Method and apparatus for improving a mobile station cell change operation in the general packet radio system (GPRS)

• US 7,447,181 B1
• Filed: 12/05/2001
• Issued: 11/04/2008
• Est. Priority Date: 12/05/2001
• Status: Active Grant

• Current Assignee: Conversant Wireless Licensing S.à.r.l. (f/k/a Core Wireless Licensing S.a.r.l.) (MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management))
• Original Assignee: Nokia Corporation
• Inventors: Forssell, Mika
• Primary Examiner(s): Orgad, Edan
• Assistant Examiner(s): PARK, JUNG H
• Application Number:
  US10/004,723
• Time in Patent Office: 2,526 Days
• Field of Search: 370/331, 455/436
• US Class Current: 370/336
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04M 15/00 Arrangements for metering, time-control or time indication ; Metering, charging or billing arrangements for voice wireline or wireless communications, e.g. VoIP
• CPC Class Codes: H04M 15/8033 location-dependent, e.g. business or home
• CPC Class Codes: H04M 15/8038 Roaming or handoff
• CPC Class Codes: H04M 15/81 Dynamic pricing, e.g. change of tariff during call
• CPC Class Codes: H04M 2215/0112 Dynamic pricing, e.g. change of tariff during call
• CPC Class Codes: H04M 2215/22 Bandwidth or usage-sensitve billing
• CPC Class Codes: H04M 2215/32 Involving wireless systems
• CPC Class Codes: H04M 2215/34 Roaming
• CPC Class Codes: H04M 2215/7435 Location dependent, e.g. Bussiness or home
• CPC Class Codes: H04M 2215/7442 Roaming
• CPC Class Codes: H04W 28/10 Flow control between communication endpoints
• CPC Class Codes: H04W 36/0016 Hand-off preparation specially adapted for end-to-end data sessions
• CPC Class Codes: H04W 36/02 Buffering or recovering information during reselection ; Modification of the traffic flow during hand-off
• CPC Class Codes: H04W 72/52 based on load
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A mobile station executed method, wherein upon changing from a current cell to a new cell in a wireless packet data network the mobile station enters the new cell; generates a cell change packet data unit (PDU) message for informing the network of the location of the mobile station in the new cell; buffers the cell change PDU message into a PDU transmit queue before any buffered PDUs that were present before the mobile station entered the new cell; and transmits the buffered cell change PDU before any of the buffered PDUs that were present before the mobile station entered the new cell. In accordance with another method for informing the wireless network of the MS cell change, the following steps are executed: (i) in response to the MS making access in a new cell, sending a Channel Request that indicates a Cell Update operation; (ii) establishing an uplink (UL) Temporary Block Flow (TBF) for transferring Logical Link Control (LLC) Packet Data Units (PDUs) from the MS to the network; (iii) in response to the network receiving an unknown Temporary Logical Link Identifier (TLLI) from the MS, sending a message to a Serving GPRS Support Node (SGSN) and (iv) based on the message, determining with the SGSN the new cell location of the MS.

Claims

1. A mobile station executed method comprising:

entering a new cell;

generating a cell change logical link control packet data unit massage for informing the network of the location of the mobile station in the new cell;

buffering the cell change logical link control packet data unit message into a logical link control packet data unit message transmit queue such that it is selected for transmission prior to any buffered packet data units that were present before the mobile station entered the new cell;

a radio link control/medium access control unit of a mobile station initiating an uplink temporary block flow in the new cell;

indicating to a radio link control/medium access control of the network if an ACK or an UNACK radio link control mode is to be used when transmitting the cell change packet data unit message; and

transmitting the buffered cell change packet data unit before any of the buffered packet data units that were present before the mobile station entered the new cell.

2. A method as in claim 1, wherein the transmitting includes requesting an uplink resource for transmitting the cell change packet data unit.

3. A method as in claim 1, wherein the transmitting includes requesting an uplink temporary block flow for transmitting the cell change packet data unit.

4. A method of claim 1, wherein, in response to receiving the cell change packet data unit downlink packet data units for the mobile station are transmitted into the new cell.

5. A method as in claim 1, wherein the generated cell change packet data unit is transmitted only if a first packet data unit in the transmit queue exceeds a predetermined length, otherwise the cell change packet data unit is discarded and the first packet data unit in the transmit queue is transmitted instead.

6. A method as in claim 1, where the cell change logical link control packet data unit has a length that fits within one radio link control data block.

