Abstract:
A method and apparatus of communicating with a plurality of cellular communication networks employing different communication protocols using a single mobile endpoint device, e.g., a cellular phone, are disclosed. In one embodiment, a user cellular phone is provided with a communication protocol conversion or switching module that is adapted for interfacing with different cellular networks operating in a region where the cellular phone is presently located. When a request for an incoming call or an outgoing call is received, the present method evaluates at least one performance factor in selecting one of the plurality of different communication protocols to service or process the incoming call or outgoing call.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention generally relates to a field of communication devices and, in particular, to user communication devices of cellular telephone networks. 
         [0003]    2. Description of the Related Art 
         [0004]    One of the solutions for expanding services of cellular telephone networks is offered by Mobile Virtual. Network Operators (MVNOs). A MVNO usually does not own any network infrastructures but instead enters into business agreements with various regional cellular telephone networks to buy the airtime and then offers cellular services to retail users. 
         [0005]    However, a conventional cellular phone is designed to operate only using a particular cellular communication protocol. As such, a MVNO can integrate only the service regions where the cellular services are provided by networks using the same communication protocol. Traveling users are specifically impacted by inoperability of their cellular phones outside of a service region of the respective cellular network. 
         [0006]    Therefore, there is a need in the art for a method and apparatus for providing multi-network cellular communications. 
       SUMMARY OF THE INVENTION 
       [0007]    In one embodiment, the present invention discloses a method and apparatus of communicating with a plurality of cellular communication networks employing different communication protocols using a single mobile endpoint device, e.g., a cellular phone. According to the present method, a user cellular phone is provided with a communication protocol conversion or switching module that is adapted for interfacing with different cellular networks operating in a region where the cellular phone is presently located. Namely, these different cellular networks employ different communication protocols. When a request for an incoming call or an outgoing call is received, the present method evaluates at least one performance factor in selecting one of the plurality of different communication protocols to service or process the incoming call or outgoing call. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which: 
           [0009]      FIG. 1  depicts a high-level schematic diagram of a multi-system cellular service area according to one embodiment of the present invention; 
           [0010]      FIG. 2  depicts a flow diagram of a method for providing multi-network cellular communications according to one embodiment of the present invention; and 
           [0011]      FIG. 3  depicts a high-level block diagram of an exemplary multi-network cellular phone suitable for facilitating the method of  FIG. 2  according to one embodiment of the present invention. 
       
    
    
       [0012]    To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. 
         [0013]    It is to be noted, however, that the appended drawings illustrate only exemplary embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. 
       DETAILED DESCRIPTION 
       [0014]    The present invention will be generally described within the context of cellular communication networks and relates to a method and apparatus for providing multi-network cellular communications using a single mobile endpoint device, e.g., a cellular phone. 
         [0015]      FIG. 1  depicts a high-level schematic diagram of a multi-system cellular service area  100  according to one embodiment of the present invention. In the depicted embodiment, the area  100  illustratively includes overlapping service areas or regions  101 - 103 , however, in other embodiments, a number of the overlapping service areas may be either smaller or greater than three areas or regions. Each of the service areas  101 - 103  is serviced by a provider of cellular services that, in the respective area, operates its own network infrastructure. Regions  104 - 107  relate to portions of the regions where two of the service areas  101 - 103  overlap. Accordingly, a region  108  corresponds to a portion of the regions where all service areas  101 - 103  overlap. 
         [0016]    In one embodiment, in each of the service areas  101 - 103 , cellular networks may utilize different and non-compatible communication protocols, e.g., different modulation schemes, formats, link protocols, wavelength, signal structures, signal waveforms, and the like. Exemplary communication protocols include the Global System for Mobile Communications (GSM) protocol, the Code Division Multiple Access (CDMA) protocol (e.g., IS-95 or CDMA2000), the Wideband CDMA (WCDMA) protocol, the Time Division Multiple Access (TDMA) protocol, the American National Standard Institute-136 (ANSI-136) protocol and the like. 
         [0017]      FIG. 2  depicts a flow diagram of a method  200  for multi-network cellular communications according to one embodiment of the present invention. The method  200  starts at step  202  and proceeds to step  204 . 
