Patent Publication Number: US-11641289-B1

Title: Method, apparatus and system for retrofitting a vehicle

Description:
TECHNICAL FIELD 
     The present disclosure relates to a method, apparatus and system for retrofitting a vehicle. 
     BACKGROUND OF THE INVENTION 
     Being able to easily alert emergency responders in case of an automobile accident is highly desirable. Mobile application service providers (such as OnStar®) address this need for their subscribers by offering an emergency call button located within reach of the driver of an automobile. Upon pressing the emergency call button an emergency telephone call is placed from a cellular telephone which is embedded in the vehicle through a wireless telecommunication network and a public switched telephone network to a service center operated by the mobile application service provider. An emergency call to the service provider may also be initiated automatically, e.g. upon airbag deployment. 
     In case of an incoming emergency call the mobile application service center silently obtains vehicle position information, e.g. information from a GPS receiver that is also embedded in the vehicle. The mobile application service center as part of an emergency assistance service informs public safety authorities of the emergency and conveys the vehicle&#39;s position. The emergency assistance service is typically available only to those who register (for a fee) with the mobile application service provider. Registration with the mobile application service providers includes an underlying registration with the wireless telecommunication network. Several elements of one such system are described in U.S. Pat. No. 6,812,832 (Lobaza), which is hereby incorporated by reference. 
     The embedded cellular telephone may also be used to place hands free telephone calls. Dialing the embedded cellular telephone may utilize a speech recognition engine that is capable of recognizing spoken telephone numbers or voice tags associated with telephone numbers. To facilitate dialing the embedded cellular telephone may also be connected to an external keypad, e.g. a telephone-style keypad located in the vehicle&#39;s dashboard or a virtual keypad displayed on a touch screen display. The external keypad may communicate with the embedded cellular telephone by sending a telephone dial command message through the vehicle communication network. The embedded cellular telephone is accordingly configured to receive telephone dial command messages on the vehicle communication network and establish a telephone call to the requested telephone number. 
     US law obligates commercial mobile radio service providers to transmit all wireless 911 emergency calls without respect to their call validation process to a Public Safety Answering Point (PSAP), or, where no Public Safety Answering Point has been designated, to a designated statewide default answering point or appropriate local emergency authority. The law extends to voice capable cellular telephones embedded in vehicles. An embedded cellular telephone can hence be used in an emergency to directly alert public safety authorities by dialing 911 regardless of registration status with the mobile application service provider or the underlying wireless telecommunication network. However, the user interface provided to dial 911 is inferior to single button activation and may e.g. require use of the voice recognition interface. Changes in an operator&#39;s voice during an emergency frequently cause the voice recognition engine to fail detecting a spoken “dial 9-1-1” command and thereby preclude the operator from receiving the help he is seeking. 
     What is therefore needed is a method for combining the benefits of legally mandated free wireless 911 access to a Public Safety Answering Point with the advantageous single button user interface for placing emergency calls to a mobile application service center. 
     SUMMARY OF THE INVENTION 
     In one aspect of the present invention an integrated vehicle communication system includes a telecommunication apparatus in communication with a vehicle data bus. An emergency call apparatus is also in communication with the vehicle data bus, the emergency call apparatus further providing an emergency call push button switch to initiate an emergency telephone call to a Public Safety Answering Point. When the emergency call push button switch is pressed the emergency call apparatus transmits a telephone dial command message including a telephone number to be dialed on the vehicle data bus. The telecommunication apparatus is configured to receive the telephone dial command and establish communication with the requested telephone number. To initiate an emergency call to a Public Safety Answering Point in the United States the emergency call apparatus may e.g. transmit a telephone dial command message requesting the telecommunication apparatus to dial “911”. 
     In a further aspect the emergency call apparatus may include an input for an external switch. In this aspect the emergency call push button switch may be remote from the emergency call apparatus and may e.g. be located within reach of the driver of the vehicle whereas the emergency call apparatus may be located somewhere else hidden in the vehicle. 
     In another aspect the emergency call apparatus may be added to the vehicle during a retrofit. In this aspect the vehicle may be originally equipped with an embedded telecommunication apparatus and an emergency call push button switch connected thereto. Before the retrofit pressing the emergency call button is detected by the telecommunication apparatus which responsive to the button press initiates an emergency call to a mobile application service center. 
     During the retrofit an emergency call apparatus is added to the vehicle. The electrical connection between the emergency call push button switch and the telecommunication apparatus is separated and the emergency call push button switch is rewired and connected to the emergency call apparatus. 
     After the retrofit pressing the emergency call push button is detected by the emergency call apparatus which responsive to the button press transmits a telephone dial command message on the vehicle data bus. The telephone dial command message may request the telecommunication apparatus to dial the telephone number 911. The telecommunication apparatus responsive to receiving the telephone dial command message establishes a voice call to a Public Safety Answering Point. 
     In yet another aspect the emergency call apparatus may be configured to detect a trigger condition and responsive thereto request the telecommunication apparatus to establish communication with a Public Safety Answering Point. The trigger condition may be a manual emergency call push button press. As part of an automatic emergency calling system the trigger condition may also be the receipt of one or more messages on the vehicle data bus which are reflective of a vehicle accident, e.g. a message signaling airbag deployment. Upon detecting a trigger condition the emergency call apparatus may transmit a telephone dial command message on the vehicle data bus requesting the telecommunication apparatus to dial 911. The telecommunication apparatus responsive to receiving the telephone dial command message establishes a voice call to a Public Safety Answering Point. 
