PATENT DOCUMENT

Publication Number: US-9049745-B2
Application Number: US-201213347641-A
Country: US
Kind Code: B2

Title: Wireless electronic devices with dual circuit architecture

Abstract:
Electronic devices may have multiple wireless integrated circuits such as first and second baseband processor integrated circuits. The first baseband processors may be used exclusively for handling packet switched traffic, whereas the second baseband processor may be used exclusively for handling circuit switched traffic. Radio-frequency front end circuitry may be used to couple multiple antennas to the baseband processors and associated radio-frequency transceivers. The first baseband processor may be coupled to a first universal integrated circuit card (UICC) storing a first subscriber profile, whereas the second baseband processor may be coupled to a second UICC storing a second subscriber profile. The first baseband processor may be used to support any desired circuit switched radio access technology, whereas the second baseband processor may be used to support any desired packet switched radio access technology.

Claims:
What is claimed is: 
     
       1. A method for wirelessly transmitting and receiving packet switched traffic and circuit switched traffic in an electronic device that has first and second baseband processor integrated circuits, comprising:
 transmitting and receiving the packet switched traffic using the first baseband processor integrated circuit; 
 transmitting and receiving the circuit switched traffic using the second baseband processor integrated circuit, wherein the first baseband processor integrated circuit is coupled to the second baseband processor integrated circuit via an inter-processor communications path; 
 with a universal integrated circuit card connected to the first baseband processor integrated circuit, providing subscriber identity module (SIM) profile data to the first baseband processor integrated circuit; and 
 conveying control signals that include the SIM profile data from the first baseband processor integrated circuit to the second baseband processor integrated circuit via the inter-processor communications path to enable the second baseband processor integrated circuit to register with a wireless network. 
 
     
     
       2. The method defined in  claim 1 , further comprising:
 performing packet switched network registration using the SIM profile data; and 
 performing circuit switched network registration using the SIM profile data. 
 
     
     
       3. The method defined in  claim 1 , wherein the wireless network is associated with a service provider. 
     
     
       4. A method for wirelessly transmitting and receiving packet switched traffic and circuit switched traffic in an electronic device that has first and second baseband processor integrated circuits, comprising:
 transmitting and receiving the packet switched traffic using the first baseband processor integrated circuit; 
 transmitting and receiving the circuit switched traffic using the second baseband processor integrated circuit, wherein the first baseband processor integrated circuit is coupled to the second baseband processor integrated circuit via an inter-processor communications path; 
 with a universal integrated circuit card connected to the second baseband processor integrated circuit, providing subscriber identity module (SIM) profile data to the second baseband processor integrated circuit; and 
 conveying control signals that include the SIM profile data from the second baseband processor integrated circuit to the first baseband processor integrated circuit via the inter-processor communications path to enable the first baseband processor integrated circuit to register with a wireless network. 
 
     
     
       5. The method defined in  claim 4 , further comprising:
 performing packet switched network registration using the SIM profile data; and 
 performing circuit switched network registration using the SIM profile data. 
 
     
     
