Will Your Cellular Phone Work During Emergency?

Will Your Cellular Phone Work During Emergency?

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Emergency communication is of the utmost importance. Emergency services need to coordinate their response in time, but the situation becomes more complicated when the rest of the public needs to contact their loved ones and figure out what is happening. The problem is that there’s no way to make it possible for everyone to use the cellular network simultaneously, especially in heavily populated areas. An good example would the attack in London on July 2005, when many have tried in vain to make contact via cellphones in different parts of central London. Unfortunately, Israel has an experience with this problem, when after terror attacks the cellular networks are always backed up, just when everyone wants to know that their loved ones are safe.

The problem with the cellular networks during the London attack wasn’t due to damage caused by the attack, but due to the fact that emergency services blocked public access to them. Networks of all types are designed to cope with typical traffic demands, and so in exceptional circumstances they become massively overloaded. Therefore, cellular networks’ operators must prioritize access to the network so that the emergency services will be first priority. In fact, it can even be defined to specific geogrpahical areas, so there’s actually no need to shut down all of the nation’s cellular phones.

Prioritizing access to the network is done by using the cellphone SIM card. Every card has information that authenticates and identifies subscribers on their network. Each SIM is also assigned to a privilege access class, which is a code number between 0-14. For general users this will be in the range 0-9, while emergency services responders are assigned classes 12-14. During an emergency the privilege access class is checked and the network will drop attempts to connect from non-emergency class SIMs.

The attack in London on 2005 created a situation where only some of the emergency services’ staff had cellphone with emergency-class SIM and so those who didn’t, had their calls blocked just like the rest of the public. After the investigation regarding these faults, the problem had since then been taken care off, and since 2005 England’s emergency services have been using their own digital communications system called TETRA (TErrestrial Trunked RAdio). However, after it encountered several problems, the government decided to replace it.

Nowadays emergency services seek to increase use of real-time video applications and mapping services, and those services require a network with a greater data-handling capacity. It is highly recommended, then, that governments start working on new cellular and internet services, especially designed for the needs of emergency services.

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