Campus-Wide 802.11AC WiFi – University of Westminster Case Study

If you want to know how to build best-of-breed networks, universities can be good places to look. London’s University of Westminster is no exception: its network has grown and changed vendors over the years as the demands on it have increased. It is now on its third iteration of Wi-Fi, for which it chose Aruba Networks, running via an HP wired network and a Brocade core.

“We introduced our first Wi-Fi network in the early 2000s. It’s grown exponentially from there and now it’s a must-have utility,” explains Daniel Halter, the University of Westminster’s Head of IT Infrastructure. “Our previous wireless wasn’t entirely working as desired, so we went to market to see what to see what else was around. As a result, we installed Aruba last summer.”

To give an idea of the scale involved, Halter says there is an average of 47,000 unique devices seen on the wireless network, which comprises some 500 Aruba access points connected to a pair of 7220 controllers. While some of the devices are laptops loaned by the University library, many belong to students, and each brings its own connectivity challenges.

“We had two major issues before – one was that we had never done proper RF [radio frequency] planning, so while our Wi-Fi coverage wasn’t bad, it had grown organically,” Halter says. “The other was that our previous system had become unmanageable. We also had different controllers and wireless networks, with separate configurations for each which made it hard to manage. We had no statistics on usage, no metrics, no proactive support data.” Compared to that, moving to Aruba was a revelation. “Our evaluation was 40/60 on cost/quality – the Aruba was not the cheapest, but it was competitive on cost and then won it on quality,” he explains. “The thing is it’s a packaged solution, not just a wireless service or raw connectivity. It was really important for us that our new network made things better for us, that it enabled our support team to become proactive, not just reactive. Now, with Aruba it’s all about the ability to plan, to identify peaks and troughs.”

The University uses both Aruba Airwave for alerting, reporting and planning, and ClearPass for 802.1x authentication and reporting. ClearPass also helped simplify the wireless network, not least because it integrates with eduroam, which is a world-wide scheme for academic institutions to authenticate network users. This enables all staff, students and academic visitors to use a single SSID (a named wireless network), and this in turn reduces both residence, and the University Sports Ground in Chiswick, West London. Halter says that Aruba’s Remote Access Point (RAP) technology has been particularly useful, as it can extend the core Wi-Fi network to a remote site over a simple broadband connection. “Most of the challenges were logistical,” he continues. “Our RF planning dictated new cabling in some of our estate – we put in CAT-5e for future-proofing to support the multigigabit uplinks needed for 802.11ac, and in greenfield sites we put CAT-6. The next refresh will be to deploy Class 4 Power over Ethernet (PoE). We only have Class 3 now, and for the full spectrum of 802.11ac Wave 2 [which will bring higher data rates and the ability to focus transmissions at a particular client] we will need up to 30W per port, which means Class 4 PoE. “11ac increases capacity by getting users on and off the network quicker, although I suspect that eventually that advantage will disappear as they will simply use it more! There’s only a few 11ac devices now, but we needed to replace 11n and we couldn’t wait for 11ac Wave 2 which needs new chipsets. “There’s also seasonal timing effects,” he says. “For instance, arranging the logistics so your external contractors can cable the parts of the estate used for learning when they’re vacant. And give yourself more time than you think you need for it to bed in and for you to start using the tools proactively.” Halter notes that while the University’s previous Wi-Fi networks included some 330 APs, it bought 500 from Aruba.

The increase was partly to cover more buildings, but he says that it is also important to buy a few spares.“Even after RF planning you can still have density issues, for example you might find you need more capacity in the learning spaces allocated for students – especially since we now have to plan for maybe three or four devices per user,” he explains. And of course demand can only grow, especially as more and more of the academic staff embrace Wi-Fi within their teaching plans. “This is a significant investment by the University, so we are really keen to see how the academics embrace wireless and use it to deliver teaching and learning, and for delivering content in the classrooms. “There’s a whole drive around ‘learning futures’, with IT natively embedded in every lesson, and that means building a platform where that can happen. Our previous network wasn’t where it needed to be – this one is!”