       6. The method defined in  claim 4 , wherein the wireless network is associated with a service provider.

Description:
This application claims the benefit of provisional patent application No. 61/433,162, filed Jan. 14, 2011, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     This relates to electronic devices such as cellular telephones and, more particularly, to methods for handling packet switched and circuit switched traffic in an electronic device. 
     Electronic devices such as cellular telephones contain wireless circuitry such as radio-frequency transceiver integrated circuits and associated wireless baseband integrated circuits. These wireless baseband integrated circuits may be used in handling wireless voice and data communications. 
     Wireless traffic for an electronic device such as a cellular telephone typically includes circuit switched (CS) traffic and packet-switched (PS) traffic. Circuit switched traffic commonly includes voice calls, but can also include data. Packet-switched traffic commonly includes data, but can also include voice (e.g., voice over internet protocol phone calls). 
     Examples of circuit switched wireless protocols include 3G protocols such as Universal Mobile Telecommunications System (UMTS) and Code Division Multiple Access (CDMA) 1xRTT and 2G protocols such as Global System for Mobile Communications (GSM). Examples of packet switched wireless protocols include 4G protocols such as the Long Term Evolution (LTE), 3G protocols such as Evolution-Data Optimized (EV-DO) and High Speed Packet Access (HSPA), and 2G protocols such as Enhanced Data Rates for GSM Evolution (EDGE) and General Packet Radio Service (GPRS). 
     Modern wireless integrated circuits such as 4G wireless integrated circuits that support LTE protocols often offer legacy support for 3G/2G services. Using 4G wireless integrated circuits to support legacy services can, however, be inefficient, because the 4G wireless integrated circuits are not always as optimized as the 3G/2G chips when performing 3G/2G functions. 
     It would therefore be desirable to provide improved ways in which to support wireless communications in electronic devices. 
     SUMMARY 
     To take advantage of optimized 3G/2G wireless integrated circuits, a cellular telephone or other electronic device may be provided with dual wireless integrated circuits (e.g., dual baseband processor integrated circuits and corresponding radio-frequency transceiver circuits). A first of the baseband processor integrated circuits (e.g., a 4G chip that is optimized for handling packet switched traffic such as LTE data traffic) may handle exclusively packet switched traffic. A second of the baseband processor integrated circuits (e.g., a 3G/2G chip that is optimized for handling circuit switched traffic such as GSM voice traffic) can be used to handle exclusively circuit switched traffic. 
     In one suitable arrangement, the first baseband processor integrated circuit may be coupled to a first universal integrated circuit card (UICC) while the second baseband processor integrated circuit may be coupled to a second UICC. The first and second UICCs may be used to store separate subscriber identity module (SIM) data provided from the same wireless carrier or from different wireless carriers. In another suitable arrangement, the electronic device may only contain one UICC that is only coupled to one of the two baseband processor integrated circuits. In this example, one wireless carrier (i.e., the wireless carrier associated with the one UICC) is providing both voice and data service. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device with wireless communications circuitry in accordance with an embodiment of the present invention. 
         FIG. 2  is a schematic diagram of a wireless network including a base station and an illustrative electronic device with wireless communications circuitry in accordance with an embodiment of the present invention. 
         FIG. 3  is a diagram of an illustrative electronic device operable to communicate with both circuit switched (CS) and packet switched (PS) cellular networks in accordance with an embodiment of the present invention. 
         FIG. 4  is a diagram of illustrative wireless communications circuitry having a data baseband processing integrated circuit coupled to a first associated universal integrated circuit card (UICC) and having a voice baseband processing integrated circuit coupled to a second associated UICC, where the wireless communications circuitry is capable of receiving radio-frequency signals using four separate antennas in accordance with an embodiment of the present invention. 
         FIG. 5  is a diagram of the wireless communications circuitry of the type shown in  FIG. 4  that is capable of receiving radio-frequency signals using two separate antennas in accordance with an embodiment of the present invention. 
         FIG. 6  is a diagram of illustrative wireless communications circuitry having only one UICC that is directly coupled to the voice baseband processor integrated circuit in accordance with an embodiment of the present invention. 
         FIG. 7  is a diagram of illustrative wireless communications circuitry having only one universal integrated circuit card that is directly coupled to the data baseband processor integrated circuit in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may be provided with wireless communications circuitry. The wireless communications circuitry may be used to support wireless communications in multiple wireless communications bands using one or more antennas. The antennas can include loop antennas, inverted-F antennas, strip antennas, planar inverted-F antennas, slot antennas, patch antennas, hybrid antennas that include antenna structures of more than one type, or other suitable antennas. Conductive structures for the antennas may be formed from conductive electronic device structures such as conductive housing structures (e.g., a ground plane and part of a peripheral conductive housing member or other housing structures), traces on substrates such as traces on plastic, glass, or ceramic substrates, traces on flexible printed circuit boards (“flex circuits”), traces on rigid printed circuit boards (e.g., fiberglass-filled epoxy boards), sections of patterned metal foil, wires, strips of conductor, other conductive structures, or conductive structures that are formed from a combination of these structures. 
     An illustrative electronic device of the type that may be provided with one or more antennas (e.g., two antennas, three antennas, four antennas, five or more antennas, etc.) is shown in  FIG. 1 . Electronic device  10  may be a portable electronic device or other suitable electronic device. For example, electronic device  10  may be a laptop computer, a tablet computer, a somewhat smaller device such as a cellular telephone, a media player, a wrist-watch device, pendant device, headphone device, earpiece device, or other wearable or miniature device, etc. 
     Device  10  may include a housing such as housing  12 . Housing  12 , which may sometimes be referred to as a case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of these materials. In some situations, parts of housing  12  may be formed from dielectric or other low-conductivity material. In other situations, housing  12  or at least some of the structures that make up housing  12  may be formed from metal elements. 
