Methods and apparatus for resource management in a multi-carrier telecommunications system

• US 8,620,335 B2
• Filed: 04/27/2010
• Issued: 12/31/2013
• Est. Priority Date: 04/27/2009
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Lindstrom, Magnus, Parkvall, Stefan, Pelletier, Ghyslain, Wager, Stefan
• Primary Examiner(s): SAMS, MATTHEW C
• Application Number:
  US12/767,959
• Publication Number:
  US 20100285809A1
• Time in Patent Office: 1,344 Days
• Field of Search: 455/68, 455/69, 455/73, 455450-453, 455/509, 455/515, 370/252, 370/329, 370/330, 370/335, 370/341, 370/342, 370/479
• US Class Current: 455/450
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 36/0016 Hand-off preparation specially adapted for end-to-end data sessions
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

The embodiments of the present invention relate to apparatuses and methods for resource management in a multi-carrier system wherein a plurality of component carriers (CCs) is defined per cell. According to a method in an apparatus corresponding to a radio base station, a message is assembled comprising information on the structure of the cell served by the radio base station; the information including one or more CCs used in the cell that is/are available for a user equipment for performing initial access in the cell. The method also comprises, transmitting the assembled message to the user equipment and indicating to the user equipment to what resources to use for random access in the cell. The exemplary embodiments of the present invention also relates to a method in the user equipment, to a radio base station and to a user equipment.

Claims

1. A method in a radio base station, for resource management in a multi-carrier system comprising a cell served by the radio base station and wherein a plurality of component carriers (CCs) are defined for said cell, the method comprising:

assembling a message comprising information on a structure of the cell, said information including at least one CC used in the cell that is available for a user equipment (UE), for performing random access in the cell, wherein the information in said message further comprises at least one dedicated preamble to use by said UE for an initial random access in the cell and further comprises an indication of on which said at least one CC the at least one preamble is valid;

transmitting said message to the UE; and

indicating to said UE to what at least one resource the UE is to use for random access in the cell.

2. The method according to claim 1, wherein the information in said message further comprises a physical random access channel (PRACH) configuration for each CC included in said message.

3. The method according claim 2, wherein the information further comprises, for each of said at least one CC, a dedicated preamble for which the UE is allowed to use at least one PRACH resource.

4. The method according to claim 1, wherein the information in said message further comprises information on a PRACH load in each CC included in said message.

5. The method according to claim 1, wherein said indicating further comprises

indicating to said UE to what at least one resource, wherein the at least one resource is a PRACH resource, the UE is to use for random access in the cell.

6. The method according to claim 1, wherein the information further including an identity (CCid) of each said at least one CC and/or a carrier frequency (carrierFreq) for each said at least one CC, and/or a bandwidth (carrierBandwidth) for each said at least one CC and/or at least one timer.

7. The method according to claim 6, wherein the information further comprises an uplink CC for at least one subsequent random access and/or a downlink for at least one subsequent random access and/or an uplink-downlink CC pair for at least one subsequent random access.

8. The method according to claim 1 wherein said transmitting further comprises

transmitting said message in a handover command during a cell preparation for a handover procedure or in a physical downlink control channel (PDCCH) random access order.

9. A method in a user equipment (UE) capable in operating in a multi-carrier system comprising a radio base station serving a cell, wherein a plurality of component carriers (CCs) are defined, the method comprising:

receiving from the radio base station a message assembled by said radio base station, said message comprising information including at least one CC used in the cell that is available for the UE for performing random access in the cell, wherein the assembled message further comprises at least one dedicated preamble to use by said UE for an initial random access in the cell and an indication of on which said at least one CC the at least one preamble is valid and for which the UE is allowed to use at least one PRACH resource;

determining, based on the received information, to what at least one resource to use in the cell;

selecting at least one resource; and

performing a random access in the cell based on the determined information.

10. The method according to claim 9 wherein said determining further comprises

determining based on the received information, in what CC of said cell to perform the random access, and said selecting further comprises selecting a first available resource for performing the random access in the determined CC of the cell.

