up a call using an emergency number known by a gsm or 3g phone, the special emergency call setup takes place. the actual number is not even transmitted into the network, but the network redirects the emergency call to the local emergency desk. most gsm mobile phones can dial emergency numbers even when the phone keyboard is locked, the phone is without a sim card, emergency number is entered instead of the pin or there is not a network signal (busy network). most gsm mobile phones have 112, 999 and 911 as pre-programmed emergency numbers that are always available. the sim card issued by the operator can contain additional country-specific emergency numbers that can be used even when roaming abroad. the gsm network can also update the list of well-known emergency numbers when the phone registers to it. using an emergency number recognized by a gsm phone like 112 instead of another emergency number may be advantageous, since gsm phones and networks give special priority to emergency calls. a phone dialing an emergency service number not recognized by it may refuse to roam onto another network, leading to trouble if there is no access to the home network. dialing a known emergency number like 112 forces the phone to try the call with any available network. on some networks, a gsm phone without a sim card may be used to make emergency calls, and most gsm phones accept a larger list of emergency numbers without sim card, such as 112, 911, 118, 119, 000, 110, 08, and 999. however, some gsm networks will not accept emergency calls from phones without a sim card, or even require a sim card that has credit. for example, latin american networks typically do not allow emergency calls without a sim, nor british networks due to the prevalence of hoax calls. the gsm phones may regard some phone numbers with one or two digits as special service codes. it might be impossible to make an emergency call to numbers like 03 or 92 with a mobile phone. in those cases the emergency number has to be called by using a landline telephone or with an additional first/last digit (for example 922 or 992 instead of 92 and 003 or 033 instead of 03). in the united states, the fcc requires networks to route every mobile-phone and payphone 911 call to an emergency service call center, including phones that have never had service, or whose service has lapsed. as a result, there are programs that provide donated used mobile phones to victims of domestic violence and others especially likely to need emergency services. over the next six years, emergency responders will be able to better locate callers who dial 911 on their cellphones from indoors as the u.s. wireless industry improves caller-location for the majority of such calls. the "heightened location accuracy," available to supporting networks and handsets, will find callers through nearby devices connected to wi-fi or bluetooth that will be logged with a specific location in a special emergency-services database. mobile phones generate additional problems for emergency operators, as many phones will allow emergency numbers to be dialed even while the keypad is locked. since mobile phones are typically carried in pockets and small bags, the keys can easily be depressed accidentally, leading to unintended calls. a system has been developed in the uk to connect calls where the caller is sent to an automated system, leaving more operators free to handle genuine emergency calls.