Abstract:
According to one aspect of the present invention, a method for providing an in-vehicle notification service by means of a head unit device comprises the steps of: requesting a mobile device to start a notification service; receiving, upon the occurrence of an event which a user is to be notified of, information on the event from the mobile device; and displaying the information on the event to the user.

Description:
PRIORITY 
       [0001]    This application is a National Phase Entry of PCT International Application No. PCT/KR2012/005866, which was filed Jul. 23, 2012, and claims priority to Korean Patent Application Nos. 10-2011-0072694 and 10-2011-0094326 filed Jul. 21, 2011 and Sep. 19, 2011, respectively, the entire contents of each of which are hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to a method for using an in-vehicle notification service, and more particularly to a method for performing unidirectional or bidirectional notification in a particular situation such as call reception, message reception or a device status alarm between an in-vehicle head unit device and a mobile device. 
         [0004]    2. Description of the Related Art 
         [0005]    A car is not only used for the purpose of driving, but also is recognized as a place in which a user can enjoy various types of entertainment. According to this trend, infotainment has been developed to enable a user to receive various pieces of information or enjoy media, such as music or a video, through a mobile device in a vehicle. 
         [0006]    A system which provides the infotainment is used to provide information to users. The information is typically provided to the users in the form of an audio, a video, or a combination thereof. Interaction between a mobile device and an in-vehicle head unit device within a vehicle increases user convenience. 
         [0007]    As described above, the interaction between the mobile device and the in-vehicle head unit device increases the user convenience by providing various pieces of information in response to specific demands of the users. 
         [0008]    However, currently, no notification mechanism has been disclosed for services requiring a notification, such as the transmission of call information, that of message information, or that of device status information. 
       SUMMARY OF THE INVENTION 
       [0009]    Therefore, an aspect of the present invention is to define a new notification mechanism in which unidirectional or bidirectional notification in a particular situation, such as the transmission of call information, that of message information or that of device status information, is performed between a head unit device and a mobile device according to in-vehicle characteristics. 
         [0010]    In accordance with an aspect of the present invention, there is provided a method for providing an in-vehicle notification service by a head unit device, which includes: sending a request for start of a notification service to a mobile device; receiving information on an event from the mobile device, according to occurrence of the event which becomes a target of notification; and displaying the information on the event to a user. 
         [0011]    In accordance with another aspect of the present invention, there is provided a method for providing an in-vehicle notification service by a mobile device, which includes: receiving a request for start of a notification service from a head unit device; and transmitting information on the event to the head unit device, according to occurrence of the event which becomes a target of notification, wherein the event corresponds to one of call reception, call origination, a change in a call status, message reception, a change in a message status and a device status alarm. 
         [0012]    In accordance with still another aspect of the present invention, there is provided a machine-readable storage medium storing a program for executing the method for providing the in-vehicle notification service. 
         [0013]    In accordance with yet another aspect of the present invention, there is provided a mobile terminal including the machine-readable storage medium. 
         [0014]    In accordance with yet another aspect of the present invention, there is provided a head unit device for providing an in-vehicle notification service, the head unit device comprising: a user interface; a communication unit for communicating with a mobile device; and a controller configured for: sending a request for start of a notification service to the mobile device through the communication unit; receiving information on an event from the mobile device through the communication unit, according to occurrence of the event which becomes a target of notification; and displaying the information on the event to a user through the user interface. 
         [0015]    In accordance with yet another aspect of the present invention, there is provided a mobile device for providing an in-vehicle notification service, the mobile device comprising: a communication unit for communicating with a head unit device; and a controller configured for: receiving a request for start of a notification service from the head unit device through the communication unit; and transmitting information on an event to the head unit device, according to occurrence of the event which becomes a target of notification through the communication unit, wherein the event corresponds to one of call reception, call origination, a change in a call status, message reception, a change in a message status and a device status alarm. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a block diagram illustrating a configuration of a system for providing an in-vehicle notification service according to a first exemplary embodiment of the present invention; 
           [0017]      FIG. 2  is a signal flow diagram illustrating a method for providing an in-vehicle notification service according to a first exemplary embodiment of the present invention; 
           [0018]      FIG. 3  is a view illustrating a state diagram describing a change in a call status related to an incoming call information notification; 
           [0019]      FIG. 4  is a signal flow diagram illustrating an action request and a response to the action request; 
           [0020]      FIG. 5  is a view illustrating a state diagram describing a change in a call status related to an outgoing call notification; 
           [0021]      FIG. 6  is a view illustrating a state diagram describing a change in a message status related to an incoming message notification; 
           [0022]      FIG. 7  is a signal flow diagram illustrating a signal flow which is based on a CDB architecture illustrated in  FIG. 1 , according to a first embodiment of the present invention; 
           [0023]      FIG. 8  is a state diagram illustrating an example of a change in a call status in a case where a media session is unexpectedly disconnected, according to a first embodiment of the present invention; 
           [0024]      FIG. 9  is a block diagram illustrating a configuration of a system for providing an in-vehicle notification service according to a second exemplary embodiment of the present invention; 
           [0025]      FIG. 10  is a view illustrating a state diagram describing a change in a call status related to an outgoing call notification using a Universal Plug and Play (UPnP) telephony; and 
           [0026]      FIG. 11  is a signal flow diagram illustrating a method for performing media streaming between an in-vehicle head unit device and a mobile device, according to a second embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0027]    Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following description includes specific details such as elements, etc., and the specific details are only provided in order to help a more comprehensive understanding of the present invention. Therefore, it will be apparent to those having ordinary knowledge in the technical field of the present invention that predetermined changes in form and details can be made in the specific details without departing from the scope of the present invention. Further, when it is determined that a detailed description of the known art related to the present invention may obscure the subject matter of the present invention, the detailed description thereof will be omitted. 
         [0028]    Although terms including ordinal numbers, such as first and second, may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of the present invention. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
         [0029]    The terminology used herein is merely used to describe particular embodiments of the present invention, and is not intended to limit the present invention. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. In the present specification, it is to be understood that the terms “comprising,” “including” or “having” are intended to indicate the existence of the features, numbers, steps, operations, elements, parts, or combinations thereof disclosed in the specification, and are not intended to preclude the possibility that one or more other features, numbers, steps, operations, elements, parts, or combinations thereof may exist or may be added. 
         [0030]    Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those having ordinary knowledge in the technical field, to which the present invention pertains. Terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
         [0031]      FIG. 1  is a block diagram illustrating a configuration of a system for providing an in-vehicle notification service according to a first exemplary embodiment of the present invention. The system includes a head unit device  100  and a mobile device  200  which are installed in a vehicle. 
         [0032]    The head unit device  100  includes a first user interface  110 , which includes a first speaker  112 , a first microphone  114  and a first display unit  116 , a first sensor unit  120 , a first memory  130 , a first communication unit  140 , a first camera  150 , and a first controller  160 . 
         [0033]    Examples of the mobile device  200  may include a smart phone, a mobile phone, a video game console, a laptop computer, a tablet Personal Computer (PC), a Personal Media Player (PMP), a Personal Digital Assistant (PDA), or the like. The mobile device  200  may be implemented as a portable mobile device having a wireless communication function. 
         [0034]    The mobile device  200  includes a second user interface  210 , which includes a second speaker  212 , a second microphone  214  and a second display unit  216 , a second sensor unit  220 , a second memory  230 , a second communication unit  240 , a second camera  250 , and a second controller  260 . Hereinafter, basic functions that the mobile device  200  and the head unit device  100  have in common, will be first described as follows. In the following description, for example, in the case of the user interfaces  110  and  210 , the user interface is termed the first user interface  110  in the head unit device  100 , and the user interface is termed the second user interface  210  in the mobile device  200 . In other words, the following description may be regarded as a description of functions that elements of the mobile device  200  perform or that of mutual relations between the elements of the mobile device  200 . Otherwise, the following description may be regarded as a description of functions that elements of the head unit device  100  perform or that of mutual relations between the elements of the head unit device  100 . 
         [0035]    The user interface  110  or  210 , which is a means for receiving user input or notifying a user of information, may further include multiple buttons, a vibration motor, a connector, a keypad, or the like. For example, cursor control such as a mouse, a trackball, a joystick or cursor direction keys, although not limited thereto, may be provided to the user interface  110  or  210  in order to transmit and receive information to/from the controller  160  or  260  and in order to control the movement of a cursor on a screen of the display unit  116  or  216 . 
         [0036]    According to the control of the controller  160  or  260 , the speaker  112  or  212  may output sounds matched to various signals (e.g., a wireless signal, a broadcast signal, a digital audio file, a digital moving image file, and photography) to the outside of the device  100  or  200 . The speaker  112  or  212  may output a sound matched to a function that the device  100  or  200  performs. The one speaker  112  or  212  or multiple speakers  112  or  212  may be disposed at an appropriate position or appropriate positions of the device  100  or  200 . 
         [0037]    According to the control of the controller  160  or  260 , the microphone  114  or  214  receives a voice or sound as input, and generates an electrical signal. 
         [0038]    The buttons may be disposed on a front surface, a lateral surface or a rear surface of the device  100  or  200 , and may include a power/lock button (not illustrated), a volume button (not illustrated), a menu button, a home button, a back button, a search button, or the like. 
         [0039]    According to the control of the controller  160  or  260 , the vibration motor may convert an electrical signal into a mechanical vibration. For example, when the device  100  or  200  in a vibration mode receives a voice call or a video call through the communication unit  140  or  240 , the device  100  or  200  may operate the vibration motor thereof. The one vibration motor or multiple vibration motors may be mounted within the device  100  or  200 . The vibration motor may operate in response to a touch gesture of the user who touches the screen of the display unit  116  or  216  and a touch drag gesture of the user on the screen of the display unit  116  or  216 . 
