Abstract:
This inventions relates to an identity suspension method and system for a mobile device designed for operation with a subscriber identification module (SIM) card, wherein the mobile device further includes a virtual SIM device. The virtual SIM device acts as a bridge between a remotely located SIM card, and the mobile device. The virtual SIM device can detect when the mobile device requests an identity or when the cellular services provider is attempting to authenticate the identity associated with the mobile device. Should the virtual SIM device sense that the process may not be completed for any reason, the virtual SIM device returns a transient error to the mobile device and effectively present a new “parking” identity to the mobile device using procedures defined in SIM toolkit.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the United States National Phase of Patent Application No. PCT/IL2015/050023 filed 6 Jan. 2015, which claims priority to Israeli Patent Application No. 230345 filed 6 Jan. 2014, each of which is incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention, in some embodiments thereof, relates to wireless communication and, more particularly, but not exclusively, to methods and devices for establishing and maintaining communication sessions with cellular network subscribers. 
     BACKGROUND OF THE INVENTION 
     The present invention, in some embodiments thereof, relates to wireless communication and, more particularly, but not exclusively, to methods and systems to establish and maintain communication sessions with cellular network subscribers. 
     As commonly known, there are many mobile or cellular services providers in the world, usually more than one in a single country. These cellular services providers include, but are not limited to, service providers who provide mobility services using global system for mobile communications (GSM), general packet radio service (GPRS), third generation (3G), code division multiple access (CDMA), time division multiple access (TDMA), personal handy phone system (PHS), wideband CDMA (WCDMA), integrated digital enhanced network (IDEN) and wireless local loop (WLL) technologies or their variants. These cellular services providers provide voice, cellular messaging and data services to their own subscribers and to subscribers from other networks. 
     As commonly known, wireless networks use numeric identifiers to communicate with Mobile Stations (MS) over an air interface. Messages or communications exchanged between the wireless network and MS contain remotely acquired identification data that permits the network to distinguish between different MS while performing operations related to calls and roaming. For example, GSM based wireless networks are specified to support an international mobile station identity (IMSI) as the identifier for MS so that billable services can be provided to international roamers. The IMSI is a unique identifier up to 15 digits in length allocated to each mobile subscriber. The IMSI is a unique identifier is stored, for example, in a subscriber identification module (SIM) card, along with other confidential information known only to the SIM and the cellular services provider to whom the SIM card belongs. 
     The term “identification data” as defined herein, refers to data that contains information regarding the identity of a mobile device such as a mobile phone, a mobile tablet, smart cameras and a portable computer, wherein the identity information is typically kept on a removable device such as SIM card (the removable device is referred to herein, with no limitations, as a “SIM card”). It should be noted that the mobile device may store identification data on the SIM card. Example SIM cards that are currently in use include SIM cards, USIM cards and UICC cards. They may be marked as such or a combination thereof. 
     When a mobile device in a GSM network attempts registration to a particular cellular services provider, the most basic mandatory element the mobile device is required to provide is a global unique identity, i.e. the IMSI, so that the cellular services provider may be able to provision billable services for that mobile device. This unique identity is typically stored in a particular SIM card, along with other confidential information known only to that particular SIM and to the cellular services provider that owns that particular SIM. 
     Upon presentation of the unique identity, and optionally periodically, the cellular services provider attempts to authenticate the received unique identity through procedures described in 3GPP 33.102, which is incorporated herein by reference, by sending an authentication message to the SIM card via the mobile device. Using confidential data known only to the SIM and the cellular services provider, the SIM generates a response message and the mobile device sends that response message to the cellular services provider. 
     In embodiments where no SIM card is presented and the identity of the mobile device is effectively stored remotely, as described in WO/2012/140654, which is incorporated herein by reference as if fully set forth herein, there may be situations in which time no valid identity can be presented or the previously presented identity cannot complete the initial authentication process or a periodic authentication process. This may be due to the fact that a connection to the remote identity has yet to be established, configuration issues, connectivity issues between the mobile device and the remotely stored identity, or other transient ailments. 
     Under normal conditions this would typically result in the mobile device prompting the user that no SIM card exists and that he/she must reboot his/her mobile device. The mobile device may also prompt the user with a message to replace the SIM card or remove the SIM card. 
     There is therefore a need, when the identity of the mobile device is effectively stored remotely, and no valid identity can be presented or be authenticated, to prevent the mobile device from prompting the user with a notification that no SIM card exists and that he/she must reboot his/her mobile device. 
