Email Over High-Frequency Radio in West Africa 192
Guillaume Filion writes "LinuxJournal has a fascinating article about Radio Email in West Africa over HF links. 'Deep inside the warm green interior of Guinea, centered in the frontal lobe of West Africa, field personnel in the widely scattered village-towns of Dabola, Kissidougou and Nzerekore now enjoy access to regular internet e-mail, directly from their desktops. Here we have bridged the digital divide, and there isn't a telephone line or satellite dish in sight.' Talk about Wireless Fidelity!"
Oh No! (Score:2, Funny)
Reminds me of Packet Radio (Score:4, Informative)
* "Hi", "How's the weather at your house", "Are you going to Dayton?", "Can I ride with you?"
Re:Reminds me of Packet Radio (Score:3, Informative)
Re:Reminds me of Packet Radio (Score:4, Informative)
If I can find out what freq they're on, all their mail are belong to us.
Re:Reminds me of Packet Radio (Score:3, Interesting)
I've used my kenwood th-d7 to irc many a time, but on private channels where i know nobody will be swearing etc.
Encryption is not allowed, but I must say that I'm guilty of visiting the occasional ssl site, and I'm not totally sure how the FCC feels about that.
-k6gnu
encryption and ham packet (Score:2)
Or does this refer to the rule against hams using private codes or language to communicate with (voice, CW, or whatever). I can't believe the FCC would mandate insecure data communications. Perhaps the rule is a throwback to the days when data security wasn't as big an issue (and there wasn't a public internet to gateway to, etc.)?
Do you have a URL to the rules, perhaps? Also, knowing what paragraph, etc., in the rules would be handy.
Arrggh. My ticket just lapsed a few days ago, I just realized (I'm KD4TFF).
Anyway, I'm wanting to get into packet, and was discussing this very topic with another ham last week.
Re:encryption and ham packet (Score:3, Informative)
Bottom line is, if you want secure transmissions don't use the amateur radio service. If you really want secure transmissions, don't use wireless at all.
However, I don't think the FCC will come after you for encrypting a password, like how hotmail uses ssl for login and then drops it afterward. They've always supported the right of private access codes for repeater control, etc.
I think hams are accustomed to a certain lack of privacy. It's the price we pay for free bandwidth.
73 de KD7KME
Re:Reminds me of Packet Radio (Score:5, Informative)
One correction... (Score:3, Interesting)
The GRAPES and WA4DSY modems are (I believe) 56k units, designed for 440 and above. (One of those might be a G3RUH-compatible 9600 design...)
In Europe, 76k on 440 is common, and the Baycom folks have quite a bit of hardware for this.
Some guys in Slovenia are doing 1.1 Mbps in the 1.2 GHz band.
Re:One correction... (Score:2)
Another Correction (Score:2)
At last check, you COULD send MIDI data over packet radio. This was in one of the ARRL's guidebooks. The MIDI data (and hence MP3) was considered data. I think the example given was one of controlling a musical keyboard remotely.
Then again, the ARRL has changed their mind about things a few times. I have a 10-year-old "Now You're Talking" that said you could call mayday over a broken down car, since motorists have been killed alongside highways. Newer editions state that you cannot.
Re:Another Correction (Score:2)
Re[2]:Another Correction (Score:2)
Umm... the original ARRL book did indeed call being on the side of the road broken down life threatening, as "motorists have been killed waiting for aid alongside the road." The obvious (idiot) case would be opening your door into traffic. I need to find my pre-no-code-Tech copy again; it's actually quite interesting how quite a few paragraphs throughout the ARRL's "Now You're Talking" have reversed their positions.
But yes, the FCC is indeed the final authority on this. I have not seen a ruling for music over digital mediums; I just know what the ARRL has said historically -- the new voice codes some HTs have (that could code music digitially) might change things.