11. The method according to claim 9 further comprises reading system information on a frequency of the CC to acquire information on a structure of the cell comprising the CCs of the cell;

and

selecting one of the CCs for determining to what at least one resource to use in the cell for performing random access in the cell.

12. The method according to claim 11 wherein said selecting comprises selecting randomly or selectively one of the CCs of the cell.

13. The method according claim 9 wherein said receiving comprises

receiving in the assembled message a physical random access channel (PRACH) configuration for each CC included in said message and/or information on a PRACH load in each CC included in said message.

14. The method according to claim 9, wherein said receiving comprises

receiving said assembled message in a handover command during a cell preparation for a handover procedure or in a physical downlink control channel (PDCCH) random access order.

15. A radio base station for resource management in a multi-carrier system comprising a cell served by the radio base station and wherein a plurality of component carriers (CCs) are defined for said cell, the radio base station comprising:

an assembler configured to assemble a message comprising information on a structure of the cell, said information including at least one CC used in the cell that is available for a user equipment (UE) for performing random access in the cell, wherein the information in said message further comprises at least one dedicated preamble to use by said UE for an initial random access in the cell and further comprises an indication of what said at least one CC the at least one preamble is valid; and

a transceiver configured to transmit said message to the UE and further configured to indicate to said UE to what at least one resource the UE is to use for random access in the cell.

16. The radio base station according to claim 15, wherein the information in said message further comprises a physical random access channel (PRACH) configuration for each CC included in said message.

17. The radio base station according to claim 15, wherein the information in said message further comprises information on a PRACH load in each CC included in said message.

18. The radio base station according to claim 15, wherein the transceiver is configured to indicate to said UE what at least PRACH resource, the UE is to use for random access in the cell.

19. The radio base station according to claim 15, wherein the information in said message assembled by the assembler further includes an identity (CCid) of each said at least one CC and/or a carrier frequency (carrierFreq) for each said at least one CC and/or a bandwidth (carrierBandwidth) for each said at least one CC and/or at least one timer.

20. The radio base station according to claim 15, wherein the information further includes an uplink CC for at least one subsequent random access and/or a downlink for at least one subsequent random access and/or an uplink-downlink CC pair for at least one subsequent random access.

21. The radio base station according to claim 15, wherein the information further includes, for each of said at least one CC, a dedicated preamble for which the UE is allowed to use at least one PRACH resource.

22. The radio base station according to claim 15, wherein the transceiver is configured to transmit the message in a handover command during a cell preparation for a handover procedure or in a physical downlink control channel (PDCCH) random access order.

23. A user equipment (UE) capable in operating in a multi-carrier system comprising a radio base station serving a cell wherein a plurality of component carriers (CCs) are defined, the UE comprises:

a transceiver configured to receive from the radio base station a message assembled by said radio base station, said message comprising information including at least one CC used in the cell that is available to the UE for performing random access in the cell, wherein the transceiver is further configured to receive in the assembled message at least one dedicated preamble to use by said UE for an initial random access in the cell and further receive in said message an indication of on which said at least one CC the at least one preamble is valid and for which the UE is allowed to use at least one PRACH resource;

a processing unit configure to determine, based on the received information, to what at least one resource to use in the cell, and further configured to select at least one resource and the UE is further configured to perform a random access in the cell based on the determined information.

24. The user equipment according to claim 23, wherein the processing unit is configured to determine based on the received information, in what CC of said cell to perform the random access, and further configured to select a first available resource for performing the random access in the determined CC of the cell.

25. The user equipment according to claim 23 is further configured to read system information on a frequency of the CC to acquire information on a structure of the cell comprising the CCs of the cell, and to select one of the CCs for determining to what at least one resource to use in the cell for performing random access in the cell.

26. The user equipment according to claim 25 is configured to randomly or selectively select one of the CCs of the cell.

27. The user equipment according to claim 23, wherein the transceiver is configured to receive in the assembled message a random access channel (PRACH) configuration for each CC included in said message and/or information on a PRACH load in each CC included in said message.

28. The user equipment according to claim 23, wherein the transceiver is configured to receive the message in a handover command during a cell preparation for a handover procedure or in a physical downlink control channel (PDCCH) random access order.