Most of the enterprise-class wireless LAN access point makers say they can triangulate the location of a wireless VoIP call to within a few meters of an AP. This bodes well for E-911 over WLANs.
For now, though, there are a few hitches. First, there seems to have been little integration work done to link that location information to premises IP PBXs, other than by companies that make both WLANs and IP PBXs, such as Cisco and Nortel. The IP PBXs, in turn, forward the location information to the nearest public safety answering point (PSAP) to alert first responders.
But despite the voice-over-WLAN hoopla, WLAN-based E-911 doesn't seem an industry priority. This is because, in part, while federal regulation addresses legal obligations for mobile WAN network operators, no such national mandates exist on the wireline side. And the WLAN is an extension of the wired corporate network.
However, 11 states do have some level of regulation about emergency calling in the workplace. In addition, enterprises should consider their potential legal liability. And, of course, some employers might just plain care about the welfare of the people who work for them.
These are among the reasons IP PBX vendors are building E-911 solutions for their wired VoIP switches.
I mentioned the WLAN E-911 issue at a panel discussion about voice over WLANs at last week's Wi-Fi Planet show in San Jose. I was startled to hear the representative of a wireless voice company reply that, basically, WLAN-based E-911 services aren't necessary, because 99.99% of the time, callers can simply tell the called party their whereabouts.
I don't think the vendor community's answer to the question, "How do you do WLAN E-911?" should be, "You don't need to do it." These are days of potential terrorist crises, and someone experiencing a heart attack or a diabetic in insulin shock doesn't have a long time to chat on the phone.
A long, long time ago, I worked in Oak Brook, Ill., a fairly swanky community where "vanity addresses," such as "One Oak Brook Plaza" were the rage. One evening, an after-hours employee in a building nearby was killed in a fire, because her company was listed in the PSAP's automatic location identification database with such a vanity address, which had no geographic meaning. No one could find her. She didn't know the "real" street address herself and was overcome by smoke inhalation before she could direct anyone to her.
Perhaps this is partly why Illinois is one of the 11 states with an E-911 mandate today.