Enterprise WLAN provider Aruba Networks has teamed with E911 vendor RedSky Technologies to introduce a Wi-Fi-based emergency call-location solution for campuses, branch offices and teleworker offices.

Wi-Fi call location has been tricky because most solutions have relied on IP parsing that translates the IP address of the closest Ethernet switch or router to a physical location. However, the benefit of Wi-Fi calling inside buildings is the ability for workers to talk on the move; as a result, they may be far away from the Ethernet switch. The RedSky solution, in simple terms, can match a phone with the nearest access point to determine the location of an E911 call and give 911 call-takers the address, building and floor where a caller is located.

The location process takes three steps. Aruba's wireless LAN sends real-time location updates to RedSky’s E911 Manager application as voice clients move around on the network. The caller's location is triangulated by processing signal strength and other data from nearby Aruba access points that is forwarded to RedSky. The E911 Manager then updates internal, external and IP-PBX databases with the location of the clients. When a voice client dials 911, RedSky’s application then provides instructions to the IP-PBX to route the call and notifies internal security personnel with location information derived from floor plans of the facility.

The Aruba/RedSky collaboration addresses a major concern regarding Wi-Fi voice, said Mike Tennefoss, head of strategic marketing with Aruba. "What we find as we talk to customers, the majority are interested in voice-over-Wi-Fi services, but as soon as you get to the emergency-calling discussion, we've been stopped at the gate. ... They are very concerned about 911 capability," he said.

Tennefoss said the desire for E911-over-Wi-Fi primarily is in the education sector, where college campuses are looking to prepare for major events such as school shootings. "A general concern is that as dual-mode (3G/Wi-Fi) handsets become more popular on campus, the primary method for calling will be Wi-Fi, and dispatchers can't send first-responder help," he said.

For the enterprise, retiring existing PBX equipment and moving to all Wi-Fi hasn't been possible because of this E911 barrier. With the availability of the Aruba/RedSky solution, Tennefoss believes many enterprises will move toward Wi-Fi voice, especially since the solution can be dropped into an existing network.

For larger enterprises — such as a university — that not only have their own security-and-response team, but also their own PSAP, the solution can push out floor plans that identifies all of the campus’s Wi-Fi devices.

"That feature is quite valuable because dispatchers can either talk directly to emergency services or meet them and guide them," said Peter Thornycroft, Aruba's wireless applications manager.

For example, the University of Cincinnati has incorporated an application-programming interface that can query a MAC address and receive critical information back, such as phone numbers and types of phones, in conjunction with the Wi-Fi 911 call, Thornycroft said.