And as an aside, were you at the COARES (Centrol Ohio ARES) meeting this past night? If not, you should join ( www.qsl.net/coares ). Just going by your email address :)
Re:Re[2]:Another Correction (Score:2)
Re:Reminds me of Packet Radio (Score:2)
Also - the max keying rate is thus (last I checked)
160-12 meters 300 bps, 10-6 1200 bps, and 2m up 9600 bps.
That doesn't mean you can't use some fancy modulation to get more speed - for instance you can use spread spectrum at 70cm and up - like jstar which is 128kbps on 1.2 ghz.
Forget PGP too! (Score:2)
Re:Reminds me of Packet Radio (Score:1, Interesting)
Wow, finally a use for packet radio (Score:2)
Life at 9600baud is more fun anyhow
picking nits (Score:5, Informative)
'bps' is faster to type anyhow.
Re:picking nits (Score:1)
Re:picking nits (Score:3, Informative)
In other news... (Score:3, Funny)
Drivers carry less than 20 shiny rocks and buttons on them.
Re:In other news... (Score:1)
Thanx for the laugh.
Re:In other news... (Score:2)
Glad you liked it!
Re:In other news... (Score:1, Offtopic)
Future of networking (Score:5, Interesting)
If you think about it, much of the last 2 decades' innovations and progress have had the effect (deliberate or not) of making life (at least for those who could afford it) more open and footloose. The company I work for used to have a Chicago address, just because nobody would believe that a large, international, reputable organization would be based in Salt Lake City. Nowadays nobody even thinks about that sort of thing. Even now, with telecommuting technologies, it's not necessary to have all your employees come to the office every day. Maybe in the future, the term "headquarters" will be obsolete, because organizations can be so distributed.
Okay, it's a little off-topic, but the article makes me think about the steps we're taking, technologically, and where they're leading.
Re:Future of networking (Score:2, Insightful)
Re:Future of networking (Score:3, Funny)
Re:Future of networking (Score:1)
Re:Future of networking (Score:3, Insightful)
I don't buy that at all. Although it would be nice, it will always be cheaper and more practical to, say, run a wire from your computer to your monitor than to have wireless hubs in each device.
It is certainly cheaper to go wireless than it used to be, and I think technology will help us get rid of some of the more restrictive and inconvenient wiring, but your prediction sounds a lot like the empty promises of old...like "someday everyone will drive a flying car", or "in the future, everyone will use conveyor belts instead of walking to their destination."
Technology obviously helps us in many circumstances, but much of the time it's just too expensive to be convenient.
Re:Future of networking (Score:3, Insightful)
Will computers still be so modular as they are today? I mean, the iMac has been around for a while and it's not modular. Even though I don't find them very aesthetically pleasing, I saw a single-unit computer the other day while I was looking for a new monitor, which I thought was really cool. It consists of a flat-screen monitor with the computer built into the back of it.
I think that computers will become less modular than they are now. (Probably not production computers like servers and whatnot, but I refer to user-end models.)
As for other computer-related things, like keyboards, I think wireless will also become more popular there. You said "it will always be cheaper and more practical" to run wires. Well, with wireless becoming easier and easier, "practicality" might be rated not on price of the unit in question, but on convenience. I, for one, prefer a wireless keyboard and mouse because I hate the wires limiting my mobility.
The other term you used is "cheaper." A device that uses wireless connections doesn't need a long cord. That's savings right there. And while wireless IS a touch more expensive to make right now, soon the price involved may be low enough that wireless is economically easier. Especially when you need multiple connections to a device. A TV (or other video device) needs several IN and OUT jacks to connect to all the things that people want them to connect to, like Antenna, VCR, DVD-player, etc. What if there was just one transceiver that could communicate both ways with all those devices? And your computer? And your WiFi remote? Forget directly programming your VCR or even your TiVo. You could just do it all through your computer.
