Patent Publication Number: US-8526919-B2

Title: Message injection system and method

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/414,823, filed Nov. 17, 2010, which is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is directed to a device and method for injecting media information into a cellular communication. 
     2. Background of the Invention 
     Devices capable of sending and receiving communications, such as phone calls, text messages, electronic mail, instant messaging requests, and other electronic updates and information are becoming increasingly prevalent. Such devices come in a wide variety and may be generally stationary, such as a desktop computer, TV/Set-Top box, static game console, etc., or may be easily portable, such as a smart phone, tablet computer, notebook computer, personal digital assistant (“PDA”), portable game console, portable media device, etc. Further, such devices may send and receive communications through a wide variety of wired or wireless connections, standards, or protocols, such as the Internet, an intranet, voice over internet protocol (“VOIP”), satellite, 3G, SMS, MMS, 4G, WIMAX, etc. 
     The ability to record audio messages and store these messages in the memory of these devices is widely known. In addition, the ability to encode live audio and route the live audio to a network, such as a cellular network, is also widely known. However, current devices do not allow the transmission of stored audio to a cellular network. Accordingly, only live audio streams can be uplinked to a cellular network. Because of this gap, a mobile communication device is dependent on the network it is connected to for storage of audio messages transmitted from the network, such as a voice mail server. This limits the use of audio recordings on cellular devices. Consequently, there is a need for device that has the ability to transmit recorded media information to devices on a wireless network. 
     SUMMARY OF THE INVENTION 
     Various embodiments of the present invention include a mobile communication device including an application unit in a first memory of the device that includes an application, an application audio framework that is communicatively coupled to the application, and a telephony unit communicatively coupled to the application. The device also includes a radio transmission unit, operating in a second memory of the device, with the radio communication unit including a radio interface unit that is communicatively coupled to the telephony unit, a radio audio framework communicatively coupled to the radio interface unit, and a hardware driver unit communicatively coupled to the radio interface unit. The hardware driver unit is configured to initiate a communication connection between the mobile communication device and another communication device. The device also includes an audio switching unit communicatively coupled to the application unit and the radio transmission unit, where the application transmits an audio signal stored in the first memory over a wireless network via the audio switching unit and radio transmission unit. 
     These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Details of the present invention, including non-limiting benefits and advantages, will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying drawings, wherein: 
         FIG. 1  illustrates a schematic representation of a mobile communication device; 
         FIG. 2  illustrates a schematic representation of the interaction between an application processing unit and radio communication unit in the mobile communication device of  FIG. 1 ; 
         FIG. 3A  illustrates a schematic representation of an audio switch unit in the mobile communication device of  FIG. 1 ; 
         FIG. 3B  illustrates a schematic representation of the audio switch unit of  FIG. 3A  when a telephone call is active; 
         FIG. 4  depicts an illustrative example of the mobile communication device of  FIG. 1  transmitting an audio signal to a speaker on the mobile communication device; 
         FIG. 5A  depicts the audio switch unit in the mobile communication device of  FIG. 1  with an audio path opened between the application audio unit and radio audio unit; 
         FIG. 5B  depicts a schematic representation of a process used to transmit a prerecorded audio file over a wireless network via the radio interface unit in the mobile communication device of  FIG. 1 ; 
         FIG. 5C  depicts a schematic representation of a process used to transmit an analog signal from an application in the mobile communication device of  FIG. 1  to the wireless network when a call is received by the mobile communication device of  FIG. 1 ; 
         FIG. 5D  depicts a schematic representation of the mobile communication device of  FIG. 1  that is capable of transmitting video over a wireless network; 
         FIG. 6A  depicts a configuration of the audio switch unit in the mobile communication device of  FIG. 1 ; 
         FIG. 6B  depicts a schematic representation of a process to transmit an audio signal from the mobile communication device of  FIG. 1  over a wireless network; 
         FIG. 7A  depicts a schematic representation of the mobile communication device of  FIG. 1  connected to an external device that transmits a prerecorded audio signal over a wireless network; and 
         FIG. 7B  depicts a schematic representation of a process to transmit an audio signal from an external device over a wireless network through the mobile communication device of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described one or more embodiments with the understanding that the present disclosure is to be considered illustrative only of the invention and is not intended to limit the invention to any specific embodiment disclosed herein. 
