Method and system for enabling emergency sessions to be established in abnormal cases

• US 20040121755A1
• Filed: 12/08/2003
• Published: 06/24/2004
• Est. Priority Date: 04/27/2001
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Hurtta, Tuija
• Granted Patent: US 7,437,142 B2
• Time in Patent Office: Days
• US Class Current: 455/404.1
• CPC Class Codes: H04W 4/24 Accounting or billing
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 76/50 for emergency connections

Abstract

The invention relates to a method and system for connecting a user equipment to a network in abnormal situations normally not allowing the network element to conduct a call. For establishing an emergency session, the network element is adapted to send an indication to the network, the network, when receiving the indication, accepting the call request and establishing the connection for conducting the emergency session.

As an alternative, the network, when receiving the indication, may reject the session request whereupon the user equipment initiates an Anonymous Access PDP Activation procedure with the network. To save time, the network, when receiving the indication, may directly return an Anonymous Access PDP Activation Request message to the user equipment for initiating the Anonymous Access PDP Activation procedure. The network, when receiving the session request including the called number, may be adapted to analyze the called number and, when detecting that the called number is an emergency number, to accept the call request and establish the connection for conducting the emergency session.

Claims

1. A method for preventing barring of bearer establishment for an emergency session in a wireless communication system, the system including at least one user equipment associated with a subscriber and a first network element authorizing bearer establishment, the method comprising the following steps:

sending, when an emergency session is to be set up by the user equipment, a first type of connection establishment request from the user equipment to said system, the first type of connection establishment request including an indication indicating that the session to be established is an emergency session;

receiving said indication in said first network element, said first network element authorizing, or being controlled to authorize, bearer establishment in response to said indication,

wherein the system checks that the session established after the first type of connection establishment request is an emergency session, and wherein, if the session established after the first type of connection establishment request is no emergency session, the session is forcibly terminated.

2. Method according to claim 1, wherein the barring is due to defective subscriber information.

3. Method according to claim 1 or 2, wherein the subscriber has a prepaid account for prepaid billing, and the barring is due to the prepaid account being empty.

4. Method according to claim 1, 2, or 3, wherein the barring is due to roaming of the subscriber.

14. Method according to any one of claims 1 to 4, 10, or 11, wherein the first type of connection establishment request is sent to a Call State Control Function, CSCF (5), which analyses the indication for detecting whether or not it is an emergency number.

15. Method according to claim 14, wherein the Call State Control Function, CSCF, is a Proxy Call State Control Function, P-CSCF (5), which sends a message including an emergency indication to a Serving Call State Control Function, S-CSCF (4).

16. Method according to claim 15, wherein the S-CSCF (4) sends a message including an emergency indication to a network element (3) which informs the first network element (2) to continue with the session.

5. Method according to any one of the preceding method claims, wherein the first network element is a serving network element (SGSN).

6. Method according to claim 5, wherein the serving network element is a Serving GPRS Support Node (SGSN).

7. Method according to any one of the preceding method claims, wherein the indication is sent in the attach request or a PDP context activation request.

8. Method according to any one of the preceding method claims, wherein the said first network element forwards said indication to a third network element, the third network element checking the indication and deciding on authorizing the first network element to establish a bearer connection with the user equipment.

9. Method according to claim 8, wherein said third network element detects the saldo of a prepaid account provided for the user equipment and regardless of the saldo authorizes the bearer establishment procedure.

10. Method according to any one of the preceding method claims, wherein said indication is the called address.

11. Method of claim 10, comprising the step of extracting the indication from the called address.

12. Method according to any one of the preceding method claims, wherein the first type of connection establishment request is an attach request.

13. Method according to any one of the preceding method claims, wherein, when the user equipment is already attached to the network, the user equipment sends an Activate PDP Context Activation request to the network which request includes the indication.

17. System for preventing barring of bearer establishment for an emergency session in a wireless communication system, the system including at least one user equipment associated with a subscriber and a first network element authorizing bearer establishment,

wherein the user equipment is adapted to send, when an emergency session is to be set up by the user equipment, a first type of connection establishment request from the user equipment to said system, the first type of connection request including an indication indicating that the session to be established is an emergency session;

the first network element being adapted to receive said indication and to authorize bearer establishment in response to said indication, wherein the system is adapted to check that the session established after the first type of connection establishment request is an emergency session, and wherein, if the session established after the first type of connection establishment request is no emergency session, the system is adapted to forcibly terminate the session.

18. System according to claim 17, wherein the barring is due to defective subscriber information.

19. System according to claim 17 or 18, wherein the subscriber has a prepaid account for prepaid billing, and the barring is due to the prepaid account being empty.

20. System according to claim 17, 18, or 19, wherein the barring is due to roaming of the subscriber.

30. System according to any one of claims 17 to 20, 26, or 27, wherein the first type of connection establishment request is sent to a Call State Control Function, CSCF (5), which is adapted to analyse the indication for detecting whether or not it is an emergency number.

31. System according to claim 30, wherein the Call State Control Function, CSCF, is a Proxy Call State Control Function, P-CSCF (5), which is adapted to send a message including an emergency indication to a Serving Call State Control Function, S-CSCF (4).

32. System according to claim 31, wherein the S-CSCF (4) is adapted to send a message including an emergency indication to a network element (3) which informs the first network element (2) to continue with the session.

21. System according to any one of the preceding system claims, wherein the first network element is a serving network element (SGSN).

22. System according to claim 21, wherein the serving network element is a Serving GPRS Support Node (SGSN).

23. System according to any one of the preceding system claims, wherein the indication is sent in the first type of connection establishment request or a PDP context activation request.

24. System according to any one of the preceding system claims, wherein said first network element is adapted to forward said indication to a third network element, the third network element being adapted to check the indication and to decide on authorizing the first network element to establish a bearer connection with the user equipment.

25. System according to claim 24, wherein said third network element is adapted to detect the saldo of a prepaid account provided for the user equipment and to authorize, regardless of the saldo, the bearer establishment procedure.

26. System according to any one of the preceding system claims, wherein said indication is the called address.

27. System of claim 26, being adapted to extract the indication from the called address.

28. System according to any one of the preceding system claims, wherein, when the user equipment is already attached to the network, the user equipment is adapted to send an Activate PDP Context Activation request to the network which request includes the indication.

29. System according to any one of the preceding system claims, wherein the first type of connection establishment request is an attach request.