7. A method as in claim 6, wherein the generating operates a logical link control unit to use a service access point indicator of a general purpose radio service mobility management unit to form an empty a general purpose radio service mobility management packet data unit, and where a mobile station location update procedure is triggered by a serving general packet radio service support node when the a general purpose radio service mobility management packet data unit is received.

8. A method as in claim 6, wherein the radio link control/medium access control unit of the mobile station selects either the ACK or the UNACK radio link control mode based on the UNACK radio link control mode of a next queued logical link control packet data unit in the transmit queue.

9. A method as in claim 1, wherein the generating includes setting a priority level of the cell change packet data unit such that the buffering the cell change packet data unit message into the packet data unit transmit queue causes the cell change packet data unit to be transmitted before any lower priority packet data units.

10. An apparatus comprising:

a packet data buffer and a controller that is responsive to changing location from a previous cell to a new cell in a wireless packet data network for generating a cell change logical link control packet data unit message for informing the wireless packet data network of the presence of the apparatus in the new cell and for buffering the cell change logical link control packet data unit message into the packet data buffer such that it is selected for transmission prior to any buffered packet data units that were present before the apparatus entered the new cell, the controller being arranged to operate a radio link control/medium access control unit to initiate an uplink temporary block flow in the new cell, and to indicate to a radio link control/medium access control of the network if an ACK or an UNACK radio link control mode is to be used when transmitting the cell change logical link control packet data unit, said apparatus comprising a transmitter for transmitting the buffered cell change logical link control packet data unit message for informing the wireless packet data network of the cell in which the apparatus is currently located so that packet data intended for the apparatus is not transmitted into the previous cell by the wireless packet data network.

11. An apparatus as in claim 10 wherein the controller, prior to operating said transmitter for transmitting the buffered cell change logical link control packet data unit, requests an uplink resource for transmitting the cell change logical link control packet data unit.

12. An apparatus as in claim 10 wherein the controller, prior to operating said transmitter for transmitting the buffered cell change packet data unit, request an uplink temporary block flow for transmitting the cell change packet data unit.

13. An apparatus as in claim 10, wherein the generated cell change packet data unit is transmitted only if a first packet data unit in the transmit buffer exceeds a predetermined length, otherwise the cell change packet data unit is discarded and the first packet data unit in the transmit queue is transmitted instead.

14. An apparatus as in claim 10, where the cell change logical link control packet data unit has a length that fits within one radio link control data block.

15. An apparatus as in claim 14, wherein the controller, when generating the cell change packet data unit, operates a logical link control unit to use a service access point indicator of a general purpose radio service mobility management unit to form an empty general purpose radio service mobility management packet data unit, and where a apparatus location update procedure is triggered by a serving general purpose service support node when the general purpose radio service mobility management packet data unit is received.

16. An apparatus as in claim 14, wherein the radio link control/medium access control unit of the apparatus selects either the ACK or the UNACK radio link control mode based on the radio link control mode of a next queued logical link control packet data unit in the transmit buffer.

17. An apparatus as in claim 10, wherein controller sets a priority level of the cell change packet data unit such when buffering the cell change packet data unit message into the packet data unit transmit queue the cell change packet data unit is caused to be transmitted before any lower priority packet data units.

18. A method comprising:

changing from a first cell to a second cell with a mobile station; and

prior to a serving general packet radio service support node receiving at least one of a packet data unit and a message from the mobile station, notifying the serving general packet radio service support node of the mobile station cell change, wherein notifying the serving general packet radio service support node of the mobile station cell change comprises

in response to the mobile station making access in the second cell, sending a channel request that indicates a cell update operation;

establishing an uplink temporary block flow for transferring logical link control packet data units from the mobile station to the network;

in response to the network receiving an unknown temporary logical link identifier from the mobile station, sending a message to the serving general packet radio service support node; and

based on the message, determining with the serving general packet radio service support node that the mobile station is located in the second cell.

19. A method as in claim 18, wherein the temporary logical link identifier is received in a packet resource request message, in the case of a two phase access, or in a first radio link control data block, in the case of a one phase access.

20. A method as in claim 18, wherein the notifying occurs in response to the mobile station being assigned a time division multiple access frame number of when to make the cell change.

21. A method as in claim 18, wherein the notifying occurs in response to the network receiving a radio link control/medium access control message from the mobile station.

22. A method as in claim 18, wherein the notifying occurs in response to the network receiving a temporary logical link identifier from the mobile station.