     The present disclosure is directed to one or more communication devices capable of transmitting an audio signal over a wireless network, such as a cellular network, to a second device. The transmission of the audio signal may be part of a larger communication management system which is used to notify callers that the user of the mobile communication device is unavailable. The audio signal may be sent as a single transmission, or may be appended to another audio signal that was received in real time. 
       FIG. 1  illustrates a mobile communication device  100 . The mobile communication device  100  includes an application processing unit  102  that includes a central processing unit (CPU)  104  and a digital signal processor (DSP)  106 , a radio communication unit  108  that includes a CPU  110  and DSP  112 , a memory  114 , an input output (IO) unit  116  that includes an audio switch unit  118 , a display  120 , and a secondary storage unit  122 . The radio communication unit  108  is configured to communicate across a wireless network. The radio communication unit  108  may be configured to communicate over a wireless cellular network using any cellular protocol including, but not limited to, code division multiple access (CDMA), global system for mobile communications (GSM), and universal mobile telecommunications system (UMTS), or any other cellular communication protocol. 
     The IO Unit  116  is coupled to a speaker  124  and a microphone  126  via the audio switch unit  118 . The audio switch unit  118  is configured to receive an audio signal from the microphone  126 , and to adjust various characteristics of the received audio signal. The audio switch unit  118  may adjust the volume of the audio, side tone generation, comfort noise generation, echo cancelation, automatic gain, noise suppression, tone generation, or any other characteristic of the audio signal. The audio switch unit  118  also routes audio signals received by the microphone  126  to the application processing unit  102 , or the radio communication unit  108 , and also routes audio from the application processing unit  102  and radio communication unit  108  to the speaker  124 . 
       FIG. 2  illustrates a schematic representation of the interaction between the application processing unit  102  and radio communication unit  108 . The application processing unit  102  includes an operating system  200  running in the CPU  104  of the application processing unit  102 . The operating system  200  may be any commercially available operating system including Linux, Windows Mobile, Google Android, or any other operating system capable of running on a mobile device. The operating system  200  controls the operation of the CPU  104  and DSP  106  in the application processing unit  102 . An application  202  operating in the operating system  200  interacts with different components of the mobile device  100 , such as the display  120 , speaker  124 , and microphone  126 , via an application programming interface (API)  204 . 
     The radio communication unit  108  includes a radio interface unit  220 , a radio daemon unit  222 , a radio audio unit  224 , and a driver unit  226  operating via the CPU  110  and DSP  112 . The radio audio unit  224  is communicatively coupled to the audio switch unit  118 , such that the audio switch unit  118  transmits audio captured by the microphone  126  for transmission over the wireless network by radio hardware coupled to the driver unit  226 . The radio audio unit  224  also transmits audio information received from the radio hardware via the driver unit  226  to the speaker  126  via the audio switch unit  118 . 
     The radio interface unit  220  performs high level operations to initiate a connection between the mobile device  100  and another device connected to the wireless network via the driver unit  226 . The radio interface unit  220  is also communicatively coupled to a telephony unit  206  in the application processing unit  102 . As an illustrative example, the radio interface unit  220  may receive a command from the telephony unit  206  to initiate a phone call between two mobile devices. The radio interface unit  220  communicates with the radio audio unit  224  and driver unit  226 , via the radio daemon unit  222 , to connect to the wireless network and initiate a call between the two devices. The radio interface unit  220  also communicates with the telephony unit  206  to notify the telephony unit  206  that a phone call has been initiated either by the mobile device  100  or by an external device that is calling the mobile device  100 . The telephony unit  206  communicates with the application  202  running in the application processing unit  102  to provide a status of the radio transmission unit  208 , and to initiate actions in the radio transmission unit  108 . 
