Patent Abstract:
A system and method of communication disclosed which may include establishing a telephone call for a cell phone at a first end of the call to a second end of the call, the cell phone receiving communication service from a cellular phone network; substantially continuously detecting a signal level of the cellular phone network available to the cell phone; and transferring the telephone call from the cellular phone service to a second network having a link back to a core network of said cellular phone network only if the detected signal level of the cellular phone service falls below a specified threshold.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation of U.S. patent application Ser. No. 13/353,472, filed Jan. 19, 2012, which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Support for cell phones and other devices using cellular telephone network technology may vary substantially due to variation in the strength of the signal at a given location at given moment in time. The variation is due to several factors including the distribution of cellular service towers compatible with a particular cell phone&#39;s communication protocol and brand name, the topography of the area the cell is located in, the level data traffic at the local cell phone tower and/or within the cellular phone system the tower works within, among other factors. Very low signal strength may lead to unintelligible conversations, dropped calls, failed data transmissions among other undesirable events. 
     Alternative communication techniques may be deployed as a backup in the event of the unavailability of cell phone service. However, discontinuing the use of a cell phone, and starting to use separate equipment, such as satellite telephone equipment, takes a substantial amount of time, can be highly inconvenient, and leads to considerable discontinuity in personal conversation and/or in data transmission which is undesirable. 
     Accordingly, there is a need in the art for improved systems and methods for ensuring continuity of communication sessions for mobile devices. 
     SUMMARY OF THE INVENTION 
     According to one aspect, the present invention is directed to a method of communication which may include establishing a telephone call for a cell phone at a first end of the call to a second end of the call, the cell phone receiving communication service from a cellular phone network; substantially continuously detecting a signal level of the cellular phone network available to the cell phone; and transferring the telephone call from the cellular phone service to a second network having a link back to a core network of said cellular phone network only if the detected signal level of the cellular phone service falls below a specified threshold. 
     Other aspects, features, advantages, etc. will become apparent to one skilled in the art when the description of the preferred embodiments of the invention herein is taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For the purposes of illustrating the various aspects of the invention, there are shown in the drawings forms that are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. 
         FIG. 1  is a block diagram of a system for providing multiple communication paths between a portable communication device and a communication network in accordance with an embodiment of the present invention; 
         FIG. 2  is a block diagram of a system for providing multiple communication paths between a cell phone within a vehicle and a core network servicing the cell phone in accordance with an embodiment of the present invention; 
         FIG. 3  is a block diagram of a computer system useable in conjunction with one or more embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following description, for purposes of explanation, specific numbers, materials and configurations are set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one having ordinary skill in the art that the invention may be practiced without these specific details. In some instances, well-known features may be omitted or simplified so as not to obscure the present invention. Furthermore, reference in the specification to phrases such as “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of phrases such as “in one embodiment” or “in an embodiment” in various places in the specification do not necessarily all refer to the same embodiment. 
       FIG. 1  is a block diagram of a system  10  for providing multiple communication paths between a portable communication device  102  and a communication network  300  in accordance with an embodiment of the present invention. 
       FIG. 1  shows system  10  including cellular core network  300 , cell tower  350 , communication link  302  between core network  300  and cell tower  350 , cell phone  102  and disjointed communication paths  112 -A and  112 -B between cell phone  102  and cell tower  350 , which are blocked by obstruction  50 . System  10  may also include bypass link  250  which may include communication link  251 , multiple-mode communication device  252 , link  254 , which preferably leads to cell tower  256 . 
     Obstruction  50  may be anything that diminishes the strength of the signal from cell tower  350  as received by cell phone  102  to the extent where cell phone  102  is unable to properly communicate with tower  350 . For instance, obstruction  50  may be a building, tunnel, bridge, mountain, or even free air loss due to distance. In some cases, obstruction  50  may be temporary environmental condition such as a rain storm, or electromagnetic interference. At a more conceptual level, obstruction  50  could be anything that inhibits normal operation of a properly functioning communication link  112  between cell phone  102  and tower  350  including high demand for the available bandwidth of tower  350 , a malfunction of tower  350  or a portion of core network  350 . 
     Bypass link  200  may be any communication mechanism for bypassing the standard communication path between cell phone  102  and core network  300 . Bypass link  200  may include the use of one or more technologies that may be used in the alternative or in combination. In one embodiment discussed herein, bypass link  200  may include at least one satellite communication link. However, the present invention is not limited to the use of satellite communication links. 
     In another embodiment, the bypass link need not extend all the way from cell phone  102  to core network  300 . Instead, the bypass link may be configured to re-connect with the cellular communication network (which may include cellular core network  300  and all cell towers in communication with cellular core network  300 ) at a selected cell tower within the cellular communication network. Thus, bypass link  250  may enable cell phone  102  to connect to cell tower  256  by means other than a standard 3G or 3G cell phone communication link. Cell tower  256  would preferably be equipped with whatever type of communication port is needed to send and receive data over link  254 . 