         [0040]    A connector may be used as an interface for connecting the device  100  or  200  to an external device or a power source (not illustrated). According to the control of the controller  160  or  260 , through a wired cable connected to the connector, data stored in the memory  130  or  230  of the device  100  or  200  may be transmitted to the external device or data may be received from the external device. Through the wired cable connected to the connector, power may be supplied by the power source or a battery may be charged. 
         [0041]    The keypad may receive key input from the user in order to control the device  100  or  200 . The keypad includes a physical keypad mounted on the device  100  or  200  or a virtual keypad displayed by the display unit  116  or  216 . 
         [0042]    The display unit  116  or  216  displays an image on the screen according to an image signal which is input from the controller  160  or  260 . The display unit  116  or  216  may be implemented by a Liquid Crystal Display (LCD), a touch screen, and/or the like. The display unit  116  or  216  displays an image according to the control of the controller  160  or  260 . When a user input means (e.g., a finger or a stylus) touches the screen of the display unit  116  or  216 , the display unit  116  or  216  generates a key touch interrupt, and outputs user input information including input coordinates and an input state to the controller  160  or  260 , according to the control of the controller  160  or  260 . 
         [0043]    The display unit  116  or  216  may provide the user with a graphical user interface matched to various services or functions (e.g., an in-vehicle notification service, a telephone call, data transmission, broadcasting, capturing of photographs and/or moving images). The display unit  116  or  216  may provide touch information (i.e., user input information) which is input to the graphical user interface, to the controller  160  or  260 . The display unit  116  or  216  may receive, as input, at least one touch information through the user&#39;s body part (e.g., fingers including a thumb) or an input means (e.g., a stylus pen) enabling a touch. 
         [0044]    According to embodiments of the present invention, a touch is not limited to a contact between the display unit  116  or  216  and the user&#39;s body part or the input means enabling a touch, but includes a non-contact (e.g., a case in which a detectable distance between the display unit  116  or  216  and the user&#39;s body part or the input means enabling a touch is less than or equal to 1 mm). The display unit  116  or  216 , for example, may be implemented by a resistive touch screen, a capacitive touch screen, an infrared touch screen, an acoustic wave touch screen, and/or the like. 
         [0045]    The sensor unit  120  or  220  includes at least one sensor for detecting the state (e.g., location, bearing, movement, etc.) of the device  100  or  200 . For example, the sensor unit  120  or  220  may include a proximity sensor for detecting whether the user is close to the device  100  or  200  and how close the user is to the device  100  or  200 , and a motion/bearing sensor for detecting the movement (e.g., rotation, acceleration, deceleration, vibration, etc.) of the device  100  or  200 . Also, the motion/bearing sensor may include an acceleration sensor, a gravity sensor, a geomagnetic sensor, a gyro sensor, a shock sensor, a Global Positioning System (GPS) sensor, and a compass sensor. The sensor unit  120  or  220  detects the state of the device  100  or  200 , generates a signal corresponding to the detection, and transmits the generated signal to the controller  160  or  260 . For example, the GPS sensor receives a radio signal from each of multiple GPS satellites (not illustrated) in the Earth&#39;s orbit, and calculates a location of the device  100  or  200  by using the Time Of Arrival (TOA) of the received radio signal from each of the GPS satellites (not illustrated) to the device  100  or  200 . The compass sensor calculates an attitude or a bearing of the device  100  or  200 . 
         [0046]    The communication unit  140  or  240  connects the device  100  or  200  to a server or an external device, directly or via a network, and may be a wired or wireless communication unit. The communication unit  140  or  240  transmits data received from the controller  160  or  260 , the memory  130  or  230 , or the camera  150  or  250 , by wire or wirelessly. Otherwise, the communication unit  140  or  240  receives, by wire, data through an external communication line, or wirelessly receives data transmitted over the air, and delivers the received data to the controller  160  or  260 , or stores the received data in the memory  130  or  230 . 
         [0047]    The communication unit  140  or  240  may include at least one of short-range communication modules, such as a mobile communication module, a Wireless Local Area Network (WLAN) module  144  or  244 , a Bluetooth (BT) module  142  or  242 , and a Universal Serial Bus (USB) module  146  or  246 . Other examples of the communication unit  140  or  240 , although not limited thereto, include an Integrated Services Digital Network (ISDN) module, a modem, an Infrared Data Association (IrDA) module, a Zigbee module, and the like. 
         [0048]    According to the control of the controller  160  or  260 , the mobile communication module connects the device  100  or  200  to an external device via a Wide Area Network (WAN) such as a mobile communication network by using at least one antenna (not illustrated). The mobile communication module transmits and receives a wireless signal to/from an external device, such as a mobile phone, a smart phone, or a tablet PC, which has a telephone number or a network address, in order to conduct a voice call or a video call or to exchange data including a Short Message Service (SMS) message, a Multimedia Messaging Service (MMS) message, or the like. 
         [0049]    According to the control of the controller  160  or  260 , the WLAN module  144  or  244  is connected to the Internet at a place where a wireless Access Point (AP) (not illustrated) is installed, or performs wireless communication between the device  100  or  200  and an external device. The WLAN module  144  or  244  supports the WLAN standard (i.e., IEEE 802.11x) of the Institute of Electrical and Electronics Engineers (IEEE), Wireless Fidelity (Wi-Fi), Wi-Fi Direct, or the like. 
         [0050]    According to the control of the controller  160  or  260 , the short-range communication module performs short-range wireless communication between the device  100  or  200  and an external device. Short-range communication schemes may include Bluetooth, IrDA, USB communication, and the like. 
         [0051]    The camera  150  or  250  may include a lens system, an image sensor, a flash, and the like. The camera  150  or  250  converts an optical signal, which has been received (or captured) through the lens system, into an electrical image signal, and outputs the electrical image signal to the controller  160  or  260 . The user captures a moving image or a still image by using the camera  150  or  250 . 
         [0052]    The lens system forms an image of the subject by causing light incident from the outside to converge. The lens system includes at least one lens, and each lens may be a convex lens, an aspheric lens, or the like. The lens system has symmetry with respect to an optical axis passing through the center of the lens system, and the optical axis is defined as a central axis. The image sensor detects an optical image formed by external light incident on the lens system, as an electrical image signal. The image sensor includes multiple pixel units arranged in the structure of an M×N matrix, and each pixel unit includes a photo diode and multiple transistors. Each pixel unit accumulates charges generated by the incident light, and a voltage according to the accumulated charges represents the illuminance of the incident light. In the case of processing a still image or one image included in a moving image file, an image signal which is output from the image sensor is formed by a set of voltages (i.e., pixel values) which are output from the pixel units. The image signal represents one frame (i.e., a still image). Also, a frame includes M×N pixels. Examples of the image sensor may include a Charge-Coupled Device (CCD) image sensor, a Complementary Metal-Oxide Semiconductor (CMOS) image sensor, and the like. 
         [0053]    A driver drives the image sensor according to the control of the controller  160  or  260 . According to a control signal received from the controller  160  or  260 , the driver exposes all pixels of the image sensor or only pixels within a region of interest among all the pixels of the image sensor, and causes image data which is generated by the pixels, to be output to the controller  160  or  260 . 
         [0054]    The controller  160  or  260  processes an image received from the camera  150  or  250 , or an image stored in the memory  130  or  230 , on a frame-by-frame basis, and outputs an image frame which is converted to meet the characteristics (e.g., size, image quality and resolution) of the screen of the display unit  116  or  216 . 
         [0055]    The memory  130  or  230  may store applications for various functions or services such as an in-vehicle notification service, navigation, a video call and games; images for providing a Graphical User Interface (GUI) related to the applications; user information; documents; data (e.g., messages, set values, etc.) related to an in-vehicle notification service; background images (e.g., a menu screen image, a standby screen image, etc.) or operating programs, which are required to drive the device  100  or  200 ; images captured by the camera  150  or  250 ; and the like. The memory  130  or  230  is a medium readable by a machine (e.g., a computer), or a machine-readable medium. The term “machine-readable medium” is defined as a medium which provides data to the machine in order to enable the machine to perform a particular function. The machine-readable medium may be a storage medium. The memory  130  or  230  may include a non-volatile medium and a volatile medium. All of these mediums must be of a type which may be detected by a physical instrument which causes instructions delivered by the mediums to be read into the machine. 
         [0056]    The machine-readable medium, although not limited thereto, includes at least one of a floppy disk, a flexible disk, a hard disk, a magnetic tape, a Compact Disc Read-Only Memory (CD-ROM), an optical disk, a punch card, a paper tape, a Random Access Memory (RAM), a Programmable Read-Only Memory (PROM), an Erasable PROM (EPROM), and a flash-EPROM. 
         [0057]    The controller  160  or  260  executes an application according to a request of an external device, user input information, or an automatic execution setting. The application performs a program operation according to the request of the external device, the user input information, or the automatic execution setting. In the present example, the user input includes input from the keypad or the display unit  116  or  216 , or camera-based input. The controller  160  or  260  may include a bus for information exchange and a processor connected to the bus in order to process information. The controller  160  or  260  may also include a Random Access Memory (RAM) connected to the bus in order to store information required by the processor. The RAM is used to store temporary information requested by the processor. The device  100  or  200  may further include a Read Only Memory (ROM) connected to the bus in order to store static information required by the processor. The controller  160  or  260  which is a Central Processing Unit (CPU), controls an overall operation of the device  100  or  200 , and serves to perform a method for providing an in-vehicle notification service according to an embodiment of the present invention. 
         [0058]    Next, an operation between the mobile device  200  and the head unit device  100  will be described below. 
         [0059]    The head unit device  100  and the mobile device  200  communicate with each other or are connected to each other through the first and second communication units  140  and  240 , according to Transmission Control Protocol/Internet Protocol (TCP/IP). Also, the head unit device  100  and the mobile device  200 , although not limited thereto, use a service protocol such as a Common Data Bus (CDB) protocol and the like in order to implement an in-vehicle notification service. 
         [0060]    According to a communication scheme which is based on the CDB protocol, the head unit device  100  and the mobile device  200  correspond to a terminal mode client and a terminal mode server, respectively. The head unit device  100  includes a first CDB endpoint  170 , which includes: a first CDB source endpoint  174  serving as a data source which transmits data to the mobile device  200 ; a first CDB sink endpoint  172  serving as a data sink which receives data from the mobile device  200 ; and a first notification module  176  taking charge of an in-vehicle notification service. The mobile device  200  includes a second CDB endpoint  270 , which includes: a second CDB source endpoint  274  serving as a data source which transmits data to the head unit device  100 ; a second CDB sink endpoint  272  serving as a data sink which receives data from the head unit device  100 ; and a second notification module  276  taking charge of an in-vehicle notification service. The CDB endpoint  170  or  270  corresponds to a function module within the relevant controller  160  or  260 . A function that the CDB endpoint  170  or  270  performs can be described as being performed by the relevant controller  160  or  260 , or by the relevant device  100  or  200 . 
         [0061]    The CDB protocol which is based on a TCP/IP connection is defined in Table 1 below. 
         [0000]    
       