         [0018]    At step  204 , a phone is provided with a multi-system cellular capability via a communication protocol conversion (or switching) module (CPCM). In one embodiment, the CPCM may have built-in hardware and/or software capabilities to support two or more cellular communication protocols or, alternatively, operate in a software-defined mode utilizing, e.g., the SoftRadio technology. In operation, a communication protocol used by such a cellular phone may be selectively changed from one protocol to another protocol, either manually by the user or automatically, to be compatible with the communication protocol of the cellular network operating in the region where the cellular phone is currently located. 
         [0019]    At step  206 , the multi-system cellular phone performs a routine of receiving an incoming call. Specifically, when the incoming call is detected in any of the service areas  101 - 109 , the multi-system cellular phone automatically configures the CPCM to the communication protocol of the cellular network that initiated the incoming call (i.e., service request). 
         [0020]    In one exemplary embodiment, in a stand-by mode, the CPCM automatically switches, with a pre-determined periodicity, between different communication protocols to detect the service request. In another embodiment, the CPCM may be pre-configured, either by a user manually or automatically, to the communication protocol of a known regional provider of the cellular services in the region where the multi-system cellular phone is currently located. 
         [0021]    At step  208 , outgoing calls from the multi-system cellular phone are facilitated from any one of the service areas  101 - 109 . Specifically, such calls are handled using the communication protocol of the cellular network operating in the region where the multi-system cellular phone is currently located. 
         [0022]    In one embodiment, determination of the communication protocol is provided by sequentially generating service requests using the communication protocols supported by the CPCM. In another embodiment, the CPCM may be pre-configured to the communication protocol of a known regional provider of the cellular services for the region where the phone is currently located. In yet another embodiment, when the phone is located in one of the service areas  105 - 108  where multiple communication protocols may be employed, a choice of the CPCM configuration can be defined by one or more factors (broadly defined as performance factors), such as the subscriber&#39;s location, signal strength (receive and/or transmit), the called party&#39;s location, cost of the airtime to the subscriber, time of day or day of week, subscriber specified preference, and the like. For example, if the subscriber&#39;s location is in an overlapped region covered by two service providers, e.g., edge of a region covered by a first service provider and a non-edge region covered by a second service provider, then the method may prefer using the protocol of the second service provider. In another example, the method will select the protocol associated with a higher signal strength. In another example, the method will select the protocol associated with a lower cost to the subscriber. In another example, the subscriber may set a predefined preference, e.g., for one protocol over another protocol, for one service provider over another service provider, and so on. 
         [0023]    At step  210 , the multi-system cellular phone may be provided with optional means of the wireless fidelity (WiFi) connectivity and/or the Bluetooth interface. Such multi-system cellular phone is capable of interfacing with both cellular and cordless communication networks. At step  212 , the method  200  ends. 
         [0024]      FIG. 3  depicts a high-level exemplary block diagram of an exemplary multi-network cellular phone  300  suitable for performing the method of  FIG. 2  according to one embodiment of the present invention. For better understanding of the present invention, the reader should simultaneously refer to both  FIGS. 2 and 3 . 
         [0025]    In one exemplary embodiment, the multi-network cellular phone  300  may comprise a radio-frequency (RF) antenna  302 , a CPCM  304 , a selector  306  of communication protocols, a display  312 , a dual tone multi-frequency (DTMF) keypad  314 , a central processor unit (CPU)  316 , a speaker  322 , a microphone  324 , and a battery  326 . 
         [0026]    In the depicted embodiment, the cellular phone  300  may also include an optional module  308  for WiFi connectivity, an optional Bluetooth interface  310 , optional connectors  323  and  325  for coupling to external speaker(s) (e.g., a headset, earpiece, and the like) and microphone(s), respectively (both not shown), and a connector  327  for coupling to a battery charging device (not shown). In another embodiment, the cellular phone  300  may also include an industry-standard slot for an optional memory card (e.g., flash memory card) and an Universal Serial Bus (USB) interface (both not shown). 