     For the above-discussed tunnel communication scenario to work, device  252  may conduct 3G or 4G communication with cell phone  102  and wired communication with tower  256 . Using a wired connection for communication link  251  is merely one possible way of bypassing the obstacle to standard 3G communication imposed by the tunnel walls. However, the invention is not limited to employing a wired connection. Other connection technologies may be used for this purpose. 
     In the following, a more specific embodiment of the above concept is discussed in connection with  FIG. 2 . 
       FIG. 2  is a block diagram of a system  10  for providing multiple communication paths between a cell phone  102  within a vehicle  100  and a core network  300  servicing the cell phone, in accordance with an embodiment of the present invention. The embodiment of  FIG. 2  may include vehicle  100 , cell phone  102  (or other mobile-communication enabled device such as a laptop computer, tablet computer etc.), dual mode device (DMD)  202 , satellite  204 , internet  206 , core network  350  and communication links  122 ,  212 ,  214 ,  216 ,  220 ,  112 , and  302 . Aspects of the various communication links will be discussed as the links arise in the discussion below of the operation of the system of  FIG. 10 . 
     Prior to discussing the operation of system  10 , we direct attention to dual-mode device  202 . In this embodiment, dual-mode device  202  (DMD) may bridge two wireless communication links: the cellular link  122  from cell phone  102  and a satellite communication link  212  to satellite  204 . Dual-mode device  202  therefore preferably includes at least a first communication port operable to send/receive data (which may include voice data) over 3G or 4G (or other mobile-phone type communication link) to/from cell phone  102  (or other mobile-communication-enabled device) and a second communication port operable to send/receive data to/from satellite  204  and/or other satellites within a satellite communication system. DMD  202  preferably also includes data-communication conversion circuitry for performing any needed conversions of data formatting, communication protocols and the like for transferring data received on 3G link  122  into a form suitable for transmitting out of satellite communication link  212 , and for performing the reverse conversion for data arriving from link  212  for transmission out of link  122 . 
     Furthermore, DMD  202  may include the ability to determine the strength of the cellular signal from the nearest cellular towers and a processing engine to determine when it is optimal to increase its own signal strength to enable the cellular phone to switch over to the DMD  202  for reception. In another embodiment, the DMD may receive instructions from either DMD core network  360  or cellular core network  300  to increase the DMD  202  signal strength so as to enable the cellular phone(s)  102  hand over data traffic to the DMD  202 , and thereby obtain good reception even if the local cellular service is weak. In another embodiment, the DMD  202  may include a GPS link and either internally, or based upon commands from the DMD core network  360 , control the DMD  202  signal strength as a function of the location indicated by the GPS link. Thus, for example, where the local cellular signal strength is weak, DMD core network  360  may instruct DMD  202  to increase its signal strength in a manner perceptible to cell phone  102 , so as to prompt cell phone  102  to switch its communication link from cellular link  112  to link  122  to DMD  202 . 
     DMD  202  is not limited to the above-described configuration. In other embodiments, DMD  202  may include more than two communication ports and/or may be capable of accommodating more than two types of communication links. Moreover, DMD  202  may be operable to communicate over links having communication protocols other than the 3G or 4G cell phone type link  122  and the satellite link  212 . Further, DMD  202  is not limited to communicating over wireless links In embodiments in which DMD  202  is situated in a stationary environment, DMD  202  may be enabled to service one or more wired communication links, optical links, in addition to, or alternatively to servicing multiple types of wireless radio-frequency communication links. 
     In one embodiment, the DMD  202  may placed on or in a vehicle  100 , as shown in  FIG. 2 . If vehicle  100  enters an area with poor cell phone service coverage, the cell phone  102  may be operable to switch from using the usual cell tower  350  service over mobile link (i.e. 3G link or other mobile protocol)  112  to using DMD  202  and its sequence of connections along bypass path  200  to maintain the continuity of a telephone call that is already under way. We refer to this alternative sequence of connections that may be configured to continue and/or establish a telephone call as bypass path  200 . Cell phone  102  may use communication link  122  to request that DMD  202  complete a communication connection back to core network  300  using bypass communication path  200 . 
     In the embodiment of  FIG. 2 , bypass path  200  extends from cell phone  102  to core network  300  and preferably includes the following links and devices, in order their occurrence along bypass path  200  from cell phone  102  to core network  300 . Specifically, bypass path  200  extends from cell phone  102  to communication link  122  (which may be a 3G or 4G link) to DMD  202 , to satellite communication link  212 , to satellite  204 , to satellite-to-ground communication link  214 , to internet  206  (the connections through which are preferably, but not necessarily, terrestrial), on to link  216  (which may be a conventional wired, broadband communication link) to cellular core network  300 . The above describes one possible bypass path  200  to serve as alternative to the traditional path along link  112 , tower  350 , and link  302  from cell phone  102  to core network  300 . However, the present invention is not limited to the specifics of bypass path  200 . Other possible bypass paths, using other communication technologies, in addition to, or as an alternative to, those shown in bypass path  200  in  FIG. 2 , may be implemented. 
