The deadline is approaching and you have just finished your assignment. You have 15 minutes to upload the file to Blackboard when — without rhyme or reason — your Internet connection is lost.
Many U of T students are familiar with this experience, though students have noticed some slight improvements over the years.
Aliya Bhatia, a fourth-year international relations and art student, said she’s noticed improved wireless connectivity in a number of locations on campus, especially Hart House. “It used to be so bad. But it got much better last year,” she said.
Bhatia also noticed that some residences have installed wireless networks over the years, including Teefy Hall and Sorbara Hall, where she used to be a resident.
Wireless network rollout
Since 2010, the university has been taking steps to expand and optimize the network across all three campuses by strategically allocating wireless Access Points (APs) based on the functions of the building, expected user-density, and performance requirements.
Douglas Carson, manager of network infrastructure, said the project is progressing well. “There are currently 3,400 access points deployed on the St. George campus. When the wireless network rollout is complete, we expect to have about 5,500 access points on this campus and about 7,000 across all three campuses,” Carson said.
The network currently supports around 52,000 users, with the expectation that the number will eventually grow upwards of 100,000.
“Wireless networks in each building are designed to the specific requirements and functions of that building. For example, a 200-seat lecture theatre may have four to six APs in the same room, while an office area may have only a few APs for the entire floor,” Carson added.
It should come as no surprise, then, that 211 APs provide full service to the Robarts Library. According to chief librarian Larry Alford, 18,000 people visit Robarts Library on a busy day.
Mike Peng, a second-year civil engineering student, said he attends seven lectures a week at the Lassonde Mining Building. Although the building is listed as having seven APs, Peng said the building’s WiFi capability is poor.
According to Carson, deployment of the network on the St. George campus is only 65 per cent complete, and some buildings may still experience poor connectivity as a result.
“The deployments at UTM and UTSC are now essentially complete. However, because of its size and complexity, full coverage for the St. George [campus] is expected to require a few more years to finish,” Carson said, adding that full wireless service will be installed in the Lassonde Mining Building this winter.
High-performance infrastructure
Good WiFi is not just the product of a large number of APs. On a typical afternoon, the wireless network on the St. George campus generates four gigabits per second of traffic. To support peak usage, an appropriate network design with enough bandwidth is required to get data from the Internet to user devices.
Carson said that, if needed, the capacity of the network can be upgraded to accommodate more connections. “Each [AP] is backed by two data cables, each capable of carrying up to 10 gigabits per second of traffic. Each AP is connected to a central switch at 1 [gigabit per second]. These switches are, in turn, connected to a high-performance network specifically designated to handle wireless traffic,” he said.
When asked about the university’s network design, Ahmed Seoudy, a manager at Nokia Network Solutions, praised the university’s network setup. “[It’s] very scalable and puts into consideration future growth… ensuring redundancy and allowing for easy upgrades,” Seoudy said.
Some students have complained about turning off mobile WiFi access while on campus in a bid to avoid connectivity issues, instead relying on a cellular operator’s Long-Term Evolution (LTE) network.
Solving this issue would require smart offloading, whereby the network switches between WiFi and LTE/3G, depending on signal strength. This switch is mostly decided by the particular device in use and the cellular service provider.
According to Seoudy, however, U of T “can reach agreements with major cellular providers on offloading rules to prevent congestion and allow optimal user experience.”
This sort of data switching is relatively new and its rollout has been slow, particularly due to its complexity and its effect in reducing the service provider’s revenue when offloading to WiFi. However, to provide better coverage, cellular operators sometimes use it in highly congested areas like shopping malls.
Carson added that, although the university’s wireless network does not formally support Voice over Internet Protocol (VoIP), it is investigating whether to allow applications like Skype or Viber to transfer VoIP calls from a cellular network to the university’s WiFi.
