Will somebody actually email 911? Part 3 of 4.

For the longest time, the standard joke offered by PBX vendors as to why IP Telephony needs a lot of work, is that they'd remind people that "Nobody emails 911."

In the previous 2 articles, we reviewed how E911 works today for circuit switched implementations, how it works in wireless networks and how it should use information about the physical network (L1 and L2) to map IP address to physical port and end point so E911 can work in enterprise LANs.

It's not just about picking up the telephone and dialing E911. Could I use a soft phone to make an E911 call?

With 3Com VCX IP Telephony implementation, there is no system distinction with respect to how the IP Telephony module reacts to emergency calls – it busy outs other services to that station and keeps a port open to the receptionist designate. So, if a call is made from a PC, the emergency response team should go there too.

802.11a/b/g WiFi networks are gaining popularity in modern hospital facilities: where professionals are not bound to a specific desk or administration station, but instead are frequently mobile, providing service to patients where they are. This is the place where enterprise mobile telephony will be a worthwhile and pervasive investment. Deploying a WiFi network around the hospital, with Access Points and intelligent Wireless Switches that can handle hand-offs from one zone to another without call interruption will be the norm. Session Initiation Protocol (SIP) phones for WiFi are only now coming available from popular vendors like Motorola and Research In Motion.

Nurses and doctors will be immediately accessible through WiFi. The need however, will be able to use the wireless triangulation function for wireless operators to pinpoint the location of the nurse dialing 911 with the WiFi SIP phone. In fact, it would seem to be useful to flag LOCATION to presence subscribers, so that nurses know when and which doctors are nearby, and vice versa.