Latest wireless goings-on at Duke University

Campus works to unify disparate wireless networks

From cellular to Wi-Fi to two-way radio to FMC, Duke University is working toward consolidating its many and varied wireless networks and applications. In this way, the Durham, N.C., university is becoming a strong role model for making integrated decisions that span disparate wireless technologies across an enterprise.

Well known as one of the world's largest Wi-Fi deployments, with more than 2,500 Cisco access points covering 6 million square feet, the university most recently has turned its attention to cellular. It has expanded its indoor multi-frequency distributed antenna system (DAS) from ADC to the out of doors, plugging intermittent gaps in AT&T and Verizon Wireless/Alltel mobile WAN coverage around campus.

The other wireless networks in use at Duke might piggyback the same DAS someday, too.

"What everyone really wants in the marketplace is a single system to handle cellular and two-way radio and Wi-Fi," says Bob Johnson, senior director of communications infrastructure for the university's campuses and hospitals, which serve about 50,000 wireless network users each day.

"We're talking to Cisco about putting Wi-Fi on the hybrid DAS," which has been live since last fall, Johnson says. "We don't want to support multiple [wireless] infrastructures." ADC has not yet publicly announced plans for Wi-Fi support on its DAS, though competitors such as InnerWireless do support all flavors of Wi-Fi, including 802.11n in MIMO mode.

Historically, DASs have boosted one or more operators' signals indoors from an internal base station across a building's internal cabling plant to distributed antennas. Duke's DAS covers 29 buildings indoors. However, some DASs, like ADC's, have expanded to also deliver cellular signals to dead zones outside, as well.

To augment the cellular outdoor coverage, the university piggybacked its DAS on an existing outdoor voice alert system comprising tall poles scattered around campus with large speakers mounted on them. ADC's ruggedized DAS antennas affix to these poles.

Today, ADC's indoor InterReach Fusion and outdoor Flexwave Prism DASs ship with separate management systems. However, ADC says a unified Fusion/Prism management system is imminent, and for now, SNMP alerts from both systems can be collected by a network management system.

The biggest driver for the indoor/outdoor DAS was for emergency communications in the wake of the 2007 Virginia Tech shootings, Johnson says. Another was the green campus initiative, which includes "skins" being put outside of buildings that help keep heat and air conditioning in, but in doing so, block cellular signals.

Duke footed the bill for about 60% of the system, while the mobile network operators paid the rest, Johnson says.

Duke is also in lab pilots with fixed-mobile convergence startups Agito Networks and Varaha Systems for enabling Wi-Fi and cellular calls to be handed off across networks as users roam without interruption.

Two-way radios are also in use. While Duke is considering the Sprint Nextel iDEN push-to-talk system, it is also vetting Verizon Wireless and other PTT systems. The reason? "We don't want another overlay network," Johnson says.

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