Method and apparatus for effectively controlling cell reselection priority of user equipment in CSG cell

• US 9,432,927 B2
• Filed: 04/10/2012
• Issued: 08/30/2016
• Est. Priority Date: 04/11/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Sangbum, Kim, Soenghun, Jeong, Kyeongin
• Primary Examiner(s): Jain, Ankur
• Application Number:
  US13/443,199
• Publication Number:
  US 20120258750A1
• Time in Patent Office: 1,603 Days
• Field of Search: 455/525
• US Class Current: 1/1
• CPC Class Codes: H04W 12/02 Protecting privacy or anonymity, e.g. protecting personally identifiable information [PII]
• CPC Class Codes: H04W 12/037 of the control plane, e.g. signalling traffic
• CPC Class Codes: H04W 12/10 Integrity
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 36/0083 Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
• CPC Class Codes: H04W 36/04 Reselecting a cell layer in multi-layered cells
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0254 detecting a user operation or a tactile contact or a motion of the device
• CPC Class Codes: H04W 72/56 based on priority criteria
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B
• CPC Class Codes: H04W 92/00 Interfaces specially adapted for wireless communication networks
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method by which a User Equipment (UE) controls a cell reselection priority in a Closed Subscriber Group (CSG) cell and an apparatus thereof are provided. The method of reselecting a cell by a UE in a mobile communication system includes receiving priority information about a cell reselection priority by frequencies transmitted from the mobile communication system, performing a cell reselection process according to the received priority information, determining whether a CSG cell to which the UE is allowed to connect is reselected, and assigning a highest cell reselection priority to a frequency for the CSG cell in reselecting the CSG cell.

Claims

1. A method of reselecting a cell by a user equipment (UE) in a mobile communication system, the method comprising:

receiving system information including first priority information for cell reselection;

if second priority information is in dedicated signaling, ignoring the first priority information provided in the system information;

while the UE is camped on a suitable closed subscriber group (CSG) cell, considering a current frequency to be a highest priority frequency for cell reselection irrespective of the first priority information and the second priority information,

deleting the second priority information provided by a dedicated signaling if the UE enters a radio resource control connected (RRC CONNECTED) state, or if a T320 timer expires, or a public land mobile network (PLMN) selection is performed on request by non-access stratum (NAS).

2. The method of claim 1, further comprising:

if the UE is on any cell state, applying the first priority information provided by the system information,

wherein the any cell state indicates that the UE camps on any cell.

3. The method of claim 1, further comprising:

if the UE in camped normally state has only the second priority information provided by a dedicated signaling, considering a current frequency to be the lowest priority frequency.

4. The method of claim 1, further comprising:

if reselecting another cell except for the CSG cell, assigning a lowest cell reselection priority to a frequency for the CSG cell.

5. A user equipment (UE) for reselecting a cell in a mobile communication system, the UE comprising:

a transceiver configured to control for transmitting and receiving a signal or data to and from a base station; and

a controller configured to;

control for receiving system information including first priority information for cell reselection,

control for ignoring the first priority information provided in the system information if second priority information is in dedicated signaling, and

while the UE is camped on a suitable Closed Subscriber Group (CSG) cell, consider a current frequency to be a highest priority frequency for cell reselection irrespective of the first priority information and the second priority information,

wherein the controller is configured to control to delete the second priority information provided by a dedicated signaling if the UE enters a radio resource control connected (RRC CONNECTED) state, or if a T320 timer expires, or a public land mobile network (PLMN) selection is performed on request by non-access stratum (NAS).

6. The UE of claim 5, wherein the controller is configured to control for applying the first priority information provided by the system information if the UE is on any cell state, and

wherein the any cell state indicates that the UE camps on any cell.

7. The UE of claim 5, wherein the controller is configured to control for considering a current frequency to be the lowest priority frequency if the UE in camped normally state has only the second priority information provided by a dedicated signaling.

8. The UE of claim 5, wherein the controller is configured to control for assigning a lowest cell reselection priority to a frequency for the CSG cell if reselecting another cell except for the CSG cell.