     SUMMARY OF THE INVENTION 
     The principal intentions of the present invention include providing an identity suspension method for a mobile device designed for operation with a SIM card, wherein the mobile device further includes a virtual SIM device. The virtual SIM device is operatively disposed in the mobile device instead of a conventional SIM card, and acts as a bridge between a remotely located SIM card, and the mobile device. The virtual SIM device can detect when the mobile device requests an identity (typically during power up) or when the cellular services provider is attempting to authenticate the identity associated with the mobile device (typically during power up and periodically according to a myriad of factors). 
     Should the virtual SIM device sense that the process may not be completed for any reason, the virtual SIM device returns a transient error to the mobile device (e.g. when the cellular services provider is requesting authentication and the communication flow between the virtual SIM device and the remotely located SIM card is lost, the virtual SIM device may respond with 0x9862—“Authentication error, application specific” according to TS 102.221) and effectively present a new “parking” identity to the mobile device using procedures defined in SIM toolkit (including, but not limited to, a UICC reset request). 
     The “parking” identity is a specially tailored identity that satisfies the requirement of the mobile device for a valid identity, but does not trigger an authentication process, since that valid identity does not belong to any cellular services provider. For example, the identity may be an identity of MCC/MNC 00101 that is assigned to “GSM Test Network” cellular services provider. 
     Once the virtual SIM device regains the ability to retrieve and authenticate a cellular services provider owned identity, the virtual SIM presents the retrieved identity to the mobile device using the same methods used to present the “parking” identity. 
     According to the teachings of the present invention there is provided an identity suspension method of remotely updating a portable-storage-device, the portable-storage-device uses an updating unit, operatively connected to a remote unit, for receiving identification data, the method including the step of monitoring the operational connectivity between the portable-storage-device and the remote unit, wherein upon detecting no operational connectivity between the updating unit and the remote unit, setting a remote-connectivity-status to a no-connectivity state, and wherein upon detecting operational connectivity between the updating unit and the remote unit, setting the remote-connectivity-status to an operational state. 
     Upon the portable-storage-device receiving an authentication request form a hosting-mobile-device, during the operational state, the method proceeds with obtaining new identification data by the portable-storage-device from the remote unit, over a network, typically a wireless network; updating the portable-storage-device with the new identification data received from the remote unit the through the updating unit; and providing the new identification data to the hosting-mobile-device, after the new identification data is updated in the portable-storage-device. 
     Upon the portable-storage-device receiving an authentication request form the hosting-mobile-device, during the no-connectivity state, the method proceeds as follows:
         When detecting loss of connectivity between the updating unit and the remote unit, changing the identity stored in the portable storage device to a temporary identity and instructing the hosting-mobile-device to use the temporary identification.   When detecting reestablishment of operational connectivity between the updating unit and the remote unit, changing the temporary identity stored in the portable storage device to an identity provided by the remote unit and instructing the hosting-mobile-device to use the newly provided identity.       

     Preferably, the temporary identification includes instructions to the hosting-mobile-device not to search for a cellular communication network except for mandatory emergency call services. 
     Typically, the wireless network is selected from the group including an internet communication network and a cellular communication network. 
     Typically, the portable-storage-device is emulating a SIM card or a UICC/USIM. 
     Optionally, the identity suspension method further including enabling at least two of the portable-storage-devices to interface with the hosting-mobile-device, where only one of the at least two portable-storage-devices is communicating with the hosting-mobile-device at any time. 
     According to further teachings of the present invention there is provided a portable-storage-device, including a memory component for storing identification data, an identification-card-interface-component operatively connected to a hosting-mobile-device to provide the hosting-mobile-device with the identification data, an update-interface-component operatively connected to an updating unit to thereby receive new identification data from a remote unit, to be stored in the memory component, and a control component for controlling the memory component, the hosting-mobile-device, the update-interface-component, and for monitoring the operational connectivity between the portable-storage-device with the remote unit. 
     Upon detecting no operational connectivity between the updating unit and the remote unit, setting a remote-connectivity-status to a no-connectivity state. 
     Upon detecting operational connectivity between the updating unit and the remote unit, setting the remote-connectivity-status to an operational state; and 
     Upon the portable-storage-device receiving a data authentication request form the hosting-mobile-device, during the no-connectivity state, then when detecting loss of connectivity between the updating unit and the remote unit, changing the identity stored in the portable storage device to a temporary identity and instructing the hosting-mobile-device to use the temporary identification; and when detecting reestablishment of operational connectivity between the updating unit with the remote unit, changing the temporary identity stored in the portable storage device to an identity provided by the remote unit and instructing the hosting-mobile-device to use the newly provided identity. 
