Efficient reselections in the presence of closed subscriber group cells

• US 8,504,039 B2
• Filed: 10/26/2009
• Issued: 08/06/2013
• Est. Priority Date: 11/04/2008
• Status: Expired due to Fees

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility LLC (Lenovo Group Ltd.)
• Inventors: Narasimha, Murali, Krishnamurthy, Sandeep H, Kuchibhotla, Ravi
• Primary Examiner(s): PHAM, TIMOTHY X
• Application Number:
  US12/605,759
• Publication Number:
  US 20100113026A1
• Time in Patent Office: 1,380 Days
• Field of Search: 455/436, 455/63.1, 455/67.11, 455/444
• US Class Current: 455/436
• CPC Class Codes: H04W 36/0079 in case of hand-off failure or rejection
• CPC Class Codes: H04W 36/04 Reselecting a cell layer in multi-layered cells
• CPC Class Codes: H04W 36/20 for optimising the interference level
• CPC Class Codes: H04W 48/02 Access restriction performed under specific conditions
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal

Abstract

A mobile station and a method therein for avoiding interference to restricted access cells, including detecting presence of a restricted access cell, determining that a measured path-loss is larger than a path-loss threshold, determining that the mobile station is not allowed to access the restricted access cell, and barring a carrier frequency on which the restricted access cell is deployed when the measured path-loss is larger than the path-loss threshold and when the mobile station is not allowed access to the restricted access cell.

Claims

1. A mobile station for avoiding interference to restricted access cells, the mobile station comprising:

a wireless transceiver,

the mobile station configured to detect presence of a restricted access cell and to determine that the mobile station is not allowed to access the restricted access cell; and

the mobile station configured to determine that a measured path-loss of a serving cell signal is larger than a path-loss threshold and

to bar a carrier frequency on which the restricted access cell is deployed when the measured path-loss is larger than the path-loss threshold and when the mobile station is not allowed access to the restricted access cell;

wherein the mobile station is further configured to;

receive from the restricted access cell an indication that intra-frequency reselection is not allowed, and

bar the carrier frequency on which the restricted access cell is deployed when all of the following conditions are satisfied;

the measured path-loss is larger than the path-loss threshold,

the mobile station is not allowed access to the restricted access cell, and

an indication that intra-frequency reselection is not allowed is received.

2. The mobile station according to claim 1, wherein the mobile station is configured to receive the path-loss threshold from a serving cell.

3. The mobile station according to claim 1 wherein the mobile station is further configured to:

determine that the measured path-loss of the serving cell signal is not larger than the path-loss threshold, and

continue to operate on a carrier frequency on which the restricted access cell is deployed when the measured path-loss is not larger than the path-loss threshold.

4. The mobile station according to claim 1, wherein the mobile station is further configured to determine the measured path-loss based on a signal from a serving cell, wherein the serving cell and the restricted access cell share the carrier frequency.

5. The mobile station according to claim 1, wherein the mobile station is further configured to:

receive from the restricted access cell an indication that intra-frequency reselection is allowed, and

operate on the carrier frequency on which the restricted access cell is deployed when any one of the following conditions is satisfied;

the measured path-loss is not larger than the path-loss threshold,

the mobile station is allowed access to the restricted access cell,

an indication that intra-frequency reselection is allowed is received.

6. The mobile station according to claim 1, wherein the mobile station is further configured to determine the measured path-loss, wherein the measured path-loss is a transmit power of the serving cell signal minus a received power of the serving cell signal.

7. A method in a wireless communication device comprising:

receiving, at the wireless communication device, at least a path-loss threshold;

measuring path-loss from a serving base station;

determining whether the wireless communication device is allowed to access a restricted access cell detected by the wireless communication device;

reselecting to a different frequency or radio access technology in response to determining that the wireless communication device is not allowed to access the restricted access cell and that the measured path-loss from the serving base station is equal to or greater than the path-loss threshold;

receiving from the restricted access cell an indication of whether intra-frequency reselection is allowed; and

determining that the wireless communication device is required to reselect to a different frequency or radio access technology in response to determining that the wireless communication device is not allowed to access the restricted access cell, that the measured path-loss from the serving base station is equal to or greater than the path-loss threshold, and receiving an indication from the restricted access cell that intra-frequency reselection is not allowed.

8. The method according to claim 7, further comprising determining that the wireless communication device is not required to reselect to a different frequency or radio access technology in response to determining that the wireless communication device is not allowed to access the restricted access cell and that the measured path-loss from the serving base station is less than the path-loss threshold.

9. The method according to claim 7 determining that the wireless communication device is not required to reselect to a different frequency or radio access technology in response to determining that the wireless communication device is not allowed to access the restricted access cell and that the measured path-loss from the serving base station is equal to or greater than the path-loss threshold, and receiving an indication from the restricted access cell that intra-frequency reselection is allowed.