| 摘要 |
A global mobile emergency call system uses modern digital radio networks and should allow a person (children, aged persons, skiers, mountain climbers, women jogging in a park, victims of car accidents, etc.) to trigger an emergency call in any situation. The alarm system is integrated in a wristwatch to ensure that it is triggered in an emergency situation. When the system is actuated, at the same time a fixed connection is established between the top and bottom parts of the wristwatch, preventing the support of the system from being separated from the person. The emergency call warns an emergency call central exchange which determines the persons to be notified depending on a call identification and controls their notification. A coarse localisation is ensured by the subdivision of the radio network into cells, as the radio cell from which the emergency call has been emitted can be identified. A more precise localisation is then achieved by ground scanning based on the direction finding signal broadcast by the same emitter that emitted the emergency call. |
