U.S. patent application number 14/717536 was filed with the patent office on 2016-11-24 for out-of-service scanning for multi-sim devices.
The applicant listed for this patent is Apple Inc.. Invention is credited to Sang Ho Baek, Madhusudan Chaudhary, Harshit Chuttani, Thanigaivelu Elangovan, Someet K. Lal, Li Su.
Application Number | 20160345245 14/717536 |
Document ID | / |
Family ID | 57211110 |
Filed Date | 2016-11-24 |
United States Patent
Application |
20160345245 |
Kind Code |
A1 |
Chuttani; Harshit ; et
al. |
November 24, 2016 |
Out-of-Service Scanning for Multi-SIM Devices
Abstract
Apparatuses, systems, and methods for multi-SIM user equipment
(UE) devices to search for service. A UE may determine that a first
SIM of the UE is out-of-service. The UE may scan for service for
the first SIM of the UE using a second SIM of the UE. An indication
may be provided to the first SIM if service (or service
information) is found for the first SIM. If the second SIM is also
out-of-service, the UE may scan for service for the first SIM and
the second SIM jointly.
Inventors: |
Chuttani; Harshit; (Newark,
CA) ; Su; Li; (San Jose, CA) ; Chaudhary;
Madhusudan; (Campbell, CA) ; Baek; Sang Ho;
(Palo Alto, CA) ; Lal; Someet K.; (Fremont,
CA) ; Elangovan; Thanigaivelu; (Santa Clara,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Apple Inc. |
Cupertino |
CA |
US |
|
|
Family ID: |
57211110 |
Appl. No.: |
14/717536 |
Filed: |
May 20, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
Y02D 70/1242 20180101;
Y02D 70/164 20180101; H04W 88/06 20130101; H04W 4/025 20130101;
Y02D 30/70 20200801; Y02D 70/26 20180101; Y02D 70/1264 20180101;
Y02D 70/144 20180101; Y02D 70/168 20180101; Y02D 70/23 20180101;
Y02D 70/142 20180101; H04W 52/0225 20130101; H04W 48/16 20130101;
Y02D 70/1262 20180101 |
International
Class: |
H04W 48/16 20060101
H04W048/16; H04W 4/02 20060101 H04W004/02; H04W 52/02 20060101
H04W052/02; H04L 29/08 20060101 H04L029/08 |
Claims
1-15. (canceled)
16. A non-transitory computer accessible memory medium, comprising
program instructions for a wireless user equipment (UE) device
that, when executed by the UE device, cause the UE to: determine
that both a first subscriber identity module (SIM) of the UE device
and a second SIM of the UE device are out-of-service (OOS); align
service scanning timing for the first SIM and the second SIM; merge
frequency scanning lists for the first SIM and the second SIM to
produce a merged frequency scanning list; and perform service
scanning for both the first SIM and the second SIM using the merged
frequency scanning list according to the aligned service scanning
timing.
17. The memory medium of claim 16, wherein service scanning for
both the first SIM and the second SIM is performed by one of the
first SIM or the second SIM, wherein the other of the first SIM or
the second SIM operates in a low power state while the service
scanning for both the first SIM and the second SIM is
performed.
18. The memory medium of claim 17, wherein when executed, the
program instructions further cause the UE to: activate the SIM
operating in the low power state if service information is
discovered for the SIM operating in the low power state.
19. The memory medium of claim 16, wherein when executed, the
program instructions further cause the UE to: perform system
selection for one or both of the first SIM or the second SIM based
on the service scanning for both the first SIM and the second
SIM.
20. The memory medium of claim 16, wherein performing service
scanning for both the first SIM and the second SIM is also based at
least in part on one or more of a location of the UE or motion
detection of the UE.
21. The memory medium of claim 16, wherein the program instructions
are further executable to: scan, using the first SIM of the UE, for
service for the second SIM of the UE; provide, by the first SIM of
the UE, an indication to the second SIM of the UE if service is
found for the second SIM of the UE.
22. The memory medium of claim 21, wherein said scanning and
providing is performed while the second SIM is OOS and the first
SIM is in service.
23. A method, comprising: at a user equipment (UE): determining
that both a first subscriber identity module (SIM) of the UE device
and a second SIM of the UE device are out-of-service (OOS);
aligning service scanning timing for the first SIM and the second
SIM; performing service scanning, by the second SIM of the UE, for
both the first SIM and the second SIM according to the aligned
service scanning timing; and providing, by the second SIM of the
UE, an indication to the first SIM of the UE if service is found
for the first SIM of the UE.
24. The method of claim 23, wherein the first SIM operates in a low
power state while the service scanning for both the first SIM and
the second SIM is performed.
25. The method of claim 24, further comprising: activating the
first SIM operating in the low power state if service is found for
the first SIM operating in the low power state.
26. The method of claim 23, further comprising: performing system
selection for one or both of the first SIM or the second SIM based
on the service scanning for both the first SIM and the second
SIM.
27. The method of claim 23, wherein performing service scanning for
both the first SIM and the second SIM is also based at least in
part on one or more of a location of the UE or motion detection of
the UE.
28. The method of claim 23, further comprising: scanning, using the
first SIM of the UE, for service for the second SIM of the UE;
providing, by the first SIM of the UE, an indication to the second
SIM of the UE if service is found for the second SIM of the UE.
29. The method of claim 28, wherein said scanning and providing is
performed while the second SIM is OOS and the first SIM is in
service.
30. An apparatus, comprising: one or more processing elements,
wherein the one or more processing elements are configured for dual
subscriber identity module (SIM) operation, wherein the one or more
processing elements are configured to: determine that both a first
subscriber identity module (SIM) of the UE device and a second SIM
of the UE device are out-of-service (OOS); merge frequency scanning
lists for the first SIM and the second SIM to produce a merged
frequency scanning list; perform, by the second SIM, service
scanning for both the first SIM and the second SIM using the merged
frequency scanning list; and provide, by the second SIM of the UE,
an indication to the first SIM of the UE if service is found for
the first SIM of the UE.
31. The UE of claim 30, wherein the first SIM operates in a low
power state while the service scanning for both the first SIM and
the second SIM is performed.
32. The UE of claim 31, wherein the one or more processing elements
are further configured to: activate the first SIM operating in the
low power state if service is found for the first SIM operating in
the low power state.
33. The UE of claim 30, wherein the one or more processing elements
are further configured to: perform system selection for one or both
of the first SIM or the second SIM based on the service scanning
for both the first SIM and the second SIM.
34. The UE of claim 30, wherein performing service scanning for
both the first SIM and the second SIM is also based at least in
part on one or more of a location of the UE or motion detection of
the UE.
35. The UE of claim 30, wherein the one or more processing elements
are further configured to: scan, using the first SIM of the UE, for
service for the second SIM of the UE; provide, by the first SIM of
the UE, an indication to the second SIM of the UE if service is
found for the second SIM of the UE.
