When disaster calls

Delta, 17 June 2010

The Netherlands will become the first country to send emergency messages to cell phones via the cell broadcast system. This system will be introduced early next year. TU Delft researcher and psychologist, Simone Sillem (MSc), has discovered some glitches, however.

Every first Monday of the month, an eerie wailing sound is heard across the Netherlands. It is the national warning system, which consists of a network of sirens dating back to the Second World War to warn against air raids. Nowadays the message is still much the same: get indoors, close all doors and windows and listen to your local radio for more information. The cause for the alarm could be anything from a toxic cloud or  terrorist attack to an incoming asteroid. The siren warning always sounds the same. Yet, surveys have revealed that as much as a one-third of the population does not hear the siren, because, for instance, a person may be vacuum cleaning indoors or singing along with their car radio at full blast. In short, the national warning system could do with an update.
The cell broadcast system offers interesting possibilities. It allows for sending sms-like messages to all cell phones within reach of a number of specified antennas, and thus allows for a precise targeting of an area, within which (almost) all people can be reached. Another interesting feature, as Simone Sillem, of the Safety Science Group at the faculty Technology, Policy and Management, explains, is that cell broadcasts not only warn, but can also inform and call for action as well. A typical message could read: ‘Alarm mayor. Risk explosion Delft centre. Go inside, close doors + windows. More info: TVWest’.
A cell broadcast differs from sending sms-messages in the sense that it does not require cell phone numbers. All cell phones within reach will receive the message. Even when the local gsm network is overloaded with people trying to reach one another, the cell broadcasts will still come through unhindered. The system has some 65,000 channels,  of which one will be assigned as the national alarm channel. Other possible applications include traffic information, weather warnings or local police information about a criminal on the run.
In a test, Sillem has determined that text messages by cell phones can improve the siren’s reach. Messages were sent out simultaneously with the monthly siren test, requesting people to send messages back if they had been reached. It turned out that the text messages decreased the percentage of people that remained ignorant of the alarm from 32 to 26 percent.
But what about the others? Except for the most banal explanations – like my phone wasn’t switched on or it was misplaced – there have been some other technical hindrances as well. In principle all antennas have been set to transmit cell broadcasts, but cases are known in which the correct settings were undone by software updates. Cell phones should also be set correctly to receive the cell broadcasts. Currently some are and others are not. Instructions on how to set the proper menus differ for each cell phone brand and model. But even with the right instructions at hand, some 20 percent of the phone owners still do not get the settings right.
The real problem however is not to reach people, but rather to get them to take action. “That’s hard to simulate”, Sillem admits. She has done tests with messages urging people to go to a certain place or to get information elsewhere and then text back. Generally though, the more people were asked to do, the lower the response was.

Sillem, who will defend her thesis on the cell broadcast system and other ways of improving the effectively of warning systems at the end of this month, will have a number of other unanswered questions about the system once it comes into use. For instance: people tend to listen more attentively to authorities they trust. How to cope then with the eroding confidence in governance and politicians? Or: commercials through the cell broadcast system could make the system more affordable or even profitable. But how can you prevent people from becoming irritated by spam messages and switching off entirely?

Simone Sillem, Warning citizens – Influencing self-reliance in emergencies, PhD thesis defense, 28 June 2010. Supervisor: professor Ben Ale (TPM).

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