a signal for no other reason than to JAM another user of the spectrum.

You really suck.
 
RE: 802.11B and Amateur Networks  
by N9LYA on May 3, 2006 Mail this to a friend!
K3ROJ

What a LID...

That is intentional Interference.. Malicous Interference.. You should have been sited...
You have no right to force anyone off any freq... Shared is Shared.. You are a bad example of an Amateur Radio Op... If I were your unlicensedd neighbor I would have found the source of my problems and colleted data for several weeks.. Proven Intentional Interference.. Etc....


73 Jerry N9LYA
 
RE: 802.11B and Amateur Networks  
by K4RAF on May 4, 2006 Mail this to a friend!
"I was told to leave my transmitter on for long periods and to transmit indentification on the video to make it legal and by doing this for several days the interference went away. I later heard that the 802.11b units were taken out of service since they couldn't be depended upon and the networks were hardwired with CAT5. That proves that most wireless lans are not needed and people should use wired hookups to prevent interference with amateur service."

Jamming is jamming: This only proves that K3ROJ suffers from typical amateur a-hole behavior that will ultimately lead to the FCC deciding amateur radio is not needed.
 
RE: 802.11B and Amateur Networks  
by WA4MJF on May 4, 2006 Mail this to a friend!
Internet lawyers strike again.

A Part 15 device has NO protection
from licensed services and the agreement
is that the Part 15 devices ACCEPT
interference from licnesed services
and NOT interfere with licensed services,
be they Part 97, Part 90, or whatever.

As long as the licensed service is
operating WITHIN the regulations for
their service, then it means the Part
15 operator needs to go see his pastor,
priest, iman, or whatever and get his
TS card punched.

You let these unlicensed folks take over
your frequencies, be they 10 Meter or
13 cm, you invite all the unwashed in and
soon YOUR licensed frequencies are
useless.



73 de Ronnie
 
RE: 802.11B and Amateur Networks  
by K4RAF on May 4, 2006 Mail this to a friend!
Ronnie,

You are actually IN FAVOR of jamming networks off the air for the sake of amateur radio muscle flexing?

How does that reflect on an amateur's "character to remain a licensee" being an intentional malcontent jammer? Why would someone ever want to become "one of US"?

He openly admits "proving his 'point' (whatever that 'proves')" by malicious means & WILLFUL INTENT. There is more to this story since he also knew the resolution of his intentional jamming. As intentional as it gets...

I don't think it takes a lawyer to spot an a-hole amongst us. I have spotted several over the years & they never made a repeat performance. Many regret the experience. Come crash my networks...

What makes it easier these days is the availability of good, directional 2.4GHz antennas & spectrum analyzers.

You can run but you sure won't hide, license or not!

k4raf@yahoo.com
 
RE: 802.11B and Amateur Networks  
by WA4MJF on May 4, 2006 Mail this to a friend!
You must have missed where I
said WITHIN regulations. I'm not
sure a licensed service
"jam" an unlicensed service.
Just like on a shared band. For example,
70 cm is shared with NTIA. The Navy
runs shipboard radar in port on
the 70 cm band at the Norfolk Naval
Station. They are aware that it affects
the hams, but we are secondary,
so we just have to go to the
Chaplain and get our card punched.

I do ATV on 13 cm and if my
signal bothers a Part 15 user,
well, that is TS. I do not
leave my signal up all the
time but when Dave or I are in
ATV QSO I gab and look as long as I
want.

You can DF all you want, but in the
end your device says you can't cause
harmful interference and you
have to ACCEPT it.
What is so hard about that? Your
idea seems to be
if a Part 15 user wants to take over
a ham band, then we hams should just
fold our tents and leave. You may
operate that way, but I and most folks
don't. BTW, with your attitude, why are you
one of us ?


73 de Ronnie
 
RE: 802.11B and Amateur Networks  
by WA4MJF on May 4, 2006 Mail this to a friend!
Actually, after I think a bit longer,
one doesn't need to DF, just look up
the call sign and come to the source.

My receive antenna is just below the
top of the tower with a preamp and
the tx antenna above the tribander.

However, I doubt that you would here
me up there.

73 de Ronnie
 
RE: 802.11B and Amateur Networks  
by WA4MJF on May 4, 2006 Mail this to a friend!
hear vice here
in first line last para

 
RE: 802.11B and Amateur Networks  
by K4RAF on May 4, 2006 Mail this to a friend!
How would you actually know for sure if the 802.11 user you are intentionally running off (by jamming him off) isn't a fellow ham using HSMM? If I chose to run my devices under Part 97, that is intentional interference, is it not? If I ID in my native mode, with my callsign in the SSID, you bet your K1ZZ it is!

The quandry over this band is if you don't bother to monitor 802.11 FIRST, how would you actually know?

"Don't care"? You are required to care about fellow Part 97 users.

I don't have ATV, nor do I want it on 2.4Ghz. You can bet I could & would find the source by DF'ing if it ripped up my connection. The intended idea (totally foreign to most hams) IS SHARING. I know most children are hard pressed to accomplish this by themselves & fight over controlling the sandbox.

What I find so funny is this perverted "King of the Hill" attitude of entitlement, as expressed so well by K3ROJ. If you fail to see that it is morally wrong to jam ANYONE, then you are just as guilty as ROJ, for possession of ignorance with intent-to-distribute. Especially if the jamming is merely to prove some half-assed "point" hatched by a mental tinhorn...

"Mine is BIGGER & I'm registered" has no place in maliciously denying the sharing of space. You see my point?



 
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