Description
FIELD
[0001] The present application relates to wireless devices,
including apparatuses, systems, and methods for multi-SIM wireless
devices to search for service.
DESCRIPTION OF THE RELATED ART
[0002] Wireless communication systems are rapidly growing in usage.
Further, wireless communication technology has evolved from
voice-only communications to also include the transmission of data,
such as Internet and multimedia content. In certain scenarios a
wireless device may include or be capable of utilizing multiple
subscriber identity modules (SIMs). Determining how to operate
effectively and efficiently with multi-SIM capability may be a
challenging problem. Thus, improvements in the field are
desired.
SUMMARY
[0003] Embodiments are presented herein of apparatuses, systems,
and methods for a multi-SIM device to search for service.
[0004] According to the techniques described herein, when a SIM of
a multi-SIM device goes out-of-service (OOS), it may be possible to
utilize another SIM to scan for service for the OOS SIM. This may
allow the OOS SIM to remain fully asleep while the in-service SIM
periodically scans for service for the OOS SIM, which may help the
multi-SIM device conserve power.
[0005] Furthermore, according to the techniques described herein,
in certain scenarios when multiple SIMs of a multi-SIM device go
OOS, it may be possible to jointly scan for service for all of the
OOS SIMs, using just one SIM of the device. Such a joint scan may
include aligning timing of the OOS scans for the OOS SIMs, and/or
merging frequency channel/band scan lists for the OOS SIMs (e.g.,
to avoid redundant scanning for bands common to multiple scan
lists), which may also help the multi-SIM device conserve
power.
[0006] The techniques described herein may be implemented in and/or
used with a number of different types of devices, including but not
limited to cellular phones, tablet computers, wearable computing
devices, portable media players, and any of various other computing
devices.
[0007] This Summary is intended to provide a brief overview of some
of the subject matter described in this document. Accordingly, it
will be appreciated that the above-described features are merely
examples and should not be construed to narrow the scope or spirit
of the subject matter described herein in any way. Other features,
aspects, and advantages of the subject matter described herein will
become apparent from the following Detailed Description, Figures,
and Claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] A better understanding of the present subject matter can be
obtained when the following detailed description of various
embodiments is considered in conjunction with the following
drawings, in which:
[0009] FIG. 1 illustrates an example wireless communication system
according to some embodiments;
[0010] FIG. 2 illustrates a base station (BS) in communication with
a user equipment (UE) device according to some embodiments;
[0011] FIG. 3 illustrates an example block diagram of a UE
according to some embodiments;
[0012] FIG. 4 illustrates an example block diagram of a BS
according to some embodiments; and
[0013] FIGS. 5-8 are flowchart diagrams illustrating example
methods by which a multi-SIM capable UE may search for service,
according to some embodiments.
[0014] While the features described herein may be susceptible to
various modifications and alternative forms, specific embodiments
thereof are shown by way of example in the drawings and are herein
described in detail. It should be understood, however, that the
drawings and detailed description thereto are not intended to be
limiting to the particular form disclosed, but on the contrary, the
intention is to cover all modifications, equivalents and
alternatives falling within the spirit and scope of the subject
matter as defined by the appended claims.
DETAILED DESCRIPTION
Terms
[0015] The following is a glossary of terms used in this
disclosure:
[0016] Memory Medium--Any of various types of non-transitory memory
devices or storage devices. The term "memory medium" is intended to
include an installation medium, e.g., a CD-ROM, floppy disks, or
tape device; a computer system memory or random access memory such
as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; a non-volatile
memory such as a Flash, magnetic media, e.g., a hard drive, or
optical storage; registers, or other similar types of memory
elements, etc. The memory medium may include other types of
non-transitory memory as well or combinations thereof. In addition,
the memory medium may be located in a first computer system in
which the programs are executed, or may be located in a second
different computer system which connects to the first computer
system over a network, such as the Internet. In the latter
instance, the second computer system may provide program
instructions to the first computer for execution. The term "memory
medium" may include two or more memory mediums which may reside in
different locations, e.g., in different computer systems that are
connected over a network. The memory medium may store program
instructions (e.g., embodied as computer programs) that may be
executed by one or more processors.
[0017] Carrier Medium--a memory medium as described above, as well
as a physical transmission medium, such as a bus, network, and/or
other physical transmission medium that conveys signals such as
electrical, electromagnetic, or digital signals.
[0018] Programmable Hardware Element--includes various hardware
devices comprising multiple programmable function blocks connected
via a programmable interconnect. Examples include FPGAs (Field
Programmable Gate Arrays), PLDs (Programmable Logic Devices), FPOAs
(Field Programmable Object Arrays), and CPLDs (Complex PLDs). The
programmable function blocks may range from fine grained
(combinatorial logic or look up tables) to coarse grained
(arithmetic logic units or processor cores). A programmable
hardware element may also be referred to as "reconfigurable
logic".
[0019] Computer System--any of various types of computing or
processing systems, including a personal computer system (PC),
mainframe computer system, workstation, network appliance, Internet
appliance, personal digital assistant (PDA), television system,
grid computing system, or other device or combinations of devices.
In general, the term "computer system" can be broadly defined to
encompass any device (or combination of devices) having at least
one processor that executes instructions from a memory medium.
[0020] User Equipment (UE) (or "UE Device")--any of various types
of computer systems devices which are mobile or portable and which
performs wireless communications. Examples of UE devices include
mobile telephones or smart phones (e.g., iPhone.TM.,
Android.TM.-based phones), portable gaming devices (e.g., Nintendo
DS.TM., PlayStation Portable.TM., Gameboy Advance.TM., iPhone.TM.),
laptops, wearable devices (e.g. smart watch, smart glasses), PDAs,
portable Internet devices, music players, data storage devices, or
other handheld devices, etc. In general, the term "UE" or "UE
device" can be broadly defined to encompass any electronic,
computing, and/or telecommunications device (or combination of
devices) which is easily transported by a user and capable of
wireless communication.
[0021] Base Station--The term "Base Station" has the full breadth
of its ordinary meaning, and at least includes a wireless
communication station installed at a fixed location and used to
communicate as part of a wireless telephone system or radio
system.
[0022] Processing Element--refers to various elements or
combinations of elements. Processing elements include, for example,
circuits such as an ASIC (Application Specific Integrated Circuit),
portions or circuits of individual processor cores, entire
processor cores, individual processors, programmable hardware
devices such as a field programmable gate array (FPGA), and/or
larger portions of systems that include multiple processors.
