Location-based SMS

The public authorities choose the warning channels according to the impact and seriousness of the event that needs to be warned or informed about. Location-based SMS (LB-SMS), for example, is used when the event in question is likely to present a definite or significant danger to the population.

The sender of warning and information messages sent via location-based SMS (LB-SMS) is always “LU-Alert”.

However, for some foreign telephone numbers, the sender of the message may be a telephone number instead of “LU-Alert”. This is because the “LU-Alert” system makes several attempts to reach foreign telephone numbers directly. If these attempts fail, the request to transmit the message is then diverted to the operator in the country of origin. The message received on the mobile device may not display the sender “LU-Alert”. This is because some countries do not accept the display of alphanumeric codes as sender, in this case “LU-Alert”, and transform them into telephone numbers.

The triggering of warning and information messages to the population via location-based SMS sends a request to the mobile network operators to transmit the messages entered in the platform by the various public authorities. The mobile network operators then transmit these messages to the population, without any modification, via their own equipment. All mobile devices located in the area to be warned at the time the transmission of the messages is triggered are therefore targeted.

Yes. Any person in the area to be warned, who is connected to a mobile phone relay antenna operated by a Luxembourg mobile network operator at the time the message is sent, will normally receive the warning and information message sent by location-based SMS.

Mobile network operators transmit the warning/information message by location-based SMS (LB-SMS) via their equipment to any person in the area to be warned, who is connected to a mobile phone relay antenna of a Luxembourgish mobile network operator at the time the message is sent. There are several reasons why a location-based SMS may not have been received:

• If you were near a border, it is possible that your mobile device was connected to a mobile phone relay antenna in the neighbouring country, even if you were physically in the targeted area;
• It is possible that your mobile device was connected to a relay antenna in a neighbouring area that wasn’t-targeted, even if you were physically in the targeted area. Several factors determine which mobile phone relay antenna the mobile device is connected to. The warning and information system is dependent on these factors and cannot influence them;
• When the location-based SMS was sent, your mobile device was switched off or in “airplane”, “do not disturb”, “bedtime”, “concentration” mode;
• When the location-based SMS was sent, your mobile device was not connected to a network (weak network in certain regions, buildings, cellars, underground parking, etc.);
• You were not in the targeted area or you were abroad at the time of the alert;
• Some messaging applications may interfere and filter messages from unknown senders. For Android users, please regularly check the spam folder.

A certain delay between the sending of the location-based SMS by the mobile network operators and its reception by the user may be normal, especially when a large number of location-based SMS need to be sent at the same time.