Radio E-mail in West Africa: The Complete Version

I worked as a Radio operator for NGOs in Guinea and experienced the "huddle" and difficulties involved in it, especially during the time of tight security. Can you imagine rebels (killers) just infront of your office and you are responsible to say inform the HQ office in some where around 600 Kms (NZerekore or Macenta)? I think Wayne can do something by creating a second type "Geekocop". This is amazing, the budget is less than nothing. I worked with IRC and know how strict and small is the operating budget for communication is. Now, as a Network & Systems Engineer myself, I greatly admire Wayne and Paula who took over from Mustafa Elkanzi (Former IRC Country Director & personal friend of mine). Paula you should have the praise for this hard job done by Wayne....

Wayne, I will always be your admirer and fan. Infact, you have inspired me to dig into the Unix /Linux world. I already carry Microsoft Certificates in my pocket and Cisco.

Bravo, bravo and thanks to OpenSource

M. Pathe Jalloh,

Former refugee and IRC staff

Now working with Ashanti Goldfields, Siguiri-Guinea

pathe.diallo@ashantigold.com

www.ashantigold.com

When I picked a copy of Linux Journal up from the stands, I had no idea what a great article I was about to read.

The North-South digital divide is something I think a lot about, though I am just learning to appreciate the difficulties of connectivity in less-developed countries.

I'm involved with Indymedia.org (that is, a member of one of over 75 Independent Media Centres world-wide). Some of our American IMCs have been behind a push to send used technology to South American IMCs -- about 250 configured old PIIs are on a ship heading south as I write this.

Yes, those machines will all end up in urban settings. But we now have a real and tangible solution for reaching outside the cities, where the needs are arguably greater.

Those 250 PIIs are just the start of a long-term project. And now it seems there may be no end to it.

Thanks very much for a very inspiring read.

All the best,

David H.

Six years ago I set up a similar system for a christian missionary organisation "Operation Mobilisation". At that time you even got in Singapure Harbour a very bad telephone line that was only capable of 300-1200 baud (with a Trailblazer PEP modem). Not to speak for some locations more remote.

In the end we had an central e-mail hub that could do SMTP, UUCP over Modem und UUCP over TCP/IP. Some of the "clients" had DOS based UUCP systems with UUPC and Pegasus Mail for DOS, some had Windows based systems, and some had Linux servers with Pegasus-Mail for Windows. You see, many operation modes were possible and we were able to adjust to the different technology levels of the various countries. Some used SMTP with their local providers.

In not-so-advanced countries we used UUCP-over-TCPIP if we got a local ISP, sometimes we had to use UUCP-over-Modem. In this case we used the uucp-g protocol because of it's efficiency. To my knowledge, we did not use radio-transmitting, althought some people looked into packet-radio like technology.

However, the choice of transpartion was surprisingly often not a function of the available infrastructure. Instead it was quite often a result of the locally available expertise. A missionary organisation does not generate profits, it lives from donation. Therefore money is usually scarce. It was simply not possible to train all operators worldwide up to the same level of expertise, just the flight tickets would have cost us a fortune. And of course not every country had techy-aware people there. So it was good to have different options to choose the right one from.

By the way: the Linux-Server site was interesting, because a simple menu hacked together from "dialog", "bash" and "perl" allowed even novice operators to setup up and create users and an e-mail connection. The system was dubbed "OM Standard Linux Server" because it later also became file-server (samba), print-server (lpr) and so on.

However, we had a different problem domain (getting e-mail in countries without internet access, not getting e-mail to remote areas of countries with full area covering internet access). So we did, up to my best knowledge, not use radio based links.

HolgerSchurig has a mailbox at gee-emm-ex point dee-eeh :-)

Check out the NATO Standard for HF Data Transmission (STANAG 5066) and the newer standards for HF data modems (MIL-STD-188-110B and STANAG 4539). I'd love to see low-cost (no-cost) implementations of these from the open-source community to complement the existing commercial implementations (which are kinda' pricey). But the data modems support rates up to 9600 bps in a standard 3 kHz bandwidth, and support adaptive data rate when the channel goes to crap. The data transmission standard (STANAG 5066) supports e-mail and IP-over-HF using ARQ or non-ARQ modes. All of the advantages cited by the article were identified by the military HF industry as good reasons to develop the standards and equipment. Think of it as long-haul wireless internet and ISP access from the days when 9600 bps telephone modems were hot stuff. With a minimum of costly infrastructure.

