Scheduling prioritized network searches for a multi-mode communication device

• US 9,253,714 B2
• Filed: 09/04/2013
• Issued: 02/02/2016
• Est. Priority Date: 09/04/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Lou, Wenping, Zhao, Wen
• Primary Examiner(s): Brandt, Christopher M
• Application Number:
  US14/018,326
• Publication Number:
  US 20140066061A1
• Time in Patent Office: 881 Days
• Field of Search: 455/434, 455/422.1, 455/63.2, 455/450, 455/524, 455/525, 455/62, 455/161.1, 455/423, 455/424, 455/425, 455/426.1, 455/426.2, 455/436, 455/432.2, 455/432.3, 455/433, 455/435.1, 455/444, 455/435.2, 455/435.3, 370/329, 370/350, 370/208, 370/315, 370/319, 370/341, 370/342, 370/331, 370/332, 370/235, 370/236
• US Class Current: 1/1
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information

Abstract

A multi-mode communication device having a scan optimizer capable of prioritizing scan frequencies for different radio access technologies (RATs) during a network search. The scan frequency prioritization may be based on various network coverage considerations associated with RAT availability, RAT density within a region, geographic location, historic attachment for the multi-mode device, an operation mode of the multi-mode device, etc. The multimode device can utilize its scan optimizer to generate an optimized scan schedule to be employed for a limited duration during a network search to improve its likelihood of success in detecting and/or attaching to a network associated with a prioritized RAT. A default scan schedule having equal scan frequency prioritization can be employed by the multi-mode device at a time when the limited duration of the optimized scan schedule expires and no networks associated with a prioritized RAT have been acquired.

Claims

1. A method for scheduling a network search for a multi-mode communication device, the method comprising:

identifying one or more network coverage considerations for the multi-mode communication device;

generating a prioritized scan schedule including information associated with a plurality of frequency resources to scan during the network search based at least in part on the identified one or more network coverage considerations;

in accordance with the prioritized scan schedule, scanning a first frequency of the plurality of frequency resources more often than a second frequency of the plurality of frequency resources during a limited duration of a first scanning interval of the network search,

wherein the first frequency of the plurality of frequency resources is associated with a first radio access technology (RAT) and the second frequency of the plurality of frequency resources is associated with a second RAT;

in response to determining that the limited duration of the first scanning interval has expired, employing a default scan schedule during a second scanning interval of the network search; and

in accordance with the default scan schedule, scanning the first frequency of the plurality of frequency resources equally with the second frequency of the plurality of frequency resources during the second scanning interval of the network search.

2. The method of claim 1, wherein the identified one or more network coverage considerations are associated with an operation mode of the multi-mode communication device being in a connected mode, an idle mode, a sleep mode, a registered mode, or an unregistered mode.

3. The method of claim 1, further comprising generating the prioritized scan schedule in response to determining that the multi-mode communication device has disconnected from a wireless network associated with the first RAT,

wherein the multi-mode communication device attempts to reacquire the wireless network associated with the first RAT by prioritizing scanning of the first frequency over other frequencies of the plurality of frequencies resources, including the second frequency.

4. The method of claim 1, further comprising generating the prioritized scan schedule in response to determining that the multi-mode communication device is not registered with a wireless network,

wherein the multi-mode communication device attempts to acquire a wireless network associated with the first RAT by prioritizing scanning of the first frequency over other frequencies of the plurality of frequencies resources, including the second frequency.

5. The method of claim 1, wherein the first RAT is associated with fourth generation (4G) Long Term Evolution (LTE) or LTE Advanced, and wherein the second RAT is a third generation (3G) legacy RAT that is associated with Universal Mobile Telecommunications System (UMTS) or Code Division Multiple Access 2K (CDMA 2000).

6. The method of claim 5, further comprising:

in accordance with the prioritized scan schedule, scanning a third frequency of the plurality of frequency resources more often than the second frequency of the plurality of frequency resources during the first scanning interval of the network search based at least in part on the identified one or more network coverage considerations,

wherein the third frequency of the plurality of frequency resources is associated with a second generation (2G) legacy RAT that is associated with Global Systems for Mobile (GSM).

7. The method of claim 5, further comprising:

in accordance with the prioritized scan schedule, scanning the first frequency of the plurality of frequency resources more often than a third frequency of the plurality of frequency resources during the first scanning interval of the network search based at least in part on the identified one or more network coverage considerations,

wherein the third frequency of the plurality of frequency resources is associated with a second generation (2G) legacy RAT that is associated with Global Systems for Mobile (GSM).

