VSE Notifier is an application, that alerts owner of the phone, when directional sms comes.
Phone responds to directional sms by playing alarm of maximum volume.
Duration of the alarm is specified in received message.
Application set the volume to original value, as soon as alarm stops.
Application sends sms to inform dispatcher that alarm was played.
Alarm starts when directional sms comes from relevant phone number and contains relevant code.
Owner of the phone can specify relevant phone numbers and relevant codes by changing application settings.