You could run your whole house through your computer, without expensive interconnected wiring for everything. Have your computer turn on all your lights while you're on vacation. And if you get a new device, it'll already link with the rest of everything, so you don't have to run new wires even to a central hub.
I know, I know, it's what visionaries have been predicting all along, but now we can see a direct path from where we are now to where we could be. (Unlike with flying cars or ubiquitous conveyor belts.) I don't KNOW that this is the path that society will take, but I don't find it too far-fetched.
I don't think its impossible... (Score:2, Insightful)
We think of wires as being 'free', but they're not. You have to wire up some kind of connector between the board and the "transmission device", be it wires or wireless or a carrier pigeon gate or whatever.
An especially good possibility is that the hubs will be practically required equipment. If, in this case, the hubs are multi-purpose, the wire-based connection will be an additional cost. Why pay more for wires when you've already bought wireless?
I guess the case I'm specifically thinking about is computer to keyboard/mouse/monitor/peripherals.
What wire-based communications can you think of that are not particularly suited to wireless?
$.02
-Zipwow
Wire is cool (Score:3, Insightful)
Wireless is fine for low-speed connections, or medium-speed connections that don't have to go very far, and can either interoperate between multiple users in the same space or else do some non-interference trick like spread spectrum. And it's really nice to have freedom of movement and ability to get some kind of service wherever you are, which means wireless in the most general case (though LANs with DHCP and VPNs are a good start.)
But fundamentally, wire-like technologies (including fiber as well as copper) are much more practical for high-speed connections, and can fit arbitrarily large capacity in a given area because separate wires don't interfere with each other, unlike multiple sets of radio waves. For high-speed connections over non-short distances, wireless needs line-of-sight, while wires don't need to be in straight lines, can leap under tall buildings at a single bound, wrap around mountains and curved planets, etc. Also, the physics for devices that mess with wires make it easy to put huge bandwidths on a fiber, limited by the cost of the high-tech equipment on the ends (which gets Moore's Law kinds of price/performance effects) - practical bandwidths get into the gigabit range for cheap short-distance equipment ($59 at Fry's) and into the terabit range per fiber for long-distance telco-quality equipment.
There is some relatively high-speed line-of-site equipment that can fit multiple separate connections in nearly the same space - free-space optics is the most focused, and there are microwave systems that are pretty tight. They can't do long distances, because of weather as well as because of the earth's curvature, but some of them are in the half-gigabit speed range over a few kilometers. They're really nice as a backup for building data feeds - they get rain fade, but they don't get backhoe fade, don't usually need permits to cross highways, and are surprisingly tolerant of earthquakes.
Re:Future of networking (Score:3, Insightful)
Speed: Generally speed isn't very good on wireless connections. Show me how to get 100megs/sec out of any common wireless connection. This is the wired standard - but you need the bandwidth in wireless connections, and that leads nicely in to my next point:
Bandwidth: Anything wireless needs bandwidth. Generally faster means more data which means more bandwidth. There is a finite amount of bandwidth. It's pretty much maxed out already (In the US at least; there's lots of military applications, broadcast TV takes a chunk, radio, the ham bands, cell phones, satellite signals, radio astronomy...etc). There's only so much usable spectrum. To put it another way; what happens when your entire city/company/neighborhood/household runs on one connection (t3/t1/cable/dsl respectivly, just for the example)? you oversaturate the avalible bandwidth. Same thing would happen with wireless. If the entire country starts using HF bands for email; your avalible connection speed is going to be shared across thousands of connections...making checking your email a pain in the rear.
Cost: Look at the cost of a wireless NIC compared to a wired NIC of the same approximate bandwidth capabilites. Do they even make 10meg cat5 NICs anymore? 10/100 seems to be the standard, and even that is cheaper than a wireless card that only can do 11 megs at it's peak.
There are more but I'm tired of typing...just got back to the room after a long day in the rain. Message me or reply if you have questions or comments. Feedback is welcome!