[0023] Channel--a medium used to convey information from a sender
(transmitter) to a receiver. It should be noted that since
characteristics of the term "channel" may differ according to
different wireless protocols, the term "channel" as used herein may
be considered as being used in a manner that is consistent with the
standard of the type of device with reference to which the term is
used. In some standards, channel widths may be variable (e.g.,
depending on device capability, band conditions, etc.). For
example, LTE may support scalable channel bandwidths from 1.4 MHz
to 20 MHz. In contrast, WLAN channels may be 22 MHz wide while
Bluetooth channels may be 1 Mhz wide. Other protocols and standards
may include different definitions of channels. Furthermore, some
standards may define and use multiple types of channels, e.g.,
different channels for uplink or downlink and/or different channels
for different uses such as data, control information, etc.
[0024] Band--The term "band" has the full breadth of its ordinary
meaning, and at least includes a section of spectrum (e.g., radio
frequency spectrum) in which channels are used or set aside for the
same purpose.
[0025] Automatically--refers to an action or operation performed by
a computer system (e.g., software executed by the computer system)
or device (e.g., circuitry, programmable hardware elements, ASICs,
etc.), without user input directly specifying or performing the
action or operation. Thus the term "automatically" is in contrast
to an operation being manually performed or specified by the user,
where the user provides input to directly perform the operation. An
automatic procedure may be initiated by input provided by the user,
but the subsequent actions that are performed "automatically" are
not specified by the user, i.e., are not performed "manually",
where the user specifies each action to perform. For example, a
user filling out an electronic form by selecting each field and
providing input specifying information (e.g., by typing
information, selecting check boxes, radio selections, etc.) is
filling out the form manually, even though the computer system must
update the form in response to the user actions. The form may be
automatically filled out by the computer system where the computer
system (e.g., software executing on the computer system) analyzes
the fields of the form and fills in the form without any user input
specifying the answers to the fields. As indicated above, the user
may invoke the automatic filling of the form, but is not involved
in the actual filling of the form (e.g., the user is not manually
specifying answers to fields but rather they are being
automatically completed). The present specification provides
various examples of operations being automatically performed in
response to actions the user has taken.
FIGS. 1 and 2--Communication System
[0026] FIG. 1 illustrates a simplified example wireless
communication system, according to some embodiments. It is noted
that the system of FIG. 1 is merely one example of a possible
system, and that features of this disclosure may be implemented in
any of various systems, as desired.
[0027] As shown, the example wireless communication system includes
a base station 102A which communicates over a transmission medium
with one or more user devices 106A, 106B, etc., through 106N. Each
of the user devices may be referred to herein as a "user equipment"
(UE). Thus, the user devices 106 are referred to as UEs or UE
devices.
[0028] The base station (BS) 102A may be a base transceiver station
(BTS) or cell site (a "cellular base station"), and may include
hardware that enables wireless communication with the UEs 106A
through 106N.
[0029] The communication area (or coverage area) of the base
station may be referred to as a "cell." The base station 102A and
the UEs 106 may be configured to communicate over the transmission
medium using any of various radio access technologies (RATs), also
referred to as wireless communication technologies, or
telecommunication standards, such as GSM, UMTS (associated with,
for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE-Advanced
(LTE-A), HSPA, 3GPP2 CDMA2000 (e.g., 1.times.RTT, 1.times.EV-DO,
HRPD, eHRPD), etc. Note that if the base station 102A is
implemented in the context of LTE, it may alternately be referred
to as an `eNodeB`.
[0030] As shown, the base station 102A may also be equipped to
communicate with a network 100 (e.g., a core network of a cellular
service provider, a telecommunication network such as a public
switched telephone network (PSTN), and/or the Internet, among
various possibilities). Thus, the base station 102A may facilitate
communication between the user devices and/or between the user
devices and the network 100. In particular, the cellular base
station 102A may provide UEs 106 with various telecommunication
capabilities, such as voice, SMS and/or data services.
[0031] Base station 102A and other similar base stations (such as
base stations 102B . . . 102N) operating according to the same or a
different cellular communication standard may thus be provided as a
network of cells, which may provide continuous or nearly continuous
overlapping service to UEs 106A-N and similar devices over a wide
geographic area via one or more cellular communication
standards.
[0032] Thus, while base station 102A may act as a "serving cell"
for UEs 106A-N as illustrated in FIG. 1, each UE 106 may also be
capable of receiving signals from (and possibly within
communication range of) one or more other cells (which might be
provided by base stations 102B-N and/or any other base stations),
which may be referred to as "neighboring cells". Such cells may
also be capable of facilitating communication between user devices
and/or between user devices and the network 100. Such cells may
include "macro" cells, "micro" cells, "pico" cells, and/or cells
which provide any of various other granularities of service area
size. For example, base stations 102A-B illustrated in FIG. 1 might
be macro cells, while base station 102N might be a micro cell.
Other configurations are also possible.
[0033] Note that a UE 106 may be capable of communicating using
multiple wireless communication standards. For example, the UE 106
may be configured to communicate using a wireless networking (e.g.,
Wi-Fi) and/or peer-to-peer wireless communication protocol (e.g.,
Bluetooth, Wi-Fi peer-to-peer, etc.) in addition to at least one
cellular communication protocol (e.g., GSM, UMTS (associated with,
for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE-A, HSPA,
3GPP2 CDMA2000 (e.g., 1.times.RTT, 1.times.EV-DO, HRPD, eHRPD),
etc.). The UE 106 may also or alternatively be configured to
communicate using one or more global navigational satellite systems
(GNSS, e.g., GPS or GLONASS), one or more mobile television
broadcasting standards (e.g., ATSC-M/H or DVB-H), and/or any other
wireless communication protocol, if desired. Other combinations of
wireless communication standards (including more than two wireless
communication standards) are also possible.
[0034] FIG. 2 illustrates user equipment 106 (e.g., one of the
devices 106A through 106N) in communication with a base station
102, according to some embodiments. The UE 106 may be a device with
cellular communication capability such as a mobile phone, a
hand-held device, a wearable device, a computer or a tablet, or
virtually any type of wireless device.
[0035] The UE 106 may include a processor that is configured to
execute program instructions stored in memory. The UE 106 may
perform any of the method embodiments described herein by executing
such stored instructions. Alternatively, or in addition, the UE 106
may include a programmable hardware element such as an FPGA
(field-programmable gate array) that is configured to perform any
of the method embodiments described herein, or any portion of any
of the method embodiments described herein.
[0036] The UE 106 may include one or more antennas for
communicating using one or more wireless communication protocols or
technologies. In one embodiment, the UE 106 may be configured to
communicate using, for example, CDMA2000
(1.times.RTT/1.times.EV-DO/HRPD/eHRPD) or LTE using a single shared
radio and/or GSM or LTE using the single shared radio. The shared
radio may couple to a single antenna, or may couple to multiple
antennas (e.g., for MIMO) for performing wireless communications.