     Optionally, the identification-card-interface-component is installed in an identification-card-socket of the hosting-mobile-device, facilitating communication between the identification-card-interface-component and the hosting-mobile-device. 
     Preferably, the hosting-mobile-device complies with ISO/IEC 7816 specification. 
     Optionally, the updating unit is integrated with the portable-storage-device. 
     Optionally, the updating unit is built into the portable-storage-device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention.  10  In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced. 
       In the drawings: 
         FIG. 1  is a schematic illustration of an exemplary remote update system for remote update of a portable storage device which is plugged into an identification card socket, according to some embodiments of the present invention. 
         FIG. 2  is a schematic flow chart showing an exemplary connectivity-state monitoring method of the portable-storage-device with the remote unit, according to embodiments of the present invention. 
         FIG. 3  is a schematic flow chart showing an exemplary basic suspended-state method of providing identity suspension to hosting-mobile-device, according to embodiments of the present invention, when the identity of the mobile device is effectively stored remotely and is not available. 
         FIG. 4  (prior art) is a schematic sequence diagram illustration of an exemplary typical communication sequence between a remote unit, a hosting-mobile-device and a portable-storage-device, typically installed in an identification-card-socket, including when communication flow is lost. 
         FIG. 5  is a schematic sequence diagram illustration of an exemplary typical communication sequence between a hosting-mobile-device and a portable-storage-device, typically installed in an identification card socket, according to some embodiments of the present invention, including handling loss of communication flow. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided, so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
     An embodiment is an example or implementation of the inventions. The various appearances of “one embodiment,” “an embodiment” or “some embodiments” do not necessarily all refer to the same embodiments. Although various features of the invention may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention may also be implemented in a single embodiment. 
     Reference in the specification to “one embodiment”, “an embodiment”, “some embodiments” or “other embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least one embodiments, but not necessarily all embodiments, of the inventions. It is understood that the phraseology and terminology employed herein is not to be construed as limiting and are for descriptive purpose only. 
     Methods of the present invention may be implemented by performing or completing manually, automatically, or a combination thereof, selected steps or tasks. The term “method” refers to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the art to which the invention belongs. The descriptions, examples, methods and materials presented in the claims and the specification are not to be construed as limiting but rather as illustrative only. 
     Meanings of technical and scientific terms used herein are to be commonly understood as to which the invention belongs, unless otherwise defined. The present invention can be implemented in the testing or practice with methods and materials equivalent or similar to those described herein. 
     It should be noted that orientation related descriptions such as “bottom”, “up”, “upper”, “down”, “lower”, “top” and the like, assumes that the associated item is operationally situated, that is generally vertical and facing the user. 
     As used herein, the singular form “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a compound” or “at least one compound” may include a plurality of compounds, including mixtures thereof. 
     The word “exemplary” is used herein to mean “serving as an example, instance or illustration”. Any embodiment described as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments and/or to exclude the incorporation of features from other embodiments. 
     The word “optionally” is used herein to mean “is provided in some embodiments and not provided in other embodiments”. Any particular embodiment of the invention may include a plurality of “optional” features unless such features conflict. 
     Reference is made to the drawings.  FIG. 1  is a schematic illustration of an exemplary remote update system  100  for a remote update of a portable storage device  110 . The portable storage device  110  is typically plugged into an identification card socket  24 , according to some embodiments of the present invention. Remote update system  100  includes portable-storage-device (alternatively termed as virtual SIM device)  110 , an updating unit  120  and a remote unit  130 . Typically, portable-storage-device  110  emulates a subscriber identification module (SIM) card or a UICC/USIM (Universal Integrated Circuit Card/Universal Subscriber Identity Module). 
     Portable-storage-device  110  includes a memory component  112  for storing identification data, an identification-card-interface-component  114 , an update-interface-component  116  and a control component  118 . Identification-card-interface-component  114  is operatively connected to a hosting-mobile-device  20  to thereby provide hosting-mobile-device  20  with identification data obtained from remote unit  130 . Update-interface-component  116  is operatively connected to updating unit  120  to thereby receive new identification data from remote unit  130 , to be stored in memory component  112 . Control component  118  operatively controls memory component  112 , identification-card-interface-component  114  update-interface-component  116 , and monitors the operational connectivity between portable-storage-device  110  with remote unit  130 . 