     Device  10  may, if desired, have a display such as display  14 . Display  14  may, for example, be a touch screen that incorporates capacitive touch electrodes. Display  14  may include image pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electronic ink elements, liquid crystal display (LCD) components, or other suitable image pixel structures. A cover glass layer may cover the surface of display  14 . Portions of display  14  such as peripheral regions  201  may be inactive and may be devoid of image pixel structures. Portions of display  14  such as rectangular central portion  20 A (bounded by dashed line  20 ) may correspond to the active part of display  14 . In active display region  20 A, an array of image pixels may be used to display images for a user. 
     The cover glass layer that covers display  14  may have openings such as a circular opening for button  16  and a speaker port opening such as speaker port opening  18  (e.g., for an ear speaker for a user). Device  10  may also have other openings (e.g., openings in display  14  and/or housing  12  for accommodating volume buttons, ringer buttons, sleep buttons, and other buttons, openings for an audio jack, data port connectors, removable media slots, etc.). 
     Housing  12  may include a peripheral conductive member such as a bezel or band of metal that runs around the rectangular outline of display  14  and device  10  (as an example). The peripheral conductive member may be used in forming the antennas of device  10  if desired. 
     Antennas may be located along the edges of device  10 , on the rear or front of device  10 , as extending elements or attachable structures, or elsewhere in device  10 . With one suitable arrangement, which is sometimes described herein as an example, device  10  may be provided with one or more antennas at lower end  24  of housing  12  and one or more antennas at upper end  22  of housing  12 . Locating antennas at opposing ends of device  10  (i.e., at the narrower end regions of display  14  and device  10  when device  10  has an elongated rectangular shape of the type shown in  FIG. 1 ) may allow these antennas to be formed at an appropriate distance from ground structures that are associated with the conductive portions of display  14  (e.g., the pixel array and driver circuits in active region  20 A of display  14 ). 
     If desired, a first cellular telephone antenna may be located in region  24  and a second cellular telephone antenna may be located in region  22 . Antenna structures for handling satellite navigation signals such as Global Positioning System signals or wireless local area network signals such as IEEE 802.11 (WiFi®) signals or Bluetooth® signals may also be provided in regions  22  and/or  24  (either as separate additional antennas or as parts of the first and second cellular telephone antennas). Antenna structures may also be provided in regions  22  and/or  24  to handle WiMax (IEEE 802.16) signals. 
     In regions  22  and  24 , openings may be formed between conductive housing structures and printed circuit boards and other conductive electrical components that make up device  10 . These openings may be filled with air, plastic, or other dielectrics. Conductive housing structures and other conductive structures may serve as a ground plane for the antennas in device  10 . The openings in regions  22  and  24  may serve as slots in open or closed slot antennas, may serve as a central dielectric region that is surrounded by a conductive path of materials in a loop antenna, may serve as a space that separates an antenna resonating element such as a strip antenna resonating element or an inverted-F antenna resonating element such as an inverted-F antenna resonating element formed from part of a conductive peripheral housing structure in device  10  from the ground plane, or may otherwise serve as part of antenna structures formed in regions  22  and  24 . 
     Antennas may be formed in regions  22  and  24  that are identical (i.e., antennas may be formed in regions  22  and  24  that each cover the same set of cellular telephone bands or other communications bands of interest). Due to layout constraints or other design constraints, it may not be desirable to use identical antennas. Rather, it may be desirable to implement the antennas in regions  22  and  24  using different designs. For example, the first antenna in region  24  may cover all cellular telephone bands of interest (e.g., four or five bands) and the second antenna in region  22  may cover a subset of the four or five bands handled by the first antenna. Arrangements in which the antenna in region  24  handles a subset of the bands handled by the antenna in region  22  (or vice versa) may also be used. Tuning circuitry may be used to tune this type of antenna in real time to cover either a first subset of bands or a second subset of bands and thereby cover all bands of interest. 
     A schematic diagram of a system in which electronic device  10  may operate is shown in  FIG. 2 . As shown in  FIG. 2 , system  11  may include wireless network equipment such as base station  21  (sometimes referred to as a base transceiver station). Base stations such as base station  21  may be associated with a cellular telephone network or other wireless networking equipment. Device  10  may communicate with base station  21  over wireless link  23  (e.g., a cellular telephone link or other wireless communications link). 
     Device  10  may include control circuitry such as storage and processing circuitry  28 . Storage and processing circuitry  28  may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in storage and processing circuitry  28  and other control circuits such as control circuits in wireless communications circuitry  34  may be used to control the operation of device  10 . This processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio codec chips, application specific integrated circuits, etc. 
     Storage and processing circuitry  28  may be used to run software on device  10 , such as internet browsing applications, voice-over-internet-protocol (VoIP) telephone call applications, email applications, media playback applications, operating system functions, etc. To support interactions with external equipment such as base station  21 , storage and processing circuitry  28  may be used in implementing communications protocols. Communications protocols that may be implemented using storage and processing circuitry  28  include internet protocols, wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as WiFi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, IEEE 802.16 (WiMax) protocols, cellular telephone protocols such as the “2G” Global System for Mobile Communications (GSM) protocol, the “2G” Code Division Multiple Access (CDMA) protocol, the “3G” Universal Mobile Telecommunications System (UMTS) protocol, the “4G” Long Term Evolution (LTE) protocol, etc. 
     Circuitry  28  may be configured to implement control algorithms that control the use of antennas in device  10 . For example, circuitry  28  may configure wireless circuitry  34  to switch a particular antenna into use for transmitting and/or receiving signals. In some scenarios, circuitry  28  may be used in gathering sensor signals and signals that reflect the quality of received signals (e.g., received paging signals, received voice call traffic, received control channel signals, received traffic channel signals, etc.). Examples of signal quality measurements that may be made in device  10  include bit error rate measurements, signal-to-noise ratio measurements, measurements on the amount of power associated with incoming wireless signals, channel quality measurements based on received signal strength indicator (RSSI) information (RSSI measurements), channel quality measurements based on received signal code power (RSCP) information (RSCP measurements), channel quality measurements based on signal-to-interference ratio (SINR) and signal-to-noise ratio (SNR) information (SINR and SNR measurements), channel quality measurements based on signal quality data such as Ec/lo or Ec/No data (Ec/lo and Ec/No measurements), etc. This information may be used in controlling which antenna is used. Antenna selections can also be made based on other criteria. 