In general, a radio may include any combination of a baseband
processor, analog RF signal processing circuitry (e.g., including
filters, mixers, oscillators, amplifiers, etc.), or digital
processing circuitry (e.g., for digital modulation as well as other
digital processing). Similarly, the radio may implement one or more
receive and transmit chains using the aforementioned hardware. For
example, the UE 106 may share one or more parts of a receive and/or
transmit chain between multiple wireless communication
technologies, such as those discussed above.
[0037] In some embodiments, the UE 106 may include separate
transmit and/or receive chains (e.g., including separate antennas
and other radio components) for each wireless communication
protocol with which it is configured to communicate. As a further
possibility, the UE 106 may include one or more radios which are
shared between multiple wireless communication protocols, and one
or more radios which are used exclusively by a single wireless
communication protocol. For example, the UE 106 might include a
shared radio for communicating using either of LTE and 1.times.RTT
(or LTE and GSM), and separate radios for communicating using each
of Wi-Fi and Bluetooth. Other configurations are also possible.
FIG. 3--Block Diagram of a UE
[0038] FIG. 3 illustrates an example block diagram of a UE 106,
according to some embodiments. As shown, the UE 106 may include a
system on chip (SOC) 300, which may include portions for various
purposes. For example, as shown, the SOC 300 may include
processor(s) 302 which may execute program instructions for the UE
106 and display circuitry 304 which may perform graphics processing
and provide display signals to the display 360. The processor(s)
302 may also be coupled to memory management unit (MMU) 340, which
may be configured to receive addresses from the processor(s) 302
and translate those addresses to locations in memory (e.g., memory
306, read only memory (ROM) 350, NAND flash memory 310) and/or to
other circuits or devices, such as the display circuitry 304,
wireless communication circuitry 330, connector I/F 320, and/or
display 360. The MMU 340 may be configured to perform memory
protection and page table translation or set up. In some
embodiments, the MMU 340 may be included as a portion of the
processor(s) 302.
[0039] As shown, the SOC 300 may be coupled to various other
circuits of the UE 106. For example, the UE 106 may include various
types of memory (e.g., including NAND flash 310), a connector
interface 320 (e.g., for coupling to a computer system, dock,
charging station, etc.), the display 360, and wireless
communication circuitry 330 (e.g., for LTE, LTE-A, CDMA2000,
Bluetooth, Wi-Fi, GPS, etc.).
[0040] As noted above, the UE 106 may be configured to communicate
wirelessly using multiple wireless communication technologies. As
further noted above, in such instances, the wireless communication
circuitry 330 may include radio components which are shared between
multiple wireless communication technologies and/or radio
components which are configured exclusively for use according to a
single wireless communication technology. As shown, the UE 106 may
include at least one antenna (and possibly multiple antennas, e.g.,
for MIMO and/or for implementing different wireless communication
technologies, among various possibilities), for performing wireless
communication with cellular base stations and/or other devices. For
example, the UE device 106 may use antenna(s) 335 to perform the
wireless communication.
[0041] The UE 106 may also include and/or be configured for use
with one or more user interface elements. The user interface
elements may include any of various elements, such as display 360
(which may be a touchscreen display), a keyboard (which may be a
discrete keyboard or may be implemented as part of a touchscreen
display), a mouse, a microphone and/or speakers, one or more
cameras, one or more buttons, and/or any of various other elements
capable of providing information to a user and/or receiving or
interpreting user input.
[0042] As shown, the UE 106 may also include or be coupled to a SIM
(Subscriber Identity Module) 370. The SIM 370 may be implemented as
an application on a smart card, in some embodiments. The smart card
may itself be referred to as a SIM card in some cases. As one
example, the SIM 370 may be an application which executes on a
Universal Integrated Circuit Card (UICC). The smart card may also
include (e.g., store and/or execute) one or more other
applications, if desired. The smart card may be removable.
[0043] Alternatively, the SIM 370 may be implemented as an embedded
SIM (eSIM). In this case, the SIM 370 may be implemented in device
hardware and/or software. For example, in some embodiments, the UE
106 may include an embedded UICC (eUICC), e.g., a device which is
built into the UE 106 and is not removable. The eUICC may be
programmable, such that an eSIM may be implemented on the eUICC. In
other embodiments, the eSIM may be installed in UE 106 software,
e.g., as program instructions stored on a memory medium (such as
memory 306 or NAND 310) executing on a processor (such as processor
302) in the UE 106.
[0044] In some embodiments, the UE 106 may be a multi-SIM device,
or may at least be multi-SIM capable. Each SIM of such a UE 106 may
be implemented in any of various ways, including as a removable SIM
or as an embedded SIM, among various possibilities. Dual SIM dual
standby (DSDS) and dual SIM dual active (DSDA) are two examples of
possible multi-SIM configurations which may be implemented by a UE
106, according to various embodiments.
[0045] The subscriber identity information may be used to identify
the UE 106 to its subscriber's carrier cellular network. The
subscriber identity may also be used outside of the "home" area in
which the subscriber's carrier provides cellular service in some
situations, for example if the subscriber's carrier has arranged
any roaming agreements with other network operators so that the
visited network will recognize the subscriber identity information
and allow access to the network.
[0046] Note that the area in which a subscriber identity may be
used to obtain cellular service via the carrier with which the
subscriber identity is associated may be considered a "local
service area" for the subscriber identity, in which locations the
subscriber identity may be considered "local". In other words, as
used herein, a UE 106 may be considered able to obtain "local
service" in a location using a subscriber identity if the carrier
associated with (e.g., which provided) the subscriber identity
provides cellular service in that location.
[0047] Any areas in which the subscriber identity may be used to
obtain cellular service via another carrier than that with which
the subscriber identity is associated (e.g., via one or more
roaming agreements) may be considered a "roaming service area" for
the subscriber identity. In other words, as used herein, a UE 106
may be considered able to obtain "roaming service" in a location
using a subscriber identity if carrier with which a roaming
agreement has been negotiated by the carrier associated with the
subscriber identity provides cellular service in that location.
[0048] Any areas in which the subscriber identity may not be used
to obtain cellular service via the carrier with which the
subscriber identity is associated or any other may be considered a
"no service area" for the subscriber identity. In other words, as
used herein, a UE 106 may be considered able to obtain "no service"
in a location using a subscriber identity if neither the carrier
associated with the subscriber identity nor any other carrier with
which a roaming agreement has been negotiated by the carrier
associated with the subscriber identity provides cellular service
in that location. Note that cellular service may still be available
(for example using a different subscriber identity associated with
a local carrier) in locations for which no service is available
using a particular subscriber identity, though it is also possible
that no cellular service may be available at all in some (e.g.,
remote) locations.