     When control component  118  detects no operational connectivity between updating unit  120  and remote unit  130 , control component  118  sets a remote-connectivity-status indicator to a “no-connectivity state”. The no-connectivity situation may occur, for example, when the mobile device is in a highway tunnel or a railroad tunnel. Otherwise, the remote-connectivity-status is set to an “operational state”. 
     When portable-storage-device  110  receives an identification data request form hosting-mobile-device  20 , if control component  118  detects a loss of connectivity between updating unit  120  and remote unit  130 , control component  118  notifies hosting-mobile-device  20  of a change of identity to a temporary identification. When detecting reestablishment of operational connectivity between updating unit  120  and remote unit  130 , control component  118  notifies hosting-mobile-device  20  of a change in identity, providing hosting-mobile-device  20  with the identity derived from the newly received identification data. 
     Preferably, the notification of a temporary identification includes instructions to hosting-mobile-device  20  not to search for a cellular communication network except for mandatory emergency call services. Hence, since hosting-mobile-device  20  cannot verify its identity, such an instruction prevents repeatable attempts by hosting-mobile-device  20  to authenticate its identity. 
     Typically, identification-card-interface-component  114  is installed in an identification-card-socket  24  of hosting-mobile-device  20 , facilitating communication between identification-card-interface-component  114  and hosting-mobile-device  20 . Preferably, hosting-mobile-device  20  complies with ISO/IEC 7816 specification. 
     Optionally, updating unit  120  is integrated with portable-storage-device  110  or built into portable-storage-device  110 . 
     Reference is now made to  FIG. 2 , a schematic flow chart, showing an exemplary connectivity-state monitoring method  200  of portable-storage-device  110  with remote unit  130 , according to embodiments of the present invention. 
     It is an aspect of the present invention to monitor the communication flow of portable-storage-device  110  with remote unit  130 , such as by using connectivity-state monitoring method  200 . Such monitoring is required to provide identification data, when requested. 
     connectivity-state monitoring method  200  includes with the following steps:
     Step  210 : begin a cycle of monitoring the connectivity of portable-storage-device  110 .
       Control component  118  continuously monitors the operational connectivity between portable-storage-device  110  with remote unit  130 , cycle by cycle.   
       Step  215 : checking what is the remote-connectivity-status.
       Control component  118  checks what is the current state of the remote-connectivity-status indicator.   If the current state of the remote-connectivity-status indicator is “no-connectivity state”, go to step  255 .   
       Step  225 : checking if has just detected loss of communication flow between portable-storage-device  110  and remote unit  130 .
       Control component  118  checks if it has just detected loss of communication flow between portable-storage-device  110  and remote unit  130 .   If no loss of communication flow, between portable-storage-device  110  and remote unit  130  was detected, go to step  210 .   
       Step  230 : setting remote-connectivity-status to “no-connectivity state”.
       Having just detected loss of communication flow, between portable-storage-device  110  and remote unit  130 , control component  118  sets remote-connectivity-status indicator to “no-connectivity state”.   Go to step  210 .   
       Step  255 : checking if has just reestablished communication flow between portable-storage-device  110  and remote unit  130 .
       Control component  118  checks if communication flow, between portable-storage-device  110  and remote unit  130 , has just been reestablished.   If communication flow, between portable-storage-device  110  and remote unit  130 , has not just been reestablished, go to step  210 .   
       Step  260 : setting remote-connectivity-status to “operational state”.
       The remote-connectivity-status indicator being in a “no-connectivity state” and having just detected, there is re-established communication between portable-storage-device  110  and remote unit  130 , control component  118  sets remote-connectivity-status indicator to “operational state”.   Go to step  210 .   
       Step  265 : checking if the currently presented identity, to hosting-mobile-device  20 , is a temporary identity.
       Control component  118  checks if the currently presented identity, to hosting-mobile-device  20 , is a temporary identity.   If the currently presented identity is not a temporary identity, go to step  210 .   
       Step  270 : notifying the hosting-mobile-device of a change of identity.
       Control component  118  notifies hosting-mobile-device  20  of a change of identity. Go to step  210 .
 
[end of method  200 ]
   
       

     Reference is now made to  FIG. 3 , a schematic flow chart, showing an exemplary basic suspend-state method  500  of providing suspend identity to hosting-mobile-device  20 , according to embodiments of the present invention, when the identity of hosting-mobile-device  20  is effectively stored remotely and is not available. 