     Input-output circuitry  30  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output circuitry  30  may include input-output devices  32 . Input-output devices  32  may include touch screens, buttons, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, tone generators, vibrators, cameras, accelerometers (motion sensors), ambient light sensors, and other sensors, light-emitting diodes and other status indicators, data ports, etc. A user can control the operation of device  10  by supplying commands through input-output devices  32  and may receive status information and other output from device  10  using the output resources of input-output devices  32 . 
     Wireless communications circuitry  34  may include radio-frequency (RF) transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive RF components, one or more antennas, and other circuitry for handling RF wireless signals. 
     Wireless communications circuitry  34  may include satellite navigation system receiver circuitry such as Global Positioning System (GPS) receiver circuitry  35  (e.g., for receiving satellite positioning signals at 1575 MHz). Transceiver circuitry  36  may handle 2.4 GHz and 5 GHz bands for WiFi® (IEEE 802.11) communications and may handle the 2.4 GHz Bluetooth® communications band. Circuitry  34  may use cellular telephone transceiver circuitry  38  for handling wireless communications in cellular telephone bands such as bands at 850 MHz, 900 MHz, 1800 MHz, 1900 MHz, and 2100 MHz or other cellular telephone bands of interest. Wireless communications circuitry  34  can include circuitry for other short-range and long-range wireless links if desired (e.g., WiMax circuitry, etc.). Wireless communications circuitry  34  may, for example, include, wireless circuitry for receiving radio and television signals, paging circuits, etc. In WiFi® and Bluetooth® links and other short-range wireless links, wireless signals are typically used to convey data over tens or hundreds of feet. In cellular telephone links and other long-range links, wireless signals are typically used to convey data over thousands of feet or miles. 
     Wireless communications circuitry  34  may include antennas  40 . Antennas  40  may be formed using any suitable types of antenna. For example, antennas  40  may include antennas with resonating elements that are formed from loop antenna structures, patch antenna structures, inverted-F antenna structures, closed and open slot antenna structures, planar inverted-F antenna structures, helical antenna structures, strip antennas, monopoles, dipoles, hybrids of these designs, etc. Different types of antennas may be used for different bands and combinations of bands. For example, one type of antenna may be used in forming a local wireless link antenna and another type of antenna may be used in forming a remote wireless link antenna. As described in connection with  FIG. 1 , there may be multiple cellular telephone antennas in device  10 . For example, there may be one cellular telephone antenna in region  24  of device  10  and another cellular telephone antenna in region  22  of device  10 . These antennas may be fixed or may be tunable. 
     In some embodiments of the present invention, device  10  may be described that supports the circuit switching (CS) technology and packet switching (PS) technology. Circuit switching involves establishing a dedicated/exclusive communications channel through a network before any user data is transmitted. A channel established using circuit switching guarantees the full bandwidth of the channel and remains connected for the entire duration of the session (e.g., the channel remains unavailable to other users until the session is terminated and the channel is released). 
     Traditionally, the Public Switched Telephone Network (PTSN) is implemented using circuit switching. Device  10  may include a baseband processing circuit configured to support circuit switching technologies such as the 3G CDMA2000 1xRTT radio access technology, the 3G Universal Mobile Telecommunications System (UMTS) radio access technology, and the 2G GSM radio access technology (as examples). The baseband processing integrated circuit that is being operated to support circuit switching cellular telephone communications protocols may therefore sometimes be referred to as a “voice” baseband processor integrated circuit. 
     Packet switching involves organizing data to be transmitted into groups referred to as packets in accordance with the Internet Protocol (IP). Each packet may contain the IP address of the source node, the IP address of the destination node, user data (often referred to as data load or payload), and other control information. Unlike circuit switching, packet switching shares available network resources among multiple users. Each packet being sent may be routed independently to the desired destination, and as a result, each packet may experience varying packet transfer delays. Packets arriving at the destination node may be buffered until at least some of the transmitted packets have arrived. Once a sufficient number of packets have reached their destination, the packets can be reassembled to recover the original transmitted data at the source. 
     The Internet and most local area networks rely on packet switching. Device  10  may include a baseband processing circuit configured to support packet switching technologies such as the 3G Evolution-Data Optimized (sometimes referred to herein as “EV-DO”) radio access technology, the 4G LTE radio access technology, the 3G High Speed Packet Access (HSPA) radio access technology, the 2G Enhanced Data Rates for GSM Evolution (EDGE) radio access technology, and the 2G General Packet Radio Service (GPRS) radio access technology (as examples). The baseband processing integrated circuit that is being operated to support packet switching radio access technologies may therefore sometimes be referred to as a “data” baseband processor integrated circuit. 
     In one suitable arrangement of the present invention, device  10  may include a first baseband processing circuit  202  that is used exclusively (or primarily) for handling packet switched “data” traffic and a second baseband processing circuit  204  that is used exclusively (or primarily) for handling circuit switched “voice” traffic (see, e.g.,  FIG. 3 ). First and second baseband processing circuits  202  and  204  may be separate integrated circuits that are mounted on a printed circuit board secured within housing  12  of device  10 . Using separate integrated circuits for data and voice, in general, provides greater performance and deployment flexibility. For example, voice baseband processor  204  may optimized for power consumption (thereby offering longer talk times), whereas data baseband processor  202  may be optimized to support the latest evolution in data speeds (e.g., baseband processor  202  may be used to support LTE regardless of the type of CS technology that is be supported by processor  204 ). 
     Baseband processor  202  may be selected to support at least one type of PS technology including (but not limited to) LTE, EV-DO, HSPA, EDGE, and GPRS, whereas baseband processor  204  may be selected to support at least one type of CS technology (including but not limited to) UMTS, CDMA 1xRTT, and GSM. As an example, baseband processor  202  may include memory and control circuitry for implementing the LTE protocol stack to handle LTE functions while baseband processor  204  may include memory and control circuitry for implementing the UMTS protocol stack to handle UMTS functions. 