Re:Future of networking (Score:2)
Wireless tech isn't there yet, but it will be.
Yes, But.... (Score:5, Funny)
It's sad really (Score:2, Insightful)
"The International Rescue Committee (IRC) has one of their largest operations in Guinea, providing services and support to a population of up to 200,000 refugees quartered in many camps established throughout the country." I applaud their efforts with refugees and truely do think Guinea is an island of peace in a otherwise bleak sea. But seriously do these 200,000 refugees need google?
Well enough with this rant.. I do believe that this is a great tech and email is something that I use everyday. Now when on vay-k I will rest assured that i will have email in Guinea!!
Go ahead and mod me down i know its kinda offtopic but I just needed to say it.
Hunger is no longer problem #1 (Score:2, Offtopic)
How they would benefit... (Score:5, Insightful)
Re:It's sad really (Score:5, Interesting)
Decent infrastructure has more benefits than you can imagine. My dad works for the World Food Program [wfp.org] and that org has used many different technologies for communication throughout the world.
At his last post (Nicaragua) they used Toyota Land Cruisers to get around. Those vehicles were equipped with a multitude of antennas, including some to communicate in the UHF range. For more remote locations they used motorcycles to transport satellite phones where needed. Now he's heading up operations in Angola and i'm not sure what sorts of techs they use there, but i've heard talk of satellite phones and in the capital, Luanda, he uses a cel phone (talking to him from MI, USA is a pain, phone cuts out and is quite laggy).
While starving sucks, it sucks even more when you can't communicate with anyone that you are hungry. In the past it was necessary to physically visit every single location to see how situations were there. Now, with better communication devices, when something serious happens (hurricane, landslide, refugee influx, etc) it can be communicated much quicker, response times are faster, and more lives can be saved.
Re:It's sad really (Score:2)
>lots of world applications. But why do I get the
>sense that what these people really need isnt
>wireless email to their laptops. How many africans
>benifit from this? Do they now when hungry email
>their american counterpart and ask him to describe
>the BigMac?
(I really wanted to let this one go, but when I saw the +1 insightful mod I just couldn't help myself)
What did your post do to help African refugees today?
Obviously you shouldn't have sent that post because it didn't help African refugees!
Re:It's sad really (Score:3, Interesting)
Guinea possesses major mineral, hydropower, and agricultural resources, yet remains an underdeveloped nation. Let's ignore the mineral part, and note that agriculture is probably to mainstay of most of the population. Internet access, by supporting better agricultural management, will help improve productivity in this area. For example:
Market and commodity information to assist in export [msu.edu]
Botany, the science of plants [ou.edu] including pest control, plant breeding, etc.
Etc. [agricta.org]
Maybe they don't wire to find out what a Big Mac tastes like, but they may ask about financing export, funds for development projects, scientific information on crop cultivation, etc.
There is more to the Internet than games and pr0n.
Re:It's sad really (Score:2, Insightful)
Disclaimer I'm a normal pampared USian and have no first hand or even second hand exposure to this issue.
I have read reports that this kind of connectivity is a god-send for refugees. The power of email in those circumpstances is related to be irreplacable. The ability to get messages from or to friends, family, or other loved ones is the difference between years of wondering whether some person you care about is alive, and knowing for sure that they are at least breathing and relatively safe (or not, depending on the circumpstances). Since many of these refugees may have family who are working in other countries, it allows them to get messages about state of affairs and to express worries, love, etc. Additionally, the ability to get news from some other source than the camp rumor mill should not be under-estimated.
Not saying you're wrong, just pointing out that there are many non-trivial uses for technology and that what we take for granted can be a very different experience in contexts that we can not even imagine.
Re:All the replys are good ones.. (Score:2)
Ivory Coast's warriors take war to Web [cnn.com]
Choice quote:
Ho hum (Score:2, Interesting)
No phones or dishes? (Score:2, Funny)
Nuts. As an American, I now have to put Guinea on my "can not visit" list. Thanks, /.