         
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
             
             
               
                 StartService: 
                 Request CDB source endpoint to start a specific 
               
               
                   
                 service 
               
               
                 StopService: 
                 Request CDB source endpoint to stop a specific 
               
               
                   
                 service 
               
               
                 ServicesSupported: 
                 Provide a list of supported data services 
               
               
                 ServicesRequest: 
                 Requests the list of supported services 
               
               
                 ServicePayload: 
                 Deliver the service specific payload 
               
               
                 ServiceErrorResponse: 
                 Indicate an error within one service 
               
               
                 BusError: 
                 Indicate an error within the Common Data Bus 
               
               
                 Ping: 
                 Message to check the connection 
               
               
                 ServiceOkResponse: 
                 Responds to a Ping, StartService and 
               
               
                   
                 StopService message 
               
               
                   
               
             
          
         
       
     
         [0062]    The current CDB protocol does not define a notification mechanism for services requiring a notification, such as the transmission of call information, that of message information, or that of device status information. 
         [0063]    The present invention provides a new notification mechanism in which unidirectional or bidirectional notification in a particular situation, such as the transmission of call information, that of message information or that of device status information, is performed between the head unit device  100  and the mobile device  200  according to in-vehicle characteristics. 
         [0064]      FIG. 2  is a signal flow diagram illustrating a method for providing an in-vehicle notification service according to a first exemplary embodiment of the present invention.  FIG. 2  sequentially illustrates messages transmitted and received between the head unit device  100  serving as a notification service sink and the mobile device  200  serving as a notification service source. As described above, the head unit device  100  and the mobile device  200  communicate with each other according to the TCP/IP and the CDB protocol. Each message is generated by the relevant CDB endpoint  170  or  270 . The relevant CDB endpoint  170  or  270  transmits and receives each message through the relevant communication unit  140  or  240 . 
         [0065]    In step S 210 , the head unit device  100  generates a register message which requests registration (or a subscribe message which requests subscription), and transmits the generated register message to the mobile device  200 . The register message is used to register the type of notification, which the head unit device  100  desires to receive, in the mobile device  200 , or is used to register an intention to use a preset notification service or all available types of notification services in the mobile device  200 . 
         [0066]    Similarly, an unregister (or unsubscribe) message which requests the cancellation of registration (or subscription) is used to notify the mobile device  200  of the type of notification which the head unit device  100  does not desire to receive (i.e., the type of notification, the registration or subscription of which is desired to be canceled). Otherwise, the unregister (or unsubscribe) message is used to register an intention to cancel a notification service in the mobile device  200 . 
         [0067]    In Table 2 below, the first row shows an example of the contents of a subscribe message representing that a call and message-related notification is intended to be received (i.e., a case in which the mobile device  200  will be requested to transmit a call and message-related notification). Also, the second row shows an example of the contents of an unsubscribe message representing that a call and message-related notification is not intended to be received (i.e., a case in which the mobile device  200  will be requested not to transmit a call and message-related notification). 
         [0000]    
       