     It is an aspect of the present invention to provide identity suspension methods, such as by suspend-state method  500 , for remotely updating a portable-storage-device  110 , wherein portable-storage-device  110  uses an updating unit  120 , operatively connected to a remote unit  130 , for receiving identification data. Typically, updating unit  120  and remote unit  130  are interconnected by a non-cellular wireless network  50 , such as a wireless internet network, or by a partially-cellular wireless network  50 . 
     Suspend-state method  500  includes with the following steps:
     Step  200 : monitoring connectivity of portable-storage-device  110 .
       Control component  118  monitors the operational connectivity between portable-storage-device  110  with remote unit  130 .   
       Step  505 : checking if received a request for identification data.
       Control component  118  checks if received a request for identification data to be obtained by portable-storage-device  110  from remote unit  130 .   If no such request for identification data was received, go to Step  200 .   
       Step  515 : checking what is the remote-connectivity-status.
       Control component  118  checks what is the current state of the remote-connectivity-status indicator.   If the current state of the remote-connectivity-status indicator is “no-connectivity state”, go to step  580 .   
       Step  520 : obtaining new identification data.
       Portable-storage-device  110  obtains new identification data from remote unit  130 , typically, over a wireless network.   
       Step  525 : checking if has just loss of communication flow between portable-storage-device  110  and remote unit  130 .
       Control component  118  checks if communication flow, between portable-storage-device  110  and remote unit  130 , has just been lost.   If communication flow, between portable-storage-device  110  and remote unit  130 , has not just been lost, go to step  540 .   
       Step  530 : returning an authentication error message and notifying the hosting-mobile-device of a change of identity to a temporary identification.
       Preferably, control component  118  returns an authentication error message to hosting-mobile-device  20 .   Control component  118  notifies hosting-mobile-device  20  of a change of identity to a temporary identification.   Go to step  200 .   
       Step  540 : updating portable-storage-device  110  with the new identification data.
       Control component  118  stores the newly obtained identification data in memory component  112 .   
       Step  550 : providing the new identification data to hosting-mobile-device  20 .
       Control component  118  provides the new identification data to hosting-mobile-device  20 , typically, with no limitations, through identification-card-interface-component  114 .   Go to step  200 .   
       Step  580 : returning an authentication error message.
       Preferably, control component  118  returns an authentication error message to hosting-mobile-device  20 .   Go to step  200 .
 
[end of method  500 ]
   
       

     It should be noted that when a hosting-mobile-device allows usages of at least two of portable-storage-devices, the method includes enabling the at least two of portable-storage-devices to interface with the hosting-mobile-device, where only one of the at least two portable-storage-devices is communicating with the hosting-mobile-device at any time. 
     Reference is now made to  FIG. 4  (prior art), schematically illustrating a sequence diagram  300  of an exemplary typical communication sequence between a remote unit  130 , a hosting-mobile-device  20  and a portable-storage-device  110 . Portable-storage-device  110  is typically, with no limitations, installed in an identification-card-socket  24 , including when communication flow is lost. 
       FIG. 4  describes the communication flow prior to applying identity suspension method  200 , described here above, in embodiments where no SIM card is presented and the identity of hosting-mobile-device  20  is effectively stored remotely, in remote unit  130 . When communication flow is sustained between portable-storage-device  110  and remote unit  130 , portable-storage-device  110  obtains the IMSI from remote unit  130 , as shown by communication segment  312  of time instance  310 . Portable-storage-device  110  provides the IMSI to hosting-mobile-device  20  in communication segment  314 , and hosting-mobile-device  20  registers with the cellular services provider  40  that owns the SIM being emulated, or in the case of roaming, with another cellular services provider having operational relationship with cellular services provider  40 , that owns the SIM being emulated. 
     When that cellular services provider  40  sends an authentication message to that SIM card via hosting-mobile-device  20  (communication segment  326  of time instance  320 ), the authentication request is provided to portable-storage-device  110  (communication segment  324 ) that in turns forwards the authentication request to remote unit  130 , as shown by communication segment  322 . The requested identification data is retrieved by remote unit  130  (as shown by communication segment  331 ) that returns the retrieved identification data to portable-storage-device  110 , as shown by communication segment  332 . Portable-storage-device  110  provides the retrieved identification data to hosting-mobile-device  20  (communication segment  336 ) that in turns provides the retrieved identification data to cellular services provider  40 , as shown by communication segment  336 . 