-DDT
Support Infrastructure (Score:2, Insightful)
Carts and horses... (Score:2)
But these do not just get installed by gnomes.
They require a functioning goverment and decent civil institutions.
These do not survive in countries where power and politics are aligned with tribal sympathies.
The best way to get around that is to create middle classes who do not care what tribe you are from.
But middle classes need access to information and markets, and email is one of the best tools for this in West Africa.
So this kind of infrastructure is not redundant - it is very important and possibly one of the keys to creating better-functioning societies in much of Africa.
Speed? (Score:1)
Cool technology, but its still years behind...
Maybe they've got some of those old BBS programs running. 300 baud + BBS would be great to reminisce to...
Re:Speed? (Score:2, Informative)
73, KD7KME
31 baud? Telnet? (Score:2)
SailMail (Score:5, Informative)
The last time I sailed across the ocean last July (in the Pacific Cup Race [pacificcup.org]) we used an Iridium phone with the data option. We were able to send back a couple of digital pictures but the phone bill for the week was something like $200. Next time we'll save the pix till we hit land.
Re:SailMail (Score:2)
Radio Ga Ga (Score:1)
Re:Radio Ga Ga (Score:2)
Careful, folks (Score:2, Informative)
What the article doesn't talk much about is how these waves are actually transmitted. And as science buffs, we're all probably intelligent and curious enough to read a bit about the details of such a feat as this. It may seem complex at first, but it's nothing but physics, which is nothing more than a few algebra rules that most of you learned back in 9th grade.
The simplest approach to describing radio wave propagation is to solve for the index of refraction h = (m e)1/2, where m is the magnetic permeability (1.25664 x 10-6 H m-1) and e is the dielectric constant.
The index of refraction, in turn, describes the relationship between the angles of incidence and refraction through Snell's Law.
To put it simply, all that that mumbo-jumbo really shows is that there's a finite maximum usable frequency (MUF) that will reflect off the ionosphere and allow still higher frequencies to pass through relatively unchanged.
Bottom line -- email rocks.
Re:Careful, folks (Score:1)
Somebody help us all!
Re:Careful, folks (Score:2)
A nit to pick: HF radio is from 3MHz to 30MHz. MF is from 300KHz to 3MHz. LF is from 3KHz to 300 KHz. Each band is a decade.
Its a step up (Score:5, Funny)
Yes, the previous method had many flaws. (Score:5, Funny)
Re:Its a step up (Score:2, Funny)
"You've got mail AND lunch!"
Who's got a recipe for modem flambee'?
Nigeria has plenty of money floating around (Score:5, Funny)
Email over radio? (Score:2)
You thought email was insecure BEFORE..... (Score:5, Informative)
Seriously though, hams have been doing this kind of stuff for a while, on various bands. BBSes and email are commonly used (and tied together). There are TCP/IP networks (granted, most of them on bands like 2m which have higher throughput) with internet gateways. As a matter of fact, amateur radio operators have their own Class A (i belive it's 44.x.x.x)
PSK31 is used on the HF bands and gives you a real matrix feel. You can see the information coming down throughout the band, and click on the stream to see the text moving through it. Here's a screenshot: http://users.skynet.be/on1dht/media/rxpsk_scrn1.g
definitly cool stuff.
73, k6gnu
Re:You thought email was insecure BEFORE..... (Score:4, Interesting)
http://hamradio.ucsd.edu/
They don't have this problem here (Score:2)
Since they're using SMTP, a *really* simple thing to do is to enable STARTTLS, which does encryption on SMTP connections if both sides support it, which doesn't have the user-visibility that PGP does and is simpler than IPSEC.
Why so slow? What about contention? (Score:4, Insightful)
What? No Mention that the Linux Kernel (Score:4, Interesting)
supports this already through the ax25 modules?