         
               
               
             
           
               
                   
                 TABLE 2 
               
               
                   
                   
               
             
             
               
                   
                 &lt;Subscribe&gt; 
               
               
                   
                   &lt;Type&gt;Call, Message&lt;/Type&gt; 
               
               
                   
                 &lt;/Subscribe&gt; 
               
               
                   
                 &lt;Unsubscribe&gt; 
               
               
                   
                   &lt;Type&gt;Call, Message&lt;/Type&gt; 
               
               
                   
                 &lt;/Unsubscribe&gt; 
               
               
                   
                   
               
             
          
         
       
     
         [0068]    In step S 215 , in response to the register message, the mobile device  200  transmits a register (or subscribe) response message which responds to the registration (or subscription) request, to the head unit device  100 . Table 3 below shows an example of the contents of a subscribe response message. The subscribe response message includes subscription success (i.e., OK) or subscription failure (i.e., error), which corresponds to a result of determining the subscription request. In Table 3 below, the first row shows an example of the contents of a subscribe response message which represents subscription success. Also, the second row shows an example of the contents of a subscribe response message which represents subscription failure. An error code may be defined in such a manner as to be variously extended as the need arises. 
         [0000]    
       
         
               
               
             
           
               
                   
                 TABLE 3 
               
               
                   
                   
               
             
             
               
                   
                 &lt;SubscribeResponse&gt; 
               
               
                   
                   &lt;Type&gt;Call, Message&lt;/Type&gt; 
               
               
                   
                   &lt;Result&gt;OK&lt;/Result&gt; 
               
               
                   
                 &lt;/SubscribeResponse&gt; 
               
               
                   
                 &lt;SubscribeResponse&gt; 
               
               
                   
                   &lt;Type&gt;Call, Message&lt;/Type&gt; 
               
               
                   
                   &lt;Result&gt;Error&lt;/Result&gt; 
               
               
                   
                   &lt;ErrorCode&gt;500&lt;/ErrorCode&gt; 
               
               
                   
                 &lt;/SubscribeResponse&gt; 
               
               
                   
                   
               
             
          
         
       
     
         [0069]    Before step S 210 , the head unit device  100  may transmit a StartService message (i.e., a CDB message), which requests the start of a notification service, to the mobile device  200  according to the CDB protocol. 
         [0070]    Selectively, when the StartService message corresponding to the CDB message causes the notification service to start in the head unit device  100  and the mobile device  200 , the registration steps (i.e., steps S 210  and S 215 ) may be omitted, and the head unit device  100  may be automatically set so as to enable the head unit device  100  to receive all types of notifications from the mobile device  200  without limiting the type of notification. 
         [0071]    After the registration steps are performed, the head unit device  100  receives a call information notification message from the mobile device  200  in step S 220 , or receives a message information notification message from the mobile device  200  in step S 225 . Otherwise, the head unit device  100  transmits a set value information (i.e., SetValues) message to the mobile device  200  in step S 230 , the head unit device  100  receives a SetValues response message from the mobile device  200  in step S 235 , and then the head unit device  100  receives a device StatusAlarm notification message or a device status information notification message from the mobile device  200  in step S 240 . 
         [0072]    In step S 250 , the head unit device  100  transmits an unregister message, which requests registration cancellation, to the mobile device  200 . In step S 255 , the head unit device  100  receives an unregister response message from the mobile device  200 . 
         [0073]    Notification types are classified into 4 types. Specifically, the notification types are classified into an incoming call information notification, an outgoing call information notification, a message information notification, and device status information notification. 
         [0074]    Call information notifications are classified into an incoming call information notification and an outgoing call information notification according to two call types. Each call information notification includes information on a call status (i.e., call information). 
         [0075]      FIG. 3  is a view illustrating a state diagram describing a change in a call status related to an incoming call information notification. 
         [0076]    Referring to  FIG. 3 , the incoming call information notification includes four call statuses, such as called (or ringing), connected, disconnected and talking 
         [0077]      FIG. 3  illustrates a process of transition of a series of call statuses from ringing to disconnected in an incoming call. 
         [0078]    When an incoming call arrives in step S 310 , the mobile device  200  transmits a ringing notification message including call status information, which represents ringing, to the head unit device  100 . In response to the ringing notification message, the head unit device  100  transmits an action request message, which includes one action command selected from among three action commands (i.e., which requests that the selected action is intended to be performed), to the mobile device  200 . The three action commands correspond to IgnoreCall, AcceptCall, and RejectCall. 
         [0079]    First, in step S 315 , when the mobile device  200  in the ringing status receives, from the head unit device  100 , an IgnoreCall action request message (i.e., a message including an IgnoreCall( ) command) according to user input received by the first user interface  110  or the first camera  150 , or according to an automatic setting, the mobile device  200  continues to maintain the ringing status, and each of the head unit device  100  and the mobile device  200  displays a status, in which the telephone seems to be hung up, to the user. For example, a screen that the display unit  116  or  216  displays is not a telephone screen, but returns to a screen before being called (e.g., a screen for another application different from a telephone application, or a home screen), and each of the mobile device  200  and the head unit device  100  does not output a ringing tone (i.e., a ringtone) notifying of reception of a call, through the speaker. 
         [0080]    When the mobile device  200  receives, from the head unit device  100  in the ringing status, an AcceptCall action request message (i.e., a message including an AcceptCall( ) command) according to user input received by the first user interface  110  or the first camera  150 , or according to an automatic setting, a call status changes (or transitions) depending on a current connection status of a media session for transmitting a voice or/and an image between the mobile device  200  and the head unit device  100 . When the media session is not connected between the mobile device  200  and the head unit device  100 , a call status of the mobile device  200  changes from the ringing status to the connected status in step S 320 , and the mobile device  200  transmits a connection notification message including call status information representing the connected status, to the head unit device  100 . 
         [0081]    In contrast, when the media session is connected between the mobile device  200  and the head unit device  100 , a call status of the mobile device  200  changes from the ringing status directly to the talking status without passing through the connected status in step S 325 , and the mobile device  200  transmits a talking notification message including call status information representing the talking status, to the head unit device  100 . 
         [0082]    In step S 345 , when the mobile device  200  in the connected status receives, from the head unit device  100 , a LaunchApplication action request message (i.e., a message including a LaunchApplication( ) command) according to user input received by the first user interface  110  or the first camera  150 , or according to an automatic setting, a call status of the mobile device  200  changes from the connected status to the talking status, the mobile device  200  and the head unit device  100  respectively execute corresponding applications (e.g., media streaming applications for connecting a media session) for connecting a media session, and the mobile device  200  transmits a talking notification message including call status information representing the talking status, to the head unit device  100  during the media session. In the connected status, media data such as voice data and/or image data is input and is output to/from the mobile device  200 . In the talking status, media data such as voice data and/or image data is input and is output to/from the head unit device  100 . 
         [0083]    Meanwhile, in step S 330 , when the mobile device  200  in the ringing status receives, from the head unit device  100 , a RejectCall action request message (i.e., a message including a RejectCall( ) command) according to user input received by the first user interface  110  or the first camera  150 , or according to an automatic setting, a call status of the mobile device  200  changes from the ringing status to the disconnected status, and the mobile device  200  transmits a disconnection notification message including call status information representing the disconnected status, to the head unit device  100 . When, even in the ringing status, a user (i.e., a caller) who makes a telephone call cancels the telephone call, or a user (i.e., a callee) who receives the telephone call rejects the telephone call through the mobile device  200 , a call status of the mobile device  200  changes to the disconnected status from the ringing status. 
         [0084]    In steps S 335  and S 340 , when the mobile device  200  in the connected status or talking status receives, from the head unit device  100 , a StopCall action request message (i.e., a message including a StopCall( ) command) according to user input received by the first user interface  110  or the first camera  150 , or according to an automatic setting, a call status of the mobile device  200  changes from the talking status to the disconnected status, and the mobile device  200  transmits a disconnection notification message including call status information representing the disconnected status, to the head unit device  100 . When, even in the connected status or talking status, a user (i.e., caller) who makes a telephone call terminates the telephone call or a user (i.e., callee) who receives the telephone call stops the telephone call through the mobile device  200 , a call status of the mobile device  200  changes to the disconnected status from the connected status or talking status. 
         [0085]    The ringing notification message, the connection notification message, the disconnection notification message and talking message as described above correspond to the types of call information messages. 
         [0086]      FIG. 4  is a signal flow diagram illustrating an action request and a response to the action request. 
         [0087]    In step S 410 , an action request (i.e., requests such as AcceptCall, RejectCall, IgnoreCall, StopCall, etc.) of the head unit device  100  is transmitted from the head unit device  100  to the mobile device  200  through an action request message including an action type. In step S 420 , in response to the action request message, the mobile device  200  transmits a response action message, which responds to the action request, to the head unit device  100 . The response action message includes action success (i.e., OK) or action failure (i.e., error), which corresponds to a result of determining the action request. The action request message may be transmitted as a response to a call information notification message, and steps S 410  and S 420  may be performed immediately after step S 220  illustrated in  FIG. 2 . 
         [0088]      FIG. 5  is a view illustrating a state diagram describing a change in a call status related to an outgoing call notification. 
         [0089]    Referring to  FIG. 5 , the outgoing call notification includes four call statuses, such as calling (or ringing), connected, disconnected and talking. 
         [0090]      FIG. 5  illustrates a process of transition of a series of call statuses from a time point when a user makes a telephone call to the outside to a time point when the user hangs up the telephone (or stops the telephone call), in an outgoing call. 
         [0091]    First, in step S 510 , when the user makes a telephone call, a call status of the mobile device  200  changes to the calling status (or the ringing status), and the mobile device  200  transmits a calling notification message (or a ringing notification message) including call status information representing the calling status, to the head unit device  100 . 
         [0092]    When a callee receives the telephone call in the calling status (i.e., when the mobile device  200  receives a response such that a mobile device of the callee has accepted the telephone call, through a wide area network such as a mobile communication network), a call status changes depending on a connection status of a media session for transmitting a voice or/and an image between the mobile device  200  and the head unit device  100 . When the media session is not connected between the mobile device  200  and the head unit device  100 , a call status of the mobile device  200  changes from the calling status to the connected status in step S 520 , and the mobile device  200  transmits a connection notification message including call status information representing the connected status, to the head unit device  100 . In contrast, when the media session is connected between the mobile device  200  and the head unit device  100 , a call status of the mobile device  200  changes from the calling status directly to the talking status without passing through the connected status in step S 525 , and the mobile device  200  transmits a talking notification message including call status information representing the talking status, to the head unit device  100 . 
         [0093]    In step S 545 , when the mobile device  200  in the connected status receives, from the head unit device  100 , a LaunchApplication action request message according to user input received by the first user interface  110  or the first camera  150 , or according to an automatic setting, a call status of the mobile device  200  changes from the connected status to the talking status, the mobile device  200  and the head unit device  100  respectively execute corresponding applications (e.g., media streaming applications for connecting a media session) for connecting a media session, and the mobile device  200  transmits a talking notification message including call status information representing the talking status, to the head unit device  100  during the media session. In the connected status, media data such as voice data and/or image data is input and is output to/from the mobile device  200 . In the talking status, media data such as voice data and/or image data is input and is output to/from the head unit device  100 . 
         [0094]    Meanwhile, in step S 530 , when the mobile device  200  in the calling status receives, from the head unit device  100 , a RejectCall action request message according to user input received by the first user interface  110  or the first camera  150 , or according to an automatic setting, a call status of the mobile device  200  changes from the calling status to the disconnected status, and the mobile device  200  transmits a disconnection notification message including call status information representing the disconnected status, to the head unit device  100 . When, even in the calling status, a user (i.e., a callee) who receives a telephone call rejects the telephone call, or a user (i.e., a caller) who makes the telephone call stops the telephone call through the mobile device  200 , a call status of the mobile device  200  changes to the disconnected status from the calling status. 
         [0095]    In steps S 535  and S 540 , when the mobile device  200  in the connected status or talking status receives, from the head unit device  100 , a StopCall action request message according to user input received by the first user interface  110  or the first camera  150 , or according to an automatic setting, a call status of the mobile device  200  changes from the talking status to the disconnected status, and the mobile device  200  transmits a disconnection notification message including call status information representing the disconnected status, to the head unit device  100 . When, even in the connected status or talking status, a user (i.e., a callee) who receives a telephone call terminates the telephone call, or a user (i.e., a caller) who makes the telephone call stops the telephone call through the mobile device  200 , a call status of the mobile device  200  changes to the disconnected status from the connected status or talking status. The calling notification message, the connection notification message, the disconnection notification message and the talking message as described above correspond to the types of call information messages. 
         [0096]    A notification related to messages such as a Short Message Service (SMS) message, a Multimedia Messaging Service (MMS) message and an e-mail, as well as a call may be transmitted from the mobile device  200  to the head unit device  100  through a notification message. Table 4 below shows an example of a format of a message information notification message. 
         [0000]    
       