     In this embodiment, DMD  202  preferably communicates with satellite  204  over satellite communication link  212 . Satellite  204 , in turn, then preferably conducts communication with the internet  206  over link  214 , where link  214  may include a backhaul link down to a satellite-dish-equipped ground station which is connected to the internet  206 . Finally, internet  206  may connect to core network  300  over link  216 . Once the call has been transferred to the control of DMD  202 , the call may continue to be serviced by DMD  202  until cell phone  102  detects a sufficiently strong signal from tower  350 , at which point cell phone  102  may switch the call connection from DMD  202  back to link  112  to cell tower  350 . 
     In the embodiment illustrated in  FIG. 2 , bypass path  200  extends from cell phone  102  all the way to core network  300 . However, in alternative embodiments, bypass paths may be implemented that reconnect with the cellular communications network without extending all the way to core network  300 . Instead, a bypass path could reconnect with the cellular communications network by establishing communication with the closest cell tower to the location of cell phone  102  that is operational and that communication devices along the bypass path  200  can establish a communication link with. 
     A concept similar to this was discussed in connection with  FIG. 1  where communication link  254  extended through a physical obstacle that obstructed standard 3G cell phone communication. However, communication link  254 , instead of extending all the way to core network  300 , reconnects with the cellular communication network at a cell tower  256  that is nearest to an exterior of the item obstructing the 3G communication link. 
     Similarly, in the embodiment of  FIG. 2 , satellite  204  and/or devices within a portion of internet  206  may communicate with a selected cell tower within the cellular communication network controlled by core network  300 , instead extending all the way to core network  300 . The selected cell tower (not shown) may be configured to able to handle two modes of communication: (1) the usual 3G and/or 4G communication; and (2) whatever the bypass communication protocol/method is. For instance, in the embodiment of  FIG. 2 , cell tower  350  could be placed in communication with a satellite system ground station capable of communication with satellite  204 . 
     In another embodiment, DMD  202  may detect, over link  220 , the strength of the signal from cell tower  350  and/or signals from one or more other cell towers as vehicle  100  travels along its trajectory. If DMD  202  determines that the signal from the nearest cell tower has fallen below an acceptable threshold, DMD  202  may notify cell phone  102  over link  122  of a need to allow DMD  202  to take over any ongoing communication being conducted by cell phone  102 . Cell phone  102  may then respond to this notification by transferring telephone call servicing to DMD  202  and bypass  200  until the available cellular phone service improves. 
     In an embodiment, DMD  202  may detect the signal strength of a local cell tower, such as cell tower  350 . However, DMD  202  may diminish the strength of its own signal that can be detected by cell phone  102 , preferably over link  122 . The reduction in strength of the DMD  202  signal tends to work against cell phone  102  switching its telephone call service from cell tower  350  to DMD  202 . If DMD  202  determines that the reduction in signal strength from tower  350  (or other comparable cell tower) has diminished below an acceptable threshold, DMD  202  may increase the strength of its own outgoing signal, over link  122 , to thereby cause cell phone  102  to determine that the DMD  202  signal is stronger than the signal from cell tower  350 , and thereby prompt cell phone  102  to shift an ongoing telephone call (or other communication session) to DMD  202 . 
     In another embodiment, a core network  360  for the provider of the DMD  202  services, using satellite  204 , may be in communication with the cellular system core network  300 , over communication link  304  and may receive information about parameters of the local cell tower (such as tower  350 ) operations. If, for example, a cell tower is congested, a disclosure of the congestion condition may be transmitted to the DMD  202  core network  360  so that the DMD  202  may take over communication to and from cell phone  102 , to thereby avoid overloading local cell tower  350 , or other similar cell tower. 
       FIG. 3  is a block diagram of a computing system  400  adaptable for use with one or more embodiments of the present invention. Central processing unit (CPU)  402  may be coupled to bus  404 . In addition, bus  404  may be coupled to random access memory (RAM)  406 , read only memory (ROM)  408 , input/output (I/O) adapter  410 , communications adapter  422 , user interface adapter  406 , and display adapter  418 . 
     In an embodiment, RAM  406  and/or ROM  408  may hold user data, system data, and/or programs. I/O adapter  410  may connect storage devices, such as hard drive  412 , a CD-ROM (not shown), or other mass storage device to computing system  400 . Communications adapter  422  may couple computing system  400  to a local, wide-area, or global network  424 . User interface adapter  416  may couple user input devices, such as keyboard  426 , scanner  428  and/or pointing device  414 , to computing system  400 . Moreover, display adapter  418  may be driven by CPU  402  to control the display on display device  420 . CPU  402  may be any general purpose CPU. 
     It is noted that the methods and apparatus described thus far and/or described later in this document may be achieved utilizing any of the known technologies, such as standard digital circuitry, analog circuitry, any of the known processors that are operable to execute software and/or firmware programs, programmable digital devices or systems, programmable array logic devices, or any combination of the above. One or more embodiments of the invention may also be embodied in a software program for storage in a suitable storage medium and execution by a processing unit. 
     Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.

Technology Classification (CPC): 7