[0049] As described herein, the UE 106 may include hardware and
software components for implementing part or all of the methods
described herein. The processor 302 of the UE device 106 may be
configured to implement part or all of the methods described
herein, e.g., by executing program instructions stored on a memory
medium (e.g., a non-transitory computer-readable memory medium). In
other embodiments, processor 302 may be configured as a
programmable hardware element, such as an FPGA (Field Programmable
Gate Array), or as an ASIC (Application Specific Integrated
Circuit). Alternatively (or in addition) the processor 302 of the
UE device 106, in conjunction with one or more of the other
components 300, 304, 306, 310, 320, 330, 335, 340, 350, 360 may be
configured to implement part or all of the features described
herein.
FIG. 4--Block Diagram of a Base Station
[0050] FIG. 4 illustrates an example block diagram of a base
station 102, according to some embodiments. It is noted that the
base station of FIG. 4 is merely one example of a possible base
station. As shown, the base station 102 may include processor(s)
404 which may execute program instructions for the base station
102. The processor(s) 404 may also be coupled to memory management
unit (MMU) 440, which may be configured to receive addresses from
the processor(s) 404 and translate those addresses to locations in
memory (e.g., memory 460 and read only memory (ROM) 450) or to
other circuits or devices.
[0051] The base station 102 may include at least one network port
470. The network port 470 may be configured to couple to a
telephone network and provide a plurality of devices, such as UE
devices 106, access to the telephone network as described above in
FIGS. 1 and 2.
[0052] The network port 470 (or an additional network port) may
also or alternatively be configured to couple to a cellular
network, e.g., a core network of a cellular service provider. The
core network may provide mobility related services and/or other
services to a plurality of devices, such as UE devices 106. In some
cases, the network port 470 may couple to a telephone network via
the core network, and/or the core network may provide a telephone
network (e.g., among other UE devices serviced by the cellular
service provider).
[0053] The base station 102 may include at least one antenna 434,
and possibly multiple antennas. The antenna(s) 434 may be
configured to operate as a wireless transceiver and may be further
configured to communicate with UE devices 106 via radio 430. The
antenna(s) 434 communicates with the radio 430 via communication
chain 432. Communication chain 432 may be a receive chain, a
transmit chain or both. The radio 430 may be configured to
communicate via various wireless communication standards,
including, but not limited to, LTE, LTE-A, GSM, UMTS, CDMA2000,
Wi-Fi, etc.
[0054] The base station 102 may be configured to communicate
wirelessly using multiple wireless communication standards. In some
instances, the base station 102 may include multiple radios, which
may enable the base station 102 to communicate according to
multiple wireless communication technologies. For example, as one
possibility, the base station 102 may include an LTE radio for
performing communication according to LTE as well as a Wi-Fi radio
for performing communication according to Wi-Fi. In such a case,
the base station 102 may be capable of operating as both an LTE
base station and a Wi-Fi access point. As another possibility, the
base station 102 may include a multi-mode radio which is capable of
performing communications according to any of multiple wireless
communication technologies (e.g., LTE and Wi-Fi, LTE and UMTS, LTE
and CDMA2000, UMTS and GSM, etc.).
[0055] As described further subsequently herein, the BS 102 may
include hardware and software components for implementing or
supporting implementation of features described herein. The
processor 404 of the base station 102 may be configured to
implement or support implementation of part or all of the methods
described herein, e.g., by executing program instructions stored on
a memory medium (e.g., a non-transitory computer-readable memory
medium). Alternatively, the processor 404 may be configured as a
programmable hardware element, such as an FPGA (Field Programmable
Gate Array), or as an ASIC (Application Specific Integrated
Circuit), or a combination thereof. Alternatively (or in addition)
the processor 404 of the BS 102, in conjunction with one or more of
the other components 430, 432, 434, 440, 450, 460, 470 may be
configured to implement or support implementation of part or all of
the features described herein.
FIGS. 5-9--Flowchart Diagrams
[0056] As previously noted, in some scenarios a wireless device may
be capable of utilizing multiple subscriber identity modules
(SIMs). For example, dual SIM support may enable a device to be
simultaneously registered with two SIMs, potentially on two
different networks. Dual SIM support may include dual SIM dual
standby (DSDS) support, in which a device may be simultaneously
registered with two SIMs but may actively communicate with one of
the networks at a time (e.g., using a shared radio), or dual SIM
dual active (DSDA) support, in which a device may be simultaneously
registered with two SIMs and may simultaneously actively
communicate two networks at a time, among various dual SIM
configurations.
[0057] Dual SIM support may be implemented in any of various ways,
as desired. For example, a wireless device may provide dual SIM
functionality only when the device is in a roaming state, or only
when the device is registered with a home network, or both when the
device is roaming and when the device is registered with a home
network, among various possibilities. As another example, when dual
SIM functionality is implemented different SIMs may have different
availabilities with respect to voice and data communication. Thus
as one possibility, a primary SIM (e.g., corresponding to a first
subscription) might be made available for voice communication,
while a secondary SIM (e.g., corresponding to a second
subscription) might be made available for data communication.
Alternate arrangements (e.g., primary SIM available for data,
secondary SIM available for voice; both primary and secondary SIMs
available for both voice and data; both primary and secondary SIMs
available for voice only or for data only, etc.) are also possible.
As a still further example, when dual SIM functionality is
implemented, different SIMs may have different availabilities with
respect to different radio access technologies (RATs); for example,
one or more RATs available to one SIM might not be available to the
other SIM (and/or vice versa), and/or one or both SIMs might have
different RAT availability depending on whether the wireless device
is operating in a dual SIM mode or a single SIM mode. As one
possible configuration, a SIM might be configured to use any of
GSM, WCDMA, and/or LTE for voice and/or data communications when
operating in a single SIM mode, and might be configured with the
same capabilities or only a subset of those capabilities (e.g.,
voice only and GSM only, as one possibility) when operating in a
dual SIM mode. Numerous other configurations are also possible and
should be considered within the scope of this disclosure.
[0058] Note also that in some instances, the specific configuration
of a dual SIM capable wireless device at a particular time may
result from any combination of hardware and/or software features of
the wireless device, subscription characteristics of the SIMs used
with the wireless device, and/or user preference(s), among various
possible considerations and/or constraints.
[0059] While it may be possible to operate each SIM entirely
independently, in at least some instances, it may be beneficial to
share data and/or operations between SIMs under certain
circumstances. The optimal manner and circumstances under which to
implement such data and/or operation sharing may depend on the
configuration of a given wireless device. In many instances,
however, it may be the case that such data and/or operation sharing
may reduce device power consumption and/or improve user experience,
e.g., in comparison to operating each SIM independently of each
other SIM of a multi-SIM capable wireless device.