     The radio audio unit  224  in the radio communication unit  108  is communicatively coupled to the audio switch unit  118 , such that the radio audio unit  224  instructs the audio switch unit  118  to send audio signals from the microphone  126  to the radio audio unit  224 , and to transmit audio signals from radio audio unit  224  to the speaker  124  via the audio switch unit  118 . The hardware driver unit  226  is communicatively coupled to the radio hardware in the mobile device  100  such that the hardware driver unit  226  initiates a connection with a wireless network, via the radio hardware, and controls the transmission and receipt of audio signals onto and from the wireless network. The hardware driver unit  226  is communicatively coupled to the radio audio unit  224  via the radio interface unit  220  and the radio daemon unit  222 , such that the radio audio unit  224  provides audio signals from the microphone  126  to the hardware driver unit  226  for transmission over the wireless network. The hardware driver unit  226  also transmits audio signals received from the wireless network to the radio audio unit  224  for transmission to the speaker  124 . 
       FIG. 3A  illustrates a schematic representation of the audio switch unit  118  transmitting audio to the speaker  124  and/or microphone  126 . The audio switch unit  118  is communicatively coupled to the speaker  124 , the microphone  126 , and an external device  300 . The audio switch unit  118  receives a signal from the application  202 , via the application audio unit  208 , requesting the creation of an audio path  302  between the speaker  124 , microphone  126  or external device  300 . Upon receiving the request, the audio switch unit  118  creates an audio path  302  between the requested devices and the application audio unit  208 . The application audio unit  208  applies the appropriate filters to the audio signal sent to, or received from, the audio switch unit  118 , and routes the audio signal to the audio switch unit  118 . The application  202  transmits audio signals to the speaker  124 , or external device  300 , via the audio path  302 , and receives audio signals from the microphone  126 , or external device  300 , via the audio path. The audio signals may be in any format used to store audio including, but not limited to MP3, MPEG, WAV or any other digital audio format. The application audio unit  208  may convert the audio signals to analog audio signals before transmitting the analog audio signals to the audio switch unit  118 . 
       FIG. 3B  illustrates a schematic representation of the audio switch unit  118  when the radio transmission unit  108  is managing a call between the mobile communication device  100  and another device via a wireless network. When the audio switch unit  118  receives a signal from the radio interface unit  220 , via the radio audio unit  224 , to open an audio path  304  between the radio interface unit  220 , the speaker  124 , microphone  126 , or the external device  300 , the audio switch unit  118  closes all open audio paths, and opens audio paths  304  between the radio interface unit  220  and the speaker  124  and between the radio interface unit and the microphone  126 , or between the radio interface unit  220  and the external device  300 . The radio audio unit  224  includes all necessary filters required to prepare the audio signal received from the microphone  126  for transmission over the wireless network via the radio interface unit  220  and the driver unit  226 . 
       FIG. 4  depicts an illustrative example of a mobile communication device  100  transmitting an audio signal to the speaker  124 . In step  402 , a user requests an application  202  transmit an audio signal to the speaker  124 . The application  202 , in step  404 , requests the status of the speaker  124  from the audio switch unit  118 . If an audio path is open between the speaker  124  and the radio interface unit  220 , the application  202  waits for the speaker  124  to become available. If the speaker  124  is available, the application  202  requests the status of the radio interface unit  220 , via telephony unit  206 , at step  406 . The radio interface unit  220  returns a status of “IN CALL” indicating a telephone call is incoming, or “AT REST” indicating that the radio interface unit  220  is not currently receiving a telephone call. 
     If the radio interface unit  220  returns a status of “IN CALL,” the application  202  directs the audio switch unit  118  to open an audio path  302  between the application  202  and the speaker  124  to transmit a pre-assigned ringtone audio signal, via the application audio unit  208 , to the speaker  124  in step  408 . The audio switch unit  118  closes any open audio connections to the speaker  124 , and opens an audio path  302  between the application  202  and the speaker to transmit the pre-assigned audio signal to the speaker  124 . While the ringtone audio signal is being transmitted to the speaker  124 , the telephony unit  206  requests the caller information from the radio interface unit  220 , which is passed to the application  202  for display to a user via the display  120  of the mobile device  100 . The application  202  also presents buttons on the display  120  that ask the user if they would like to accept or decline the incoming call. 
