Look for Wi-Fi to play a bigger role in wireless 911 location
The FCC is mulling some big changes to the way wireless and VoIP calls provide 911 location data.
Last week the commission issued a Notice of Proposed Rulemaking (NPRM) seeking comment on whether, among other things, existing 911 rules apply to two-way interconnected VoIP services, as well as to outbound-only interconnected VoIP services. In addition, the FCC is grappling with how to make wireless 911 calls more accurate and planning for the future when many wireless calls will be VoIP calls.
One of the more intriguing aspects of the NPRM has to do with leveraging commercial location technologies and adding them to the emergency location mix to enhance accuracy. Commercial location services have taken off, and mobile operators have a vested revenue-generating interest in making sure that these types of applications provide enhanced accuracy. Today, wireless 911 technology is a separate piece in mobile networks, consisting of assisted GPS and network-based technologies.
One commercial location method leverages Wi-Fi access points, which are exploding in growth. The commission is seeking comment on the potential use of Wi-Fi to support location accuracy, especially in indoor environments.
However, some elements would need to be added to make this a reality. As the FCC notes, Wi-Fi isn’t used for 911 location because current deployments for Wi-Fi location are based on proprietary implementations; support for transporting Wi-Fi measurements to the Wi-Fi location server are not available in the E-911 control plane interface standards; only a small number of mobile phones in the marketplace have Wi-Fi capability; and the use of Wi-Fi positioning reduces a device’s battery life.
But leveraging Wi-Fi location services definitely should be taken into consideration given the fact that the country’s major mobile operators all have embraced Wi-Fi as a data offload strategy. Operators are aiming to make Wi-Fi a carrier-grade extension of their existing mobile networks.
For example, AT&T Mobility is building hotzones — large Wi-Fi coverage areas — in many major cities. Cable provider Cablevision now owns a massive Wi-Fi network in New York City with tens of thousands of outdoor access points and thousands of indoor locations across the metro area.
Wi-Fi also is becoming standard technology in smartphones and a number of independent companies already are involved in the Wi-Fi location space. Google is keen on building up its Wi-Fi location capabilities because they complement its search business.
Skyhook, in particular, has been around since 2003 and powers several commercial applications such as Citysearch, Mapquest and Priceline.com.
The company’s software-based location system touts device location with 10- to 20-meter accuracy by collecting raw data from Wi-Fi access points, GPS satellites and cell towers with advanced hybrid positioning algorithms.The client is optimized so that it communicates with the location server only when the location cannot be determined by the device. This behavior minimizes the user’s data cost while maximizing battery life.
Meanwhile, Wi-Fi technology provider Devicescape entered the Wi-Fi location space last year, offering a software-based positioning service called SoftGPS that can be incorporated into Wi-Fi-enabled mobile devices and provide location awareness without GPS hardware. The service can function over many types of Wi-Fi networks without full authentication and can be embedded on the device to function in a standalone manner. The firm said that SoftGPS also can be utilized to translate Wi-Fi access locations into geocodes, allowing location data to be determined later by mobile- and server-based applications.
Of course, these solutions would need to be modified for public-safety use. While I believe all commercial methods for tracking callers should be considered as part of the 911 accuracy equation, I realize that the public-safety community would like to see some cohesiveness when it comes to location accuracy among U.S. mobile operators, so that they know what sort of location accuracy to expect. That means the FCC would have to mandate the use of Wi-Fi and other commercial technologies down the line, not just encourage them.
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