         
               
             
           
               
                 TABLE 4 
               
               
                   
               
             
             
               
                 &lt;NewMessages&gt; 
               
               
                   &lt;Message&gt; 
               
               
                     &lt;Overview&gt; 
               
               
                 Preview of the Message (i.e.,SMS from + 390112288046:Hallo,how...) 
               
               
                     &lt;/Overview&gt; 
               
               
                   &lt;/Message&gt; 
               
               
                   &lt;!-- Any other new Message(if any) go here.--&gt; 
               
               
                 &lt;/ NewMessages &gt; 
               
               
                   
               
             
          
         
       
     
         [0097]    Selectively, elements for entering information, such as a message title, a message body, a message type (e.g., SMS, MMS, E-Mail, etc.), a telephone number and an e-mail address, may be defined below a &lt;Message&gt; element (or field). Also, the contents of a message which are entered in an &lt;Overview&gt; element may be entered separately from the elements for entering the information, such as a message title, a message body, a message type, a telephone number or an e-mail address, as described above. 
         [0098]    Differently from a call information notification, the message information notification message is not immediately transmitted whenever a message is received, but the mobile device  200  transmits the message information notification message to the head unit device  100 , when the mobile device  200  fails to receive another new message during a preset time period from a time point when the mobile device  200  receives a new message. 
         [0099]      FIG. 6  is a view illustrating a state diagram describing a change in a message status related to an incoming message notification. 
         [0100]    Referring to  FIG. 6 , when a new message arrives at the mobile device  200  in step S 610 , a status of the mobile device  200  changes from an Init status (or an arrived status) to a waiting status, in step S 620 . Immediately after the status of the mobile device  200  changes to the waiting status, the mobile device  200  begins to count a particular predetermined time period. In step S 630 , when another new message arrives before the predetermined time period elapses (i.e., expires), the mobile device  200  maintains the waiting status without any change, and again counts the predetermined time period from the beginning. In step S 650 , when the predetermined time period elapses (i.e., expires) in the waiting status, a message status of the mobile device  200  changes from the waiting status to a send status (or a talking status), and the mobile device  200  transmits new messages, which the mobile device  200  has received in the Init status and the waiting status, in the format shown in Table 4 to the head unit device  100  through a message information notification message. In addition, when the predetermined time period does not expire while new messages continue to arrive at the mobile device  200  in the waiting status, the mobile device  200  may face an infinite loop situation in which a message information notification message fails to be transmitted. Accordingly, when the status of the mobile device  200  changes from the Init status to the waiting status, the mobile device  200  begins to count the value of a preset maximum setting time period. Even when a new message arrives in the waiting status, the value of the preset maximum setting time period does not begin to be counted again, but continues to be counted. Even when the predetermined time period which begins to be counted again whenever a new message arrives does not expire, if the value of the preset maximum setting time period expires, a status of the mobile device  200  automatically changes to a send status, and transmits new messages, which have been received during a time period until the status of the mobile device  200  automatically changes to the send status, through a notification message. When the notification message has been transmitted as described above, a status of the mobile device  200  changes from the send status to the Init status. A state diagram related to the message information notification message is managed within the mobile device  200 , and the mobile device  200  does not transmit status information to the head unit device  100  whenever a status thereof changes. 
         [0101]    As another notification message type, a device status type or a device status alarm type exists. A notification message of this type can be activated by only a SetValue action message, differently from notification messages of other types. Table 5 below shows parameter values included in a SetValue action message. 
         [0000]    
       
