Apple Patent To Safeguard 911 Cellphone Calls

MojoKid writes "Engineers from Apple have applied for a patent on an 'emergency' mode for cell phones that would squeeze every last drop of energy out of the batteries. The phone would recognize emergency calls when the user dialed an emergency number, such as 911 in the United States. But another number could also be stored as an 'emergency number' on the phone (a spouse, child, or parent, for example) or the user could manually put the phone in emergency mode. The process would do a variety of things. It would disable 'non-essential hardware components' and applications on the phone, reduce power to the screen and potentially reduce the phone's processor speed. It also would make it harder to disconnect the call and enable 'emergency phrase buttons' on the phone."

Comments

Cellphones already do some of this

[DrDitto]

I used to work for a major cellphone manufacturer.

Cellphones already go into a special emergency mode. All phones definitely scan for more towers beyond those in the PRL list (preferred roaming list). I believe phones may also increase Tx power if battery is good and the CDMA noise floor is high.

One big problem I recall: it is not as well tested. The Verizon phone guys aren't going to yell "do you hear me now" at 911 operators. We had once instance where it was discovered that the 911 mode had a software bug and caused the phone to crash. That caused an immediate "stop ship". We definitely had to improve the synthetic 911 testing environment...

Mod parent up.

[Animats]

Mod parent up. Most of this is already standard, and mandated by the FCC. The new stuff is just some iPhone-specific problems that Apple has to deal with. All the nonessential guck in the phone needs to be switched off during emergency calls.

911 calls have at least the following FCC-mandated features.

• Billing problems must be bypassed. 911 calls must go through even if the cell phone has no account, the billing system is down, the phone is roaming out of area, or the local provider can't contact the home provider for billing passthrough.
• Transmit power management is disabled. Cell phones go to full power in emergency mode. (Yes, battery drain goes up.)
• If the phone cannot connect to a cell site of its own system, after 17 seconds it must try to connect to any cell site of any system it can reach. Phones used to fall over to analog roam when necessary, before analog AMPS went down.
• GPS information is transmitted.
• A higher QoS is specified within the cell phone network, so emergency calls get in ahead of non-emergency traffic.
• The call is not easily disconnected until the emergency operator releases it, although there's usually some way to force disconnect from the cell phone end.

It's not like Apple just invented "emergency mode".