AVOIDING UNLIMITED NUMBER OF UNSUCCESSFUL LOCATION UPDATE OR PACKET DATA CONNECTION ESTABLISHMENT ATTEMPTS

• US 20150029978A1
• Filed: 11/22/2012
• Published: 01/29/2015
• Est. Priority Date: 03/14/2012
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Olsson, Lasse, Tranberg, Hkan
• Granted Patent: US 9,392,566 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 60/04 using triggered events
• CPC Class Codes: H04W 60/06 De-registration or detaching
• CPC Class Codes: H04W 76/12 Setup of transport tunnels
• CPC Class Codes: H04W 76/18 Management of setup rejection or failure
• CPC Class Codes: H04W 88/16 Gateway arrangements

Abstract

The application relates to the procedures Routing Area Update RAU in UTRAN and Tracking Area Update TAU in LTE. Furthermore, it relates to PDP context procedure in UTRAN as well as PDN connection procedure in LTE. In the current RAU procedure, a SGSN, which fails to update the Routing Area, e.g. because it receives the DNS return error, sends a RAU Reject with the cause code CC#17 indicating a network failure back to the user equipment (114b). The cause code CC#17 in the RAU Reject causes the user equipment to send a new RAU Request. Thus, the user equipment is stuck in a loop of sending a RAU Request and receiving a RAU Reject. This problem is solved by the present application in that SGSN keeps track of the number of rejections when doing RAU. When the number of rejections is above a certain threshold, the SGSN will send a RAU Reject with cause code CC#10 to the user equipment (115b), whereby the cause code CC#10 indicates implicit detach of the user equipment. In other words, the cause code is changed from CC#17 to CC#10 and in order to avoid further looping. The same principle is applied to TAU in LTE as well as to PDP procedures in UTRAN and LTE.

Claims

1. A method in a first network node (101b, 401) for handling a user equipment (410) in a communication network (100b, 200b, 300b, 400), wherein the first network node (101b, 401) is connected to the user equipment (410), the method comprising:

receiving (111b, 212b, 312b, 501) a request message from the user equipment (410), which request message is a request for an update related to an area to which the user equipment (410) has moved, or which request message is a request for transmitting data in the communication network (100b, 200b, 300b, 400);

obtaining (113b, 214b, 313b, 503) information about rejection of the request message;

increasing (504) a parameter indicating a number of rejections associated with the user equipment (410) based on the obtained information; and

transmitting (115b, 216b, 315b, 507), to the user equipment (410), instructions to detach the user equipment (410) from the first network node (101b, 401) when the parameter is above the threshold.

2. The method according to claim 1, further comprising:

transmitting (114b, 215b, 314b, 506) a reject message to the user equipment (410) when the parameter is below the threshold.

3. The method according to claim 2, wherein the reject message comprises an information indicating a first cause of the rejection, and wherein the instructions to detach the user equipment (410) comprises information indicating a second cause of the rejection, which second cause is different from the first cause.

4. The method according to claim 3, wherein the first cause indicates a failure of the communication network (100b), and wherein the second cause indicates detach of the user equipment (410) from the first network node (101b, 401).

5. The method according to any of the preceding claims, wherein the obtaining (113b, 214b, 313b, 503) information about rejection of the request message further comprises:

receiving (113b, 214b, 503a) information about the rejection from a second network node (105b, 207b, 405), wherein the second network node (105b, 207b, 405) is a Domain Name Server, DNS (105b) or a Gateway General packet radio service Support Node, GGSN (207b) or a Serving GateWay, SGW or a Packet data network GateWay, PGW, or a radius server;

or

determining (503b) that the request message should be rejected.

6. The method according to any of the preceding claims, further comprising:

transmitting (112b, 213b, 502) information indicating the request message to a second network node (105b, 207b, 405).

7. The method according to any of the preceding claims, further comprising:

clearing (505) the parameter when a time parameter associated with the received rejection information is above a limit.

8. The method according to any of the preceding claims, further comprising:

receiving (116b, 217b, 316b, 508) an attach request message from the user equipment (410) when the user equipment (410) has been detached.

9. The method according to any of the preceding claims, wherein the request message is a Routing Area Update, RAU, message or a Tracking Area Update, TAU, message;

wherein the instruction to detach the user equipment (410) is comprised in a RAU reject message or a TAU reject message; and

wherein the information about rejection is obtained by receipt from a Domain Name Server, DNS (105b), or internally within the first network node (101b, 401) or from a cooperating Serving General packet radio service Support Node, SGSN.

