Station and method for LTE only attach optimization

• US 11,356,837 B2
• Filed: 05/11/2017
• Issued: 06/07/2022
• Est. Priority Date: 09/22/2016
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Mbonye, Gahima S., Venkataraman, Vijay, Nimmala, Srinivasan, Elangovan, Thanigaivelu, Ai-Khudairi, Abdul-Munem, Goyal, Anish K., Rivera-Barreto, Rafael L., Zhu, Yifan, Booth, Ryan, Kavuri, Lakshmi, Manepalli, Venkateswara Rao
• Primary Examiner(s): Manoharan, Muthuswamy G
• Application Number:
  US15/592,980
• Publication Number:
  US 20180084401A1
• Time in Patent Office: 1,853 Days
• CPC Class Codes: H04W 48/12 using downlink control channel
• 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 8/02 Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks
• CPC Class Codes: H04W 8/06 Registration at serving network Location Register, VLR or user mobility server
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A method performed by a station that includes receiving information from a cell of a Public Land Mobile Network (PLMN), determining whether the information indicates the cell supports circuit switched fallback (CSFB) voice calls, when the CSFB voice calls are not supported, determining whether at least one packet switched voice property of the station satisfies a predetermined condition and attaching to the cell of the PLMN when the predetermined condition is satisfied. A further method performed by a station connected to a PLMN that includes identifying cells of the PLMN available for the station to camp on, determining whether the station is capable of executing packet switched calls, when the station is not capable of executing packet switched calls, determining whether the identified cells have a neighbor cell that supports CSFB voice calls and prioritizing the cells that are identified as having neighbor cells that support CSFB voice calls.

Claims

1. A method comprising:

at a station;

receiving information from a cell of a Public Land Mobile Network (PLMN);

identifying that-the information indicates circuit switched fallback (CSFB) voice calls are not supported by the PLMN;

determining whether at least one packet switched voice property of the station satisfies a predetermined condition, wherein a roaming agreement and partner agreements for the PLMN are stored at the station, wherein the partner agreements prohibit a roaming station from using VoLTE services;

when the at least one packet switched voice property satisfies the predetermined condition, selecting the PLMN based on identifying that CSFB voice calls are not supported by the PLMN; and

attaching to the cell of the PLMN based on selecting the PLMN.

2. The method of claim 1, wherein the information is received in a System Information Block (SIB) transmitted by the cell, wherein the SIB is one of SIB 1, SIB 6, SIB 7 or SIB 8.

3. The method of claim 1, further comprising:

searching for an alternative PLMN when the at least one packet switched voice property fails to satisfy the predetermined condition.

4. The method of claim 3, further comprising:

de-prioritizing the PLMN when the at least one packet switched voice property fails to satisfy the predetermined condition such that when the station performs a subsequent PLMN search, the PLMN will not be searched until after other non-deprioritized PLMNs are searched.

5. The method of claim 1, wherein the at least one packet switched voice property comprises whether the station is packet switched voice capable.

6. The method of claim 1, wherein the at least one packet switched voice property comprises whether the station is packet switched voice enabled.

7. The method of claim 1, wherein the at least one packet switched voice property comprises whether a carrier configuration profile of the station is packet switched voice enabled.

8. The method of claim 1, wherein the at least one packet switched voice property comprises whether the PLMN is a roaming network and the roaming agreement allows for packet switched voice calls on the roaming network.

9. The method of claim 1, wherein the at least one packet switched voice property is a VoLTE property.

10. The method of claim 1, wherein the method is initiated by one of the station booting up, an airplane mode setting of the station being turned off, a packet switched voice setting in the station being toggled, or the station leaving boundaries of a previously attached to PLMN.

11. The method of claim 1, further comprising:

determining whether CSFB voice calls are supported by a first type of radio access network; and

only when it is determined that CSFB voice calls are not supported by the first type of radio access network, determining whether CSFB voice calls are supported by a second type of radio access network.

12. The method of claim 1, wherein the at least one packet switched voice property comprises one of whether the station is packet switched voice capable, whether the station is packet switched voice enabled, whether a carrier configuration profile of the station is packet switched voice enabled, or whether the PLMN is a roaming network and the roaming agreement allows for packet switched voice calls on the roaming network.

13. A station, comprising:

a transceiver; and

a processor configured to execute instructions, wherein the instructions cause the processor to perform operations comprising;

receiving information from a cell of a Public Land Mobile Network (PLMN);

identifying that the information indicates circuit switched fallback (CSFB) voice calls are not supported by the PLMN;

determining whether at least one VoLTE property of the station satisfies a predetermined condition, wherein a roaming agreement and partner agreements of the PLMN are stored at the station, wherein the partner agreements prohibit a roaming station from using VoLTE services; and

when the at least one VoLTE property satisfies the predetermined condition, selecting the PLMN based on identifying that CSFB voice calls are not supported by the PLMN; and

causing the station to attach to the cell of the PLMN based on selecting the PLMN.

14. The station of claim 13, wherein the information is received in a System Information Block (SIB) transmitted by the cell, wherein the SIB is one of SIB 1, SIB 6, SIB 7 or SIB 8.

15. The station of claim 13, wherein the operations further comprise:

searching for an alternative PLMN when the at least one packet switched voice property fails to satisfy the predetermined condition; and

de-prioritizing the PLMN when the at least one packet switched voice property fails to satisfy the predetermined condition such that when the station performs a subsequent PLMN search, the PLMN will not be searched until after other non-deprioritized PLMNs are searched.

16. A method comprising:

at a station connected to a Public Land Mobile Network (PLMN);

identifying a plurality of cells of the PLMN that are available for the station to camp on;

determining whether the station is capable of executing packet switched calls;

when the station is not capable of executing packet switched calls, determining whether each of the plurality of cells of the PLMN have a neighbor cell that supports circuit switched fallback (CSFB) voice calls;

when at least one of the plurality of cells of the PLMN are determined to have the neighbor cell that supports CSFB voice calls, prioritizing the at least one of the plurality of cells of the PLMN; and

when no cells of the plurality of cells of the PLMN are determined to have the neighbor cell that supports CSFB voice calls, performing or re-performing a different method of intelligent cell selection depending on whether a new cell is identified by the station prior to or after camping on the PLMN.

17. The method of claim 16, wherein the determining whether each of the plurality of cells of the PLMN have the neighbor cell that supports circuit switched fallback (CSFB) voice calls is based on System Information Blocks (SIBs) received from each of the identified plurality of cells of the PLMN.

18. The method of claim 16, when at least one of the plurality of cells of the PLMN are determined to have the neighbor cell that supports CSFB voice calls, any of the plurality of cells of the PLMN that are determined not to have the neighbor cell that supports CSFB voice calls are not available for camping.

19. The method of claim 16, wherein the at least one of the plurality of cells of the PLMN are further prioritized based on at least one of a quality of service metric, a transmit power metric and a data throughput metric.

20. The method of claim 16, further comprising:

when no cells of the plurality of cells of the PLMN are determined to have the neighbor cell that supports CSFB voice calls, camping on one of the plurality of cells of the PLMN; and

when a new cell of the PLMN is identified by the station, re-performing the method.