Abstract:
In one aspect there may be provided a method. The method may include detecting, during a first call associated with a first subscriber identity module included in a user equipment, a page representative of a second call associated with a second subscriber identity module; determining, during the first call associated with the first subscriber identity module included in the user equipment, caller identification information associated with the second call by at least inhibiting the first call to enable a call set up with the second subscriber identity module, the call set up established to determine the caller identification information for a caller making the second call to the second subscriber identity module; and receiving, at the user equipment, the second call by at least switching a subscriber identity module being used by the user equipment from the first subscriber identity module to the second subscriber identity module.

Description:
FIELD 
     The subject matter described herein relates to wireless communications. 
     BACKGROUND 
     A subscriber identity module (SIM) refers to a circuit that stores an International Mobile Subscriber Identity (IMSI). The SIM may securely store the IMSI and a key used to identify and authenticate a subscriber of a device accessing a mobile network. Typically, the SIM is a card that can be inserted into a device, such as a mobile phone or computer. As such, a device can be configured to operate with any given SIM, and the installed SIM uniquely identities that that user associated with the SIM is authorized to access the mobile network. 
     SUMMARY 
     Methods and apparatus, including computer program products, are provided for configuring a device to operate using two subscriber identity modules. 
     In one aspect there is provided a method. The method may include detecting, during a first call associated with a first subscriber identity module included in a user equipment, a page representative of a second call associated with a second subscriber identity module; determining, during the first call associated with the first subscriber identity module included in the user equipment, caller identification information associated with the second call by at least inhibiting the first call to enable a call set up with the second subscriber identity module, the call set up established to determine the caller identification information for a caller making the second call to the second subscriber identity module; and receiving, at the user equipment, the second call by at least switching a subscriber identity module being used by the user equipment from the first subscriber identity module to the second subscriber identity module. 
     In some exemplary embodiments, one of more variations may be made as well as described in the detailed description below and/or as described in the following features. A notification may be generated, and the notification may include the determined caller identification information associated with the second call to the second subscriber identity module. The first call may be established based on a first international mobile subscriber identity included in the first subscriber identity module. A second international mobile subscriber identity associated with the second subscriber identity module may be detected. A call back to the caller at the determined caller identification information may be established based on a second international mobile subscriber identity included in the second subscriber identity module. The first call may be disconnected, when making a call back to the caller at the determined caller identification information. The call set up may be established with the second subscriber identity module to determine the caller identification information for the caller making the second call to the second subscriber identity module. The call set up may be disconnected, when the caller identification information for the caller is determined to enable a resumption of the first call. 
     The above-noted aspects and features may be implemented in systems, apparatus, methods, and/or articles depending on the desired configuration. The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims. 
    
    
     
       DESCRIPTION OF DRAWINGS 
       In the drawings, 
         FIG. 1  depicts an example of a system including a user equipment configured to time share between two subscriber identity modules, in accordance with some exemplary embodiments; 
         FIG. 2  depicts an example of a process for checking pages for a second call associated with a second SIM, in accordance with some exemplary embodiments; 
         FIG. 3  depicts an example of a process for obtaining caller identification information for the second call associated with the second SIM, in accordance with some exemplary embodiments; 
         FIG. 4  depicts an example of a process for switching to the second call associated with the second SIM, in accordance with some exemplary embodiments; 
         FIG. 5  depicts an example of a process for configuring a user equipment to time share between two subscriber identity modules; 
         FIG. 6  depicts an example of a base station, in accordance with some exemplary embodiments; and 
         FIG. 7  depicts an example of a user equipment configured to time share between two subscriber identity modules, in accordance with some exemplary embodiments. 
     
    
    
     Like labels are used to refer to same or similar items in the drawings. 
     DETAILED DESCRIPTION 
       FIG. 1  depicts a system  100  including a base station  110  supporting a corresponding coverage area  112  (also referred to as a cell). The base station  110  may be capable of communicating with wireless devices, such as user equipment  114 , within its coverage area  112 .  FIG. 1  also depicts another base station  198  serving another coverage area  194 , which may serve user equipment  114 , when it is in the second coverage area  194 . 