10. The method according to any of the preceding claims, wherein the request message is an activate Packet Data Protocol, PDP, context request message or an activate Packet Data Network, PDN, connection request message;

wherein the instructions to detach the user equipment (410) is comprised in a detach request message; and

wherein the information about rejection is obtained by receipt from a Gateway General packet radio service Support Node, GGSN (207b), or a Serving GateWay, SGW, or a Packet data network GateWay, PGW, or a radius server.

11. The method according to any of the preceding claims, wherein the request message is an activate Packet Data Protocol, PDP, context request message or an activate Packet Data Network, PDN, connection request message;

wherein

the instructions to detach the user equipment (410) is comprised in a detach request message; and

wherein

the information about rejection of the request message is obtained internally within the first network node (101b, 401).

12. The method according to any of the preceding claims, wherein the first network node (101b, 401) is a Serving General packet radio service Support Node, SGSN (101b), or a Mobility Management Entity, MME, or a combined SGSN and MME.

13. A first network node (101b, 401) for handling a user equipment (410) in a communication network (100b, 200b, 300b, 400), wherein the first network node (101b, 401) is configured to be connected to the user equipment (410), the first network node (101b, 410) comprising:

a receiver (601) configured to;

receive a request message from the user equipment (410), which request message is a request for an update related to an area to which the user equipment (410) is configured to move, or which request message is a request for transmitting data in the communication network (100b, 200b, 300b, 400); and

to

obtain information about rejection of the request message;

a processor (602) configured to increase a parameter indicating a number of rejections associated with the user equipment (401) based on the obtained information; and

a transmitter (604) configured to transmit, to the user equipment (410), instructions to detach the user equipment (410) from the first network node (101b, 401) when the parameter is above the threshold.

14. The first network node (101b, 401) according to claim 13, wherein the transmitter (604) is further configured to transmit a reject message to the user equipment (410) when the parameter is below a threshold.

15. The first network node (101b, 401) according to claims 14, wherein the reject message comprises an information indicating a first cause of the rejection, and wherein the instructions to detach the user equipment (410) comprises information indicating a second cause of the rejection, which second cause is different from the first cause.

16. The first network node (101b, 401) according to any of the claims 13-15, wherein the first cause indicates a failure of the communication network (100b), and wherein the second cause indicates detach of the user equipment (410) from the first network node (101b, 401).

17. The first network node (101b, 401) according to any of the claims 13-16, wherein the receiver (601) is further configured to receive information about the rejection from a second network node (105b, 207b, 405), wherein the second network node (105b, 207b, 405) is a Domain Name Server, DNS (105b), or a Gateway General packet radio service Support Node, GGSN (207b), or a Serving GateWay, SGW, or a Packet data network GateWay, PGW, or a radius server;

and

wherein the processor (602) is further configured to determine that the request message should be rejected.

18. The first network node (101b, 401) according to any of the claims 13-17, wherein the transmitter (604) is further configured to transmit information indicating the request message to a second network node (105b, 207b, 405).

19. The first network node (101b, 401) according to any of the claims 13-18, wherein the processor (602) is further configured to clear the parameter when a time parameter associated with the rejection information is above a limit.

20. The first network node (101b, 401) according to any of the claims 13-19, wherein the receiver (601) is further configured to receive an attach request message from the user equipment (410) when the user equipment (410) has been detached.

21. The first network node (101b, 401) according to any of the claims 13-20, wherein the request message is a Routing Area Update, RAU, message or a Tracking Area Update message;

wherein

the instruction to detach the user equipment (410) is comprised in a RAU reject message or a TAU reject message; and

wherein the receiver (601) is further configured to obtain the information about rejection by receipt from a Domain Name Server, DNS (105b), or internally within the first network node (101b, 401) or by receipt from a cooperating Serving General packet radio service Support Node, SGSN.

22. The first network node (101b, 401) according to any of the claims 13-21, wherein the request message is an activate Packet Data Protocol, PDP, context request message or an activate Packet Data Network, PDN, connection request message;

wherein the instructions to detach the user equipment (410) is comprised in a detach request message; and

wherein the receiver (601) is further configured to obtain the information about rejection of the request message by receipt of the information from a Gateway General packet radio service Support Node, GGSN (207b), or a Serving GateWay, SGW, or a Packet data network GateWay, PGW, or a radius server.

23. The first network node (101b, 401) according to any of the claims 13-22, wherein the request message is an activate Packet Data Protocol, PDP, context request message or an activate Packet Data Network, PDN, connection request message;

wherein the instructions to detach the user equipment (410) is comprised in a detach request message; and

wherein

the receiver (601) is further configured to obtain the information about rejection of the request message internally within the first network node (101b, 401).

24. The first network node (101b, 401) according to any of the claims 13-23, wherein the first network node (101b, 401) is a Serving General packet radio service Support Node, SGSN (101b), or a Mobility Management Entity, MME, or a combined SGSN and MME.