     If the user accepts the call, via the buttons displayed by the application  202  on the display  120 , the telephony unit  206  sends a signal to the radio interface unit  220  to initiate the call in step  410 . The radio interface unit  220  initiates a connection to the wireless network via the driver unit  226 , and instructs the audio switch unit  118  to open audio paths  304  between the radio interface unit  220 , the speaker  124 , and microphone  126 . The audio switch unit  118  closes the audio path  302  between the application  202  and the speaker  124 , and opens the audio path  304  between the speaker  124 , microphone  126 , and the radio interface unit  220  via the radio audio unit  224 . Upon termination of the audio path  302  to the application  202 , transmission of the ringtone audio signal by the application  202  is terminated. In step  414 , the radio interface unit  220  waits for the call to terminate before sending a signal to the telephony unit  206  that the call has ended. Once the call has ended the application  202  returns to step  402 , and the audio switch unit  118  closes the audio path  304  between the radio interface unit  220 , the speaker  124 , and the microphone  126 . 
     In step  416 , if the radio interface unit  220  returns an indication that the phone is “AT REST,” the application  202  opens an audio path  302  between the application  202  and the speaker  124  via the application audio unit  208  and the audio switch unit  118 . In step  418 , the application  202  checks the status of the radio interface unit  220 , via the telephony unit  206 , to confirm the radio interface unit  220  is not receiving a telephone call. While the audio signal is transmitted to the speaker  124 , the application  202  checks the status of the radio interface unit  220  via the telephony unit  206 . If the radio interface unit  220  is still “AT REST,” the application  202  transmits the audio signal to the speaker  124  via the application audio unit  208  and the audio switch unit  118 , in step  420 . If the radio interface unit  220  transmits an “IN CALL” flag to the telephony unit  206 , the transmission of the audio signal to the speaker  124  stops, and the process moves to step  408 . In step  422 , the application  202  keeps the audio path  302  open while the audio signal is transmitted to the speaker  124  and the radio interface unit  220  remains at rest, and closes the audio path  302 , in step  424 , when the audio signal transmission is complete. 
       FIG. 5A  depicts the audio switch unit  118  with an audio path  500  opened between the application audio unit  208  and radio audio unit  224 . This configuration allows for an application  202  to send a pre-recorded audio signal to the radio interface unit  220  for transmission across the wireless network.  FIG. 5B  depicts a schematic representation of the process used to transmit a prerecorded audio signal over a wireless network via the radio interface unit  220 . In step  502 , the application  202  requests the transmission of a prerecorded audio signal over the wireless network via the radio interface unit  220 . In step  504 , the application  202  checks the status of the radio interface unit  220  via the telephony unit  206 . If the radio interface unit  220  returns an “AT REST” status, the application  220  returns to step  502  to wait for a call to be initiated. If the radio interface unit  220  returns an “IN CALL” status, the application  202  requests the audio path  500  be opened between the radio interface unit  220  and the application  202  in step  508 . The application may also initiate a call to another device via the telephony unit  206 , by sending an “INITIATE CALL” flag to the radio interface unit  226 . 
     In step  510 , the audio switch unit  118  opens an audio path  500  between the application  202  and the radio interface unit  220 , by first closing the audio path  304  between the radio interface unit  220  and the microphone  126 , and opening the path between the application  202  and the radio interface unit  220  via the application audio unit  208  and the radio audio unit  224 . In step  512 , the application  202  transmits the audio signal through the audio path  500  via the application audio unit  208 . The radio audio unit  224  receives the audio signal from the application audio unit  208 , and passes the audio signal through a plurality of filters that prepare the audio signal for transmission over the wireless network, via the hardware driver unit  226 . After the audio signal transmission is complete, the audio switch unit  118  may close the audio path  500 . The application  202  may also keep the audio path  500  open until the radio interface unit  220  indicates that the call is terminated. If the audio path  500  remains open while the call is active, audio received from the wireless network may be sent to the application  202  where it may be saved in the memory  114 , or the secondary storage unit  122 , of the mobile communications device  100 . 