     In some exemplary embodiments, the user equipment  114  may be configured with a first subscriber identity module (SIM)  192 A and a second SIM  192 B. Moreover, a radio of the user equipment  114  may handle a first call with the first SIM  192 A, and then momentarily pause the first call and use that radio to check for a paging signal indicative of a second call for the second SIM  192 B. If a second call is detected for the second SIM  192 B, the user equipment  114  may also gather caller identification information for the second call and then generate an indication, so that a user operating the user equipment  114  is aware of the second call for the second SIM  192 B. For example, the user equipment  114  may have a connection via the first call and an indication is generated, such as a display and/or audio indication, providing the phone number of the caller of the second call and a call back option. The user equipment  114  may remain connected to the first call on the first SIM  192 A, or, if the user decides to take and/or call back the second call for the second SIM  192 B, the user equipment  114  may establish a connection for the second call associated with the second SIM  192 B (which may include disconnecting from the first call for the first SIM  192 A and using the second SIM  192 B to establish the call back to the caller of the second call). In some exemplary embodiments, the user equipment  114  may time share its radio section between the two SIMs  192 A-B in order to take calls on both SIMs  192 A-B, without requiring separate radio sections for each of the SIMs. 
     Although  FIG. 1  depicts two base stations  110  and  198 , two cells  112  and  194 , and one user equipment  114  including two SIMs, the system  100  may include other quantities of base stations, cells, user equipment, and SIMs as well. 
     Moreover, the base station  110  may, in some exemplary embodiments, be implemented as a base station compatible with one or more standards, such as the Global System for Mobile Communications including Universal Mobile Telecommunications System (UMTS), although the base station  110  may be configured with other standards as well. Furthermore, although  FIG. 1  depicts an example of a configuration for base station  110 , the base station  110  may be configured in other ways as well. For example, the base station  110  may include relays, cellular base station transceiver subsystems, gateways, access points, radio frequency (RF) repeaters, frame repeaters, and remote radio heads and include access to other networks as well. For example, base station  110  may have wired and/or wireless backhaul links to other network elements, such as other access points, base stations, remote radio heads, radio network controllers, core networks, serving gateways, mobility management entities, and the like. 
     In some exemplary embodiments, the system  100  may include access links  122 . The access links  122  may include a downlink  116  for transmitting to the user equipment  114  and an uplink  126  for transmitting from user equipment  114  to the base station  110 . The downlink  116  may include one or more paging signals, which may include an International Mobile Subscriber Identifier (IMSI), Temporary Mobile Subscriber Identifier (TMSI), and/or other identifiers. The downlink  116  may also include a modulated radio frequency carrying information, such as user data, radio resource control (RRC) messages, location information, and the like, to the user equipment  114 , and the uplink  126  may comprise a modulated radio frequency carrying information, such as user data, RRC messages, location information, and the like, from the user equipment  114  to base station  110 . The downlink  116  and uplink  126  may, in some exemplary embodiments, each represent a radio frequency (RF) signal. The RF signal may, as noted above, include data, such as voice, video, images, Internet Protocol (IP) packets, control information, and any other type of information and/or messages. Access links  196  may be implemented in a manner similar to access links  122 . 
     In some exemplary embodiments, the user equipment  114  may be implemented as a mobile device and/or a stationary device. The user equipment  114  may be referred to as, for example, a mobile station, a mobile unit, a subscriber station, a wireless terminal, a tablet, a smart phone, a laptop, a computer, or the like. A user equipment may be implemented as, for example, a wireless handheld device, and/or a wireless plug-in accessory which inserts into another device (e.g., a computer, a tablet, or the like). In some cases, the user equipment may include a processor, a computer-readable storage medium (e.g., memory, storage, and the like), a radio, and/or a user interface. In some exemplary embodiments, the user equipment  114  may include two SIMs, and be configured to receive calls on both of the SIMs based on time sharing a portion of the radio as disclosed herein. 
       FIG. 2  depicts a process  200  in accordance with some exemplary embodiments. At  202 - 206 , the user equipment  114  may receive a first call for an IMSI associated with the first SIM  192 A, decode the call using a channel decoder, and obtain decoded frames as indicated by the “good frames.” During the first call associated with the first SIM  192 A, the user equipment  114  may, at  208 , read one or more paging signals  290  sent by the base station  110  to determine whether there is a call for the IMSI associated with the second SIM  192 B, in accordance with some exemplary embodiments. Because the same radio is used for both SIMs  192 A-B, when the user equipment  114  is reading the page at  208 , the first call may be interrupted and, as such, there is no activity (e.g., paused and the like). During this interruption, the first call for SIM  192 A may experience errors. As such, bits, such as random bits  210 , may be inserted into the frame, which when decoded at  212  may correspond to a bad frame at  214 . Depending on the reception quality and the specific timing of two received signals, the channel decoder may be able to correct some of the bit errors introduced by the random bits. In the case of a bad frame (in which the channel decoder cannot correct the bit errors), muting algorithms may be implemented in the speech decoder to mask the bad frames from the user. At  216 , the user equipment  114  may resume the first call associated with the first SIM  192 A, and proceed to decode the first call into frames at  218  and  220 . 