[0060] As one possible example of a scenario in which it may be
beneficial to share operations between SIMs of a wireless device,
in at least some instances it may be possible to reduce the power
consumption of a wireless device (e.g., a UE such as UE 106
illustrated in and described with respect to FIGS. 1-3) when
searching for service if one SIM of the device is out-of-service
(OOS) by using another SIM to search for service on behalf of the
OOS SIM. As another possible example, in at least some instances it
may alternatively or in addition be possible to reduce power
consumption of a wireless device when searching for service if both
SIMs of the device are OOS by using one SIM of the device to scan
for service for multiple OOS SIMs jointly. FIGS. 5-8 are flowchart
diagrams illustrating example methods that may be performed by a
multi-SIM capable UE to search for service under various
circumstances.
[0061] The method shown in FIG. 5 may be used in conjunction with
any of the computer systems or devices shown in the above Figures,
among other devices. This method may be used in various types of
cellular communication systems across any of a variety of cellular
technologies. In various embodiments, some of the elements of the
scheme shown may be performed concurrently, in a different order
than shown, or may be omitted. Additional and/or alternative
elements may also be performed as desired. As shown, the method of
FIG. 5 may operate as follows.
[0062] In 502, it may be determined that a first SIM of a UE is
OOS. As previously noted, a SIM may be considered OOS if no
cellular system on which the SIM may camp (e.g., according to its
subscription agreement and corresponding permissions) is available.
At least in some instances, determination that a SIM is OOS may
occur based on performing a certain amount of scanning for service
without discovering any suitable cells, and/or based on
unsuccessfully attempting to register with any discovered cells,
among various possibilities.
[0063] As noted above, the UE may be a multi-SIM capable UE. Thus,
at least in some instances, the UE may include at least a second
SIM in addition to the first SIM. The UE may be capable of
operating in a dual SIM mode (e.g., in which both the first SIM and
teh second SIM are active) or a single SIM mode (e.g., in which
just the first SIM, or just the second SIM, is active). Such a dual
SIM mode may be a dual SIM dual standby (DSDS) or dual SIM dual
active (DSDA) mode, among various possibilities. Note that, in some
instances, the first SIM and the second SIM may provide different
services, e.g., at least when in dual SIM mode. For example, it may
be the case that when in dual SIM mode the first SIM provides voice
services and the second SIM provides data services. As will be
readily recognized, other arrangements are also possible.
[0064] Since different SIMs may have different subscription
agreements with different permissions (e.g., potentially including
different permissions for using various public land mobile networks
(PLMNs) and/or various radio access technologies (RATs), it may in
some instances be possible for one SIM of a UE to have service and
for another SIM of the UE to be OOS.
[0065] The UE may operate in different modes at different times.
The UE may determine in which mode to operate at a particular time
in any of various possible ways. For example, as one possibility,
the UE may preferably operate in a single SIM mode when in a local
service area and in a dual SIM mode when in a roaming service area.
As another possibility, the UE may preferably operate in a dual SIM
mode if service is available for each SIM, but fall back to a
single SIM mode if service is only available for one SIM.
[0066] In 504, the UE may scan for service for the first SIM using
a second SIM. At least in some instances, the second SIM may be
registered for service (e.g., may be `in-service` and not OOS).
Since the second SIM may be registered for service and may operate
actively (e.g., in an idle mode or a connected mode) in order to
maintain and utilize its service (e.g., for voice and/or data
communications), at least in some instances it may be more
efficient to utilize the second SIM to perform scanning/searching
operations on behalf of the first SIM in between operations on
behalf of the second SIM itself while the first SIM is placed into
a low power (e.g., sleep) mode than using the first SIM to perform
scanning/searching operations on behalf of the first SIM.
[0067] Scanning for service for the first SIM may include scanning
one or more frequency channels and/or frequency bands for cellular
systems with which the first SIM may be able to register and obtain
service from. The frequency channels and/or frequency bands
selected for scanning may be based on any of various possible
considerations, including but not limited to frequency channels
recently used by the first SIM, frequency channels recently or
currently used by the second SIM, frequency channels for which
neighboring cell information for the second SIM is available,
frequency bands on which one or more PLMNs accessible by the first
SIM are known or believed to be deployed based on a location of the
UE, and/or any of various other possible considerations. In at
least some instances, the frequencies and/or bands scanned may be
based at least in part on subscription information for the first
SIM (e.g., from a subscription agreement corresponding to the first
SIM). Note that such frequencies and/or bands may be the same,
partially different, or entirely different than those frequencies
and/or bands that the second SIM would scan if searching for
service on its own behalf.
[0068] In other words, scanning for service if a particular SIM of
the UE goes (OOS) may include attempting to reacquire service by
executing an OOS search algorithm using another SIM of the UE. The
OOS search algorithm may attempt to balance between power usage and
acquisition performance. In order to conserve power while executing
the OOS search algorithm (and also allow the SIM which still has
service to maintain and utilize that service), the UE may alternate
between using the in-service SIM to operate in a scanning state on
behalf of the OOS SIM, which may expend power but allow for service
acquisition, and using the in-service SIM to operate normally on
behalf of the in-service SIM (which may include communicating
control and/or user data, performing cell measurements,
transitioning between connected and idle modes, and/or any of
various other possible operations, as known to those skilled in the
art), while the OOS SIM remains in a low-power (e.g., sleep) state
which may conserve power. As one possible OOS search algorithm, the
scan times may be split into scans for most recently used
frequencies and full band scans on bands likely to be found in the
last camped area. After a certain period of time, one in every x
(e.g., a configurable number) band scans may include all supported
bands. The frequency scans may be of shorter duration than the band
scans and hence may be performed at a faster rate, at least in some
instances. In some embodiments, the duration of the non-scanning
cycles of the UE may gradually increase as OOS duration (i.e., the
period of time in which a SIM has lacked service) increases.
Additionally, note that in some instances motion detection may be
considered as part of an OOS search algorithm; for example,
scanning/sleeping duty cycles may be modified depending on whether
the UE is moving or stationary, e.g., since the likelihood of
discovering service when OOS may be lower if a UE remains in the
same location that the UE became OOS than if a UE moves to a new
location.
[0069] In 506, an indication may be provided to the first SIM if
service information is found based on scanning for service for the
first SIM using the second SIM. The indication may simply indicate
to the first SIM to wake up and resume searching for service,
and/or may include any of various possible additional types/amounts
of information to assist the first SIM with re-acquiring service.
For example, if a candidate cell (or multiple candidate cells) is
(are) found during a frequency channel/band scan, the first SIM may
be informed of the absolute radio frequency channel number(s)
(ARFCN(s)) of the potential cell(s). Any of various alternative or
additional types of indication may be used, if desired, which may
provide any of various types and amounts of information to the
first SIM.
[0070] Upon receiving such an indication, the first SIM may wake up
and attempt to acquire service. This service acquisition attempt
may include frequency channel and/or band scanning to attempt to
discover a suitable cellular system from which to obtain cellular
service, attempting to obtain system information for such a
cellular system if discovered, and/or registering for cellular
service with such a cellular system. Note that if certain service
information is already available to the first SIM from scanning
performed using the second SIM (e.g., one or more potential cell
ARFCNs), the first SIM may be able to skip one or more such steps
(e.g., to proceed directly to attempt to obtain system information
for one or more potential cells for which ARFCNs were
provided).