       FIG. 5C  depicts a schematic representation of the process used to transmit an analog signal from an application  202  to the wireless network when a call is received. In step  550 , the application  202  receives an indication from the radio interface unit  220  that a call is incoming. The radio interface unit  220  may transmit an “IN CALL” flag to the application  202  via the telephony unit  206 . The radio interface unit  220  may also transmit information on the call such as, but not limited to caller identification information, caller location, or any other information related to the call to the application  202  via the telephony unit  206 . In step  552 , the application  202  confirms it is configured to auto answer an incoming call. The application  202  may use the caller information transmitted by the radio transmission unit  220  to determine if the call is to be auto answered. As an illustrative example, the application  202  may only answer calls from callers on a predefined caller list that is stored in the memory  114  of the device  100 . The application  202  may also ignore calls from users on the caller list. The application  202  may also prompt a user of the mobile communication device  100  whether to answer the call by displaying a message on the display  120 . If the application is not configured for auto answer, the application  202  ends. If the application  202  is configured to auto answer a call, the telephony unit  206  transmits an “AUTO ANSWER” flag to the radio interface unit  220 . 
     In step  554 , the radio interface unit  220 , receives the “AUTO ANSWER” flag and does not request an audio path between the speaker  124 , the microphone  126 , or the external device  300 . In step  556 , the application  202  requests an audio path  500  between the application and the radio interface unit  220  via the application audio unit  208 . In step  558 , the audio switch unit  118  opens the audio path  500 , and the radio interface unit  220  initiates the call over the opened audio path  500 . The application  202  transmits the audio signal over the audio path  500  through the application audio unit  208  and the radio audio unit  224  after the radio interface unit  220  confirms the call is initiated via the telephony unit  206 , and the driver unit  226  receives the audio signal from the radio interface unit  220 , via the radio audio unit  224 , and transmits the audio signal over the wireless network. 
     In step  560 , the application  202  determines if the audio signal has completely transmitted over the audio path  500 . If the audio signal has completely transmitted, the application  202  may request the audio path  500  be closed. The application  202  may also terminate the call by transmitting an “END CALL” flag from the telephony unit  206  to the radio interface unit  220 . The application  202  may also maintain the audio path  500  until the user of the mobile device  100  receives the call by pressing a button displayed by the application  202  on the display  120  of the mobile communication device  100 . If the user indicates that they would like to receive the call, the application  202  transmits an “IN CALL” flag to the radio interface unit  220 , which requests the audio switch unit  118  close audio path  500  and open audio path  304 . 
     The application  202  may analyze information from additional sources, such as a schedule application residing in, or external to, the mobile communication device  100 , global positioning satellite (GPS) information, or any other user specific information to determine if the “AUTO ANSWER” flag should be turned on. As an illustrative example, the application  202  may query a scheduling application on the mobile communication device  100  to determine if the “AUTO ANSWER” flag should be turned on. The application  202  may transmit the “AUTO ANSWER” flag to the radio interface unit  220  when a user receives a call when they are in a scheduled event. To determine if the user is in a scheduled event, the application  202  may compare the current time and date to a starting and ending time and date in the user&#39;s schedule to determine if the event is in progress. If the event is in progress, the application will send the “AUTO ANSWER” flag to the radio interface unit when a call is in coming. 
     The user may also supply a listing of authorized phone numbers that should not be auto answered during the event. As another illustrative example, a user may designate a specific phone number to pass through to the phone during the event such as a family member, or a client, calling the user. When the indicated phone number is transferred to the telephony unit  206  from the radio interface unit  220 , as part of the call information, the application  202  will transmit an “ACCEPT CALL” signal to the radio interface unit  220  instructing the radio interface unit  220  to open the audio path to the speaker  124  and microphone  126 . The application  202  will not open an audio path between the radio interface unit  220  and the speaker  124  if the caller information is not in the list of authorized phone numbers. 