This ties amateur ax.25 protocols directly to the Linux kernel. Works great, lasts a long time.
I suspect the "commercial" modems in use were transmitting in something other than ax.25, probably sitor/amtor/pactor, but it's all about the same at 300 baud.
The advantage with Linux is that you have to configure one driver for tcp/ip as opposed to dealing with the mgetty and ppp nonsense in the article.
Africa has an advantage (Score:4, Interesting)
In South Africa it's even more interesting: there is a definite shove in getting broadband net access working - and working well. In fact, the recent de-monopolising of the Telecoms Company Telkom has finally opened the door for broadband.
The key advantage, however, is somewhat ironic - in fact, the reason is simply that Africa does not have any decent infrastructure to begin with, this makes it easier to climb in with the leading pack and use leading technology from the start.
The problem with 802.11 is however that it is unreliable. I've had the opportunity of working with a few wireles net-frastructures using 802.11 to connect a multitude of willing volunteers to various wireless wans and lans. Unfortunately, the best uptime stats we had was around 89%, comparable to the 99.9% uptime we enjoyed with one of Africa's biggest ISPs namely iAfrica.
African countries have been connecting rather well to the net over the last few years, and doing so beneath the radar for the most part. It however will most likely not become the multi-million dollar industry like it is in the western world, but the key importance of connectivity in remote African cities and Towns is not to establish capitalistic approaches, but rather bring vital services to poverty stricken people, and offer them the opportunities that many dream the Internet still carry.
Recently I visited a very poor school where the classrooms were the great outdoors and they had one blackboard to share with several teachers. Some students were older than the teachers. The amazing thing was when I saw these kids faces when they saw a pictures of Africa and the rest of the planet we downloaded off the net via Satellite shown onto a makeshift projector screen.
Stories like this should not surprise people. What surprises me is that people in the western world still think us Africans ride lions and chase each other with spears. Africa is poor, but their is a lot of technological knowledge about. And we have that one advantage...
Clover Digital HF (Score:3, Interesting)
One problem with HF is that the ionosphere has a large, time-dependant phase dispersion. It really procludes wide-band schemes unless someone can come up with something very clever.
The Clover board claimed 500 characters per second, under good band conditions, through a 25 Hz cw filter. At the time, there was no HF scheme that came close.
I have no idea if Clover still exists -- maybe someone on Slashdot can enlighten us.
Re:Clover Digital HF (Score:2, Informative)
Good MTA, perhaps, but Open Source? (Score:3, Interesting)
It's funny the LinuxJournal editors didn't pick up on this (the article has already been published in print). I mean, there's nothing wrong with using proprietary software where it's the best option, but calling it Open Source is a bit unfair to both the original author of the software (Dan Bernstein), and the developers of actual Open Source MTAs like postfix, exim and sendmail.
Re:Good MTA, perhaps, but Open Source? (Score:2)
qmail is not open source? It is distributed as source code, not binary code. I don't see how that is anything but open source. It is not, however, free software.
Re:Good MTA, perhaps, but Open Source? (Score:2)
The fact is, the licensing of qmail makes it a legal liability to distribute, and is avoided by groups like Debian and RedHat. I have no hate for qmail but let's get our terminology right.
Re:Good MTA, perhaps, but Open Source? (Score:2)
Wrong. Again, more FUD. It is perfectly legal to distribute qmail if the binaries match his. He does this to promote compatibility. Debian does not distribute qmail because it is not Free Software, not because it isn't Open Source. Find out exactly why qmail is not in Debian as a binary package. [smarden.org] qmail is in Debian non-free as a source package [debian.org].
Re:Good MTA, perhaps, but Open Source? (Score:2)
Open Source has little to do with the right to distribute source code, and everything to do with the freedoms associated with the use of that code. Microsoft's Shared Source scheme, depraved as it is, allows the redistribution of modified source code by academic bodies. Bernstein does not grant this right to _anybody_.
