Method for location-based billing for mobile communication

1. A method for location-based billing for mobile telecommunication, which comprises:

registering mobile stations in a cellular mobile radio network formed by base stations and a network server including at least call-processing facilities, facilities for sending/receiving information, and a billing facility;

recording, forwarding, and transmitting communication information between the mobile stations and/or between the mobile stations and a network server;

forming a special billing zone by combining a subset of radio cells associated with base stations in the cellular mobile radio network and covering a geographical area;

using the billing facility to bill, based on a locally valid tariff for the special billing zone, for communication between ones of the mobile stations temporally concurrently localized within the special billing zone;

storing in a given mobile station a zone identifier as evidence of registration when the given mobile station is registered within the special billing zone; and

after re-registering the given mobile station, selecting one of:

questioning the zone identifier stored by the given mobile station with the network server, or

transmitting the zone identifier to the network server with the given mobile station.

2. The method according to claim 1 , which comprises:

providing a zone register having a collection of cell identifiers defining the special billing zone; and

using the network server to manage the zone register and to check whether the ones of the mobile stations are located within the special billing zone by comparing current cell identifiers for the ones of the mobile stations with the zone register.

3. The method according to claim 2 , which comprises:

after establishing that a first mobile station is localized within the special billing zone and after the first mobile station initiates a connection setup over the mobile communication network to a second mobile station localized within the special billing zone, using the network server to send a confirmation indicating that the second mobile station is located within the special billing zone.

4. The method according to claim 3 , which comprises indicating the confirmation visually and/or audibly on at least one of the first mobile station and the second mobile station.

5. The method according to claim 1 , which comprises:

when a first mobile station and a second mobile station are currently involved in a communication and one of the first mobile station and the second mobile station is leaving the special billing zone, sending a notification selected from a group consisting of a visual signal, an audible signal, a text

message, and a voice message to at least one of the first mobile station and the second mobile station.

6. The method according to claim 1 , which comprises:

if the special billing zone is left during an ongoing communication between a first mobile station and a second mobile station, insuring that the billing facility maintains a tariff associated with the special billing zone at least until the ongoing communication has ended.

7. The method according to claim 1 , which comprises:

communicating between at least two mobile stations based on a tariff associated with the special billing zone irrespective of whether the two mobile stations are localized within the special billing zone, provided that at least one of the two mobile stations has transmitted a zone identifier to the network server.

8. The method according to claim 1 , which comprises providing the zone identifier with a periodic validity or with a validity having a time limit.

9. The method according to claims 1 , which comprises insuring that the given mobile station prescribes the zone identifier without being initialized by the registration procedure.

10. The method according to claim 1 , wherein the given mobile station stores the zone identifier on a subscriber identification module.