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Google is Making it Easier For 911 To Find You in an Emergency (engadget.com)
An anonymous reader shares a report: When you call 911 from a cellphone, your location is typically sent to the call taker by a wireless carrier. But that information isn't always so accurate. Well Google might have a better way of going about it and it tested its system across a few states in December and January, the Wall Street Journal reports. In the states where the tests took place, Google sent location data from a random selection of 911 callers using Android phones straight to the people taking those calls. The test included 50 call centers that cover around 2.4 million people in Texas, Tennessee and Florida, and early reports of the results suggest the system is promising.
One company involved in the test told the Wall Street Journal that for over 80 percent of the 911 calls where Googl's system was used, the tech giant's location data were more accurate than what wireless carriers provided. The company, RapidSOS, also said that while carrier data location estimates had, on average, a radius of around 522 feet, Google's data gave estimates with radii around 121 feet. Google's data also arrived more quickly than carrier data typically did.
One company involved in the test told the Wall Street Journal that for over 80 percent of the 911 calls where Googl's system was used, the tech giant's location data were more accurate than what wireless carriers provided. The company, RapidSOS, also said that while carrier data location estimates had, on average, a radius of around 522 feet, Google's data gave estimates with radii around 121 feet. Google's data also arrived more quickly than carrier data typically did.
Finland commissioned an app for exactly this. For example I have the app on my Android phone. It detects automatically if I am about to call 911 (112 in Europe actually, but if you dial 911 it will work as well), uses the facilities of the cell phone to locate me, and sends the location via a side channel. It is probably much more accurate than the information cell phone towers has.
IIRC over million people (out of ~6 million living in Finland) have downloaded the app.
They also built an API for the national "911 system" so that systems integrators can develop competing applications. There is one such application already, made by a consortium of reindeer farmers or something similar. I have not looked into it, but iirc their application has extra features related to their jobs.
AML is neat, but it would be problematic implementing it in North America. Basically, AML works because Europe doesn't have E911 (Enhanced 911) services that support GPS. In E911, which is mandated on all phones, and works even if the phone cannot do data (dumbphones included - remember, this was implemented as part of 9/11 so the smartphone craze hasn't happened yet) the phone has a simple GPS receiver (generally A-GPS) inside the phone stack. That GPS receiver works alongside the towers to get your position, and the location is transmitted to the 911 operator on the control plane - it's metadata.
AML is implemented differently and reflects that Europe did not have an E911 mandate and thus does not have the functionality baked into their network to send GPS information through the control plane and have it reach emergency services. So instead of using the control plane, it uses the user plane (user plane is where "billable" happens). It opens up a data connection and sends the location information that way.
The problem is well, AML is user plane and if you're unaware, that can mean bills for its use. In an emergency, this might not matter, but you may not be aware of this and may not be able to use data. After all, most carriers in North America let you block data roaming, or if you exceed say $50, they will automatically disable all data services to keep you from running up your bill. AML will not work - the network will have to be smart enough to realize it needs to re-enable data connectivity, and then tell the phone that data works again for that data to transfer
And then you have the case where a phone is in "emergency call only" mode - i.e., there is no SIM card. This means there is no data connection because the modem doesn't have any of the required data parameters that would be stored on the SIM card. In North America, it's very common for phones to be recycled in this manner - they have no service, but are useful for emergency calls, and with E911, at least they will get location data. But there is no data service because it cannot be configured.
For those wondering how the system decides if it's emergency or not, you may not realize that ANY emergency number works! The phones do not actually dial 911 or 999 or whatever. They could, and it will reach emergency services, but it's treated as a normal phone call. When you dial 911, the software stack realizes it's emergency and goes into an emergency state - the modem is told to make an emergency call (it's a special dial command - dial emergency). This puts the modem in an emergency state - if it is not attached to a tower or has no service, it will immediately use the first one it finds, and a control message is sent to set up an emergency call. The modem doesn't have to know the emergency number, it tells the network "connect me to emergency services" and the network routes the call to the local emergency call center, regardless of the actual number you're supposed to call.
The emergency state may cause the modem to use a higher power transmit setting to make a connection, and it will tell the network that since the call is emergency, if the tower overloads then it will drop non-emergency calls. Emergency calls also get priority during handoffs so you're less likely to get cut off.