         
               
               
             
           
               
                   
                 TABLE 5 
               
               
                   
                   
               
             
             
               
                   
                 &lt;Parameters&gt; 
               
               
                   
                   &lt;Parameter&gt; 
               
               
                   
                     &lt;ParameterPath&gt; 
               
               
                   
                       /Phone/Settings/Battery/LowBatteryAlarmLevel 
               
               
                   
                     &lt;/ParameterPath&gt; 
               
               
                   
                     &lt;Value&gt; 
               
               
                   
                       30 
               
               
                   
                     &lt;/Value&gt; 
               
               
                   
                   &lt;/Parameter&gt; 
               
               
                   
                   &lt;!-- Any other parameters(if any) go here.--&gt; 
               
               
                   
                 &lt;/Parameters&gt; 
               
               
                   
                   
               
             
          
         
       
     
         [0102]    In Table 5, the parameters, for example, represent setting information on a battery danger notification. A device data model for a device status alarm may be defined, “/Phone/Settings/Battery/LowBatteryAlarmLevel” which is a path for the device data model is inserted into a &lt;ParameterPath&gt; element, and a threshold of 30 which is a value corresponding to the path may be set for &lt;value&gt;. In this case, when a battery level drops below 30%, the mobile device  200  transmits a notification message to the head unit device  100 . The transmitted device status information notification message may be expressed by Table 6 below. 
         [0000]    
       
         
               
               
             
           
               
                   
                 TABLE 6 
               
               
                   
                   
               
             
             
               
                   
                 &lt;Status&gt; 
               
               
                   
                   &lt;ParameterPath&gt; 
               
               
                   
                     /Phone/Settings/Battery/Low BatteryAlarmLevel 
               
               
                   
                   &lt;/ParameterPath&gt; 
               
               
                   
                   &lt;Value&gt; 
               
               
                   
                     30 
               
               
                   
                   &lt;/Value&gt; 
               
               
                   
                 &lt;/Status&gt; 
               
               
                   
                   
               
             
          
         
       
     
         [0103]    In Table 6, the notification message represents that a parameter path previously set in a SetValue action message is “/Phone/Settings/Battery/LowBatteryAlarmLevel” and the value has arrived at 30%. In another embodiment of the present invention, signal strength information or the like of the mobile device  200  may be reported. 
         [0104]    Each of the first or second notification modules  176  and  276  illustrated in  FIG. 1  transmits a notification message to the notification module of the counterpart device according to a notification protocol defined in Table 7 below representing a format of a notification message, Table 8 below representing a format of a register message, and Table 9 below representing a format of a unregister message. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 7 
               
               
                   
               
               
                 # bytes 
                 Type 
                 Value 
                 Description 
               
               
                   
               
             
             
               
                 2 
                 U16 
                 0xB107 
                 Message-type 
               
               
                 2 
                 U16 
                 4 + M 
                 Payload length 
               
             
          
           
               
                 2 
                 U16 
                   
                 Related Service ID 
               
               
                 2 
                 U16 
                   
                 Notification Type ID 
               
               
                 M 
                 Array of U8 
                   
                 Payload for the Notification 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 8 
               
               
                   
               
               
                 # bytes 
                 Type 
                 Value 
                 Description 
               
               
                   
               
             
             
               
                 2 
                 U16 
                 0xB108 
                 Message-type 
               
               
                 2 
                 U16 
                 2 
                 Payload length 
               
             
          
           
               
                 2 
                 U16 
                   
                 Related Service ID 
               
               
                 2 
                 U16 
                   
                 Notification Type ID 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 9 
               
               
                   
               
               
                 # bytes 
                 Type 
                 Value 
                 Description 
               
               
                   
               
             
             
               
                 2 
                 U16 
                 0xB109 
                 Message-type 
               
               
                 2 
                 U16 
                 2 
                 Payload length 
               
             
          
           
               
                 2 
                 U16 
                   
                 Related Service ID 
               
               
                 2 
                 U16 
                   
                 Notification Type ID 
               
               
                   
               
             
          
         
       
     
         [0105]    The notification message is transmitted to only a device which has previously subscribed through a register (or subscribe) message having the format represented by Table 8. 
         [0106]    A related service ID is a value for representing a notification related to a provided service. For example, a case is described in which a service for providing a status of the mobile device  200  exists and the service has a particular service ID. In this case, when a notification is intended to be transmitted in a particular status of the mobile device  200 , the particular service ID of the mobile device  200  is used to enter the value of the related service ID of the notification message. As the need arises, the related service ID may exist in an optional form within each message. 
         [0107]    In the formats of the messages, when a related service does not currently exist and a particular notification message is intended to be transmitted without the related service, “0” is entered as the value of the related service ID. A notification type ID is a field notifying of which type a notification has. For example, the notification type ID may be defined as in Table 10 below. 
         [0000]    
       
         
               
               
               
             
           
               
                 TABLE 10 
               
               
                   
               
               
                 Notification 
                 Notification 
                   
               
               
                 Type ID 
                 Type 
                 Description 
               
               
                   
               
             
             
               
                 0 
                 Call 
                 Call related notifications (ex. Incoming 
               
               
                   
                   
                 call notification) 
               
               
                 1 
                 Message 
                 . . . 
               
               
                 2 
                 Device Status 
               
               
                 3 
                 . . . 
               
               
                   
               
             
          
         
       
     
         [0108]    When an unregister message having the format defined in Table 9 is transmitted, a notification message is no longer transmitted. 
         [0109]    Then, when a service is terminated by a StopService message defined by a CDB protocol having a format defined in Table 11 below, a service ID included in the StopService message is set so as to have a value identical to a related service ID, and even a registered notification is automatically terminated without cancelling the registration. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 11 
               
               
                   
               
               
                 # bytes 
                 Type 
                 Value 
                 Description 
               
               
                   
               
             
             
               
                 2 
                 U16 
                 0xB104 
                 Message-type 
               
               
                 2 
                 U16 
                 2 
                 Payload length 
               
             
          
           
               
                 2 
                 U16 
                   
                 Service ID 
               
               
                   
               
             
          
         
       
     
