Physical-layer cell identity (PCI) partition for heterogeneous networks

Patent metadata

Field	Value
Publication number	US-9456415-B2
Application number	US-201213538775-A
Country	US
Kind code	B2
Filing date	Jun 29, 2012
Priority date	Sep 30, 2011
Publication date	Sep 27, 2016
Grant date	Sep 27, 2016

Abstract

Technology for partitioning small cell physical-layer cell identities (PCI) at a node in a heterogeneous network (HetNet) is disclosed. One method can include the node identifying at least one small cell PCI of a plurality of small cells in a macro cell. Each small cell PCI can be associated with a low power node (LPN) in the HetNet. The node can generate a small cell PCI list to include the at least one small cell PCI. The node can broadcast the small cell PCI list to a wireless device.

First claim

What is claimed is:

1. A method for partitioning small cell physical-layer cell identities (PCI) at a node in a heterogeneous network (HetNet), comprising:
identifying at a node at least one small cell PCI of a plurality of small cells in a macro cell, wherein each small cell PCI is associated with a low power node (LPN) in the HetNet;
generating a small cell PCI list to include the at least one small cell PCI;
broadcasting the small cell PCI list from the node to a wireless device; and
sending a closed subscriber group (CSG) range from the node to the wireless device, wherein the wireless device is configured to search a reduced number of PCIs by searching an overlap of PCIs specified in the small cell PCI list and the CSG range or by excluding the PCIs specified in the CSG range from the PCIS specified in the small cell PCI list in the search.

2. The method of claim 1 , wherein the small cell PCI list includes one of:
a plurality of non-consecutive small cell PCIs; and
a range of consecutive small cell PCIs.

3. The method of claim 1 , wherein the small cell PCI list includes a PCI start value for a PCI and a PCI range for a number of PCIs to search after the PCI start value.

4. The method of claim 1 , wherein broadcasting the small cell PCI list further comprises broadcasting the small cell PCI list in a mobility control information element (IE) SmallCellPhysCellIdRange or a mobility control IE PhysCellIdRange, wherein a set of range elements of the IE SmallCellPhysCellIdRange have smaller values than a set of range elements of an IE PhysCellIdRange.

5. The method of claim 1 , wherein broadcasting the small cell PCI list further comprises broadcasting the small cell PCI list in a radio resource control (RRC) information element (IE) system information block type4 (SIB4) configured to include a list of PCIs of intra-frequency neighboring small cells.

6. The method of claim 1 , wherein the small cell PCI list includes a small cell category value, wherein the small cell category value specifies the PCIs associated with a small cell type.

7. The method claim 1 , further comprising:
broadcasting a closed subscriber group (CSG) range from the node to a wireless device.

8. The method of claim 1 , wherein the small cell PCI list includes a validity time of the received small cell PCI list, wherein the validity time specifies an expiration time by which time to acquire an updated small cell PCI list.

9. At least one non-transitory machine readable medium comprising a plurality of instructions adapted to be executed to implement the method of claim 1 .

10. A physical-layer cell identity (PCI) partitioning device for partitioning small cell PCIs at a node in a heterogeneous network (HetNet), comprising:
a PCI partitioning module configured to identify at least one small cell PCI of a plurality of small cells in a macro cell, and generate a small cell PCI list to include the at least one small cell PCI, wherein each small cell PCI is associated with a low power node (LPN) in the HetNet, wherein the PCI partitioning module is comprised of code that is located in one or more digital memory devices to be executed by one or more processors or the PCI partitioning module is implemented in one or more hardware circuits; and
a downlink broadcasting module configured to:
broadcast the small cell PCI list from the node to a wireless device; and
send a closed subscriber group (CSG) range from the node to the wireless device, wherein the wireless device is configured to search a reduced number of PCIs by searching an overlap of PCIs specified in the small cell PCI list and the CSG range or by excluding the PCIs specified in the CSG range from the PCIs specified in the small cell PCI list in the search,
wherein the downlink broadcasting module is comprised of code that is located in one or more digital memory devices to be executed by one or more processors or the downlink broadcasting module is implemented in one or more hardware circuits.

11. The PCI partitioning device of claim 10 , wherein the small cell PCI list includes a plurality of non-consecutive small cell PCIs, a range of consecutive small cell PCIs, a PCI start value for a PCI and a PCI range for a number of PCIs to search after the PCI start value, a small cell category value, or combination thereof, wherein the small cell category value specifies the PCIs associated with a small cell type.

12. A method for searching a reduced number of small cell physical-layer cell identity (PCI) candidates in a search pool at a wireless device in a heterogeneous network (HetNet), comprising:
receiving a small cell PCI list from a serving node at a wireless device, wherein the small cell PCI list identifies at least one small cell PCI to search and each small cell PCI is associated with a low power node (LPN) in the HetNet;
searching a reduced number of PCIs based on the small cell PCI list;
receiving a closed subscriber group (CSG) range from the serving node; and
searching the reduced number of PCIs by searching an overlap of PCIs specified in the small cell PCI list and the CSCE range or by excluding the PCIs specified in the CSG range from the PCIS specified in the small cell PCI list in the search.

13. The method of claim 12 , wherein the small cell PCI list includes one of:
a plurality of non-consecutive small cell PCIs; and
a range of consecutive small cell PCIs.

14. The method of claim 12 , wherein the small cell PCI list includes a PCI start value for a PCI and a PCI range for a number of PCIs to search after the PCI start value.

15. The method of claim 12 , wherein the small cell PCI list is broadcast in a mobility control information element (IE) SmallCellPhysCellIdRange, wherein a set of range elements of the IE SmallCellPhysCellIdRange have smaller values than a set of range elements of an IE PhysCellIdRange.

16. The method of claim 12 , wherein the small cell PCI list is broadcast in a radio resource control (RRC) information element (IE) master information block (MIB) type 4 configured to include a list of PCIs of intra-frequency neighboring small cells.

17. The method of claim 12 , wherein the small cell PCI list includes a small cell category value, wherein the small cell category value specifies the PCIs associated with a small cell type.

18. The method of claim 12 , wherein searching the reduced number of PCIs is based on a validity time of the received small cell PCI list, wherein the validity time specifies an expiration time by which time to acquire an updated small cell PCI list.

19. The method of claim 12 , wherein searching the reduced number of PCIs is triggered when a primary cell's reference signal received power (RSRP) or reference signal received quality (RSRQ) falls below a specified threshold.

20. The method of claim 12 , wherein searching the reduced number of PCIs uses a reference signal received power (RSRP) or a reference signal received quality (RSRQ) derived from a reference signal (RS) selected from the group consisting of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and combinations thereof.

21. At least one non-transitory machine readable medium comprising a plurality of instructions adapted to be executed to implement the method of claim 12 .

22. A physical-layer cell identity (PCI) searching device for searching a reduced number of small cell PCI candidates in a search pool at a wireless device in a heterogeneous network (HetNet), comprising:
a downlink rec

Assignees

• Peng Yuefeng
• Zhang Yujian
• Etemad Kamran
• Zhu Yuan
• Fong Mo-Han
• Intel Corp

Inventors

• Peng Yuefeng
• Zhang Yujian
• Etemad Kamran
• Zhu Yuan
• Fong Mo-Han

Classifications

• H04W72/27

  between access points · CPC title

• H04W72/541

  using the level of interference · CPC title

• H04W72/20

  Control channels or signalling for resource management · CPC title

• H04W72/30

  Resource management for broadcast services · CPC title

• H04W72/23

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title