     When a communication failure between portable-storage-device  110  and remote unit  130  occurs, and the cellular services provider  40  to whom the remote SIM is assigned sends an authentication request to hosting-mobile-device  20  (communication segment  346  of time instance  340 , the authentication request is provided to portable-storage-device  110  (communication segment  344 ) that in turns attempts to forwards the authentication request to remote unit  130 , as shown by communication segment  322 . However, due to the communication failure between portable-storage-device  110  and remote unit  130 , represented by  305 , the identification data cannot be retrieved returning error messages (as shown by communication segments  354  and  356 ). 
     The cellular services provider  40  repeats the authentication process until a terminal error occurs (the cellular services provider  40  gives up or hosting-mobile-device  20  gives up, represented by communication segment  388 ). In such a case service may not resume until hosting-mobile-device  20  is rebooted. 
     Reference is also made to  FIG. 5 , illustrating a schematic sequence diagram  400  of an exemplary typical communication sequence between a remote unit  130 , a hosting-mobile-device  20  and a portable-storage-device  110 . Portable-storage-device  110  is typically, with no limitations, installed in an identification-card-socket  24 , including when communication flow is lost. 
       FIG. 5  describes the communication flow including applying identity suspension method  200 , described here above, in embodiments where no SIM card is presented and the identity of hosting-mobile-device  20  is effectively stored remotely, in remote unit  130 , including when a communication failure between portable-storage-device  110  and remote unit  130  occurs. 
     When communication flow is sustained between portable-storage-device  110  and remote unit  130 , portable-storage-device  110  obtains the IMSI from remote unit  130 , as shown by communication segment  412  of time instance  410 . Portable-storage-device  110  provides the IMSI to hosting-mobile-device  20  in communication segment  414 , and hosting-mobile-device  20  registers with the cellular services provider  40  (communication segment  416 ) that owns the SIM being emulated. When that cellular services provider  40  sends an authentication message to that SIM card via hosting-mobile-device  20  (communication segment  426  of time instance  420 ), the authentication request is provided to portable-storage-device  110  (communication segment  424 ) that in turns forwards the authentication request to remote unit  130 , as shown by communication segment  422 . The requested identification data is retrieved by remote unit  130  (as shown by communication segment  431 ) that returns the retrieved identification data to portable-storage-device  110 , as shown by communication segment  432 . Portable-storage-device  110  provides the retrieved identification data to hosting-mobile-device  20  (communication segment  436 ) that in turns provides the retrieved identification data to cellular services provider  40 , as shown by communication segment  436 . 
     When a communication failure between portable-storage-device  110  and remote unit  130  occurs (represented by  405 ), and the cellular services provider  40  to whom the remote SIM is assigned sends an authentication request to hosting-mobile-device  20  (communication segment  446  of time instance  440 , the authentication request is provided to portable-storage-device  110  (communication segment  444 ) that in turns attempts to forwards the authentication request to remote unit  130 , as shown by communication segment  442 . However, due to the communication failure between portable-storage-device  110  and remote unit  130 , the identification data cannot be retrieved returning error messages (as shown by communication segments  454  and  456 ). Portable-storage-device  110  identifies that there is no communication flow between portable-storage-device  110  and remote unit  130 , and provides hosting-mobile-device  20  with a new identity, being a temporary identification (“parking” identification, as shown by communication segments  464  and  469 ), as described in step  240  of identity suspension method  200 . Hosting-mobile-device  20  enters a “parking” state, in which state hosting-mobile-device  20  unregisters from the cellular services provider  40  that owns the SIM being emulated, and the cellular communication services for hosting-mobile-device  20  are suspended. 
     Portable-storage-device  110  continues to monitor the communication state with from remote unit  130 . Once the communication flow between portable-storage-device  110  and remote unit  130  resumes, portable-storage-device  110  detects the reestablishment of communication with remote unit  130  and retrieves the IMSI from remote unit  130  (as shown by communication segment  472 ). Portable-storage-device  110  then provides hosting-mobile-device  20  with a new identity, as retrieved from remote unit  130  (as shown by communication segment  473 ). Hosting-mobile-device  20  registers the newly received IMSI with the cellular services provider  40  (communication segment  476 ) that owns the SIM being emulated, and the cellular communication services resume. 
     The invention being thus described in terms of several embodiments and examples, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art.