Delivering cellular services on campus
College-age students have grown up with mobile phones, and they’re used to having them work when and where they want. With a 342-acre campus that has more than 11,000 students and more than 430 buildings; making mobile phones work everywhere is a tall order for Yale University.
Yale is a large and diverse place, and every type of communications device is being used. We know that the number of cell phones and tablets has dramatically increased on campus in the last few years, and the expectations for their use have equally increased. People come here with smartphones and tablets and they expect them to work in almost every nook and cranny of the campus.
Yale has tried to be very responsive to the communications needs of its community over the years. We have had a campuswide Wi-Fi network for six years, and this network was extended to all of the university’s 439 buildings in 2009. Our Wi-Fi network now features more than 6000 access points to deliver Wi-Fi everywhere on campus.
Addressing the challenges of cellular service on campus has also been a major initiative at Yale. Informal campus surveys show that essentially 100 percent of students, faculty, and staff have mobile phones, and everything from casual chats to emergency notifications rely on them working properly. The campus is served by several so-called “macro tower” cellular base stations in the New Haven area, but those signals don’t offer consistent service inside of buildings, particularly in underground facilities such as theaters and gymnasiums. Many of the recreational facilities in Yale’s residential colleges are below ground, and these also have poor cellular service. In addition, there are new buildings going up that feature low-emission glass, which also blocks cellular signals.
Over the past five years, we have heard growing complaints about mobile phone coverage. Students complain because they don’t have coverage in a quad, recreational facility, gymnasium or theater. Network capacity has also been an issue because of the proliferation of smartphones into the environment. Most students now use smartphones like the Apple iPhone, and along with voice and texting, they use those phones for Internet surfing, data downloads and video uploads. All of this puts a tremendous strain on the local cellular network.
To address these challenges, our technical staff consulted with the four largest wireless service providers in our area (AT&T, Sprint, T-Mobile, and Verizon) to find out what kinds of solutions were available. The service providers all agreed that a distributed antenna system (DAS) was the best way to handle the coverage and capacity problems. The only alternative was to deploy more macro cell base stations adjacent to the campus, but even these wouldn’t guarantee in-building wireless service.
“Unlike a macro tower that distributes signals from one place, a DAS takes the signal from the service provider (or multiple service providers’) base stations and distributes the signal through a series of fiber or coaxial cables to small antennas located throughout a network,” says John Spindler, director of Wireless Product Management at TE Connectivity. “The advantages of DAS are that it aggregates all services, is able to bring signals inside of buildings or areas underserved by surrounding macro towers, and distributes more capacity to more locations. Because each antenna serves a relatively small number of users, the DAS network can provide more capacity per user for those who use cellular data services heavily. And for the service providers, it’s a broadband network that can grow and change more easily than multiple layers of base stations.”
The disadvantages of DAS were that it would require installation in building ceilings, wiring closets, and equipment rooms in many buildings on the campus. It was a fairly large construction project that would require some disruption of campus life. In addition, some of the historic buildings on campus would need special care to blend antennas into their interiors.
Still, the advantages outweighed the disadvantages. Our administration could foresee using mobile devices for many services, including campus security, public safety notifications via text message, and communication of administrative information to specific students. Mobility could significantly streamline the university’s campuswide communications needs, if only we could depend on the mobile service.
There were several areas where improved mobile phone reception might improve the campus experience:
- For academics, students and faculty could access our LMS, view course schedules, reading lists, and other information via mobile phone.
- For safety and security, the university could adopt an automated text messaging system to alert students and faculty about on-campus emergencies, and students would know that they could always reach help via their mobile phones.
- For social needs, students could use their phones to do everything from exchange text messages to sharing videos to playing interactive games like Words with Friends.
In fact, Yale already relies on apps for the iPhone to improve student life: there’s an app for the dining hall, an app for on-campus transportation, and a generic app that offers campus news, event information, and a campus directory. The transportation app is a real-time map of the bus system on campus – it allows users to know when the bus is coming to a particular stop.
Deploying a DAS
Starting in the fall of 2009, we decided to deploy a DAS in ten of our buildings, including medical school facilities and our gymnasium. The university took on the challenge as an internal project, led and funded by the university itself. Our technical staff began negotiating with the four wireless service providers for mobile retransmission rights over the new DAS in the fall of 2009. At the same time, we issued a request for proposals (RFP) for DAS equipment.
When you build a DAS, you must get permission from the local operator or operators to transmit their signals over it. This is a process that can take the better part of a year, so we began negotiating as soon as we made the decision to go forward with the DAS.