     As another example, baseband processor  202  may include memory and control circuitry for implementing the LTE and EV-DO protocol stacks while baseband processor  204  may include memory and control circuitry for implementing the CDMA 1x protocol stack. As another example, baseband processor  202  may include memory and control circuitry for implementing the LTE and EDGE protocol stacks while baseband processor  204  may include memory and control circuitry for implementing the GSM protocol stack. These examples are merely illustrative. If desired, processors  202  and  204  and additional baseband processing circuits within device  10  may be configured to support any combination of radio access technologies. 
     A mobile network operator generally requires that wireless users be properly authenticated before wireless services are provided. The mobile network operator (MNO) is a cellular radio network company that provides wireless service for mobile subscribers and is therefore sometimes referred to as a carrier service provider (CSP), a wireless service provider, a wireless carrier, or a mobile network carrier. For example, a carrier X may maintain subscriber identity data that is used in determining whether a given user of device  10  is authorized to use the services of carrier X. The subscriber identity data may sometimes be referred to as Subscriber Identity Module (SIM) data, SIM profile information, etc. Unauthorized users (i.e., users who do not have active accounts) will be denied service. Authorized users (i.e., valid subscribers) will be allowed to establish links to make and receive voice telephone calls, to download and upload data, or to otherwise obtain the services available from carrier X. 
     Subscribe identity data may be stored on a removable smart card sometimes referred to as a Universal Integrated Circuit Card (UICC). As shown in  FIG. 3 , data baseband processor  202  may be coupled to a first dedicated UICC  250 - 1 , whereas voice baseband processor  204  may be coupled to a second dedicated UICC  250 - 2 . A UICC  250  (i.e., UICC  250 - 1  or  250 - 2 ) may contain storage circuitry (e.g., non-volatile memory elements such as read-only memory (ROM) or electrically erasable programmable read-only memory (EEPROM), volatile memory elements such as static random access memory (SRAM) or dynamic random access memory (DRAM), and other types of storage components) and processing circuitry that serves as an interface between its storage circuitry and the baseband processor to which it is connected. UICC  250  may be used to store phonebook contacts, text messages, and other subscriber-related data. A UICC  250  can therefore be used to help users easily transfer their phonebook, preferences, and wireless service from one device to another. 
     As described above, UICC  250  may be used to store information that identifies a subscriber to the mobile network operator so the operator can determine whether or not to provide wireless service to that subscriber. In some contexts, UICC  250  may be referred to as a SIM card (when referring to GSM technologies) or a Removable User Identity Module (when referring to CDMA technologies). 
     A UICC  250  may also be used to run multiple subscriber identity module (SIM) applications. For example, UICC  250  may contain a Universal SIM (USIM) application that identifies device  10  to a mobile network operator using CS technologies such as UMTS or using PS technologies such as HSPA or LTE. As another example, UICC  250  may contain a CDMA SIM (CSIM) application that enables device  10  to access CDMA networks using CS technologies such as CDMA 1xRTT or using PS technologies such as EV-DO. As another example, UICC  250  may contain a SIM application that enables device to access GSM networks using CS technologies such as the 2G GSM or using PS technologies such as GPRS. If desired, a single UICC may contain more than one of these applications, thereby enabling mobile device  10  to have access to both UMTS and GSM radio networks (e.g., device  10  may be capable of supporting desired 4G, 3G, and/or 2G wireless communications protocols by configuring the UICC accordingly). If desired, UICC  250  may also be used to communicate with the mobile network operation using the Internet Protocol (IP). 
     Each mobile device  10  may be uniquely identified using an International Mobile Equipment Identity (IMEI) number, which is burned into device  10  during device manufacturing. Device  10  may be authorized to operate with only a particular carrier or carriers. This allows a carrier to subsidize the price of a device. In contrast, information specific to the subscriber (user) may be stored in UICC  250 . For example, subscriber-related data that may be stored in UICC  250  may include International Mobile Subscriber Identity (IMSI), Temporary Mobile Subscriber Identity (TMSI), authentication key (Ki), service provider name, Local Area Identity (LAI), Registration Area Identity (RAI), and other network related information. The mobile network operator uses the IMSI of a user device to determine whether that device is a valid user for the particular network. The IMSI is rarely transmitted over the network to prevent eavesdropping. Instead, a randomly generated TMSI (i.e., a temporary identifier that is valid only for a given session) may be used as a proxy parameter and may be changed periodically for heightened security. 
     Authentication key Ki is a 128 bit value that is often paired with the IMSI when a UICC  250  is manufactured. Key Ki is used during device authentication operations to encrypt sensitive data. Key Ki should never be transmitted over the network and should not be transparent to the user of device  10  (i.e., Ki should not be extractable from a UICC). The LAI and RAI serve to identify the last known location of device  10 . Mobile network operators are typically divided into location areas, each of which may be assigned a unique local area identifier. Each user devices operating within a particular region of a mobile network operator may have a common LAI (used for CS networks) or RAI (used for PS networks) stored in its UICC  250 . 
     As shown in  FIG. 3 , device  10  may communicate directly with at least one base transceiver station (BTS). Base stations such as base stations  100  may be associated with a cellular radio network such as network  13  or other wireless networking equipment. Device  10  may communicate with base station  100  over wireless link  102  (e.g., a cellular telephone link, a data communications link, or other wireless communications link). Base station  100  may serve as the access point that bridges device  10  to the radio network. Base station  100  may contain antennas, radio-frequency front end circuitry (e.g., RF amplifiers, transceivers, combiners/splitters, duplexers, etc.), and/or baseband processing circuitry capable of handling speech encoding, data encryption, multiplexing (e.g., time division multiplexing or frequency division multiplexing), and modulation/demodulation of radio-frequency signals. The radio coverage area that is provided by base station  100  (or sometimes a group of collocated base stations  100 ) may be referred to as a “cell.” 
