Methods and means related to the maintenance of connections in a gprs network

• US 20040053623A1
• Filed: 06/25/2003
• Published: 03/18/2004
• Est. Priority Date: 12/29/2000
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Perleryd, Jonas Martin, Hoff, Per Magne, Mo, Heine
• Granted Patent: US 7,324,556 B2
• Time in Patent Office: Days
• US Class Current: 455/452.1
• CPC Class Codes: H04W 24/04 Arrangements for maintaining operational condition
• CPC Class Codes: H04W 4/16 Communication-related supplementary services, e.g. call-transfer or call-hold
• CPC Class Codes: H04W 76/12 Setup of transport tunnels
• CPC Class Codes: H04W 76/19 Connection re-establishment

Abstract

This new invention is a method of re-establishing MS-SGSN connections after a partial restart of SGSN, i.e., only the Gb-interface is restarted. The re-establishment is achieved without detaching the MS. With this method Ciphering is re-synchronised, PDP-contexts in unacknowledged mode are re-established, and SMS traffic over GPRS is re-established, while PDP-contexts in acknowledged mode are deactivated with order to re-activate. When the MS is moving within the coverage of a SGSN, the invention can be used to move the context closer to the used Gb-link. When the MS request better Quality of Service, the MS context can moved to more suitable SGSN resource with this invention.

Claims

1. A method for re-establishing a connection between a Mobile Station and a Serving GPRS Support Node after a partial restart of the Serving GPRS Support Node, in which only the Gb interface between the Serving GPRS Support Node and the Base Station System is restarted,

characterized in the following steps:

the GPRS Mobility Management &

Session Management layer in the Serving GPRS Support Node is informed about the restart of the local Gb interface,

affected Mobile Station contexts are identified,

the GPRS Mobility Management &

Session Management, Logical Link Control and Subnetwork Dependent Convergence Protocol layers in the Serving GPRS Support Node are set in a special Gb restart state,

the Mobile Station sends, or is brought to send, a Logical Link Control frame to the Serving GPRS Support Node,

on reception of the Logical Link Control frame the appropriate Logical Link Control and Subnetwork Dependent Convergence Protocol layers are re-established.

5. A method as claimed in claim 1, 2, 3 or 4,

characterized in that said step whereupon the GPRS Mobility Management &

Session Management layer is set in said special Gb restart state involves the GPRS Mobility Management &

Session Management starting the Mobile Reachable Timer in the Serving GPRS Support Node according to agreed value with the Mobile Station, and setting the GPRS Mobility Management &

Session Management state to standby-reachable.

6. A method as claimed in claim 5,

characterized in that said step in which the Logical Link Control layer is set in said special Gb restart state involves the GPRS Mobility Management &

Session Management re-entering information regarding the affected Mobile Station into the Logical Link Control layer.

7. A method as claimed in claim 6,

characterized in that the GPRS Mobility Management &

Session Management supplies the Logical Link Control layer with ciphering keys and ciphering algorithms.

8. A method as claimed in claim 6 or 7,

characterized in that the GPRS Mobility Management &

Session Management sets the Logical Link Control layer into a first suspend state with order to inform GPRS Mobility Management &

Session Management when traffic shall be sent to the Mobile Station.

9. A method as claimed in claim 8,

characterized in that the Subnetwork Dependent Convergence Protocol layer is set in said special Gb restart state by GPRS Mobility Management &

Session Management re-entering any established Packet Data Protocol context to the Subnetwork Dependent Convergence Protocol layer, when downlink payload arrives at the Gn interface in the Serving GPRS Support Node and the Mobile Station must be paged.

10. A method as claimed in claim 9,

characterized in that the layers are re-established by the Mobile Station sending a Logical Link Control frame to the Serving GPRS Support Node, the Logical Link Control layer in the Serving GPRS Support Node is set into a second suspend state, where the Logical Link Control layer is not allowed to inform the GPRS Mobility Management &

Session Management when traffic shall be sent to the Mobile Station, and GPRS Mobility Management &

Session Management in Serving GPRS Support Node orders the Logical Link Control layer to inform the Mobile Station about the need of re-initialisation of its Logical Link Control and Subnetwork Dependent Convergence Protocol layers.

11. A method as claimed in claim 10,

characterized in the Mobile Station is informed about the need of re-initialisation by the Logical Link Control layer sending a Logical Link Control-eXchange Identification message with a reset parameter to the Mobile Station.

12. A method as claimed in claim 10,

characterized in that the GPRS Mobility Management &

Session Management in the Serving GPRS Support Node will deactivate any Packet Data Protocol context in acknowledged mode, and will order the Mobile Station to re-activate the Packet Data Protocol context in question.