[0071] In 508, it may be determined that the second SIM is also
OOS. Thus, it may be the case that both the first SIM and the
second SIM are OOS.
[0072] In 510, the UE may scan for service for both the first SIM
and the second SIM jointly. At least in some instances, such joint
scanning may be performed using one SIM (e.g., either the first SIM
or the second SIM) of the UE, while the other SIM may be able to
remain in a low power (e.g., sleep) state while such scanning is
performed.
[0073] Scanning for service for both the first SIM and the second
SIM jointly may include aligning timing of service scanning for the
first SIM and the second SIM. For example, the OOS scanning
algorithm duty cycles for the first SIM and the second SIM may be
aligned such that scanning for both the first SIM and the second
SIM occur at the same time. This may be in contrast to techniques
in which each SIM scans for service for itself on an individual
basis, in which scanning times and sleeping times for the different
SIMs may generally be offset from each other (e.g., except for
coincidental occurrences). Aligning timing of service scanning for
the first SIM and the second SIM may also include restarting the
OOS scanning algorithm for one of the SIMs, e.g., if it has been
OOS for longer than the other SIM; for example, if the OOS scanning
algorithm is `telescoping` (e.g., if sleeping/scanning duty cycles
change as OOS time increases), in order to maintain alignment of
the sleeping/scanning times for the first SIM and the second SIM,
it may be helpful or even necessary for the OOS scanning algorithms
to be started together.
[0074] In addition, at least in some instances scanning for service
for both the first SIM and the second SIM jointly may include
merging frequency channel/band lists for the first SIM and the
second SIM. In other words, the frequency channels and bands to be
scanned for the first SIM and the frequency channels and bands to
be scanned for the second SIM may be combined into a single list of
frequency channels and bands to be scanned (e.g., with duplicates
removed to avoid redundancy and increase the efficiency of the
scanning).
[0075] If potential service information for either or both of the
first SIM or the second SIM based on such joint scanning, the
appropriate SIM may be notified, and may be activated to attempt to
re-acquire service.
[0076] Note that while the FIG. 5 and the corresponding description
thereof provided herein above provides a method by which OOS
service scanning for a first SIM (or multiple SIMs) of a UE is
performed using a second SIM of the UE, any of the techniques
illustrated in and described with respect to FIG. 5 may be
performed with the roles of the first SIM and the second SIM
reversed, if desired. Thus, OOS service scanning for the second SIM
(e.g., as might be triggered by the second SIM going OOS while the
first SIM remains in-service or is also OOS) may be performed using
the first SIM of the UE, according to any of the various
embodiments described herein.
[0077] The methods of FIGS. 6-8 may be illustrative of system
selection algorithms that may be used with a UE for which dual SIM
functionality is available when in a roaming state. According to
this dual SIM functionality, the first SIM, representing a first
subscription, is available for voice services using GSM (also
referred to as "G" for simplicity with respect to FIGS. 6-8), and
the second SIM, representing a second subscription, is available
for data services using GSM, WCDMA (also referred to as "W" for
simplicity with respect to FIGS. 6-8), and LTE. Furthermore, in
this particular scenario, the first SIM may be available for voice
services using GSM or WCDMA when operating in single SIM mode. At
least in some instances, the first SIM may also be available for
data services using GSM, WCDMA, and/or LTE when operating in single
SIM mode. As previously noted, any number of alternate
implementations (e.g., in which voice services using LTE also
available for the first SIM in single SIM mode, and/or in which
WCDMA and/or LTE services (for voice and/or data) are available for
the first SIM in dual SIM mode, among various possibilities) are
also possible. Note that the first SIM may alternately be referred
to as "voiceSUB", while the second SIM may alternately be referred
to as "dataSUB", with respect to FIGS. 6-8.
[0078] Note that FIGS. 6-8 and the information provided herein
below in conjunction therewith are provided by way of example of
various considerations and details relating to possible systems
with which the method of FIG. 5 may be implemented, and are not
intended to be limiting to the disclosure as a whole. Numerous
variations and alternatives to the details provided herein below
are possible and should be considered within the scope of the
disclosure.
[0079] FIG. 6 is a flowchart diagram illustrating an example method
that may be performed by a dual SIM UE to jointly perform OOS
service scanning for multiple SIMs. As shown, the method of FIG. 6
may operate as follows.
[0080] In 602, at a certain time ("Time X"), the voiceSUB may go
OOS.
[0081] In 604, an OOS system selection algorithm for the voiceSUB
may be followed. As one example possibility, the OOS system
selection algorithm for the voiceSUB may correspond to the method
of FIG. 7; alternatively, any of various other OOS system selection
algorithms for the voiceSUB may be used.
[0082] In 606, if the OOS system selection algorithm is
unsuccessful and the voiceSUB remains OOS, the UE may transition
from dual SIM mode to single SIM mode, with the dataSUB as the
active SIM.
[0083] In 608, location and motion assisted OOS scans for the
voiceSUB may continue to be scheduled and performed by the dataSUB
while the UE is operating in the single SIM mode.
[0084] In 610, at a certain time ("Time Y", where Y>X), the
dataSUB may go OOS.
[0085] In 612, an OOS system selection algorithm for the dataSUB
may be followed. As one example possibility, the OOS system
selection algorithm for the dataSUB may correspond to the method of
FIG. 8; alternatively, any of various other OOS system selection
algorithms for the dataSUB may be used. If the OOS system selection
algorithm is unsuccessful and the dataSUB remains OOS, both the
dataSUB and the voiceSUB may be OOS.
[0086] In 614, since both SIMs may be OOS, the scan states for both
the voiceSUB and the dataSUB may be restarted and aligned. One of
the SIMs (e.g., the dataSUB) may scan for both SIMs.
[0087] Scanning for both SIMs may include using a scan list in
which frequency channels and bands to be scanned for each SIM are
combined in a merged scan list. As an example of such a merged scan
list, a voiceSUB scan list 616 and a dataSUB scan list 618 are
illustrated in FIG. 6, along with an actual scan list 620 including
all of the frequency channels and bands listed in each of the
voiceSUB scan list 616 and the dataSUB scan list 618.
[0088] As previously noted, FIG. 7 is a flowchart diagram
illustrating an example method that may be performed by a dual SIM
UE to attempt to perform system selection to re-acquire service in
a scenario in which the voiceSUB goes out-of-service (OOS). As
shown, the method of FIG. 7 may operate as follows.
[0089] In 702, the voiceSUB may go OOS.
