When students returned to West Campus residence halls after winter break they got a pleasant surprise: Their cell phones finally worked there.

Because of its downhill location out-of-sight of campus cell towers and some characteristics of the buildings, West Campus had a lot of dead spots. One problem was energy-saving "low E-glass": The metallic coating that reflects heat also tends to block radio waves.

Landline phones were removed from West Campus last year, as they were from North Campus the year before, since the university now expects students to have phones in their pockets, and students are used to communicating that way.

A team from Cornell Information Technologies, Cornell Real Estate and Student and Academic Services discussed with cellular providers various approaches to improve the student mobile experience on West Campus. After evaluating a number of external antenna site options for over 18 months and finding none that would give the desired coverage, the team decided on a distributed antenna system, or "DAS," that brings cellular signals indoors. Such systems are becoming common in shopping malls, subways, basements, tunnels and airports. One has been operating since 2006 in the lower part of Martha Van Rensselaer Hall.

Verizon Wireless initially offered to fund the DAS system, and AT&T Mobility soon signed on. Negotiation of the DAS contract started in fall 2009. The contract was signed in early 2010 with a deadline for DAS activation no later than January 2011. West Campus DAS construction began in October 2010 and continued until the final exam study period. System activation and integration continued through January, and both AT&T and Verizon signals were ready for student return.

West Campus DAS consists of more than 220 antennas, similar to RedRover wireless access antennas in lecture halls, throughout 14 buildings. The system is owned and operated by Verizon, but as a "neutral host," meaning that any cellular company licensed to operate in the geographic area can negotiate to plug in, avoiding a monopolistic "only my signals work" environment. So far Verizon and AT&T have split the cost, but "If Sprint or T-Mobile would like to join in, we'd love to have them connect," said Tom Ball, voice engineering manager for CIT. "We are in discussions with both of these companies."