     During  210 , no data can be received for the first call associated with the first SIM  192 A since the radio of the user equipment  114  is being used to read pages sent by the base station  110 . As noted, the channel decoder at  212  may be provided with bits at  210 , such as stuff bits, random bits, and the like, causing bad frames at  214 , which would be perceived by the user of user equipment  114  as bad data (e.g., unintelligible speech). Although the stuff/random bits at  210  may result in a brief period of bad data (e.g., unintelligible/bade speech frames) at  214 , in the case of GSM, about 2 GSM speech frames may be errored/bad within a 0.5 second interval, without substantially impacting the user&#39;s quality of experience. 
       FIG. 3  depicts a process  300  for obtaining the caller identification information, in accordance with some exemplary embodiments. The paging may not include any caller number identification. At  302 , to obtain the caller identification information, user equipment  114  may switch from the first SIM  192 A to the second SIM  192 B. For example, user equipment  114  may, at  302 , momentarily stop communicating on the first call associated with the first SIM  192 A and then perform, at  304 , a call setup using the second SIM  192 B. While the user equipment  114  is establishing a call using the second SIM  192 B at  304 , the first call  192 A may be paused. The pause first call at  306  may not be disconnected due to lack of activity (e.g., the momentary lapse in activity on the first call is akin to going through a “tunnel” or other obstruction that inhibits calling but does not terminate the call). During this pause at  306 , the audio for the first call may be muted or a tone may be generated so that the user is informed about the incoming call on the second SIM  192 B. 
     When caller identification information (e.g., caller&#39;s phone number and the like) is obtained at  304 , the call setup on the second SIM  192 B may be ceased, and the user equipment  114  may resume using the first SIM  192  and resume the associated first call as depicted at  308 . At  310 , the user equipment  114  may generate a notification and present the notification on a user interface (UI)  390  at user equipment  114 . The notification may include the caller&#39;s phone number and a call back option. 
       FIG. 4  depicts a process  400  that may be implemented at the user equipment  114  when the caller identification information is determined and/or presented at  316 , in accordance with some exemplary embodiments. 
     At  406 , the user equipment  114  may end the first call associated with the first SIM  192 A. For example, a user may decide to initiate a call back to reach the caller of the second call associated with the second SIM  192 B. When this is the case, the user equipment  114  may terminate the first call associated with the first SIM  192 A. At  410 , the user equipment  114  may switch to using the second SIM  192 B and then proceed with the call back, establishing the second call associated with the second SIM  192 B, as depicted at  408  and  410 . Once the second call is established, the user equipment  114  proceeds with the second call on the second SIM  192 A as depicted at  412 . 
       FIG. 5  depicts a process  500  for configuring a device to operate using two SIMs, such as SIMs  192 A-B. 
     At  510 , the user equipment  114  may detect, during a first call associated with a first subscriber identity module (SIM), a page representative of a second call associated with a second SIM, in accordance with some exemplary embodiments. For example, base station  110  may transmit one or more pages including an IMSI and other like identifiers. The user equipment  114  may momentarily pause the first call and read one or more paging signals to detect a second call associated with a second SIM, as describe above at  FIG. 2 . 
     At  520 , the user equipment may obtain caller identification information associated with the second call by establishing a call set up with the second SIM  192 B, in accordance with some exemplary embodiments. In some example embodiments, the page sent by the base station  110  does not include caller identification information. As such, the identity of the caller of the second call is not known unless caller identification information is obtained. To that end, the user equipment  114  sets up a call to the base station  110  using the second SIM  192 B, and the call set up procedure proceeds at least until the user equipment  114  obtains the caller identification information associated with the second call for the second SIM  192 B (and corresponding IMSI of that second SIM  192 B). After the caller information is obtained, the user equipment may terminate the call set up with the base station as described above with respect to  FIG. 3 . 
