System and methods for increasing efficiency of a public land mobile network search in service acquisition on a multi-SIM wireless device

Patent metadata

Field	Value
Publication number	US-9319863-B2
Application number	US-201414248474-A
Country	US
Kind code	B2
Filing date	Apr 9, 2014
Priority date	Apr 9, 2014
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

Methods and devices are disclosed for enabling improved service acquisition on a first SIM of a multi-SIM wireless communication device. After the first SIM has lost service, the wireless device may detect a condition triggering a public mobile land network (PLMN) selection associated with the first SIM, receive an indication that service acquisition settings of the first SIM are set to a manual mode, and determine whether the second SIM is in idle mode. Upon determining that the second SIM is in idle mode, the wireless device may identify timing of a sleep cycle implemented by the second SIM, and perform the PLMN search using the first and second radio resources.

First claim

What is claimed is:

1. A method of improving service acquisition on a first subscriber identification module (SIM) of a multi-SIM wireless communication device having at least the first SIM associated with a first radio resource and a second SIM associated with a second radio resource, comprising:
detecting a condition triggering a public mobile land network (PLMN) selection associated with the first SIM;
receiving an indication that service acquisition settings of the first SIM are set to a manual mode;
determining whether a modem stack associated with the second SIM is in idle mode; and
in response to determining that the modem stack associated with the second SIM is in idle mode:
identifying timing of a power-saving mode cycle implemented by the modem stack associated with the second SIM; and
performing a PLMN search using the first and second radio resources.

2. The method of claim 1 , wherein performing the PLMN search using the first and second radio resources comprises:
determining whether the first SIM supports multiple radio access technologies; and
in response to determining that the first SIM supports multiple radio access technologies:
assigning frequencies associated with a first one of the multiple radio access technologies to the first radio resource; and
assigning frequencies associated with a second one of the multiple radio access technologies to the second radio resource.

3. The method of claim 2 , wherein performing the PLMN search using the first and second radio resources further comprises:
identifying frequencies associated with a single radio access technology supported by the first SIM in response to determining that the first SIM does not support multiple radio access technologies; and
determining whether the single radio access technology supported by the first SIM is also supported by the second SIM.

4. The method of claim 3 , wherein performing the PLMN search using the first and second radio resources further comprises:
assigning a first portion of the identified frequencies to the first radio resource and a second portion of the identified frequencies to the second radio resource in response to determining that the single radio access technology supported by the first SIM is also supported by the second SIM.

5. The method of claim 2 , further comprising:
scanning, by the first radio resource, frequencies associated with a first one of the multiple radio access technologies to identify channels that satisfy a signal strength threshold;
scanning, by the second radio resource during a sleep period of the power-saving mode cycle, frequencies associated with a second one of the multiple radio access technologies to identify channels that satisfy the signal strength threshold;
receiving a first group and a second group of identified PLMNs based on system information read from each channel identified by each of the first and second radio resource;
determining whether all assigned frequencies have been scanned;
generating a combined list of PLMNs based on the first and second groups of identified PLMNs in response to determining that all frequencies have been scanned; and
outputting the combined list of PLMNs.

6. The method of claim 1 , wherein performing the PLMN search using the first and second radio resources comprises:
scanning, by the first radio resource, a first set of assigned frequencies to identify channels that satisfy a signal strength threshold;
scanning, by the second radio resource during a sleep period of the power-saving mode cycle, a second set of assigned frequencies to identify channels that satisfy the signal strength threshold;
receiving a first group and a second group of identified PLMNs based on system information read from each identified channel in the respective first set and second set of assigned frequencies;
determining whether all frequencies in the first and second sets of assigned frequencies have been scanned;
generating a combined list of PLMNs based on the first and second groups of identified PLMNs in response to determining that all frequencies in the first and second sets of assigned frequencies have been scanned; and
outputting the combined list of PLMNs.

7. The method of claim 6 , further comprising:
determining whether the modem stack associated with the second SIM is exiting idle mode;
stopping the scanning of the second set of assigned frequencies by the second radio resource in response to determining that the modem stack associated with the second SIM is exiting idle mode;
identifying a completed portion of the second set of assigned frequencies already scanned by the second radio resource, wherein the received second group of identified PLMNs is based on the system information read from the identified channels in the completed portion of the second set of assigned frequencies; and
adding a remaining unsearched portion of the second set of assigned frequencies to the first set of assigned frequencies, wherein an updated first set of assigned frequencies is created.

8. The method of claim 7 , wherein scanning, by the first radio resource, the first set of assigned frequencies to identify frequency channels that satisfy a signal strength threshold comprises scanning the updated first set of assigned frequencies.

9. A wireless communication device, comprising:
a first radio resource associated with a first subscriber identification module (SIM);
a second radio resource associated with a second SIM; and
a processor coupled to the first and second SIMs and respective first and second radio resources, wherein the processor is configured to:
detect a condition triggering a public mobile land network (PLMN) selection associated with the first SIM;
receive an indication that service acquisition settings of the first SIM are set to a manual mode;
determine whether a modem stack associated with the second SIM is in idle mode; and
in response to determining that the modem stack associated with the second SIM is in idle mode:
identify timing of a power-saving mode cycle implemented by the modem stack associated with the second SIM; and
perform a PLMN search using the first and second radio resources.

10. The wireless communication device of claim 9 , wherein the processor is further configured to:
determine whether the first SIM supports multiple radio access technologies; and
in response to determining that the first SIM supports multiple radio access technologies:
assign frequencies associated with a first one of the multiple radio access technologies to the first radio resource; and
assign frequencies associated with a second one of the multiple radio access technologies to the second radio resource.

11. The wireless communication device of claim 10 , wherein the processor is further configured to:
identify frequencies associated with a single radio access technology supported by the first SIM in response to determining that the first SIM does not support multiple radio access technologies; and
determine whether the single radio access technology supported by the first SIM is also supported by the second SIM.

12. The wireless communication device of claim 11 , wherein the processor is further configured to:
assign a first portion of the identified frequencies to the first radio resource and a second portion of the identified frequencies to the second radio resource in response to determining that the single radio access technology supported by the first SIM is also supported by the second SIM.

13. The wireless communication device of claim 10 , wherein the processor is further configured to:
scan, by the first radio resourc

Assignees

• Qualcomm Inc

Inventors

• Peruru Praveen
• Sabapathi Karthikeyan
• Pulicherla Narendra

Classifications

• H04W60/005

  Multiple registrations, e.g. multihoming · CPC title

• H04W8/005 Primary

  Discovery of network devices, e.g. terminals · CPC title

• H04W88/06 Primary

  adapted for operation in multiple networks {or having at least two operational modes}, e.g. multi-mode terminals · CPC title

• H04W48/18

  Selecting a network or a communication service · CPC title

• H04W8/183

  Processing at user equipment or user record carrier · CPC title