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Science & Tech

The Next Internet

BU prof says Boston could be a national model for citywide wireless

Abraham Matta, a CAS associate professor of computer science, led a discussion of "urban mesh networks" last week. Photo courtesy of Abraham Matta

The era of everywhere Internet will soon be upon us. According to MuniWireless, a Web site that tracks municipal wireless initiatives, nearly 90 American urban areas are currently building networks for citywide wireless Internet access. Hundreds of others plan to be wireless within a few years, and one of those is Boston, which aims to have its network completed by the end of 2008. (Think they’ll make it? Vote now).

These “urban mesh networks” of wirelessly connected “nodes” atop light poles and buildings could bring affordable Internet access to all communities, rich and poor. And the same networks will serve public safety coordination and disaster response efforts, enhanced city services, environmental monitoring, and network-based research and entrepreneurs.

Urban mesh networks were one topic of discussion at a two-day national symposium on computing research infrastructure, sponsored by the National Science Foundation and held last week at Boston University’s Photonics Center, hosted by the College of Arts and Sciences computer science department. Among the presenters was Abraham Matta, an associate professor of computer sciences. BU Today spoke with Matta to learn more about the wireless access that may soon be coming to a computer near you.

BU Today:
What are urban mesh networks?

Matta: They are wireless networks of access points, or what we call access nodes, that can serve a few hundred users. And these access nodes are interconnected over wireless links. If you want to go over a larger area of a city or something, you can also have gateways for each group of access nodes. You can have, say, a gateway for Brookline, and a gateway for Newton, and eventually one of these gateways might be connected to the Internet.

Are they always connected to the Internet?

No, they don’t need to provide Internet access. Usually, people would like to have this kind of public access to the Internet, from anywhere, at any time, and so on. But there are other, possibly more important, applications for urban mesh networks. There are lots of public safety applications — so police and fire personnel can access databases and crime records and so they can communicate between themselves and other emergency services in case of disasters. You have also a lot of public service applications. For instance, you can have parking meters or traffic signals sending information back to some central location.

And the city itself might provide services or use these urban mesh networks to improve its services. City workers wouldn’t have to travel all around the city to do their jobs. They would have all these sensors around the city, and these sensors would communicate to this wireless mesh network to report any kind of events that you might be interested in.

For example, you could measure air pollution with sensors mounted over light poles all around the city. You might program the sensor nodes to report back if the air pollution level exceeds a certain threshold, and you could also then trigger a video camera next to the sensor to take a picture of a truck that is causing this high level of pollution.

How are cities planning to make this work financially?
Worldwide, there are between 1,500 and 2,000 urban mesh networks planned and some 200 already up and running. Cities usually offer access to their public assets like street lamps, buildings, and so on. Usually, they don’t invest more than that. For instance, in San Francisco, Google said it would build a network for the city for free, as long as it could have access to city resources or assets. And an operator like this would get their revenue from advertisements to mesh network users.

You can also get revenue from access fees. Usually, the city will negotiate discounted access rates for underserved communities. It’s called digital inclusion, and that’s something that’s a major driver for most cities. For instance, here in Boston, Roxbury is a target area to provide access.

What’s Boston’s overall plan?
I think Boston has an interesting approach, in the sense that the idea is to promote open innovations. In many other cities, there’s a single company that’s taking over everything, and it’s not clear that they’d allow you to do anything on their network if you want to change anything or provide new services. But here in Boston, the goal is to open it up so you can have several service providers offering different kinds of services. Everybody would benefit from this kind of competition, including researchers trying to experiment with some ideas about improving the network.

There is now a nonprofit called OpenAirBoston, and while discussions are still ongoing, basically this nonprofit would be in charge of the day-to-day operation of the network and its commercialization. But there would also be open access to the infrastructure overseen by an advisory board called a Wirelesss Innovation Center (WIC), which will be hosted by some university in Boston. We are hoping, of course, that Boston University would be that host.

That WIC should provide the long-term vision and research opportunities and allow students to have access to the infrastructure, to get them trained on the infrastructure, and to try also to incubate start-up companies that would use the network.

What sort of start-up companies might use this network?

Some entrepreneur might offer a service based on an application that could monitor traffic conditions in real time all over the city. Then the WIC would arrange access to the network and facilitate this, basically.

There are all sorts of possibilities for applications, but there is also potential for improving the protocols that support these applications, or network software infrastructure that improves the functioning of the network. You would like people to be able to improve the performance of the network and use the wireless mesh more efficiently, which is not possible in other kinds of urban networks where you have a single company that installs it and does what the city wants. In Boston, at least it’s my hope, they will allow people to play with the underlying network software itself, the infrastructure, to improve it, and then you can commercialize these access nodes using this new network software.

What are the challenges to putting these networks together?
Well, first of all, it’s the design of the network — where should these access nodes go, on which street lamps or which buildings and so on? The design has to account for the population density, and obviously there are issues in an urban setting, with obstacles such as trees and buildings.

There is also the challenge of figuring out the transport of network traffic. You might have areas that get very low connection speeds just because they are farther away from the gateway, for instance. Everybody’s going toward the gateway, which is kind of the central place where everything meets and then gets redistributed from there. So there are issues like that that require adapting the network software itself, and that’s why allowing people to do research and actually improve the network software is a possible benefit for an open infrastructure.

If all these cities are coming up with different models for mesh networks, what about compatibility between them?
That’s a matter of internetworking all these kinds of networks. And naturally, the Internet is a possible glue with these access networks interconnecting through the Internet itself. The research community is working on just these issues recently in the context of the future Internet, which is a new program sponsored by the National Science Foundation.

Part of the internetworking work, which is going on now, is creating what we have now in cellular telephone service, where you deal with roaming through your home service provider. You have a home service provider and you go to another service provider when you roam around to other cities, and it works out because they always can charge your home.

Chris Berdik can be reached at cberdik@bu.edu.