         [0027]    The phone CPU  316  may includes a controller  318  (e.g., microprocessor-based controller) and a memory module  320 . In operation, the phone CPU  316  control features and components of the multi-network cellular phone  300 , including the CPCM  304 . The memory module  320  may include various types of non-volatile, programmable, and random access electronic memory, such as flash memory, magnetic random access memory (MRAM), static random access memory (SRAM), dynamic random access memory (DRAM), and the like. The module  320  may further include a removable optional memory card (not shown) comprising an additional memory space and/or built-in programs or upgrades for the phone  300 . 
         [0028]    As discussed above in reference to  FIG. 2 , the CPCM  304  comprises hardware and/or software components for facilitating incoming and outgoing calls using a plurality of communication protocols, such as GSM, CDMA, WCDMA, TDMA, and ANSI-136 protocols. When such capabilities are implemented in a form of software, the corresponding programs and routines are generally stored in the memory module  320 . In another embodiment (not shown), the CPCM  304  may also include an internal memory space for storing such programs and routines. 
         [0029]    In one embodiment, the selector  306  provides configuration control for the CPCM  304 . In one embodiment, the selector  306  includes a user-controlled manual switch  307 . Each setting of the switch  307  corresponds to configuring the CPCM  304  for supporting one of the available cellular communication protocols. For example, the selector may analyze one or more performance factors associated with a plurality of different protocols and displays those results to a user. For example, the selector  306  may show two different airtime rates for two different available communication protocols, thereby allowing the user to manually select one of the available communication protocols. 
         [0030]    In another embodiment, in a stand-by mode, the selector  306  periodically configures, for a pre-determined time interval, the CPCM  304  to various cellular communication protocols to identify which of such protocols are supported by the cellular networks at the current location of the phone  300 . 
         [0031]    When outgoing communications are possible via more than one cellular network, the selector  306  may automatically configure the CPCM  304  for operating within the network that meets additional criteria, such as the subscriber&#39;s location, signal strength (receive and/or transmit), the called party&#39;s location, cost of the airtime to the subscriber, time of day or day of week, subscriber specified preference, and the like. Prioritized list of such criteria may be stored, e.g., in the memory module  320 . In yet another embodiment, the selector  306  may be implemented in a form of a software module or application that is stored in the memory module  320  and executed by the controller  318 . 
         [0032]    As discussed above in reference to  FIG. 2 , in a standby mode, the phone  300  may, e.g., sequentially switch between different communication protocols to detect a service request. In operation, using the CPCM  304  and selector  306 , the phone  300  detects an incoming call, defines the communication protocol used by the cellular network that has initiated the request for service, and configures the CPCM  304  for supporting that communication protocol. 
         [0033]    To facilitate an outgoing call, the phone  300  identifies communication protocol(s) of the cellular network(s) operating in the region where the phone is currently located. In one exemplary embodiment, the phone  300  sequentially initiates service requests using different communication protocols, detects which protocol was accepted by a regional cellular network, and configures the CPCM  304  for supporting that communication protocol. 
         [0034]    When more than one cellular network accepts the request for service, the phone  300  may configure the CPCM  304  for executing the outgoing call through the network meeting additional criteria, as discussed above. Upon completion of the call, the phone  300  switches to a standby mode. 
         [0035]    When only one communication protocol is supported at the current location of the phone  300 , during the standby mode the CPCM  304  may remain configured to that communication protocol using, e.g., the switch  307  or, alternatively, a command generated by the phone CPU  316  and executed using the selector  306 . 
         [0036]    It should be noted that the present invention can be implemented in software and/or in a combination of software and hardware, e.g., using application specific integrated circuits (ASIC), a general purpose computer or any other hardware equivalents. In one embodiment, the present multi-network cellular communications module or process can be loaded into memory  320  and executed by processor or controller  318  to implement the functions as discussed above. As such, the present multi-network cellular communications process (including associated data structures) of the present invention can be stored on a computer readable medium or carrier, e.g., RAM memory, magnetic or optical drive or diskette and the like. 
         [0037]    While the foregoing is directed to illustrative embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.