What’s the frequency, Kenneth?

This is a diagram for Bushmail, a system which allows users in very remote locations to send email using high-frequency radio signals. No need for a mobile signal, no need for cell towers and no need for any infrastructure.


A wire strung up over a tree is enough to act as a transmitter/receiver, and a car battery and a solar panel enough to power the whole thing. Used quite widely among the conservation community, could this be the ideal data/email solution for an ‘off-network’ African village?motorola1
This is a Motorola walkie-talkie. With a range of approximately ten square kilometres, these radios allow two-way voice communication without the need for a mobile signal, no need for cell towers and no need for any additional infrastructure. An ideal voice solution for communication within and around a remote African village?

I’ve been thinking a lot lately about intermediate technology, the ‘other’ name for appropriate technology but one which, going by my thinking, promises more of a bridge to an “optimum technology solution” rather than one trying to be an out-and-out replacement for it. A stop-gap, in other words. I’ve also been thinking about how people communicate within rural communities. When we talk about connectivity, who are we trying to connect people to? In my latest PC World article – “Where walkie-talkies dare” – I ask:

Imagine, say, 75% of a rural community’s communication needs were local, in other words among itself, and most of that community lived in, say, a 10- or 15-square-kilometre area. You could argue that a for-profit mobile network, likely run by a diesel-powered tower, is an inappropriate and over-the-top technology solution. Other technologies already exist that could do the job, technologies that don’t operate on a pay-per-use basis and don’t need costly infrastructure to work

If you want two great examples of these kinds of technologies, just look up.

Despite the spectacular advance of mobile, large swathes of some of the more remote communities in the developing world still remain disconnected – not just from us, but also from each other. While mobile technology is widely regarded by many as the ultimate solution, many communities stand little chance of getting on the radar of the “mobile for development” community until they firstly get on the radar of the mobile operators, and a tower appears somewhere in or near their village. Although exciting things happen when towers appear, I’d argue that waiting years for one to come is probably unnecessary. Turning again to my PC World article:

Right now, a traders cooperative in a rural village could easily equip itself with walkie-talkies and exchange information on commodity prices and produce availability, to organise transport and to share storm forecasts. Health care workers covering the village and nearby area could use them to communicate and technically coordinate a health care network. And why not have Village Phone Operators (VPOs) with walkie-talkies rather than mobile phones, who can sell the use of their devices for a small fee, with a near 100% profit margin? Maybe this is a new model Grameen Phone could do something with?

I’d be fascinated to hear if anyone has carried out research on the local communication needs of rural communities. How much of what they need to say is predominantly local? If my ‘grab-it-out-of-the-air’ figure of 75% is even remotely close – and we put any technology snobbery aside for a moment – then I think there could be very real opportunities to implement some very effective intermediate technology solutions within some of these communities.

So, my questions are these: Are there projects out there implementing these solutions right now? Are they working? What other (better?) options are available? What do the communities think of them? Maybe this is all just a crazy idea? I’d love to hear your thoughts.

12 thoughts on “What’s the frequency, Kenneth?

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  2. Steve Song says:

    Hi Ken,

    I think you’re on the right track in looking at the potential of commodity wireless technologies. I also think you’re right that most phone calls are local. I have a fair amount of anecdotal evidence to this effect and some research papers (which I can send you) from a few different countries. Enough to convince me that this is true, in varying degrees. The real data is with the mobile operators though and they aren’t sharing. As an aside, I wrote to Jan Chipchase to see if he might share some evidence but no dice. I imagine Nokia have to sign an NDA to get access to the mobile operators’ data. If the majority of calls are local, this knowledge is exciting because it opens up just the kind of opportunities you suggest. However, I’m not betting on walkie-talkies (although I’ve certainly been wrong before). So let me touch on the technologies you suggest and then propose another one.

    HF Radio. Bushmail is a very cool solution that uses HF or shortwave radio frequencies to span substantial distances. They aren’t the first to set up this kind of solution. BushNet in Uganda was delivering HF voice and data solutions into rural Uganda and the DRC as far back as 8 years ago (I think) using Codan radios. The upside is that you can go just about anywhere but the downside is that the equipment is still expensive and you are very limited in terms of bandwidth < 2400 bps so that you can trickle data through. Works for text emails though. The most annoying thing is that HF is licensed frequency and every user needs a license. In most countries the bureaucracy is likely to be more annoying than the application fee and the yearly renewal feel.