     Multiple base stations  100  may be coupled to a common radio network controller (RNC)  104  via fiber optic links or wireless links. Radio network controller  104  serves to control the operation of its associated base stations  100  by allocating radio-frequency channels to each mobile device, analyzing power and signal measurements obtained from device  10  to determine which of base stations  100  is best suited to service a particular call, and performing handovers from one base station to another (assuming both base stations are controlled by that RNC  104 ). Radio network controller  104  is therefore sometimes referred to as a base station controller. Radio network controller  104  may be collocated with at least one of its associated base stations  100  or may be geographically separate from each of associated base stations  100 . 
     Radio network controller  104  may be configured to route its wireless traffic based on the type of technology that is currently being used for wireless transmission. For example, if device  10  is attempting to set up a voice call, radio network controller  104  may allow device  10  to communicate with circuit switched domain registration network circuitry  130  (as indicated by path  136  in  FIG. 3 ). As another example, if device  10  is attempting to establish an active data session, radio network controller  104  may allow device  10  communicate with packet switched domain registration network circuitry  132  (as indicated by path  134  in  FIG. 3 ). 
     When a mobile device is turned on, it contacts a nearby base station  100  to register with the network. When making initial contact with the nearby base station, device  10  may use random access procedures to announce its presence to the network. 
     For example, during CS domain network registration procedures, communications between device  10  and the network may be primarily handled using a mobile switching center (MSC)  106 . Mobile switching center  106  may be used to handle call setup, call routing, and other basic network switching functions. Mobile switching center  106  may control multiple radio network controllers  104  and may also interface wither other mobile switching centers. For example, mobile switching center  106  may be used to handle inter-RNC handoffs (e.g., handoff procedures between two radio network controllers that are coupled to one common mobile switching center  106 ) and to handle inter-MSC handoffs (e.g., handoff procedures with other mobile switching centers). 
     Whenever a mobile device requests access to the network, the network must authenticate that device. Mobile switching center  106  may first query a home location register (HLR)  120  and a visitor location register (often collocated with associated mobile switching center  106 ) to determine the current location of mobile device  10 . Home location register  120  is a database that permanently stores data associated with each subscriber. For example, home location register  120  may maintain user-specific data such as the IMSI associated with each subscriber, the last known location of each subscriber, roaming restrictions (i.e., information showing whether a subscriber is allowed to have service in certain parts of the world), and other user data. The location data for device  10  may be updated during registration and may periodically be updated (whether or not the device changes its location). 
     In contrast, a visitor location register (VLR) may be a database that contains only a subset of the information that is stored on home location register  120 . Each location area (typically comprised of a group of cells) may have an associated visitor location register, and that visitor location register may only store information associated with subscribers that are currently located in its location area. The visitor location register serves to reduce the number of queries to home location register  120 , thereby reducing network traffic. 
     Once the location of device  10  has been determined, the visitor location register may be used to generate a temporary IMSI (or TMSI) corresponding to device  10  and may forward that TMSI to home location register  106  to request authentication. This new TMSI provided by the visitor location register may be generated based on an old TMSI that device  10  transmits to the network (e.g., an old TMSI obtained during a previous location update). The network may require device  10  to authenticate every time a network operation is requested (e.g., upon location update, mobile-originated call, etc.), whenever device  10  moves to a new location, after a predetermined period of time, etc. 
     When home location register  120  receives the TMSI, it checks its database to determine whether the received TMSI corresponds to a valid IMSI (i.e., a locally stored number that should be identical to the IMSI that is stored on UICC  250  in the mobile device). If the TMSI corresponds to a valid IMSI, an authentication request is forwarded to an authentication center (AuC)  118 . Authentication center  118  is a database of subscribers that are allowed to register with a given network. Authentication procedures may involve verifying the identity and validity of the SIM profile stored on UICC  250  to ensure that the subscriber has been paying their bills and is authorized access to the network (e.g., authentication center  118  may be used to ensure that a subscriber has a valid account and may also be used for billing purposes). 
     Home location register  120  may also be coupled to an Equipment Identity Register (EIR)  122 . Equipment identity register  122  is a database that tracks each manufactured device using the IMEI. Each network may have only one equipment identity register  122 . Equipment identity register  122  may, for example, contain a black list, a gray list, and a white list. The black list contains a list of IMEIs that should be denied service by the network. Reasons for denied service may include a particular device being reported as stolen or duplicated or if the device is malfunctioning or does not operate properly on the network. The gray list contains a list of IMEIs that are to be monitored for suspicious activity (i.e., for devices that are considered to be behaving oddly or exhibiting unpredictable performance). The remainder of IMEIs may populate the white list and may be given service upon proper authentication operations. Home location register  120  may check with EIR  122  prior to querying authentication center  118 . 
     Authentication center  118  may also be responsible for generating terms used for authentication and encryption on the network. Authentication center  118  may also store authentication key Ki corresponding to each IMSI on the network. In some scenarios, authentication center  118  is physically collocated with home location register  120 . 
     For example, authentication center  118  will use the received IMSI to look up an associated private key Ki and to generate a random number RAND. Key Ki is only stored on authentication center  118  and UICC  250  of the current authenticating device. Authentication center  118  then uses RAND and Ki to generate a first signed response SRES 1  using a first encryption algorithm and to generate a ciphering key Kc using a second encryption algorithm that is different than the first encryption algorithm. Crypto-variables RAND, SRES, and Kc are collectively referred to as a “triplet” (e.g., each triplet is unique to one IMSI). Authentication center  118  may generate multiple triplets and send them back to the requesting mobile switching center/visitor location register via home location register  120 . Mobile switching center  106  may store the ciphering key Kc and the first SRES 1  and forward the RAND to the registering mobile device. 
