Monthly Archives: April 2005

Emergency Call

I was in Bonn today to search for some books in a (physical) bookstore. I was walking through the pedestrian precinct when suddenly a glass bottle was smashed on the ground. The sound was followed by someone screaming and then I saw what happened: a kind of big guy, drunk or on drugs, I’m not sure, was standing in front of a shop and shouting at a woman. He got violent and started to beat and push the woman. The scene quickly attracted other people who were just looking at what happened. The person continued his strange behavior and began to beat other people.

German Police Car

Because nobody did anything, I decided to call the police. I dialed 110 with my mobile phone, Germany’s emergency number for the police. 112 would have worked as well, by the way. The call quickly went through and was picked up by a police officer. I told him what happened, he just noted my name and ordered a patrol to the location. Within 6 long minutes, two “wannabe” policemen dressed in blue suits arrived (I don’t know exactly from which organization they came, but it wasn’t real police) and urged the person to leave. He finally disappeared in a side street.

From a technical point of view, it was quite interesting to see how fast the emergency call went through. I have read a lot about how GSM networks work and in the specs of the standards, certain rules for emercency calls are defined. That is, for instance, that you don’t need a SIM card to call the police. Furthermore, emergency calls are handled with priority, even terminating non-priority calls when a cell is congested. In my case, it took only about 1 or 2 seconds to hear the dial tone. A normal call usually needs at least 5 seconds until the phone at the other end starts to ring.

Unfortunately, there is a lot of abuse of this “feature”. On some second-hand markets, where used phones are sold without a SIM card, the seller often calls one of the emergency numbers to show the potential buyer that the phone works. Needless to say that this is an absolutely unacceptable behavior. Plans exist to store the IMEI, the phone’s identification number, of the caller for a possible future prosecution.