Within the so-called numbers of social interest, the best known is, without a doubt, 112, which in Spain is served by the Autonomous Communities. These three digits are the emergency number throughout the European Union since 2008, when we left behind the old 088, and this year it is incorporating the location of calls.
It is a toll-free number that works on all telephone networks, without the need to introduce coins in telephone booths, with depleted balances on prepaid cards, on terminals blocked due to loss or theft, and, even without SIM cards or coverage from your carrier. How is that possible? Next, we explain this and other curiosities of 112.
112 comes pre-configured on your mobile
What makes the emergency service universal and unique is that is provided in GSM coverage worldwide regardless of the country of origin. Each terminal has an emergency telephone number coded depending on the country for which it is used (911 in the United States and 112 in Europe, for example), but the service generated on the network is the same.
In the case of Spain and 112, the service is regulated by the CNMC and all operators have the obligation to provide it with guarantees and conditions that are included in Royal Decree 903/1997 of June 16. The CNMC establishes the premises that the service must meet and each operator decides how to build the service.
112 must be accessible from any fixed or mobile terminal throughout the EU territory, no area or caller restrictions. The only requirement is to have mobile coverage from an operator, even if it is not yours; the mobile itself will choose the best available mobile network coverage according to its capacity and that of the network. If there is no mobile network coverage, there is the possibility of making the call over a Wi-Fi network with Internet access, provided that the terminal and the network support VoWifi capability.
If there is no mobile network coverage, there is the possibility of making the call over a Wi-Fi network with Internet access, provided that the terminal and the network support VoWifi capability
Telephone operators are responsible for maintaining the infrastructure and network elements necessary to make the call and direct it to the nearest 112 service center. The use of all these elements (nodes for interconnection with the 112 network, equipment that decides which center to direct the call to, databases…) are exclusively for the emergency servicethey are not shared with the rest of the normal course calls nor do they support any other activity.
That said, anyone can make the call even without being registered on the mobile network, without having a SIM or without coverage from their mobile operator. As Movistar explains, this is possible because all mobile phones come pre-configured to be able to launch an event on the networkan event that is universal to all mobile networks in all countries.
This event is associated a number that identifies the emergency service and that, as we said, can vary in each region or country. In the European Union, the terminals come with 112 pre-configured, while in the United States they come with 911, but the event that is generated in the network is the same regardless of the default number.
When you call that number, mobiles try to connect with base station from which they receive the most power, even if it is not the one that corresponds to them. And that is when the two possible scenarios appear: the call with the operator’s own coverage and SIM registered in the network, and the call without operator coverage or without SIM. The process varies from one to another.
Call to 112 with SIM and own coverage
In this case, the identified user dials 112 and activates the emergency service on the network. The cell that provides coverage receives the special request to call 112 and captures the information needed to route the call to the nearest 112 center.
The information that is captured from the network to be translated and sent to the 112 service is as follows: the caller’s phone number and cell from which the caller connects. With these data, the operator relates the cell with the province and the location within that province to direct the call to the nearest emergency center.
That is, the operator has to have a relationship between nearest cell, province and center 112. All this information has to be presented and sent in the process of calling the 112 service, which in this way can have a fairly approximate location of where the emergency is occurring without the caller having to give any information.
Call 112 without coverage from your operator or without SIM
In these two cases, the user dials 112, the only number that the terminal allows him to call, and wakes up the emergency event within the network that is directed to the base station or cell that gives him the most coverage at that time. It does not matter if that cell is the one that corresponds to the user or not, the service is conceived in such a way that any operator must make an emergency call without conditions or restrictions.
In this call, however, the information obtained from the network is different from the previous scenario. As there is no SIM card, the customer’s number cannot be sent, so the IMEI of the terminal is sent. If there is a SIM card, but your PIN code has not been entered to register it, the IMSI number is sent, a unique identification code for each mobile device that is integrated in the SIM card.
In addition to this information, also the cell that has registered the call is identified and, as in the previous scenario, the operator makes a translation between the cell, locality and the closest 112 center to send the emergency service the approximate place where the emergency is taking place.