     In response to receiving RAND, device  10  uses key Ki that is stored on its UICC  250  to generate a second signed response SRES 2  and ciphering key Kc using first and second encryption algorithms, respectively. Device  10  stores ciphering key Kc on UICC  250  and transmits second signed response SRES 2  back to the network. When mobile switching center  106  receives SRES 2 , center  106  compares the SRES 2  generated by device  10  to SRES 1  generated by authentication center  118 . If the first and second signed responses match, device  10  is authenticated and given access to the network. Once device  10  is authenticated, mobile switching network  106  passes ciphering key Kc to base stations  100 . Ciphering key Kc associated with each authenticated device is stored at base stations  100  and will never be transmitted over the air. From this point on, wireless traffic may be conveyed between device  10  and nearby base stations  100 , where the traffic that is being wirelessly transmitted is securely encrypted using ciphering key Kc (e.g., device  10  will operate in cipher mode). 
     Once authenticated, device  10  that is registered in the CS domain may communicate with other networks via a gateway MSC (G-MSC)  108 . For example, if a mobile subscriber wants to place a call to a regular land line, the call would have to be routed through the Public Switched Telephone Network (PSTN)  110  via gateway mobile switching center  108 . As another example, if a mobile subscriber using carrier X wants to call another subscriber using carrier Y, the call would have to be routed through gateway MSC  108  (i.e., a gateway MSC that connects the carrier X network to the carrier Y network). 
     In another suitable embodiment of the present invention, device  10  may be given Internet access by performing PS domain registration. During PS domain network registration/authentication procedures, communications between device  10  and network  13  may be primarily handled using a Serving GPRS Support Node (SGSN)  112  (as an example for a GSM-based packet switched network). As shown in  FIG. 3 , node  112  performs analogous functions as mobile switching center  106  by contacting home location register  120  and authentication center  118  in an effort to authenticate device  10  to establish an active data link. Upon authenticating device  10 , device  10  may be given access to the Internet or other desired packet data network (PDN)  116  via radio network controller  104 , support node  112 , and a gateway GPRS support node  114  (i.e., a link between two different networks analogous to gateway MSC  108  in the CS domain). 
     The network diagram of  FIG. 3  is merely illustrative and does not serve to limit the scope of the present invention. If desired, network  13  may include other networking equipment that is used for performing device registration/authentication, data/voice traffic routing, and other network switching operations. 
       FIG. 4  is a diagram showing one suitable circuit arrangement for device  10  having more than one baseband processor integrated circuit. As shown in  FIG. 4 , baseband processors  202  and  204  may be coupled to a common control circuit such as applications processor  200 . Applications processor  200  may be configured to store and execute control code for implementing control algorithms. Baseband processors  202  and  204  may be considered as part of wireless circuitry  34 , whereas applications processor  200  may be considered as part of storage and processing circuitry  28 . Baseband processors  202  and  204  may provide data traffic and voice traffic to applications processor  200  via respective paths. 
     Control signals may be conveyed between baseband processors  202  and  204  via a general purpose input-output (GPIO) path  203 . Path  203  may be a universal asynchronous receiver/transmitter (UART) based connection, a universal serial bus (USB) based connection, a serial peripheral interface (SPI) based connection, or other suitable types of inter-processor communications connection. For example, information related to the current operating modes of the baseband processors (e.g., whether each of the baseband processors are in sleep mode or traffic mode) may be shared between processors  202  and  204  so that proper reception may be coordinated. If desired, SIM data may also be shared between processors  202  and  204  via path  203 . 
     In addition to the transmitted user data, processors  202  and  204  may also provide applications processor  200  with information on whether responses (acknowledgements) are being received from a cellular telephone tower corresponding to requests from device  10 , information on whether a network access procedure has succeeded, information on how many re-transmissions are being requested over a cellular link between the electronic device and a cellular tower, information on whether a loss of signaling message has been received, information on whether paging signals have been successfully received, and other information that is reflective of the performance of wireless circuitry  34 . This information may be analyzed by applications processor  200  and/or processors  202  and  204  and, in response, applications processor  200  (or processors  202 / 204 ) may issue control commands for controlling wireless circuitry  34 . 
     As described previously in connection with  FIG. 3 , data baseband processor  202  may be coupled to an associated UICC  250 - 1 , whereas voice baseband processor  204  may be coupled to an associated UICC  250 - 2 . Having different UICCs may provide a user of device  10  with the flexibility in choosing voice and data plans from different service providers. For example, UICC  250 - 1  may include a first SIM profile for a data plan purchased from a first service provider while UICC  250 - 2  may include a second SIM profile for a voice plan purchased from a second service provider that is different from the first service provider. UICC  250 - 1  may be used during PS domain registration while UICC  250 - 2  may be used during CS domain registration (e.g., UICC  250 - 1  may contain a first IMSI that is only used during PS domain authentication operations whereas UICC  250 - 2  may contain a second IMSI that is different than the first IMSI and that is only used during CS domain authentication operations). 
     Wireless circuitry  34  may include radio-frequency transceiver circuitry such as radio-frequency transceiver circuitry (e.g., transceiver circuits  206  and  208 ) and radio-frequency front-end circuitry  210 . Some transceivers may include both a transmitter and a receiver. If desired, one or more transceivers may be provided with receiver circuitry but no transmitter circuitry (e.g., to use in implementing receive diversity schemes). 
     Radio-frequency front end circuitry  210  may be coupled between the transceiver circuitry and antennas  40 . In particular, transceivers  206  and  208  may be coupled to front end circuitry  210  via paths  212  and  214 , respectively. Radio-frequency front end  210  may be used to convey the radio-frequency signals that are produced by the radio-frequency transceiver circuitry to antennas  40 . Radio-frequency front end  210  may include radio-frequency switches, impedance matching circuits, band pass filters, duplexers, power amplifiers, low noise amplifiers, and other circuitry interposed between antennas  40  and transceivers  206  and  208 . 