The primary driver in our choice of TE Connectivity as the supplier of DAS equipment was that the TE InterReach Spectrum system was best suited to leverage our existing fiber plant. It uses fiber to connect its main hubs with expansion hubs located across campus. With some of the other solutions, their architecture had different space requirements within the buildings, and the TE solutions addressed these much better. Other systems also used heavy coaxial cabling, which would have been much harder to deploy. Cost was also a concern.
“The InterReach Spectrum system can support up to eight operator frequencies at once, so it was ideal for supporting four operators at Yale,” says Spindler.
To obtain operator signals to feed the DAS, TE Connectivity technicians deployed an external antenna for each operator on the roof of our Lippard Laboratory building. Broadband distribution amplifiers (BDAs) were housed just beneath these antennas, in the building’s penthouse. The BDAs were connected by fiber with InterReach Spectrum main hubs in the sub-basement.
We handled the physical implementation of the cabling ourselves. We took care of all the fiber and coaxial cabling, and TE Connectivity installed the antennas, BDAs, hubs, and ceiling-mounted antennas. The expansion units easily fit into racking space in telephone closets in each building where they were needed. In all, the system consists of three main hubs, 10 expansion hubs, and 45 remote amplifier units (RAUs). There are two antennas attached to each RAU.
Deployment of the system started in April, 2010 and was completed in September, 2010. While deployment was underway, we completed our retransmission agreements with the four major operators, and by the time the deployment was finished each of the operators was ready to provide signals over the system. Our team worked with TE to get specific system designs to the operators, who needed them to finalize the agreements.
There were few deployment issues. The cabling project was fairly typical of what we normally do with installing CATV cabling. The most unusual part was the addition of the antenna posts on top of one of our medical school laboratory buildings, installing BDAs in the penthouse of that building, and installing fiber from them down to the host units in the sub-basement of that building. That work was different from what we normally do, but putting coaxial cabling in the ceilings and installing electronic equipment in telephone closets are things we do all the time. Since we selected TE’s Spectrum, which was brand new to the market in 2010, there were firmware updates that had to be deployed and there were some delays in equipment shipments. Still, the actual installation wasn’t any more disruptive or challenging than things our telecom staff normally manages. Some areas of the medical school needed special clearances for us to work on the ceilings, but we always need special clearance to work in medical school research and lab environments, so this wasn’t atypical.
A Campuswide DAS
Soon after installation of the DAS was complete, one major service provider’s wireless network representatives approached Yale with a plan to extend a new network with a campuswide DAS. We wanted to understand our options and we spoke with each of the other operators, and after a request for information (RFI) we selected the original provider to deploy the campuswide DAS. It was to be an operator-neutral system. The project kicked off in August, 2011 and physical deployment started in spring of 2012. The system was due for completion at the end of 2012.
Between August, 2011 and April, 2012, TE Connectivity and the participating service provider designed a system for 150 buildings on campus. The effort included site surveys, benchmark testing, and equipment tests. We presented a list of priority buildings we wanted covered, and the service provider agreed to cover 100 buildings, including 43 buildings at the medical campus; 22 buildings at our West Campus; and six buildings at the central campus. Yale’s West Campus straddles West Haven and Orange, Connecticut, and houses medical and scientific research facilities as well as the future home of the School of Nursing. The central campus buildings support Yale College, the Law School, the School of Management, and other professional schools. As completed, the new DAS solves most of the remaining wireless connectivity issues on campus. The service provider is operating the system as a neutral host system, allowing the other three major providers to deliver services over it as well.
People have become accustomed to using their mobile phones in all circumstances. The DAS deployment has allowed us to provide trouble-free connectivity and also solved some safety-related issues: people feel safer knowing that they can be contacted at any time and can reach out for help at any time. In general, however, the DAS provides baseline support to meet the modern expectations of students and faculty.
If we had it to do over again, there’s nothing we would change about the deployment process. It went pretty much like any cabling project at the university. It was a necessary project to keep Yale up to date with wireless connectivity expectations in general. The expectations the students have for us are all about wireless – wireless phones, devices, and Wi-Fi for their computers. This is how we feel the industry is moving for all telecommunications services. Having the DAS installations on campus helps Yale fulfill its educational mission to students and faculty. With the ability to communicate anytime and anywhere, members of the Yale community can really get on with its mission to create, preserve and disseminate knowledge.
David Galassi is director of Network Services at Yale University