[0090] In 704, the voiceSUB may scan any GSM frequency channels
recently used by the voiceSUB. If any cells are found as a result
of such scanning, the voiceSUB may camp on such a cell.
[0091] In 706, if no cells are found as a result of such scanning,
it may be determined if the dataSUB PLMN is in an OPLMN list for
the voiceSUB.
[0092] In 708, if the dataSUB PLMN is in the OPLMN list for the
voiceSUB, it may be determined if the dataSUB is camped on a
serving cell that operates according to either WCDMA or LTE.
[0093] In 710, if the dataSUB is camped on a serving cell that
operates according to either WCDMA or LTE, it may be determined if
GSM neighbor info is available from the dataSUB.
[0094] In 712, if GSM neighbor info is available from the dataSUB,
the voiceSUB may scan the ARFCN(s) of the GSM cell(s) for which GSM
neighbor info is available. If any cells are found as a result of
such scanning, the voiceSUB may camp on such a cell.
[0095] In 714, if the dataSUB is not camped on a serving cell that
operates according to either WCDMA or LTE, it may be determined if
the dataSUB is camped on a serving cell that operates according to
GSM.
[0096] In 716, if the dataSUB is camped on a serving cell that
operates according to GSM, the voiceSUB may scan the ARFCN of the
GSM serving cell of the dataSUB. If any cells are found as a result
of such scanning, the voiceSUB may camp on such a cell.
[0097] In 718, if no cells are found as a result of such scanning,
or if the dataSUB is not camped on a GSM, LTE, or WCDMA serving
cell, or if the dataSUB is camped on a LTE or WCDMA serving cell
but no GSM neighbor info is available, or if the dataSUB is camped
on a LTE or WCDMA serving cell and GSM neighbor info is available
but no cells are found as a result of scanning the frequencies for
which such GSM neighbor info is available, or if the dataSUB PLMN
is not in the OPLMN list of the voiceSUB, the voiceSUB may perform
a location assisted scan. If any cells are found as a result of
such scanning, the voiceSUB may camp on such a cell.
[0098] In 720, if no cells are found as a result of such scanning,
the UE may transition to single SIM mode with the dataSUB as the
active SIM.
[0099] In 722, the dataSUB may continue to perform location
assisted scans for the voiceSUB while the voiceSUB enters and
remains in a low power (e.g., sleep) mode.
[0100] Note that while FIG. 7 relates to an exemplary scenario in
which a voiceSUB is available only for GSM in dual SIM mode, in an
alternate implementation in which the voiceSUB is additionally
available for WCDMA, LTE, and/or any of various other possible
RATs, any number of additional or alternative steps (e.g., similar
to some or all of the steps of FIG. 7) might be performed. For
example, the voiceSUB might scan for WCDMA and/or LTE cells based
on information from either or both of the voiceSUB or the dataSUB,
in addition to scanning for GSM cells, and camp on such a cell if
found.
[0101] FIG. 8 is a flowchart diagram illustrating an example method
that may be performed by a dual SIM UE to attempt to perform system
selection to re-acquire service in a scenario in which the dataSUB
goes out-of-service (OOS). As shown, the method of FIG. 8 may
operate as follows.
[0102] In 802, the dataSUB may go OOS.
[0103] In 804, the dataSUB may scan any LTE, WCDMA, or GSM
frequency channels recently used by the dataSUB. If any cells are
found as a result of such scanning, the dataSUB may camp on such a
cell.
[0104] In 806, if no cells are found as a result of such scanning,
it may be determined if the voiceSUB PLMN is in an OPLMN list for
the dataSUB.
[0105] In 808, if the voiceSUB PLMN is in the OPLMN list for the
dataSUB, it may be determined if WCDMA and/or LTE neighbor info is
available from the voiceSUB.
[0106] In 810, if WCDMA and/or LTE neighbor info is available from
the voiceSUB, the dataSUB may scan the (E)ARFCN(s) of the WCDMA/LTE
cell(s) for which WCDMA and/or LTE neighbor info is available. If
any cells are found as a result of such scanning, the dataSUB may
camp on such a cell.
[0107] In 812, if no cells are found as a result of such scanning,
or if WCDMA and/or LTE neighbor info is not available from the
voiceSUB, the dataSUB may scan the GSM ARFCN of the GSM serving
cell of the voiceSUB. If any cells are found as a result of such
scanning, the dataSUB may camp on such a cell.
[0108] In 814, if no cells are found as a result of such scanning,
or if the voiceSUB PLMN is not in the OPLMN list of the dataSUB,
the dataSUB may perform a location assisted scan. If any cells are
found as a result of such scanning, the dataSUB may camp on such a
cell.
[0109] In 816, if no cells are found as a result of such scanning,
the UE may transition to single SIM mode with the voiceSUB as the
active SIM.
[0110] In 818, the voiceSUB may continue to perform location
assisted scans for the dataSUB while the dataSUB enters and remains
in a low power (e.g., sleep) mode.
[0111] Note also that while FIG. 8 relates to an exemplary scenario
in which a voiceSUB is available only for GSM in dual SIM mode, in
an alternate implementation in which the voiceSUB is additionally
available for WCDMA, LTE, and/or any of various other possible
RATs, any number of additional or alternative steps might be
performed. For example, if the voiceSUB is camped on WCDMA or LTE,
the dataSUB might scan for the WCDMA or LTE serving cell of the
voiceSUB, in addition to scanning for WCDMA and/or LTE neighbor
cells of the voiceSUB, and camp on such a cell if found.
[0112] Embodiments of the present disclosure may be realized in any
of various forms. For example some embodiments may be realized as a
computer-implemented method, a computer-readable memory medium, or
a computer system. Other embodiments may be realized using one or
more custom-designed hardware devices such as ASICs. Still other
embodiments may be realized using one or more programmable hardware
elements such as FPGAs.
[0113] In some embodiments, a non-transitory computer-readable
memory medium may be configured so that it stores program
instructions and/or data, where the program instructions, if
executed by a computer system, cause the computer system to perform
a method, e.g., any of a method embodiments described herein, or,
any combination of the method embodiments described herein, or, any
subset of any of the method embodiments described herein, or, any
combination of such subsets.
[0114] In some embodiments, a device (e.g., a UE 106) may be
configured to include a processor (or a set of processors) and a
memory medium, where the memory medium stores program instructions,
where the processor is configured to read and execute the program
instructions from the memory medium, where the program instructions
are executable to implement any of the various method embodiments
described herein (or, any combination of the method embodiments
described herein, or, any subset of any of the method embodiments
described herein, or, any combination of such subsets). The device
may be realized in any of various forms.
[0115] Although the embodiments above have been described in
considerable detail, numerous variations and modifications will
become apparent to those skilled in the art once the above
disclosure is fully appreciated. It is intended that the following
claims be interpreted to embrace all such variations and
modifications.
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