     Incoming radio-frequency signals that are received by antennas  40  may be provided to baseband processors  202  and  204  via radio-frequency front end  210 , paths such as paths  212  and  214 , and receiver circuitry in transceivers  206  and  208 . Path  212  may, for example, be used in handling signals associated with transceiver  206 , whereas path  214  may be used in handling signals associated with transceiver  208 . Baseband processors  202  and  204  may be used to convert received signals into digital data that is provided to applications processor  200 . Baseband processors  202  and  204  may also extract information from received signals that is indicative of signal quality for the channel to which the associated transceivers are currently tuned. 
     In the example of  FIG. 4 , antennas  40  may include a first pair of antennas  40 A and a second pair of antennas  40 B. The first antenna pair may include antenna  40 A′ that can be used to transmit and receive wireless signals and may include antenna  40 A″ that can only be used to receive wireless signals. Similarly, the second antenna pair may include antenna  40 B′ that can be used to transmit and receive wireless signals and may include antenna  40 B″ that can only be used to receive wireless signals. Antennas  40 A′ and  40 B′ may sometimes be referred to as “primary” antennas (i.e., antennas capable of transmitting and receiving RF signals), whereas antennas  40 A″ and  40 B″ may sometimes be referred to as “secondary” antennas (i.e., antennas capable of only receiving RF signals). As an example, antennas  40 A may be formed in region  22  of device  10 , whereas antennas  40 B may be formed in region  24  of device  10 . If desired, antennas  40  may include less than four antennas or more than four antennas (e.g., device  10  may include any number of primary antennas and any number of secondary antennas). 
     Radio-frequency front end  210  may include switching circuitry. The switching circuitry may be controlled using control signals Vc received from applications processor  200  via path  209 . If desired, the state of radio-frequency front end  210  may also be controlled using control signals generated from at least one of baseband processors  202  and  204 . 
     As an example, the switching circuitry in front end  210  may be capable of coupling transceiver  206  to antenna  40 A (e.g., so that transceiver  206  can transmit RF signals using antenna  40 A′ and receive RF signals using at least one of antennas  40 A′ and  40 A″) while coupling transceiver  208  to antenna  40 B (e.g., so that transceiver  208  can transmit RF signals using antenna  40 B′ and receive RF signals using at least one of antennas  40 B′ and  40 B″). As another example, the switching circuitry may be capable of switching a first portion of antennas  40  into use (referred to as currently active antennas) while switching a second portion of antennas  40  out of use (referred to as inactive antennas). In this scenario, the currently active antennas may be coupled to either transceiver  206  for handling data traffic or transceiver  208  for handling voice traffic. As another example, the switching circuitry may be capable of coupling both antenna pairs  40 A and  40 B to a selected one of transceivers  206  and  208  (e.g., the selected transceiver may be coupled to any two of antennas  40  for receiving RF signals via those two antennas). As another example, the switching circuitry may be capable of coupling both transceivers  206  and  208  to one active antenna (e.g., to antenna  40 A′ or  40 B′) so that transmit signals may be radiated using a common antenna. 
     If desired, antenna selection may be made by selectively activating and deactivating transceivers without using a switch in front end  210 . For example, if it is desired to use antennas  40 A but not antennas  40 B, transceiver  208  (which may be coupled to antennas  40 A through circuitry  110 ) may be activated and transceiver  206  (which may be coupled to antennas  40 B through circuitry  110 ) may be deactivated. If it is desired to use antennas  40 B but not antennas  40 A, applications processor  200  may activate transceiver  206  and deactivate transceiver  208 . Combinations of these approaches may also be used to select which antennas are being used to transmit and/or receive signals. When it is desired to receive incoming signals such as paging signals using both antennas, transceiver  206  and transceiver  208  may be simultaneously activated to place device  10  in a dual antenna mode. The radio configuration of  FIG. 4  is merely illustrative and is not intended to limit the scope of the present invention. If desired wireless circuitry  34  may include any number of baseband processing integrated circuits and associated transceivers, any number of antennas, and any suitable circuitry for interfacing the antennas and the transceivers. 
       FIG. 5  shows another suitable arrangement for wireless circuitry  34 . As shown in  FIG. 5 , antennas  40  may include antennas  40 A and  40 B. Antennas  40 A and  40 B may each be used to transmit and receive radio-frequency signals (e.g., device  10  need not include secondary antennas). As an example, front end  210  may be configured to couple transceiver  206  to antenna  40 A and to couple transceiver  208  to antenna  40 B (e.g., so that data traffic is handled using antenna  40 A and so that voice traffic is handled using antenna  40 B). As another example, front end  210  may be configured to couple transceiver  206  to antenna  40 B and to coupled transceiver  208  to antenna  40 A (e.g., so that data traffic is handled using antenna  40 B and so that voice traffic is handled using antenna  40 A). As another example, front end  210  may be configured to couple transceivers  206  and  208  to a selected one of antennas  40 A and  40 B so that data traffic and voice traffic can be transmitted/received via a shared antenna (e.g., transceivers  206  and  208  may take turns transmitting and receiving wireless signals in a time division duplexing scheme). As another example, front end  210  may be configured to couple antennas  40 A and  40 B to only transceiver  208  so that voice traffic may be transmitted/received using both antennas  40 A and  40 B (to support multiple-input multiple-output (MIMO) wireless communications schemes). 
     In another suitable arrangement of the present invention, device  10  may only contain one UICC (see, e.g.,  FIG. 6 ). As shown in  FIG. 6 , UICC  256  may be directly coupled to voice baseband processor  204 . UICC  256  may store a single IMSI that is used for both PS and CS domain registrations (e.g., UICC  256  may be shared between baseband processors  202  and  204 ). During CS domain registration operations, voice baseband processor  204  may retrieve the IMSI and private key Ki from UICC  256 . During PS domain registration operations, data baseband processor  202  may retrieve the IMSI and private key Ki from UICC  256  via voice baseband processor  204  and inter-processor path  203 , as indicated by path  257 . If desired, shared UICC  256  may instead be coupled directly to data baseband processor  202  (see, e.g.,  FIG. 7 ). In general, UICC  256  may be directly coupled to the baseband processing integrated circuit having more stringent performance requirements. 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20120110
Publication Date: 20150602
Grant Date: 20150602
Priority Date: 20110114
Inventors: MUJTABA SYED A.
SHI JIANXIONG
MAHE ISABEL G.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W36/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W88/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W8/18", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W36/142", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W88/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W88/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W36/142", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W8/18", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 46490711