     The application  202  may also look to multiple pieces of information to determine if the “AUTO ANSWER” flag should be transmitted to the radio interface unit  220 . As an illustrative example, the application  202  may analyze the schedule information and the GPS position of the user to determine if the user is at the location of the meeting. If the user is at the location of the meeting, the “AUTO ANSWER” flag is transmitted to the radio interface unit  220  when a call is incoming. If the user is not at the location indicated by the schedule information the “AUTO ANSWER” is not transmitted. 
     The application  202  may also automatically open an audio path  304  from the radio audio unit  224  to the speaker  124  when a call from a specific device is received. As an illustrative example, the application  202  may receive caller information, and an “IN CALL” flag, from the radio interface unit  220  via the telephony unit  206 . The application  202  may compare the received caller information, such as the phone number of the device calling in, to an authorized list of phone numbers stored in the memory of the mobile communication device  100 , and may automatically accept the call and open an audio path to the speaker  124  and microphone  126  when the caller information matches a predefined caller stored in authorized list. Since the audio channel is open on both devices an intercom affect is achieved where both parties can communicate with one another over the wireless network. 
       FIG. 5D  depicts a schematic representation of a mobile device capable of transmitting video over a wireless network. Consistent with this embodiment, the mobile communication device  100  includes a video switching unit  574 , an application video unit  570 , and a video radio unit  572 . The video switch unit  574  is configured to receive a video signal from the application  202 , via the application video unit  570 , and to transfer the video signal to the radio video unit  572  via the video signal path  576 . The application video unit  570  is also configured to format the video signal into a format operable with the radio video unit  572 . The radio video unit  572  may also include a plurality of filters to format the video signal for transmission over the wireless network by the hardware driver  226 . The mobile communication device  100  may simultaneously transmit video and audio signals over the wireless network via the hardware driver  226 . The transmission of the video signal may be initiated by any of the means previously discussed, such as, the receipt of a phone call from an authorized phone number. The video signal may be generated by a camera  578  optically coupled to the application processing unit  102  via the IO unit  116 . The camera  578  can be used to record, or generate, the video signal that is transmitted over the wireless network. 
       FIG. 6A  depicts a configuration of the audio switch unit  118 . The audio switch unit  118  is coupled to the speaker  124 , microphone  126 , application audio unit  208 , and radio audio unit  224 . The audio framework  206  and the radio audio unit  224  are coupled to the audio switch unit  118  via memory locations  602  and  606 . The memory locations  602  and  606  may be partitions of the memory  114 , or partitions of the secondary storage unit  122 . Further, each memory location  602  and  606  may be partitioned into multiple memory locations. 
     The radio audio unit  224  stores audio signals received from the driver unit  226  in the memory  602 , and the audio switch unit  118  extracts the stored audio form the memory location  602 , and transmits the audio signal to the speaker  124  via the audio path  600 . The audio switch unit  118  receives audio from the microphone  126 , and stores the audio from the microphone  126  in the memory location  602  via audio path  604 . The radio audio unit  224  extracts the audio signal from the memory location  602 , and transmits the audio signal to the wireless network via the radio interface unit  220  and the driver unit  226 . The radio audio unit  224  also stores audio signals received from the wireless network in memory location  602 . Similarly, the external device  300  transmits and extracts audio signals from the memory  608  via audio path  606 . The application audio unit  208  is also coupled to the memory location  602 , and is configured to read and write audio signals into the memory location  602 . 
       FIG. 6B  depicts a schematic representation of a process to transmit an audio signal over a wireless network. In step  660 , the application  202  requests transmission of an audio signal. In step  662 , the application  202  checks the status of the radio interface unit  220  via the telephony unit  206 . If the radio interface unit  220  returns an “AT REST” status, the application  202  waits for the status to change to an “IN CALL” status. The application  202  may also initiate a call by transmitting a “INITIATE CALL” flag to the radio interface unit  220  via the telephony unit  206 . If the application  220  initiates the call, the radio interface unit  220  connects to the wireless network, via the driver unit  226 , and performs all required functions to initiate the call over the wireless network. When the intended mobile device accepts the call, the radio interface unit  220  sends an “IN CALL” flag to the telephony unit  206 , which forwards the “IN CALL” status to the application  202 . 