         [0110]      FIG. 7  is a signal flow diagram illustrating a signal flow which is based on a CDB architecture illustrated in  FIG. 1 , according to a first embodiment of the present invention. When the first CDB endpoint  170  transmits a register message to the second CDB endpoint  270  in step S 710 , the second CDB endpoint  270  transmits a notification message to the first CDB endpoint  170  whenever an event of a registered type occurs, in step S 720 . When the first CDB endpoint  170  transmits an unregister message to the second CDB endpoint  270  in step S 730 , the transmission of a notification message is interrupted. 
         [0111]    The event may be one of the call reception, the call origination, the change in the call status, the message reception, the change in the message status and the device status alarm, as described above. 
         [0112]      FIG. 8  is a state diagram illustrating an example of a change in a call status in a case where a media session is unexpectedly disconnected, according to a first embodiment of the present invention. When a media session previously connected between the in-vehicle head unit device  100  and the mobile device  200  is disconnected for an unexpected reason during a telephone call, although the telephone call is currently connected between a counterpart mobile device and the mobile device  200 , the media session is disconnected, so that a situation occurs in which it is impossible to talk on the telephone through the head unit device  100 . 
         [0113]    When the media session is unexpectedly disconnected, the mobile device  200  first identifies whether there exists its own method in which a telephone call can be urgently performed without a media session. For example, when the mobile device  200  is automatically switched to a speaker mode, a user who is driving enters a state in which the user can talk to a counterpart user on the telephone without a media session. However, because this scheme corresponds to a temporary method, the user must attempt to reconnect a media session in order to perform a telephone call through the head unit device  100 . Because it needs some time to connect the media session, the mobile device  200  needs to provide its own method in which the driver can talk on the telephone, as described above. After the mobile device  200  operates according to its own method (e.g., enters a speaker mode) as described above, the mobile device changes a call status thereof from a talking status to a connected status, in step S 810 . Then, the mobile device  200  transmits a connection notification message including call status information representing the connected status, to the in-vehicle head unit device  100 . When the in-vehicle head unit device  100  receives the connection notification message, the in-vehicle head unit device  100  reconnects a media session. When the existing media session using a Real-time Transfer Protocol (RTP) is unexpectedly disconnected and it is impossible to reconnect the existing media session, the in-vehicle head unit device  100  connects a media session by using another scheme or protocol (e.g., a BT Hands-Free Profile (BT HFP)). When the media session is connected, the mobile device  200  changes a call status thereof from the connected status to a talking status, in step S 820 . Then, the mobile device  200  transmits a talking notification message including call status information representing a talking status, to the in-vehicle head unit device  100 . 
         [0114]    When the mobile device  200  does not include its own method or protocol as described above that the mobile device  200  can use, a call status of the mobile device  200  may change to a disconnected status, or may transition to a connected status in order to reconnect a media session. When a call status of the mobile device  200  changes to a disconnected status in step S 830 , the telephone call with the counterpart user is disconnected in the mobile device  200 , and the mobile device  200  transmits a disconnection notification message including call status information representing the disconnected status, to the in-vehicle head unit device  100 . At this time, the user is induced to again talk to the counterpart user on the telephone, by inserting a particular parameter for again talking to the counterpart user on the telephone into the disconnection notification message and in such a manner that the in-vehicle head unit device  100  notifies the user that the telephone is currently in a disconnected status. 
         [0115]      FIG. 9  is a block diagram illustrating a configuration of a system for providing an in-vehicle notification service according to a second exemplary embodiment of the present invention. The system includes a head unit device  900  and a mobile device  1000 , which are installed in a vehicle. The system has an architecture which can be used in the Car Connectivity Consortium (CCC) standard. 
         [0116]    The head unit device  900  includes a first user interface  910 , which includes a first speaker  912 , a first microphone  914  and a first display unit  916 , a first sensor unit  920 , a first memory  930 , a first communication unit  940 , a first camera  950 , and a first controller  960 . 
         [0117]    The mobile device  1000  includes a second user interface  1010 , which includes a second speaker  1012 , a second microphone  1014  and a second display unit  1016 , a second sensor unit  1020 , a second memory  1030 , a second communication unit  1040 , a second camera  1050 , and a second controller  1060 . 
         [0118]    The head unit device  900  and the mobile device  1000  communicate with each other or are connected to each other through the first and second communication units  940  and  1040 , according to TCP/IP. Also, the mobile device  1000  and the head unit device  900 , although not limited thereto, use a service protocol such as a Universal Plug and Play (UPnP) protocol or the like in order to implement an in-vehicle notification service. 
         [0119]    According to a communication scheme which is based on the UPnP protocol, the mobile device  1000  and the head unit device  900  correspond to a terminal mode server and a terminal mode client, respectively. 
         [0120]    The system has a configuration similar to that of the system illustrated in  FIG. 1 . There is a difference in that the first and second controllers  160  and  260  illustrated in  FIG. 1  has a CDB architecture whereas the first and second controllers  960  and  1060  illustrated in  FIG. 9  have a UPnP architecture. Accordingly, descriptions of the first and second user interfaces  910  and  1010 , the first and second sensor units  920  and  1020 , the first and second memories  930  and  1030 , the first and second communication units  940  and  1040 , and the first and second cameras  950  and  1050  overlap the descriptions related to  FIG. 1 , and thus will be omitted in order to avoid redundancy. 
         [0121]    The second controller  1060  of the mobile device  1000  includes a terminal mode server device module  1070  for UPnP communication. The terminal mode server device module  1070  includes a Terminal Mode (TM) call management service module  1072  and a TM application server service module  1074 . The TM call management service module  1072  takes charge of call management and a call-related notification. The TM application server service module  1074  executes or terminates the execution of an application stored in the mobile device  1000 , or performs application management such as bringing an application list. The second controller  1060  includes a second Real-Time Protocol (RTP) server/client module  1080  for connecting an RTP-based media session, and a Virtual Network Computing (VNC) server module  1090  for connecting a VNC protocol-based media session. 
         [0122]    The first controller  960  of the head unit device  900  includes a terminal mode control point  970  for UPnP communication. The terminal mode control point  970  manages a media connection for a call and a VNC connection. The first controller  960  includes a first RTP server/client module  980  for connecting an RTP-based media session, and a VNC client module  990  for connecting a VNC protocol-based media session. The terminal mode control point  970  transmits a command to the TM application server service module  1074 , and thereby executes the second RTP server/client module  1080  within the mobile device  1000  and the first RTP server/client module  980  within the head unit device  900 , in order to make a media streaming connection (i.e., an RTP connection) for a telephone call between the mobile device  1000  and the head unit device  900 . Such an RTP connection may be made depending on the change in the call status described with reference to  FIG. 3  and  FIG. 4 . Also, the terminal mode control point  970  may execute the VNC server module  1090  within the mobile device  1000  and the VNC client module  990  within the head unit device  900 , in order to make a VNC connection. 
         [0123]    The descriptions of  FIG. 3  and  FIG. 5  are also applied to a configuration according to a second embodiment of the present invention. Hereinafter, a change in a call status related to an outgoing call notification will be described for illustrative purposes only. 
         [0124]      FIG. 10  is a view illustrating a state diagram describing a change in a call status related to an outgoing call notification using a UPnP telephony. 
         [0125]    Referring to  FIG. 10 , the outgoing call notification includes four call statuses, such as calling (or ringing), connected, disconnected and talking.  FIG. 10  illustrates a process of transition of a series of call statuses from a time point when a user makes a telephone call to the outside to a time point when the user hangs up the telephone (or terminates the telephone call), in an outgoing call. 
         [0126]    First, when the user makes a telephone call or the head unit device  900  transmits a StartCall or InitiateCall action request message (i.e., a message including a StartCall( ) or InitiateCall( ) command) to the mobile device  1000  in step S 1010 , a call status of the mobile device  1000  changes to the calling status, and the mobile device  1000  transmits a calling notification message including call status information representing the calling status, to the head unit device  900 . 
         [0127]    When a callee receives the telephone call in the calling status (i.e., when the mobile device  1000  receives a response such that a mobile device of the callee has accepted the telephone call, through a wide area network such as a mobile communication network), a call status changes depending on a connection status of a media session for transmitting a voice or/and an image between the mobile device  1000  and the head unit device  900 . When the media session is not connected between the mobile device  1000  and the head unit device  900 , a call status of the mobile device  1000  changes from the calling status to the connected status in step S 1020 , and the mobile device  1000  transmits a connection notification message including call status information representing the connected status, to the head unit device  900 . In contrast, when the media session is connected between the mobile device  1000  and the head unit device  900 , a call status of the mobile device  1000  changes from the calling status directly to the talking status without passing through the connected status in step S 1025 , and the mobile device  1000  transmits a talking notification message including call status information representing the talking status, to the head unit device  900 . 
