One of the big hurdles for operators preparing to introduce voice over LTE is ensuring they can provide legally mandated emergency 911 access over this IP-based voice service.
At the CTIA Wireless 2012 show last week, TeleCommunication Systems (TCS) announced its TCS 9-1-1 product, which includes SIP-based emergency call routing that natively supports the IMS-based LTE network over which E911 calls are delivered. In addition, the system uses Cell ID data as well as Wi-Fi MAC address and Femtocell ID information to route a 911 call to the appropriate public safety answering point (PSAP).
To ensure an operator can provide precise location data after call routing, TCS' location-retrieval function in the emergency call server (ELC) supports updated/precise position requests using multiple methods. These include control plane location requests using Mobile Location Protocol (MLP) to an Evolved GMLC as well as user plane location requests using MLP to a user plane location server. In addition, the TCS 9-1-1 ECS supports location continuity and location delivery to PSAPs when an E911 call switches from LTE to 2G or 3G networks.
"As carriers transition to delivering voice over 4G/LTE networks, subscribers expect that access to 911 services will be reliable and uninterrupted," said Chris Nabinger, senior vice president of the safety & security group at TCS.
Kristin Rinne, senior vice president of Network Technologies at AT&T Labs (NYSE:T), said during her keynote speech at FierceWireless' The Path to 4G event during the CTIA show that AT&T Mobility intends to launch VoLTE in 2013, but she said the operator first must ensure that its VoLTE platform meets mandates regarding law-enforcement regulations such as E911 and provides satisfactory quality of service.
While operators and vendors work to ensure 911 calls will work reliably over VoLTE, there remains the uncomfortable fact that wireless 911 in general does not work in the absence of a radio signal. This was highlighted by recent reports on the tragic story of an elderly couple who crashed their car May 3 in the rural Catskills northwest of New York City and died after nine futile attempts to call for help from their cellular handset.
- see this TCS release
- see The Washington Post article
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