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Students get blanketed in wi-fi at Brum uni
Case study: But do they care about the virtual cell architecture?

By Natasha Lomas

Published: Tuesday 18 March 2008

Students at The University of Birmingham will soon be able to roll out of bed and get onto the internet wherever they happen to have ended up on campus.

The university is in the second phase of a wi-fi rollout that will see coverage extended to all corners of its main 250-hectare Edgbaston campus and 80-hectare Selly Oak site by the end of the year - or what will be the largest university wi-fi rollout in Europe.

Currently students have wi-fi access in lecture theatres, libraries, some classrooms and social areas such as coffee shops. But wireless coverage is in the process of being extended to every square inch of both campuses - from walkways to sports pitches.

The university's vision is that an all pervasive wi-fi network will not only be a vital aid for academic activity but also a springboard for new student services - enabling live pictures of sports events to be multicast to the online student portal, for instance, along with pitch-side commentary. John Turnbull, head of networks in the university's IT services department, even has plans for an IPTV multicasting service to launch in September.

Why wireless? Ease of access, says Turnbull: "We want the students to be able to access course material anywhere on site and at any time. And the wireless is very suitable for this type of access."

But what the 30,000-odd students at Birmingham University don't get to see as they update their MySpace page over a late breakfast or browse course modules during lectures, is the network infrastructure that lies behind this moveable feast of web services.

Birmingham's wi-fi network, which began life three years ago, is costing around a quarter of a million pounds - on top of a much more expensive core fibre network (in the region of £12m). The wi-fi network would have cost more but the university was able to make a saving of £87,000 by reusing fibre freed up when the core network was recently upgraded from 8MB to 10MB, said Turnbull.

He explains: "When we upgraded to 10GB [from 8MB trunk link] through a single point, the 10GB upgrade link just uses one fibre as opposed to using eight trunked fibres so that released at least 35 fibres - pairs - across our campus."

The university has chosen to run its wireless network in parallel with its wired network for security reasons, according to Turnbull: "All the access points are on a network that's separate from our campus network but then linked back in to our campus network via a firewall so that we've got full control of the security associated with the wireless network."

This has the added advantage of meaning there is a back-up option if one network goes down. "If in a building the local wired network was down the wireless network would still be available because it's a parallel network," he explains.

Turnbull said the large-scale of the campus wi-fi rollout meant ease of installation was a key consideration in designing the network. This was one of the reasons Birmingham chose to upgrade from existing access points from switching and routing vendor Foundry Networks to the company's IronPoint Mobility Series of access points. The new kit dispenses with the costly and time-consuming business of having to do detailed surveys of buildings to locate the best sites for wi-fi access points as it boosts wi-fi access by using a virtual cell architecture.

Chris Lea, senior network specialist at the university, explains: "Instead of seeing a whole number of access points - potential connections for the client - [the client device] just see a single large, access point if you like or a single access point that covers a large area."

This means the client no longer has to make a decision about which access point to connect to as the hardware chooses for them. Roaming decisions are also controlled by the hardware.

And there are bandwidth benefits too, says Lea: "In a traditional [wi-fi network architecture] system all the clients will be contending against each other to gain the access point's availability so that they can transmit and receive traffic.

"In the new system the controller actually manages that and what it will do is assign a piece of time on the access point for each client and in a round robin fashion each client will very rapidly receive slices of time on the access point."

Lea said the network infrastructure can support up to 10 times the number of users per access point compared to a system that does not use virtual cell technology. "We've certainly seen numbers like 35 clients on a single access point with no performance issues," he adds.

The system also has built-in rogue access point detection.

More than 300 IronPoint Mobility access points and two Foundry Mobility Controllers have now been implemented - with a further 360 access points due to be installed to complete the campus-wide wi-fi rollout.

But what do the students make of such liberal access to wireless internet?

Feedback on the current wi-fi network has been positive, according to Turnbull, adding that students' use of landline phones in halls of residence has dropped so much the university may give up installing them in new builds as students now favour mobile phones and the likes of Skype over wi-fi.

He told silicon.com: "We're actually building a new hall of residence at the moment and it looks like we won't be putting handsets in there - we'll just be using the wireless and the wired network to provide voice as well."

He adds: "It's [wi-fi] becoming part of [students'] everyday normal access, part of the learning process, part of the research process and also it's part of the student experience - the student life as it were, with the other facilities like the IPTV."

A student studying politics at Birmingham said the wireless network is a "pretty useful" feature of campus life - but he warned liberal access to the net does have downsides too.

He told silicon.com: "It means I can bring my laptop in [to campus] and work pretty much anywhere, which is pretty handy as despite numerous computer clusters it's sometimes pretty tricky to find a free one. However I stopped doing this because I found when I used my laptop in lectures I connected to the net and stopped listening to the lecturers."

The student adds: "It is pretty handy though. And friends with phones with wi-fi have been pleased with it too but more for an entertainment, socialising context rather than an actual academic purpose. Other than access to e-journal's etc (which we can do via a proxy anyway) I can't really see the educational purpose behind it but perhaps I'm being short-sighted."