Wireless Networking in the Developing World/Introduction

This book aims to empower people to build DIY networks using wireless technologies. It has been compiled by a bunch of networking geeks that have been busy designing, deploying and operating wireless networks for quite some time, all of them actively participating in expanding the reach of the Internet all over the world.

We believe that people can have a significant stake in building their own communications infrastructure and also influence the wider community around them to make sure networks become affordable and available.

We hope to not only convince you that this is possible, but also show how we have done it, and to give you the information and tools you need to start a network project in your local community.

By providing people in your local community with cheaper and easier access to information, they will directly benefit from what the Internet has to offer.

The time and effort saved by having access to the global network of information translates into value on a local scale. Likewise, the network becomes all the more valuable as more people are connected to it. Communities connected to the Internet at high speed have a voice in a global marketplace, where transactions happen around the world at the speed of light.

People all over the world are finding that Internet access gives them a voice to discuss their problems, politics, and whatever else is important in their lives, in a way that the telephone and television simply cannot compete. What has until recently sounded like science fiction is now becoming a reality, and that reality is being built on wireless networks.

The country of AipotuEdit

Now lets for a moment look at a fictional country called ‘Aipotu’, in the developing world. Aipotu has been connected to the Internet merely by expensive VSAT links for a long time.

A brand new optical submarine telecommunications connection has finally arrived at the shore of Aipotu.

The challenge for Aipotu is now to roll out a complete communication infrastructure for a whole country from scratch.

 

The method of choice today is likely a three tier strategy. First and foremost Aipotu should try to roll out optical fibre lines wherever possible. Fibre lines offer the capability to transport a “sea of bandwidth”.

The cost of optical fibre is very low, considering the capacity. By upgrading the optical transceivers the capacity of a optical fibre line can be upgraded without laying new cable. If Aipotu can afford to establish a fibre connection to every household there is no reason not to go for it.

This would make our three tier model obsolete and we could stop here. However, there are probably areas in Aipotu that cannot afford fibre lines.

 

The second tier that the people of Aipotu can use in order to connect remote villages or small cities are high speed point-to-point links between high points. It is possible to establish high speed links (40 Mbps) of 30 km or more between towers of 30 metre height on flat terrain.

If mountain tops, high buildings or hill tops are available, even longer links are possible. The network technology experts of Aipotu don’t have to worry too much about the wireless technology that they are mounting on top of their towers - the cost lies mostly in building the towers, proper lightning protection, power supplies, power back-up and theft protection, rather than in the actual wireless equipment and antennas.

Like the technology of optical transceivers, wireless transceivers also keep advancing, but a wireless link will always be orders of magnitude slower than the capacity of optical fibre.

 

The third challenge for Aipotu is to solve the problem of the last mile(s): Distributing access to all the individual households, offices, production facilities and so on. Not too long ago the method of choice was to run copper wires but now there is a better choice. This third tier of our network model is clearly the domain of wireless networking technology.

Purpose of this bookEdit

The overall goal of this book is to help you build affordable communication technology in your local community by making best use of whatever resources are available.

Using inexpensive off-the-shelf equipment, you can build high speed data networks that connect remote areas together, provide broadband network access in areas where even dialup does not exist, and ultimately connect you and your neighbours to the global Internet.

By using local sources for materials and fabricating parts yourself, you can build reliable network links with very little budget.

And by working with your local community, you can build a telecommunications infrastructure that benefits everyone who participates in it.

This book is not a guide to configuring wireless for your laptop or choosing consumer grade gear for your home network. The emphasis is on building infrastructure links intended to be used as the backbone for wide area wireless networks as well as solving the last mile problem.

With those goals in mind, information is presented from many points of view, including technical, social, and financial factors.

The extensive collection of case studies included present various groups’ attempts at building these networks, the resources that were committed to them, and the ultimate results of these attempts.

 

It is also important to note that all of the resources, techniques and design methodologies described in this book are valid in any part of the world. There are many rural parts all over the globe that remain unconnected to the Internet for reasons of cost, geography, politics and so on.

Deploying wireless networking can often lead to these problems being solved thereby extending connectivity to those who as yet have not achieved it. There are many community based networking projects emerging everywhere. So whether you live in the United Kingdom, Kenya, Chile or India or anywhere else, this book can be a useful practical guide.

 

Since the first spark gap experiments at the turn of the XIX century, wireless has been a rapidly evolving area of communications technology. While we provide specific examples of how to build working high speed data links, the techniques described in this book are not intended to replace existing wired infrastructure (such as telephone systems or fibre optic backbone).

Rather, these techniques are intended to augment existing systems, and provide connectivity in areas where running fibre or other physical cable would be impractical.

We hope you find this book useful for solving your communication challenges.

Fitting wireless into your existing networkEdit

If you are a network administrator, you may wonder how wireless might fit into your existing network infrastructure.

Wireless can serve in many capacities, from a simple extension (like a several kilometre Ethernet cable) to a distribution point (like a large hub).

 

Here just a few examples of how your network can benefit from wireless technology.

 

 

Figure I 1: Some wireless networking examples.

 

How this book is organizedEdit

This book has 4 main sections called -

 

 Physics

 Networking

 Planning and Deployment

 Maintenance, Monitoring and Sustainability

At the end you will find a Glossary as well as Appendices and Case Studies.

Within the 4 main sections there are chapters written by key experts with theoretical and practical hands on experience of the topics.

There are a broad range of topics in the chapters which have been selected as being key to enabling you to start and grow a real wireless deployment in your own community. Another resource you may find useful is here -

http://wtkit.org/groups/wtkit/wiki/820cb/download_page.html

 

It is the set of presentation materials used by these same key experts to deliver wireless networking training classes around the world.

In addition all of the key experts who have written this book regularly check our Facebook page. So as you plan your deployment please do ask questions on our page - we do answer quickly.

https://www.facebook.com/groups/wirelessu