23. A method comprising:

passing a cell change logical link control packet data unit message to a radio link control unit for informing a network of the location of a mobile station in a new cell, the cell change logical link control packet data unit message having a flag for indicating a priority of the packet data unit relative to other packet data units;

storing the cell change logical link control packet data unit message into a logical link control packet data unit message transmit message queue in accordance with the indicated priority;

a radio link control/medium access control unit of a mobile station initiating an uplink temporary block flow in the new cell;

indicating to a radio link control/medium access control of the network if an ACK or an UNACK radio link control mode is to be used when transmitting the cell change packet data unit message; and

transmitting the stored cell change logical link control packet data unit to a radio channel before any stored packet data units having a lower priority.

24. A method as in claim 23, where the cell change packet data unit is assigned a highest priority.

25. A computer readable medium encoded with a computer program the execution of which in association with a device cell change operation performs operations of:

responsive to entering a new cell, generating a cell change logical link control packet data unit message for information a wireless network of the location of the device; and

buffering the cell change logical link control packet data unit message into a logical link control packet data unit message transmit queue such that it is transmitted to the network before any already buffered packet data units that were present before the mobile station entered the new cell;

a radio link control/medium access control unit of a mobile station initiating an uplink temporary block flow in the new cell;

indicating to a radio link control/medium access control of the network if an ACK or an UNACK radio link control mode is to be use when transmitting the cell change packet data unit message; and

transmitting the buffered cell change packet data unit before any of the buffered packet data units that were present before the mobile station entered the new cell.

26. A computer readable medium encoded with a computer program as in claim 25, further comprising requesting from the wireless network an uplink resource for transmitting the cell change packet data unit.

27. A computer readable medium encoded with a computer program as in claim 25, further comprising requesting from the wireless network an uplink temporary block flow for transmitting the cell change packet data unit.

28. A computer readable medium encoded with a computer program as in claim 25, where the cell change logical link control packet data unit has a length that fits within one radio link control data block, and where the generating operation operates a logical link control unit to use a service access point indicator of a general packet radio service mobility management unit to form an empty general packet radio service mobility management packet data unit, and where a device location update procedure is triggered by a serving general packet radio service support node when the general packet radio service mobility management packet data unit is received.

29. A computer readable medium encoded with a computer program as in claim 25, where the cell change link logical control packet data unit has a length that fits within one radio link control data block, and where a radio link control/medium access control unit initiates an uplink temporary block flow in the new cell.

30. A computer readable medium encoded with a computer program as in claim 29, where a device radio link control/medium access control unit selects either the ACK or the UNACK radio link control mode based on the radio link control mode of a next queued logical link control packet data unit in the transmit queue.

31. A computer readable medium encoded with a computer program as in claim 25, where the generating operation comprises setting a priority level of the cell change packet data unit such that buffering the cell change packet data unit message into the packet data unit transmit queue causes the cell change packet data unit to be transmitted before any lower priority packet data units.

32. A device, comprising:

means, responsive to entering a new cell, for generating a cell change logical link control packet data unit message for informing a wireless network of the location of the device; and

means for buffering the cell change logical link control packet data unit message into a logical link control packet data unit message transmit queue such that it is transmitted to the wireless network before any already buffered packet data units that were present before the mobile station entered the new cell;

means for initiating an uplink temporary block flow in the new cell;

means for indicating to a radio link control/medium access control of the network if an ACK or an UNACK radio link control mode is to be used when transmitting the cell change packet data unit message; and

means for transmitting the buffered cell change packet data unit before any of the buffered packet data units that were present before the mobile station entered the new cell.

33. A device as in claim 32, further comprising means for requesting from the wireless network an uplink resource for transmitting the cell change packet data unit.

34. A device as in claim 32, further comprising means for requesting from the wireless network as uplink temporary block flow for transmitting the cell change packet data unit.

35. A device as in claim 32, where the cell change logical link control packet data unit has a length that fits within one radio link control data block, and where the generating means operates a logical link control unit to use a service access point indicator of a general packet radio service mobility management unit to form an empty general packet radio service mobility management packet data unit, and where a device location update procedure is triggered by a serving general purpose radio service support node when the general packet radio service mobility management packet data unit is received.

36. A device as in claim 32, where the cell change logical link control packet data unit has a length that fits within one radio link control data block, and where a radio link control/medium access control unit initiates an uplink temporary block flow in the new cell.

37. A device as in claim 36, where a device radio link control/medium access control unit selects either the ACK or the UNACK radio link control mode based on the radio link control mode of a next queued logical link control packet data unit in the transmit queue.

38. A device as in claim 32, where the generating means sets a priority level of the cell change packet data unit such that buffering the cell change packet data unit message into the packet data unit transmit queue causes the cell change packet data unit to be transmitted before any lower priority packet data units.