Interesting. Having used amatuer digital modes on HF, I find

the application of HF for email, etc, refreshing.

However, readers (at least here in the U.S.) should note...

HF is (afaik) totally "closed" to unlicensed experimentation.

No mention of licensing or legal use was mentioned in

the article (afaict). Here in the U.S., presumably you could

get an commercial HF license for a digital mode, but

experimentation is not allowed. Unlike 802.11 (2.4ghz)

there is no unlicensed band for digital use (note that the

old "unlicensed CB" 27 mhz band only allows for AM/SSB or

remote control applications.)

I'm not totally familiar with the geographic topology of

the africa-based sites mentioned in the article, but

bandwidth (and reliability!) could be greatly improved by

going with 2.4ghz (802.11), locating repeaters on

mountain tops, and using highly directional (hence high gain)

antennas. This depends alot of on the topology and

could very well not be feasible for those sites.

Otoh, possibly 2.4ghz is closed in that part of the world

requiring the fallback to international HF frequencies.

jeff

I was reading this until I got to the description of the PPP link and remembered the days of UUCP over serial lines. Since the modem took care of the error correction they could send much more data more quickly by using straight serial UUCP instead of trying to get a PPP handshake to get TCP/IP working. A UUCP chat script was always faster than PPP in my experience.

Kris

> Remote networking with high-frequency (HF) radio and

> Dan Bernstein's qmail.

>

>

They're using PPP to establish a TCP/IP connection over HF. While it's a solution, it's not the best solution - using UUCP and eliminating the overhead of PPP and TCP/IP is a much better, more robust, and higher throughput solution for store-and-forward applications. Been there, done that.

Also, it's not necessary to use such a complicated setup such as qmail if you're using UUCP. qmail isn't Open Source - the licensing is rather restrictive, a fact that leads the major distributions to not distribute qmail.

Wouldn't your solution create a lot of traffic overhead? (PPP, IP, TCP, SMTP and neither of these are efficient protocols.) My spontaneous idea would be to re-use some of that old FidoNet software and set up something similar: store and forward of compressed packets of e-mail directly over serial links.

Greetings Wayne:

That was a super article! I have done similar with less as you are doing right now, so I think you are doing something quite special indeed.

I wonder if you ever considered Amtor or even Sitor as a way of linking over the HF ether? Amtor is a protocol adapted by amateur radio from Sitor, its commercial predecessor. Further, Pactor further enhances Amtor with better compression and frequency instabilities. I believe Pactor and Sitor are available in the public domain.

My thinking is to marry the best of Pactor with DAMA the add a layer of DHCP/CHAP/PPP so your hub could actually sustain more than just one link at a time. DAMA will ensure all new links are welcomed and added to the round table, the ppp(or whatever you use) would authenticate, and Pactor would ensure the best compression verses time verses link state. I don't think I have seen anything like this in production, but it would sure be fun to have a go with. Unlike tcp/ip packet, a broken packet can be repaired without a complete retransmission of the whole packet.

Pactor II is now available and actually does even more with compression and squeezes more data in even less bandwidth and can cope with signals that are almost inaudible. Unfortunately, it is very proprietary and the makers want a lot of money for each license. Yet it will move even more data over less channels than Pactor can.

One other nagging thought kept creeping into my mind: why don't you use either 2 meter or 6 meter single side band radios? This would effectively release the hf rigs for pure voice/emergency calls while moving the data load to that portion of the spectrum where it would be least likely to interfere with other systems. As you know, HF knows no boarders! The VHF spectrum in SSB mode has amazed and delighted many an operator over the years. The modems you now use on the HF radios would work exactly the same on the VHF rigs, and probably a little faster since transmitter to receiver turn around is likely faster on the VHF rigs. I realize this is probably not doable in tight budgets, but it sure would be fun!

Thank you for taking me on this splendid tour of your works. It seemed like you had a lot of fun making all of this system work.

Take care and happy hacking.

a_hippie@linuxfreemail.com

My sister works with Wycliffe in Mali. She's translating the Bible for the 60000 Tadaksahak people living in eastern Mali. She also uses a radio link powered by a car battery to send and get email from her place in Menaka to and from the capital city Bamako. The infrastructure is a ccMail system with an internet mail gateway provided by JAARS.

Beat Bolli