P.S. I'd avoid postfix, I found a trojoned copy from an ftp site the other day...
If you looked hard enough, you could probably find trojaned copies of pretty much every piece of shareware, freeware, Free Software, and every service pack out there.
Put that in your crackpipe and smoke it, qmail troll.
Re:Good MTA, perhaps, but Open Source? (Score:2)
What the hell?
You can find out more about Open Source here [opensource.org]. Note in particular the parts about modification and redistribution. I don't know what you think open source means but you sound confused.
When you can code as well as DJB and have proven it by implementing a full featured internet application (ftp,smtp,http take your pick)
Does a two year stint at the ISC maintaining the BIND 8 resolver and tree propagation code count? Moreover, I'd like to think that there are those who are perhaps younger and smarter than me who might be able to "fuck with" and actually do something new with the given software. That's what open source is all about.
I only reply to this trash because someone who is following this thread might be mislead by your stupid pro-qmail arguments.
Re:Good MTA, perhaps, but Open Source? (Score:3, Funny)
Oh, I get it now. You are spreading FUD about Dan's software because he can write secure DNS software [cr.yp.to] and you can't [cr.yp.to]?
digital divide (Score:2)
Psssst! I thought the digital divide mostly concerns those (and the majority) of people who live in these developing countries. Unfortunately the article seems slashdotted - but from that clip it seems like analogy to saying : "Here we have bridged the hunger problem, by taking 42 quality JUST for us". The fact that a few techno geeks can do this really means nothing - even if you describe the surroundings with words " the warm green interior of Guinea". Or do you mean this solution can be easily accessed by those who really are on the other side of the digital divide. (well, have to wait until that article gets back online, but really that clip sounds like example of black humor).
Re:digital divide (Score:2)
oh, another missing word contest: steaks.
For those actually interested in this topic... (Score:5, Informative)
The page also describes their LEO satellite system which is just now coming on line.
Rumour has it.... (Score:2)
any encryption planned? (Score:4, Interesting)
I realize that sending and receiving individual messages should be strongly encrypted, but that still doesn't necessarily obfuscate the sender or the receiver. I mean I'm glad to see such email used as the article says " the radio equipment, providing an essential lifeline for the safety and security of field office and mobile unit personnel"
What about interference? (Score:2)
Has anyone considered the question of interference to other services from this 'service?'
For that matter, has anyone considered the value of 'net connectivity as opposed to food, medical care, housing, and decent schools? Don't even get me started on the potential for cultural impact.
Hams have done this for years (Score:2, Interesting)
Opening that up to the masses here would help solve that 'last mile' problem,
among other things.
(
Re:Hams have done this for years (Score:2, Informative)
I however took four years of university for mine. (got my BSEE first)
Doesn't anyone remember ALOHANET? (Score:2)
Yep, the name of the Ethernet (as in "transmitting over the aether") protocol is a subtle salute to the pioneering work that went into building the original ALOHANET.
Not the best solution, unfortunately (Score:2, Insightful)
This is actually used often in aviation (Score:2)
These days, an airliner on a transoceanic flight may very well be doing all its communications overwater by HF text messaging, and the pilots will not actually speak to anyone for the entire ocean crossing. While it might seem strange, ACARS and CPDLC communications frees up a lot of frequency congestion for non-routine emergency messages that would otherwise be taken up by traffic such as routine status reports, etc. Think about that next time you cross the pond.
IBM analogies? (Score:2, Funny)
UUCP instead of TCP/IP (Score:3, Interesting)
Kris
AX.25, TCP/IP, Linux and HAM radio (Score:2, Informative)
AX.25 is natively supported in Linux, and could easily be leveraged to make this whole thing a lot better. With some donated HF radios, they could have routable RF network up all the time in no time. They might even be able to use APRS instead of AX.25. But, AX.25 is a more proven protocol for this type of thing. See the AX.25 Linux HOWTO [linux.org] for details. Information about the protocol can be found at TAPR's [tapr.org] website. They might even be able to get a little bit more speed, though not much, by using 10 Meter (28 MHz) FM. Though 10M can be probmatic sometimes, so I'm not sure I'd recommend that. 20M (14 MHz) and down are much better frequencies if you want something reliable. A DSP based noise filter would certainly help things in regards to speed, but they cost a bit of money.
