Cell selection and reselection for closed subscriber group cells

• US 9,973,994 B2
• Filed: 02/23/2017
• Issued: 05/15/2018
• Est. Priority Date: 03/24/2008
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Inventors: Somasundaram, Shankar, Wang, Peter S., Olvera-Hernandez, Ulises, Mukherjee, Rajat P.
• Primary Examiner(s): Pham, Chi H
• Assistant Examiner(s): Hom, Shick
• Application Number:
  US15/440,197
• Publication Number:
  US 20170164261A1
• Time in Patent Office: 446 Days
• Field of Search: None
• CPC Class Codes: H04J 11/0093 Neighbour cell search
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 36/302 due to low signal strength
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

Apparatuses and methods are provided for performing cell reselection. A method includes camping on a non-closed subscriber group (CSG) cell that is selected using frequency priorities; scanning other frequencies for non-CSG cells and CSG cells; detecting a CSG cell being a highest ranked cell on a frequency different than a frequency of the non-CSG cell that the WTRU is camped on; and selecting the detected CSG cell, being on a whitelist, and disregarding the frequency priorities in cell selection.

Claims

1. A wireless transmit/receive unit (WTRU) comprising:

a receiver and a processor configured to camp on a non-closed subscriber group (CSG) cell that is selected using frequency priorities;

the receiver and the processor are further configured to scan other frequencies for non-CSG cells and CSG cells;

the receiver and the processor are further configured to detect a CSG cell being a highest ranked cell on a frequency different than a frequency of the non-CSG cell that the WTRU is camped on; and

the receiver and the processor are further configured to select the detected CSG cell, being the highest ranked cell on the frequency different than the frequency of the non-CSG cell, and disregard the frequency priorities in cell selection, wherein the detected CSG cell is on a whitelist.

2. The WTRU of claim 1, wherein the receiver and the processor are configured to only camp on CSG cells on a whitelist.

3. The WTRU of claim 1, wherein the receiver and the processor are configured to camp on a public CSG cell regardless of being on the whitelist.

4. The WTRU of claim 1, wherein the receiver and the processor are configured to determine a highest ranked CSG cell based on a received power level of detected cells.

5. A method comprising:

camping, by a wireless transmit/receive unit (WTRU), on a non-closed subscriber group (CSG) cell that is selected using frequency priorities;

scanning, by the WTRU, other frequencies for non-CSG cells and CSG cells;

detecting, by the WTRU, a CSG cell being a highest ranked cell on a frequency different than a frequency of the non-CSG cell that the WTRU is camped on; and

selecting, by the WTRU, the detected CSG cell, being the highest ranked cell on the frequency different than the frequency of the non-CSG cell, and disregarding the frequency priorities in cell selection, wherein the detected CSG cell is on a whitelist.

6. The method of claim 5, wherein the WTRU only camps on CSG cells on a whitelist.

7. The method of claim 5, wherein the WTRU camps on a public CSG cell regardless of being on the whitelist.

8. The method of claim 5, further comprising:

determining, by the WTRU, a highest ranked CSG cell based on a received power level of detected cells.

9. A wireless transmit/receive unit (WTRU) comprising:

a receiver and a processor configured to camp on a closed subscriber group (CSG) cell, wherein the processor uses frequency priorities in cell selection; and

the receiver and the processor are further configured, on a condition that the WTRU is camped on the CSG cell, to treat frequencies having a higher priority than a frequency of the CSG cell as having a lower priority than the frequency of the CSG cell, wherein the CSG cell is on a whitelist.

10. The WTRU of claim 9, wherein the receiver and the processor are further configured to on a condition that a camped on cell is not a CSG cell, to reselect cells based on the frequency priority.

11. The WTRU of claim 9, wherein the receiver and the processor are configured to only camp on CSG cells on a whitelist.

12. The WTRU of claim 9, wherein the receiver and the processor are configured to camp on a public CSG cell regardless of being on the whitelist.

13. The WTRU of claim 9, wherein the receiver and the processor are configured to select a cell based on a received power level of detected cells.

14. A method comprising:

camping, by a wireless transmit/receive unit (WTRU), on a closed subscriber group (CSG) cell, wherein the WTRU uses frequency priorities in cell selection; and

on a condition that the WTRU is camped on the CSG cell, treating, by the WTRU, frequencies having a higher priority than a frequency of the CSG cell as having a lower priority than the frequency of the CSG cell, wherein the CSG cell is on a whitelist.

15. The method of claim 14, further comprising:

on a condition that a camped on cell is not a CSG cell, reselecting cells, by the WTRU, based on the frequency priority.

16. The method of claim 14, further comprising:

only camping, by the WTRU, on CSG cells on a whitelist.

17. The method of claim 14, further comprising:

camping on a public CSG cell regardless of being on the whitelist.

18. The method of claim 14, further comprising:

selecting, by the WTRU, a cell based on a received power level of detected cells.