segunda-feira, fevereiro 06, 2006

Connecting the world, one mesh at a time
By Holden Frith, from UK Times Online


Fans of the internet are fond of describing it as an engine of freedom, opportunity and wealth creation. In many ways they are right: the internet can be a limitless classroom for those bypassed by formal education, and a marketplace and forum for people otherwise excluded from economic or political life.

The problem is that the people who could benefit most are the least likely to be connected. The digital divide between rich and poor prevents the benefits flowing to disadvantaged Britons, as well as the vast majority in the developing world, guaranteeing that familiar inequalities persist in the virtual world.

One technology that promises to help bridge the divide both at home and abroad is wireless mesh networking. In basic terms, the mesh provides an alternative to established methods of linking computers together and connecting them to the internet. In practice, it can be used to build large networks far more quickly and cheaply than has previously been possible.

As a result, wireless networks are viable in unexpected places. New Orleans, still without a phone service after Hurricane Katrina, recently began building a free, citywide network using mesh technology, while the whole of Macedonia is now one big wireless hotspot. Networks are also providing web connections to people in the parts of the UK untouched by phone-based broadband, as well as in developing countries that have never had effective telephone networks.



The British company LocustWorld is a pioneer within this growing market. Its co-founder, Richard Lander, explains how meshes differ from other networks. Instead of having a central server which determines how data passes between computers, he says, the mesh creates a network of equals, in which individual computers find the best way to communicate with each other.

"Lots of intelligent devices all fit together to form a resilient network, and the more devices there are on a network, the more routes there are through it," Mr Lander says. "You can continue to grow it organically, piece by piece, and it will organise itself.

Data finds its way through the network in much the same way that we find our way around a city. "You don’t have a map of every route in the country in your head," he says. "You store the routes around where you live or work, or the routes you use most often. If you need to find a street in London you buy a London A to Z, or ask directions on the way."

At the heart of the network is the MeshBox, a wireless access point and router contained in a box about the size of a video recorder. A single box will provide internet access to anyone within range, but a network of several of these nodes can cover large areas as the signal leaps from box to box, spreading from each as it goes.

The ad hoc nature of the mesh makes it easy to start small and expand where necessary, without the complex reprogramming involved with adding to a traditional, top-down network. As the mesh becomes more dense its stability increases due to the greater number of potential connections: if one node fails then the network will direct data through an alternative route. Two separate meshes can even merge into a single network if they grow to the point of overlapping.

They are also relatively cheap to set up. Unlike phone or cable-based internet systems, mesh networks require minimal physical infrastructure and can be installed quickly, cheaply and without extensive training.

In mountainous Bolivia, LocustWorld worked with the International Institute for Communication and local technicians to install a two-square-mile mesh in the town of Sopachuy. The remote town had only about a dozen phone lines for a population of 1,500, but in less than a day and for a few thousand pounds, the team built a network capable of providing internet and telephone services to most of the town.

The same qualities make mesh networks attractive to small internet service providers aiming to fill the UK’s broadband blackspots. Speednet Scotland uses a mesh network to provide wireless broadband access to the area surrounding Troon, Ayreshire, where many telephone exchanges were unable to support broadband until recently.

The company was set up in 2004 and now has 150 customers, each paying either £15.99 per month for a 750Kbps connection, or £24.99 per month for 1.5Mbps. This is slightly more than they would pay for telephone-based broadband, but mesh customers don’t have to pay for a BT line, a prerequisite for most other services. Speednet Scotland also lets users connect their home phone to the mesh instead of the standard phone network, and for a monthly fee of £5 offers unlimited calls to landlines in the UK and 33 other countries.

Although the BT exchanges in the area have now been upgraded to support broadband, Speednet Scotland has managed to keep all its customers. The company’s founder, Brian Mcilwraith, explains that his three MeshBoxes, each of which cost £250, can outperform the established telecoms infrastructure. "We can get a better service through the internet than BT can," he says. "The copper lines have been in the ground for a number of years and they’re not always up to standard, especially in our rural communities."

Mesh networks have long been an area where small companies can compete with the big boys, but with growing interest – and investment – from technology giants such as Cisco and Intel, the market may soon be a lot more crowded. At LocustWorld, Mr Lander is not put off by the competition. "It’s not a question of one company replacing another," he says. "Cisco’s advertising is paying dividends for LocustWorld, raising interest in people who never would have thought of using a mesh."

The growth of meshing will undoubtedly present new challenges. One obstacle is regulation, both in the developing world, where bureaucracy can prove insurmountable, and the developed world, where telecoms companies are strongly lobbying against citywide mesh networks that threaten their business. Wireless security will also be a concern for some, although proponents of the technology argue that an encrypted mesh provides more comprehensive protection than the unencrypted cable network that most people rely on.

As with other relatively new the issue of standards and compatibility may also take some time to settle down, and as more companies become involved there is a risk that a proliferation of competing, incompatible standards could lead to frustration. Mesh remains an emerging technology, but with increasing numbers of villages, towns and cities throughout the world opting to install meshes, it is certainly emerging fast.


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