Charging in a communication system

1. A method, comprising:

initiating, at a network server, a provision of a service for at least two parties; verifying that each of the at least two parties is capable of paying for use of the service;

generating payment information by providing for communication of at least one message between the at least two parties regarding a principle for paying a fee for the use of the service and including the principle in the payment information, the principle comprising a definite choice of which of the at least two parties is responsible for paying the fee,

wherein the definite choice is determined according to a result of a use of the service by one of the at least two parties that is different from a result of a use of the service by the at least one other of the at least two parties, and

wherein providing for communication of the at least one message between the at least two parties comprises agreeing, between the at least two parties, to an occurrence that unambiguously defines a party who is responsible for paying for use of the service, and notifying the network server of the agreement; and

providing for charging for use of the service based on the payment information.

2. The method according to claim 1 , wherein the initiating comprises initiating a provision of a game.

3. The method according to claim 1 , wherein the agreeing comprises defining the occurrence to be losing a game.

4. The method according to claim 1 , further comprising reserving for a party payment resources from a prepaid account of the party and including information of the reserved payment resources in the payment information.

5. The method according to claim 4 , wherein the reserving comprises reserving the payment resources in an online charging system.

6. The method according to claim 4 , further comprising

providing for charging the service to the reserved payment resources and returning unused payment resources.

7. The method according to claim 6 , wherein the charging comprises charging the service to one of the at least two parties.

8. The method according to claim 1 , further comprising

sending at least one message in accordance with Session Initiation Protocol.

9. An apparatus, comprising:

an enabler configured to enable simultaneous provision of a service for at least two parties;

a verifier configured to verify that the at least two parties using the service are capable of paying for use of the service; and

a generator configured to provide payment information for the use of the service by the at least two parties for use in charging for the use of the service by communicating at least one message between the at least two parties regarding a principle for paying a fee for the use of the service and including the principle in the payment information, the principle comprising a definite choice of which of the at least two parties is responsible for paying the fee,

wherein the definite choice is determined according to a result of a use of the service by one of the at least two parties that is different from a result of a use of the service by the at least one other of the at least two parties, and

wherein communicating the at least one message between the at least two parties comprises agreeing, between the at least two parties, to an occurrence that unambiguously defines a party who is responsible for paying for use of the service.

10. An apparatus according to claim 9 , further comprising:

a charger configured to charge the service based on the payment information.

11. An apparatus according to claim 9 , wherein the apparatus is one of a serving controller and an application server.

12. An apparatus according to claim 11 , wherein the apparatus is a game server.

13. A computer program product comprising at least one computer readable storage medium having computer-executable program instructions stored thereon, said computer-executable program instructions configured to control a processor to perform:

initiating, at a network server, a provision of a service for at least two parties;

verifying that each of the at least two parties is capable of paying for use of the service;

generating payment information by communicating at least one message between the at least two parties regarding a principle for paying a fee for the use of the service and including the principle in the payment information, the principle comprising a definite choice of which of the at least two parties is responsible for paying the fee,

wherein the definite choice is determined according to a result of a use of the service by one of the at least two parties that is different from a result of a use of the service by the at least one other of the at least two parties, and wherein communicating the at least one message between the at least two parties comprises agreeing, between the at least two parties, to an occurrence that unambiguously defines a party who is responsible for paying for use of the service, and notifying the network server of the agreement; and

charging for use of the service based on the payment information.

14. An apparatus, comprising:

enabling means for enabling simultaneous provision of a service for at least two parties;

verifying means for verifying that the at least two parties using the service are capable of paying for use of the service; and

generating means for generating payment information for the use of the service by the at least two parties for use in charging for the use of the service by communicating at least one message between the at least two parties regarding a principle for paying a fee for the use of the service and including the principle in the payment information, the principle comprising a definite choice of which of the at least two parties is responsible for paying the fee,

wherein the definite choice is determined according to a result of a use of the service by one of the at least two parties that is different from a result of a use of the service by the at least one other of the at least two parties, and

wherein communicating the at least one message between the at least two parties comprises agreeing means for agreeing, between the at least two parties, to an occurrence that unambiguously defines a party who is responsible for paying for use of the service, and notifying the network server of the agreement.