     At  530 , the user equipment may generate a notification including the determined caller identification, in accordance with some exemplary embodiments. The generated notification may be displayed at a user interface  390  of user equipment  114  and the notification may also include a call back option, which when selected calls the caller associated with the second call. The user equipment  114  may thus receive the caller&#39;s call to the second SIM  192 B. 
       FIG. 6  depicts an example implementation of a base station  600 , which may be implemented at base station  110 . The base station may include one or more antennas  620  configured to transmit via a downlink and configured to receive uplinks via the antenna(s)  620 . The base station may further include a radio interface  640  coupled to the antenna  620 , a processor  630  for controlling the base station  600  and for accessing and executing program code stored in memory  635 . The radio interface  640  may further include other components, such as filters, converters (e.g., digital-to-analog converters and the like), mappers, a Fast Fourier Transform (FFT) module, and the like, to generate pages, symbols, and the like for a transmission via one or more downlinks and to receive symbols (e.g., via an uplink). The base station  600  may perform one or more of the functions described herein with respect to base station  110 . 
       FIG. 7  depicts a block diagram of a radio, such as a user equipment  700 . User equipment  700  may be implemented to perform one or more of the functions describe herein with respect to the user equipment, such as user equipment  114 . The user equipment  700  may include an antenna  720  for receiving a downlink including pages from the base station and for transmitting via an uplink. The user equipment  700  may also include a radio section  740 , which may include other components, such as filters, converters (e.g., digital-to-analog converters and the like), symbol demappers, signal shaping components, an Inverse Fast Fourier Transform (IFFT) module, and the like, to process pages, symbols, such as OFDMA symbols, carried by a downlink or an uplink, and the like. In some implementations, the user equipment  700  may also be compatible with WiFi, Bluetooth, GERAN, UTRAN, E-UTRAN, and/or other standards and specifications as well. The user equipment  700  may further include at least one processor, such as processor  730 , for controlling user equipment  700  and for accessing and executing program code stored in memory  735 . The user equipment may include two SIMs  192 A-B, and the processor  730  may configure the user equipment to time share the two SIMs  192 A-B by switching between the two SIMs  192 A-B, although the user equipment may switch among other quantities of SIMs as well. The user equipment may also include a user interface  725 . The user interface  725  may comprise one or more of the following: a keypad, a key board, a screen, a speaker, a microphone, and/or any other mechanism for interfacing a user. For example, the user interface  725  may present to a user the caller identification information for a call to the second SIM, while the user is on a call associated with the first SIM and another caller. Moreover, the user interface  725  may also generate an audio indication to the user as well, and the user interface  725  may present an icon to allow an automatic call back to the caller associated with the second SIM. 
     The subject matter described herein may be embodied in systems, apparatus, methods, and/or articles depending on the desired configuration. For example, the base stations and user equipment (or one or more components therein) and/or the processes described herein can be implemented using one or more of the following: a processor executing program code, an application-specific integrated circuit (ASIC), a digital signal processor (DSP), an embedded processor, a field programmable gate array (FPGA), and/or combinations thereof. These various implementations may include implementation in one or more computer programs that are executable and/or interpretable on a programmable system including at least one programmable processor, which may be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device. These computer programs (also known as programs, software, software applications, applications, components, program code, or code) include machine instructions for a programmable processor, and may be implemented in a high-level procedural and/or object-oriented programming language, and/or in assembly/machine language. As used herein, the term “machine-readable medium” refers to any computer program product, computer-readable medium, computer-readable storage medium, apparatus and/or device (e.g., magnetic discs, optical disks, memory, Programmable Logic Devices (PLDs)) used to provide machine instructions and/or data to a programmable processor, including a machine-readable medium that receives machine instructions. 
     Similarly, systems are also described herein that may include a processor and a memory coupled to the processor. The memory may include one or more programs that cause the processor to perform one or more of the operations described herein. 
     Although a few variations have been described in detail above, other modifications or additions are possible. In particular, further features and/or variations may be provided in addition to those set forth herein. For example, although the change in search pattern is described with respect to small cell base station  110 B, other types of base stations and access points may change search modes as described herein. 
     Moreover, the implementations described above may be directed to various combinations and subcombinations of the disclosed features and/or combinations and subcombinations of several further features disclosed above. In addition, the logic flow depicted in the accompanying figures and/or described herein does not require the particular order shown, or sequential order, to achieve desirable results. Other embodiments may be within the scope of the following claims.