8. A multi-mode communication device comprising:

a one or more transceivers associated with a plurality of radio access technologies (RATs);

processing circuitry coupled to the one or more transceivers; and

at least one memory coupled to the processing circuitry,

wherein the processing circuitry is configured to execute computer program instructions to cause the multi-mode communication device to;

generate a prioritized scan schedule including information associated with a plurality of frequency resources to be scanned during a network search based at least in part on one or more network coverage considerations;

in accordance with the prioritized scan schedule, scan at least two frequencies of the plurality of frequency resources to attempt to acquire a first high priority network associated with a first RAT of the plurality of RATs before a lower priority network associated with a second RAT of the plurality of RATs during a limited duration of a first scanning interval of the network search; and

in response to determining that the limited duration of the first scanning interval has expired, employ a default scan schedule during a second scanning interval of the network search,

wherein employing the default scan schedule causes the multi-mode communication device to scan the at least two frequencies of the plurality of frequency resources equally to attempt to acquire a network associated with any of the plurality of RATs.

9. The multi-mode communication device of claim 8, wherein the scan of the at least two frequencies of the plurality of frequency resources during the limited duration of the first scanning interval scans for the first high priority network associated with the first RAT more often than the lower priority network associated with the second RAT.

10. The multi-mode communication device of claim 8, wherein the limited duration of the first scanning interval of the network search is based at least in part on a relevance of the one or more network coverage considerations.

11. The multi-mode communication device of claim 10, wherein the one or more network coverage considerations are associated with a RAT density within a region, a geographic location, and/or an operational mode of the multi-mode communication device.

12. The multi-mode communication device of claim 8, wherein the first RAT is associated with fourth generation (4G) Long Term Evolution (LTE) or LTE Advanced, and wherein the second RAT is a third generation (3G) legacy RAT that is associated with Universal Mobile Telecommunications System (UMTS) or Code Division Multiple Access 2K (CDMA 2000).

13. The multi-mode communication device of claim 8, wherein the processing circuitry is further configured to execute computer program instructions to cause the multi-mode communication device to:

in accordance with the prioritized scan schedule, scan the at least two frequencies of the plurality of frequency resources to attempt to acquire a second high priority network associated with a third RAT of the plurality of RATs before the lower priority network associated with a second RAT during the network search.

14. The multi-mode communication device of claim 13, wherein the processing circuitry is further configured to execute computer program instructions to cause the multi-mode communication device to:

in accordance with the prioritized scan schedule, scan the at least two frequencies of the plurality of frequency resources to attempt to acquire the first high priority network associated with the first RAT before the second high priority network associated with the third RAT during the network search.

15. A non-transitory computer-readable storage medium storing executable instructions that, when executed by one or more processors of a multi-mode communication device, cause the multi-mode communication device to:

generate a prioritized scan schedule including information associated with a plurality of frequency resources to scan during a network search based at least in part on one or more network coverage considerations;

in accordance with the prioritized scan schedule, scan at least two frequencies of the plurality of frequency resources to attempt to acquire a high priority network associated with a first radio access technology (RAT) of a plurality of RATs before a lower priority network associated with a second RAT of the plurality of RATs during a limited duration of a first scanning interval of the network search; and

in response to determining that the limited duration of the first scanning interval has expired, employ a default scan schedule during a second scanning interval of the network search,

wherein employing the default scan schedule causes the multi-mode communication device to scan the at least two frequencies of the plurality of frequency resources equally to attempt to acquire a network associated with any of the plurality of RATs.

16. The non-transitory computer-readable storage medium of claim 15, wherein the scan of the at least two frequencies of the plurality of frequency resources during the limited duration of the first scanning interval scans for the high priority network associated with the first RAT more often than the lower priority network associated with the second RAT during the network search.

17. The non-transitory computer-readable storage medium of claim 15, wherein the limited duration of the first scanning interval of the network search is based at least in part on a relevance of an identified one or more network coverage considerations that are associated with a RAT density within a region, a geographic location, and/or an operational mode of the multi-mode communication device.

18. The non-transitory computer-readable storage medium of claim 15, wherein employing the default scan schedule causes the multi-mode communication device to scan the at least two frequencies of the plurality of frequency resources equally to attempt to acquire a network associated with any of the plurality of RATs in an unbiased manner.