As far as the modem goes... You can use a sound card and a small "control" box. All the box does is operate the PTT (push to talk) circuit. So, you might be able to do with out that if you wire things up just so. But, I have not played with that as of yet. You can also use a Terminal Node Controller (TNC) to get the signal to the radio. Some of the newer TNCs have a DSP filter built in, so that could be an advantage there. But, the best you can hope for on HF is about 2400 bps at half duplex, and 2400 is pushing it. There's just too much noise on Upper/Lower Side Band, and I'm not sure if you would want to use AM (though that might be an option).
There are a number of sites to check out if anyone is interested in digital commincations over amatuer radio. TAPR [tapr.org] is a very good one, as is RATS [rats.org]. RATS [rats.org] works with a protocol known as ROSE. There is another one called NETROM, but I don't have a link readily available for that. TCP/IP is by far the best for this type of thing though. You can also check out the ARRL's [arrl.org] site, and the FCC's [fcc.gov] amatuer radio [fcc.gov] page, for more information on amatuer radio in general here in the United States. BTW, you don't need to know morse code anymore to get on VHF/UHF. And, to get on HF you only need 5 wpm on the code, which is not all that hard.
Ok, I admit that last paragraph was a sales pitch. But, amatuer radio seems to be a dying hobby; at least here in the US. So, anything that can be done to increase interest is a good thing.
I'll step down off my soap box now.
We've been doing this for 3 or so years already (Score:2, Informative)
It is excruciatingly slow, so only e-mail is realistically usable.
We have an ISP here that we helped set up. They've got the radio modems plugged straight into a Cisco router.
This is a HOAX, I think. (Score:2)
This may be w/o Wires, but it ain't Wireless... (Score:2)
Re:Wow (Score:1, Funny)
Re:the site is down ... (Score:2)
Hurry someone tell the guy who is studying the slashdot affect that linuxjournal.com is now suffering the same fate.
Re:I Question The Durability (Score:2)
I suspect that the people mentioned in the article are using power levels not even remotely close to being able to cause the issues discussed.
Furthermore, if you're able to produce arcing and cause fluorescent tubes to light, you can forget about the data portion because you have a serious RF problem. That would be, you're lacking an effective antenna. All that power should be going out into the antenna, not into the router room.
I've worked in broadcast facilities where the combined output of all the transmitters on site was well over a 500,000 watts (that's not ERP). Not once did we have the issues you mentioned, and although I now have a third-eye, I find it helpful when typing and reading documentation at the same time.
Re:I Question The Durability (Score:2)
Bollocks. You appear to be very uneducated about HF radio communications for the last 50 odds years.
fluorescent tubes can be lit up anywhere in the surrounding room without being contacted.
Yup. A magic trick the tour guide at Radio Canada International [rcinet.ca]'s shortwave transmiter site in Sackville, New Brunswick, involved the young tour guide lighting a florescent tube by bring it outside close to the kilowatt antenna array. See the The Initiation [httphttp] as well (The Ilford Group, G3XRT).
The RF energy being generated is probably so immense and so poorly defined in frequency that probably all air-traffic communications must be jammed for a few miles around when this news system is operating.
Sigh. This is pure trolling. Stable oscillators and high/low pass filters have been around for what, 90+ years now. Stable VFOs, about 70+ years.
Re:Can the click-clack language (Score:3, Interesting)
(The only reason I know this is because my Natural Language Processing professor [jhu.edu] spent most of the first lecture in September using Xkosa an example.)