EU-Alert

There are several downloadable mobile applications on the market that often warn on natural catastrophes; however, these are often not of official, but part of private initiatives that replicate information from state agencies.[6]

All downloadable mobile applications have the issue that they are highly affected by traffic load as they require mobile data usage; therefore, especially in case of a disaster when load spikes of data (Social media, Voice and Mobile app) tend to significantly slowdown mobile networks, as multiple terrorist attacks showed.

Moreover, downloadable Mobile Apps needs to be downloaded by subscribers and the experience over the years in many countries is that only a fraction of the population will take the effort to download and use an Emergency Mobile app that is only activated a few times in a year. Examples are in Germany with 1.500.000 downloads of the Katwarn and NINA mobile application [7] reaching a maximum of 2.5M people in Germany (<3% of the German population) and France only 500.000 downloads of the SAIP mobile application (<1% of the French population) despite large investments in application development and marketing. In France because of the limited success of the downloadable Mobile App SAIP (Système d’Alerte et d’Information des Populations) the service has been stopped as of June 2018.[8][9]

As far as the network and the end user is concerned, a Location-Based-SMS (LB-SMS) message is simply a normal SMS message which is sent to a subset of the Mobile Network's attached devices, which happen to be in a particular geographical area. In order to achieve this for some mobile network topologies however, the network must maintain a database of all mobile devices in the target location for potential Public Warning Service messages. In other words, for all areas that the Mobile anticipates potentially delivering LB-SMS messages into, a list of all users currently located in those areas must be kept up to date at all times.

While mobile networks require knowledge of subscribers’ locations for normal operation, this is usually not maintained at all times at the granularity of the single cell level. Therefore, an LB-SMS implementation will usually require the deployment of a Mobile Location Cente (MLC). The methods used by the MLC to track mobile devices as they move around the network are not standardised and are subject to a certain level of inaccuracy. Some MLCs track device location to the cell level, whereas other MLC providers claim to fix device location to a greater level of accuracy. Depending on the level of location granularity stored in the MLC, the precision of targeting will vary. There may be privacy implications in tracking user locations in this manner that should be considered.

Aside from the location specific aspect, the principle difference between CB and LB-SMS services is that the mobile network for location based SMS must carry each recipient's message separately, since the SMS standards do not have a ‘one-to-many’ or a broadcast capability.

Based upon last years experience the Swedish Civil Contingencies Agency concluded in a report published in May 2018 [10] that in case of serious events it's extremely unlikely that Public Warning Messages via SMS will work and will be delivered in a timely manner (less than 1 minute).

Disadvantages to use location based SMS in national public warning systems are:

• No international recognized telecommunication standardization body has defined or will define a standard for location based SMS for Public Warning Services.
• Scalability. While mobile networks are dimensioned to carry millions of messages per day, MNOs assume a relatively flat distribution across the network in terms of both time and location. In other words, the average number of messages per second in a given cell is relatively low even in a busy network. In some alerting use cases however (for example notifying all users in a particular area by SMS) it would be possible for the radio access network to be flooded by SMS messages. In this case, messages which cannot be delivered on the first attempt are usually queued up on the MNO SMSC for further delivery attempts. In the worst case, the mobile network could take hours to deliver all queued warning messages.
• Delivery time of Location Based SMS warning messages to groups of people in the Geo-target area are long and are depending on the number of people present in the area, it can take up to several hours to reach 300.000 people in a city e.g. in the May 2018 Sweden case [11] and in the September 2019 Portugal case.[12]
• Due to the nature of international SMS routing (SMS Home routing). It should also be noted that LB SMS messages will often not reach inbound roamers as delivery of Short code based messages abroad are blocked by the home operator due to roaming charging agreement (AA19).
• The granularity of an LB-SMS warning message will depend on the accuracy of the MLC in the MNOs network, usually a single cell which has radius between 3 km and 25 km.
• LB-SMS warning messages will not produce notifications sounds or a ringtone and vibration different than an ordinary SMS message, thus end users could easily overlook warning messages.
• LB SMS messages can be easily faked and would require the deployment of security devices e.g. SMS firewall on each mobile operator international SS7 signaling links.
• When sending an LB-SMS a delivery receipt could be requested upon message submission to the MNOs SMSC. This receipt provides information about the delivery of the message to the end user device only, with no indication whether the message has been read or not. However, these delivery receipt messages may increase the network load for a given alerting event, the impact of which should be considered.