         [0128]    When the mobile device  1000  in the connected status receives, from the head unit device  900 , a LaunchApplication action request message (i.e., a message including a LaunchApplication( ) command) according to user input received by the first user interface  910  or the first camera  950 , or according to an automatic setting in step S 1045 , a call status of the mobile device  1000  changes from the connected status to the talking status, the mobile device  1000  and the head unit device  900  respectively execute corresponding applications (e.g., media streaming applications for connecting a media session) for connecting a media session, and the mobile device  1000  transmits a talking notification message including call status information representing the talking status, to the head unit device  900  during the media session. In the connected status, media data such as voice data and/or image data is input and is output to/from the mobile device  1000 . In the talking status, media data such as voice data and/or image data is input and is output to/from the head unit device  900 . 
         [0129]    Meanwhile, when the mobile device  1000  in the calling status receives, from the head unit device  900 , a StopCall action request message (i.e., a message including a StopCall( ) command) according to user input received by the first user interface  910  or the first camera  950 , or according to an automatic setting in step S 1030 , a call status of the mobile device  1000  changes from the calling status to the disconnected status, and the mobile device  1000  transmits a disconnection notification message including call status information representing the disconnected status, to the head unit device  900 . When, even in the calling status, a user (i.e., a callee) who receives a telephone call rejects the telephone call, or a user (i.e., a caller) who makes the telephone call terminates the telephone call through the mobile device  1000 , a call status of the mobile device  1000  changes to the disconnected status from the calling status. 
         [0130]    In steps S 1035  and S 1040 , when the mobile device  1000  in the connected status or talking status receives, from the head unit device  900 , a StopCall action request message according to user input received by the first user interface  910  or the first camera  950 , or according to an automatic setting, a call status of the mobile device  1000  changes from the talking status to the disconnected status, and the mobile device  1000  transmits a disconnection notification message including call status information representing the disconnected status, to the head unit device  900 . When, even in the connected status or talking status, a user (i.e., a callee) who receives a telephone call terminates the telephone call, or a user (i.e., a caller) who makes the telephone call terminates the telephone call through the mobile device  1000 , a call status of the mobile device  1000  changes to the disconnected status from the connected status or talking status. 
         [0131]    The above-described commands correspond to UPnP action commands for call management. 
         [0132]      FIG. 11  is a signal flow diagram illustrating a method for performing media streaming between an in-vehicle head unit device and a mobile device, according to a second embodiment of the present invention. 
         [0133]    When an incoming call arrives at the mobile device  1000  through a WAN  1100  in step S 1110 , the mobile device  1000  transmits a call information notification message (or a call information notification event) including call status information (i.e., CallInfo) representing a called status (or a ringing status), to the head unit device  900  in step S 1115 . When the head unit device  900  receives the call information notification message, the head unit device  900  displays a notification GUI to a user. The user views the notification GUI, and selects an accept button indicating that the user will receive a telephone call. When the user uses the accept button, the head unit device  900  transmits an AcceptCall action request message including an AcceptCall action command (i.e., AcceptCall( )) defined by the UPnP, to the mobile device  1000  in step S 1120 . In step S 1125 , when the mobile device  1000  receives the AcceptCall action request message, the mobile device  1000  transmits a signal indicating that the user will receive the telephone call, to the WAN  1100 . When a telephone call is actually connected between the mobile device  1000  and a counterpart user, a notification indicating that the telephone call has been connected (i.e., a connection notification message including call status information representing a connected status) is transmitted from the mobile device  1000 , to the head unit device  900  in step S 1130 . When the head unit device  900  receives the connection notification message, the head unit device  900  makes an RTP connection. In order to connect a telephone call, the first RTP server/client module  980  within the in-vehicle head unit device  900  needs to be driven. Also, in order to drive the second RTP server/client module  1080  within the mobile device  1000 , the head unit device  900  transmits a LaunchApplication action request message (i.e., a message including a LaunchApplication( ) command), to the mobile device  1000  in step S 1135 . As the need arises, the first and second RTP server/client modules  980  and  1080  may be previously connected to each other. When the RTP connection is successfully made, both a media streaming connection between the WAN  1100  and the mobile device  1000  and a media streaming connection (i.e., a media session connection) for a telephone call between the mobile device  1000  and the head unit device  900  are completed, in steps S 1140  and S 1145 . A call status of the mobile device  1000  changes from the connected status to a talking status in step S 1150 , and the mobile device  1000  transmits a talking notification message including call status information representing the talking status, to the head unit device  900 . The user&#39;s voice can be transmitted to the mobile device  1000  through the in-vehicle head unit device  900 . Also, a counterpart user&#39; voice can be transmitted from the mobile device  1000  to the in-vehicle head unit device  900 . 
         [0134]    In step S 1155 , when the mobile device  1000  in the talking status receives, from the head unit device  900 , a StopCall action request message (i.e., a message including a StopCall( ) command) according to user input received by the first user interface  910  or the first camera  950 , or according to an automatic setting, the mobile device  1000  terminates the call between itself and the WAN  1100  in step S 1160 , a call status of the mobile device  1000  changes from the talking status to a disconnected status, and the mobile device  1000  transmits a disconnection notification message including call status information representing the disconnected status, to the head unit device  900  in step S 1165 . In step S 1170 , the head unit device  900  transmits a TerminateApplication action request message including a TerminateApplication action command (i.e., TerminateApplication( ) to the mobile device  1000 , and thereby terminates the operation of the second RTP server/client module  1080  within the mobile device  1000 . 
         [0135]    This embodiment of the present invention describes the RTP connection, but the description of this embodiment of the present invention may also be applied to a VNC connection. 
         [0136]    According to the present invention, notification, such as an incoming/outgoing call, a new message or a device status alarm at a particular danger level, can be transmitted unidirectionally or bidirectionally between a head unit device and a mobile device in an in-vehicle environment. 
         [0137]    In the above-described embodiments of the present invention, the term “module” may be replaced in use by a unit, or may be omitted. 
         [0138]    It will be appreciated that embodiments of the present invention may be implemented in the form of hardware, software, or a combination of hardware and software. Any such software may be stored in a volatile or non-volatile storage device such as a ROM, or in a memory such as a RAM, a memory chip, a memory device or a memory integrated circuit, or in a storage medium, such as a Compact Disc (CD), a Digital Versatile Disc (DVD), a magnetic disk or a magnetic tape, which is optically or magnetically recordable and simultaneously, is readable by a machine (e.g., a computer), regardless of whether the software can be deleted or rewritten. It will be appreciated that the memory which may be included in the mobile device or the head unit device is an example of a machine-readable storage medium suitable for storing a program or programs including instructions for implementing the embodiments of the present invention. Accordingly, embodiments of the present invention include a program including codes for implementing a device or a method which is claimed in any claim of this specification, and a storage medium which stores this program and is readable by a machine. Also, this program may be electronically conveyed via any medium such as a communication signal transmitted through a wired or wireless connection, and the present invention suitably includes equivalents of this program. 
         [0139]    Also, the mobile device or the head unit device receives and stores the program from a device for providing a program, which is connected by wire or wirelessly to the mobile device or the head unit device. The device for providing a program includes a memory for storing a program including instructions which cause the mobile device or the head unit device to perform a previously-set method for providing an in-vehicle notification service, and information required for the method for providing an in-vehicle notification service; a communication unit for performing wired or wireless communication with the mobile device or the head unit device; and a controller for performing a control operation so as to transmit the relevant program to the mobile device or the head unit device, at a request from the mobile device or the head unit device or automatically. 
         [0140]    While the present invention has been shown and described with reference to embodiments thereof, it will be understood by those having ordinary knowledge in the technical field, to which the present invention pertains, that the present invention may be practiced in other specific forms without changing the technical idea or essential features of the present invention. Therefore, it should be understood that the embodiments of the present invention have been described for illustrative purposes only in all aspects and do not limit the present invention.