13. A method as claimed in claim 8 or 9,

characterized in that the layers in the Serving GPRS Support Node are re-established by sending unacknowledged traffic to the Mobile Station, whereupon the Mobile Station will send a Logical Link Control frame as an answer.

14. A method as claimed in claim 9,

characterized in that said Logical Link Control and Subnetwork Dependent Convergence Protocol layers in the Serving GPRS Support Node will be re-established by sending acknowledged traffic to the Mobile Station whereupon the Mobile Station will respond by sending a Logical Link Control frame to the Serving GPRS Support Node.

15. A computer program for controlling an Serving GPRS Support Node to perform a method according to any of the claims 2-14.

2. A method in a Serving GPRS Support Node for transferring the handling of Logical Link Control and Subnetwork Dependent Convergence Protocol layers for a connected Mobile Station to a Central Processing Unit close to the currently used Gb-link, involving a relocation of the local Gb interface,

characterized in the following steps:

the GPRS Mobility Management &

Session Management layer in the Serving GPRS Support Node is informed about the restart of the local Gb interface,

affected Mobile Station contexts are identified,

the GPRS Mobility Management &

Session Management, Logical Link Control and Subnetwork Dependent Convergence Protocol layers in the Serving GPRS Support Node are set in a special Gb restart state,

on reception of a Logical Link Control frame the appropriate Logical Link Control and Subnetwork Dependent Convergence Protocol layers are re-established.

4. A method as claimed in claim 2 or 3,

characterized in that the Serving GPRS Support Node orders the Mobile Station to send a Logical Link Control frame to the Serving GPRS Support Node.

3. A method in a Serving GPRS Support Node for transferring the handling of a connected Mobile Station internally in said Serving GPRS Support Node to hardware suited to the required Quality of Service, involving a relocation of the local Gb interface,

characterized in the following steps:

the GPRS Mobility Management &

Session Management layer in the Serving GPRS Support Node is informed about the restart of the local Gb interface,

affected Mobile Station contexts are identified,

the GPRS Mobility Management &

Session Management, Logical Link Control and Subnetwork Dependent Convergence Protocol layers in the Serving GPRS Support Node are set in a special Gb restart state,

on reception of a Logical Link Control frame the appropriate Logical Link Control and Subnetwork Dependent Convergence Protocol layers are re-established.

16. A GPRS Support Node adapted to operate as a Serving GPRS Support Node, including means for re-establishing a connection between a Mobile Station and the Serving GPRS Support Node after a partial restart of the Serving GPRS Support Node, in which only the Gb interface between the Serving GPRS Support Node and the Base Station System is restarted,

characterised in that said means for re-establishing includes means for informing the GPRS Mobility Management &

Session Management layer in the Serving GPRS Support Node about the restart of the local Gb interface, means to identify affected Mobile Station context, and means to set Logical Link Control and Subnetwork Dependent Convergence Protocol layers in the Serving GPRS Support Node in a special Gb restart state, whereupon the Logical Link Control and Subnetwork Dependent Convergence Protocol layers are re-established on reception of a Logical Link Control frame.

19. A GPRS Support Node as claimed in claim 16, 17 or 18, characterized in that said Serving GPRS Support Node includes means for ordering the Mobile Station to send a Logical Link Control frame to the Serving GPRS Support Node.

17. A GPRS Support Node adapted to operate as a Serving GPRS Support Node, including means for transferring the handling of Logical Link Control and Subnetwork Dependent Convergence Protocol layers for a connected Mobile Station to a Central Processing Unit close to the currently used Gb link, involving a relocation of the local Gb interface,

characterised in that said means for transferring includes means for informing the GPRS Mobility Management &

Session Management layer in the Serving GPRS Support Node about the restart of the local Gb interface, means to identify affected Mobile Station context, and means to set Logical Link Control and Subnetwork Dependent Convergence Protocol layers in the Serving GPRS Support Node in a special Gb restart state, whereupon the Logical Link Control and Subnetwork Dependent Convergence Protocol layers are re-established on reception of a Logical Link Control frame.

18. A GPRS Support Node adapted to operate as a Serving GPRS Support Node, including means for transferring the handling of a connected Mobile Station internally in said Serving GPRS Support Node to hardware suited to the required Quality of Service, involving a relocation of the local Gb interface,

characterised in that said means for transferring includes means for informing the GPRS Mobility Management &

Session Management layer in the Serving GPRS Support Node about the restart of the local Gb interface, means to identify affected Mobile Station context, and means to set Logical Link Control and Subnetwork Dependent Convergence Protocol layers in the Serving GPRS Support Node in a special Gb restart state, whereupon the Logical Link Control and Subnetwork Dependent Convergence Protocol layers are re-established on reception of a Logical Link Control frame.