    Walkie-Talkie. In Africa, Walkie-Talkies fall into the Personal Mobile Radio category which uses Ultra High Frequency (UHF) spectrum. Devices under half a watt in power don’t require a license. In flat countryside, you can get a minimum of a couple of kilometres from point to point, possibly more as you suggest. The plus side of this technology is that it is cheap, simple to use, and very flexible. There are even some people connecting these radios to the Internet, not legally I suspect though. There are a few downsides. First, you have no privacy. Anyone can listen to your conversation if they want to. Second, you can transcend space but not time by which I mean there is no voicemail where people could pick up messages at their convenience. Finally, these radios are never going to handle data. The only interface you have with them is a sound jack. This can be connected to the sound card of a PC and the audio encoded for transmission over the Internet. I suspect the reverse is not true though, that it would be very difficult to use a walkie-talkie as a modem to connect to another PC equipped with a walkie-talkie. Bandwidth is about the same as HF.

    So what else? Well, in the Village Telco project we are betting on meshed WiFi. Mesh WiFi can offer all of the coverage of Walkie-Talkies (thanks to the magic of the mesh) but also deliver IP-based voice and broadband data which can start with simple person-to-person voice calls and voicemail but scale to full-blown Internet services and interconnection to the PSTN. Instead of a WalkieTalkie, a user would have a Mesh Potato, which is a low-cost wireless access point and phone interface in one. We expect the retail price of the Mesh Potato will be about the same as a WalkieTalkie. Any plain old telephone can then be plugged into a Mesh Potato.

    I think this all points to the fact that what is needed is more unlicensed spectrum, more space for innovative solutions to emerge in. I think the White Spaces spectrum approved by the FCC in November in the United States offers real possibilities for rural connectivity and there ought to be a White Spaces lobby in every developing country… but that is a longer rant. πŸ™‚

    Cheers… Steve

  3. Chris Blow says:

    Excellent writeup Ken, thanks.

    It seems that this would be especially useful for ad-hoc networks in places where the communications infrastructure actually crashes during a natural disaster, is suppressed for political reasons, or is overloaded with concerned-caller traffic.

    I also would be interested in hearing about any work that has been done in this area — surely my local fire department has some plan for network connectivity without AT&T?

  4. Chris Blow says:

    I should specify that I am currently in San Francisco, USA — so I am referring to a very different situation than you are. But a significant crisis will put even this ultra-networked city into a very bush-like state when it comes to sending email.

  5. Coby says:

    Good stuff. I have been playing with open-mesh routers for a while now – similar concept to Mesh Potato but I do like the idea of integrated voice.

    Chris, I have been on the edges of a couple debates re Public Safety Networks in the US. It is both technical and political for sure and I claim no expertise. This post is an overview of some of the recent issues http://arstechnica.com/news.ars/post/20080627-nypd-cities-slam-fcc-block-d-public-safety-network-dream.html

  6. kiwanja says:

    Thanks for your comments, guys

    @steve – There’s clearly a few options available, all of which have their upsides and downsides. I’ll take a wider/longer look at some of the options you highlight – thanks for those. I’m familiar with HF and, because of some of the issues didn’t think it would be something that could be quickly and easily adopted (as your comments confirm). I think a wider post (and rant!) might be merited covering these – maybe something you’d consider writing? πŸ™‚ The main point for me is that, despite the challenges, there are alternatives to mobile and I don’t see them being discussed too much

    @chris I would guess that in places like San Francisco, and other major cities, the emergency services have their own communications networks. One thing which emerged from the London terrorists bombings a couple of years ago was the lack of emergency communications infrastructure in the London Underground – mobiles didn’t work, and where they did the network was severely congested. A new network was rolled out only last week to cover this (but I’m not sure what technology they used)

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  9. George Bailey says:

    We are just in the process of finalizing the roll out of our rural IP communications network starting in Botswana. It is a mixture of microwave and local cell with HF Radio.

    The crucial aspect here is the HF which currently handles between 512k and 2Mb over distances up-to 1000 miles. The next version of this system will break the 2 meg barrier and be about the size of a large 2 way hand held radio. The network will eventually span from the DRC to the Cape and East coast to West with the emphasis upon the rural areas where the majority of populations reside but are not served and will back haul to a 10Gbps satellite earth station we are constructing here with possible out stations in other countries.

    Just thought you may be in interested to know.

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