Determining a target cell under cell identifier confusion during handovers at a base station

Patent metadata

Field	Value
Publication number	US-2016234733-A1
Application number	US-201514617778-A
Country	US
Kind code	A1
Filing date	Feb 9, 2015
Priority date	Feb 9, 2015
Publication date	Aug 11, 2016
Grant date	—

Abstract

The present disclosure presents a method and an apparatus for determining a target cell that is under cell identifier confusion during handovers at a small cell. For example, the disclosure presents a method that includes detecting that a target cell confusion exists at a source small cell for a target physical cell identity (PCI) during a handover of a user equipment (UE) from the source small cell to a target small cell, comparing PCI information reported by the UE during the handover with PCI information of neighbors of each of the plurality of neighboring small cells with the same PCI value, determining whether the target small cell has been identified based at least on the PCI comparison, and performing the handover of the UE from the source small cell to the target small cell. As such, a target cell may be determined.

First claim

What is claimed is:

1 . A method for determining a target cell that is under physical cell identity (PCI) confusion during handovers at a small cell, comprising:
detecting that a target cell confusion exists at a source small cell for a target PCI during a handover of a user equipment (UE) from the source small cell to a target small cell, wherein the target small cell is one of a plurality of neighboring small cells with a same PCI value; comparing PCI information reported by the UE during the handover with PCI information of neighbors of each of the plurality of neighboring small cells with the same PCI value; determining whether the target small cell has been identified based at least on the PCI comparison; and performing the handover of the UE from the source small cell to the target small cell in response to determining that the target small cell has been identified.

2 . The method of claim 1 , further comprising:
comparing reference signal (RS) energy measurements received from the UE with reference energy patterns (REPs) of the plurality of neighboring small cells with the same PCI value in response to determining that the target small cell has not been identified based at least on the PCI comparison; determining the target small cell based at least on the comparing of the RS energy measurements with the REPs; and performing the handover of the UE from the source small cell to the determined target small cell.

3 . The method of claim 2 , wherein the RS energy measurements and REPs include RS received power (RSRP) and RS received quality (RSRQ) measurements of the source small cell, the plurality of neighboring small cells, and neighbors of the plurality of neighboring small cells.

4 . The method of claim 2 , further comprising:
storing the REPs of the plurality of neighboring small cells at the source small cell; and comparing the RS energy measurements received from the UE with the stored REPs of the plurality of neighboring small cells with the same PCI value giving preference to a closest REP.

5 . The method of claim 2 , further comprising:
storing the REPs of the plurality of neighboring small cells with a location and a timestamp at the source small cell; and comparing the RS energy measurements received from the UE with the stored REPs of the plurality of neighboring small cells with the target PCI value giving preference to a most recent and a closest REP that is stored at the source small cell.

6 . The method of claim 2 , wherein the PCI information and the REPs of each of the plurality of neighboring small cells are stored in a neighbor relation table (NRT) at the source small cells.

7 . A non-transitory computer readable medium storing computer executable code for determining a target cell that is under physical cell identity (PCI) confusion during handovers at a small cell, comprising:
code for detecting that target cell confusion exists at a source small cell for a target PCI during a handover of a user equipment (UE) from the source small cell to a target small cell, wherein the target small cell is one of a plurality of neighboring small cells with a same PCI value; code for comparing PCI information reported by the UE during the handover with PCI information of neighbors of each of the plurality of neighboring small cells with the same PCI value; code for determining whether the target small cell has been identified based at least on the PCI comparison; and code for performing the handover of the UE from the source small cell to the target small cell in response to determining that the target small has been identified.

8 . The computer readable medium of claim 7 , further comprising:
code for comparing reference signal (RS) energy measurements received from the UE with reference energy patterns (REPs) of the plurality of neighboring small cells with the same PCI value in response to determining that the target small cell has not been identified based at least on the PCI comparison; code for determining the target cell based at least on the comparing of the RS energy measurements with the REPs; and code for performing the handover of the UE from the source small cell to the determined target cell.

9 . The computer readable medium of claim 8 , wherein the RS energy measurements and REPs include RS received power (RSRP) and RS received quality (RSRQ) measurements of the source small cell, the plurality of neighboring small cells, and neighbors of the plurality of neighboring small cells.

10 . The computer readable medium of claim 8 , further comprising:
code for storing the REPs of the plurality of neighboring small cells at the source small cell, and code for comparing the RS energy measurements received from the UE with the stored REPs of the plurality of neighboring small cells with the same PCI value giving preference to a closest REP that is stored at the source small cell.

11 . The computer readable medium of claim 8 , further comprising:
code for storing the REPs of the plurality of neighboring small cells with a location and a timestamp at the source small cell; and code for comparing the RS energy measurements received from the UE with the stored REPs of the plurality of neighboring small cells with the same PCI value giving preference to a most recent and a closest REP that is stored at the source small cell.

12 . The computer readable medium of claim 8 , wherein the PCI information of neighbors and REPs of each of the neighboring small cells are stored in a neighbor relation table (NRT) at the source small cells.

13 . An apparatus for determining a target cell that is under physical cell identity (PCI) confusion during handovers at a small cell, comprising:
a PCI confusion detecting component to detect that a target cell confusion exists at a source small cell for a target PCI during a handover of a user equipment (UE) from the source small cell to a target small cell, wherein the target small cell is one of a plurality of neighboring small cells with the same PCI value; a PCI information comparing component to compare PCI information reported by the UE during the handover with PCI information of neighbors of each of the plurality of neighboring small cells with the same PCI value; a target cell determining component to determine whether the target small cell has been identified based at least on the PCI comparison; and a handover performing component to perform the handover of the UE from the source small cell to the target small cell in response to determining that the target small cell has been identified.

14 . The apparatus of claim 13 , further comprising:
an energy comparing component to compare reference signal (RS) energy measurements received from the UE with reference energy patterns (REPs) of the plurality of neighboring small cells with the same PCI value in response to determining that the target small cell has not been identified based at least on the PCI comparison; the target cell determining component further configured to determine the target cell based at least on the comparing of the RS energy measurements with the REPs; and the handover performing component further configured to perform the handover performing the handover of the UE from the source small cell to the determined target cell.

15 . The apparatus of claim 14 , wherein the RS energy measurements and REPs include RS received power (RSRP) and RS received quality (RSRQ) measurements of the source small cell, the plurality of neighboring small cells and neighbors of the plurality of neighboring small cells.

16 . The apparat

Assignees

• Qualcomm Inc

Inventors

• Sasanapuri Mohana Rao
• RAGHAVENDRA Pravin
• Vanjari Srinivas

Classifications

• H04W36/0061 Primary

  of neighbour cell information · CPC title

• H04W36/00835

  Determination of neighbour cell lists · CPC title

• H04W36/0085

  Hand-off measurements · CPC title