     In step  664 , the application  202  access the memory location  602  where audio transmitted to the wireless network is stored via the application audio unit  208 . The application  202  may transmit a “VIRTUAL CALL” flag to the audio switch unit  118 , which causes the audio switch unit  118  to close the audio path  604  between the microphone  126  and the memory location  602 . The application  202  may also connect to the microphone  126  and prevent the microphone  126  from transmitting an audio signal to the memory  602 . 
     In step  666 , the application  202  routes the audio signal through the application audio unit  208 , which formats the audio signal into a format compatible with the radio audio unit  224 , and then stores the converted audio signal in the memory  602 . The radio audio unit  224  extracts the audio signal from the memory location  602 , and transmits the audio signal over the wireless network via the radio interface unit  220  and the driver unit  226 . In step  668 , the application audio unit  208  determines if the audio signal has been successfully stored in the memory location  602 . If the storage is successful, the application  202  ends the process. If the storage is not successful, the application  202  attempts to store the audio signal a second time. 
       FIG. 7A  depicts a schematic representation of the mobile device  100  connected to an external device  300  that transmits prerecorded audio signal over a wireless network. The external device  300  may be configured to receive audio signals from the application  202  via the application audio unit  208  over the audio path  700 . The external device  300  includes a CPU  702  and a memory  704  that are configured to receive an audio signal from the application  202 , reformat the audio signal into a format accepted by the radio audio unit  224 , and transmit the reformatted audio signal to the radio audio unit  224  via the audio path  706 . The audio signal may be stored in the memory  704  of the external device  300  for later transmission. The application  202  may also be communicatively coupled to the external device  300  via a separate wireless connection, or a data bus. 
     The application  202  may be communicatively coupled to the external device  300  using a wireless communication protocol such as blue tooth. The application  202  may also communicatively coupled to the external device by a wired data bus, such as a universal serial bus (USB) connection, in the external device  300  and in the mobile device  100 . The application  202  may also be communicative coupled to the external device  300  by a network connection, such as a TCP/IP connection or Ethernet connection. The application  202  may also be connected to the external device  300  by a cradle that includes a serial or USB connection to the external device, the cradle being configured to hold the mobile communication device  100  in a predefined position. 
       FIG. 7B  depicts a schematic representation of a process to transmit an audio signal from an external device over a wireless network thought the mobile device  100 . When the external device  300  is connected to the mobile device  100 , the application  202  requests an audio channel  700  between the external device  300  and the application  202  from the audio switch unit  118  via the application audio unit  208 , in step  750 . In step  752 , the audio switch unit  118  opens the audio path  700  in response to a request from the application audio unit  208 . In step  754 , the application  202  transmits the audio signal to the external device  300  via the audio path  700 . The external device  300  receives the audio signal, coverts the audio signal in to a format accepted by the radio audio unit  224 , and stores the audio signal in the memory  704  in step  756 . 
     After the external device  300  stores the audio file, the application  202  monitors the status of the radio interface device  220  via the telephony unit  206  in step  758 . When the radio interface unit  220  transmits an “IN CALL” status to the telephony unit  206 , the application  202  transmits an “ACCEPT CALL” flag to the radio interface unit  220 , causing the radio interface unit  220  to connect the call via the driver unit  226  in step  760 . 
     In step  762 , the application  202  transmits an “START TRANSMISSION” signal to the external device  300  via an established wireless connection or hard wire connection between the external device  300  as previously discussed. In step  764 , the external device  300  transmits the stored audio signal to the radio audio unit  224  via the audio path  706 . The radio audio unit  224  filters the audio signal before sending the audio signal to the wireless network via the radio interface unit  220  and the driver unit  226 . 
     In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular. 
     It should be understood that various changes and modifications to the presently preferred embodiments disclosed herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present disclosure and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.