     In still another aspect the emergency call apparatus may provide an electrically controlled switch to separate the vehicle communication network into two subnets. One subnet may be used to communicate between the emergency call apparatus and the telecommunication device and the other subnet may be used to communicate between the emergency call apparatus and the rest of the vehicle. This aspect can compensate for possible loss of communication on the vehicle data bus after a vehicle crash, e.g. because a wire within the communication network is shorted to ground or battery as a result of the crash. The emergency call apparatus may be configured to detect loss of communication and responsive thereto open the electrically controlled switch, thereby dividing the communication network into the two electrically insulated subnets. In result the emergency call apparatus separates the damaged portion of the vehicle communication network from its connection to the telecommunication apparatus and thereby regains its ability to communicate with the telecommunication apparatus and initiate an emergency call even though communication with the rest of the vehicle is no longer possible. 
     In yet another aspect the emergency call apparatus may provide two vehicle data bus interfaces wherein the first interface is used to communicate with the telecommunication apparatus and the second interface is used to communicate with the rest of the vehicle. In this aspect the emergency call apparatus acts as a bi-directional gateway between the two vehicle data bus interfaces. Messages which the emergency call apparatus receives through the first vehicle data bus interface are retransmitted through the second vehicle data bus interface. Vice versa messages received through the second vehicle data bus interface are retransmitted through the first vehicle data bus interface. The two vehicle data bus interfaces are electrically insulated from each other such that the emergency call apparatus maintains its ability to communicate with the telecommunication apparatus even if communication with the rest of the vehicle can not be established, e.g. because a communication bus wire is shorted to ground or battery as may happen during an accident. 
     The following detailed description of the invention is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description of the invention. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic diagram of an exemplary wireless and a public switched telecommunication network through which emergency calls can be placed from a vehicle to a service center or Public Safety Answering Point. 
         FIG.  2 A  is a block diagram illustrating the vehicle portion of a wireless communication system for placing emergency calls used in the vehicle of  FIG.  1   . 
         FIG.  2 B  is a block diagram showing aspects of a prior art vehicle communication system for communicating with a mobile application service center before retrofit with an emergency call apparatus. 
         FIG.  2 C  is a block diagram showing aspects of a vehicle communication system for communicating with a Public Safety Answering Point after retrofit with an emergency call apparatus. 
         FIG.  3    is a block diagram illustrating a vehicle communication system showing an airbag control apparatus, a telecommunication apparatus, an emergency call apparatus and a navigation system communicating through a common vehicle data bus. 
         FIG.  4    is a block diagram illustrating an alternative embodiment of a vehicle communication system in which the telecommunication apparatus is connected to the vehicle data bus through the emergency call apparatus. 
         FIG.  5    is a block diagram illustrating an exemplary embodiment of an emergency call apparatus for a vehicle communication system configuration as shown in  FIG.  3   . 
         FIG.  6    is a block diagram illustrating an exemplary embodiment of an emergency call apparatus for a vehicle communication system configuration as shown in  FIG.  4   . 
         FIG.  7    is a block diagram of an alternative embodiment of the emergency call apparatus show in  FIG.  6   . 
         FIG.  8    is a flow diagram illustrating an exemplary method for initiating an emergency call. 
         FIG.  9    is a flow diagram illustrating an alternative embodiment of the method shown in  FIG.  8   . 
         FIG.  10    is a schematic diagram of an exemplary touch screen display. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG.  1   , there is shown a vehicle  100  featuring a mobile telecommunication apparatus, suitable for use with an embodiment of the invention, and which may be installed in the vehicle or carried into the vehicle by the subscriber. The mobile telecommunication apparatus communicates through a wireless network  102 , symbolized by a local telecommunication antenna tower, with a public switched telephone network (PSTN)  104 , to which are also connected telephones  110  and  112 . Wireless network  102  may also communicate with other wireless telecommunication devices, here symbolized by a wireless telephone  114 . The mobile telecommunication apparatus in vehicle  100 , which will be described in more detail with reference to  FIG.  2 A , may include a cellular telephone or any other wireless device that may be registered with a cellular service provider providing general dialing capability in connection with, and operation through, PSTN  104 . It may also include a cellular telephone or other wireless device that is not or that is no longer registered with a cellular service provider so long as it provides connection with and operation through PSTN  104  with a Public Safety Answering Point (PSAP)  106 . 
     The telecommunication apparatus carried in vehicle  100  may have been designed to provide access to mobile application services of a service provider such as, for example, OnStar®. Mobile application services are typically provided within a subscription business model, which requires payment of a subscription fee per period, e.g. $19.95 per month or $199 per year. The telecommunication apparatus may have been permanently installed in the vehicle at the time of vehicle assembly and the cost of the telecommunication apparatus may have been subsidized by the service provider in anticipation of future subscription revenue if the owner or lessor of vehicle  100  registers for mobile application services. The service provider generally maintains at least one service center  108 , which is connected to PSTN  104  and which the subscriber and other subscribers in other vehicles call for the mobile application services. The mobile application services may include, for example, requests for vehicle location, selection of specific points of interest and directions thereto, and emergency assistance (both requested and automatic), as well as others not named. 
     If the owner or lessor of vehicle  100  does not register with the service provider, e.g. to avoid the financial burden associated with a subscription, the service provider may refuse to provide mobile application services including emergency assistance. The mobile application service provider may also deactivate the telecommunication apparatus located within vehicle  100 . Deactivating the telecommunication apparatus may include deregistering the cellular telephone therein from wireless network  102  so that the telecommunication apparatus can no longer gain access to wireless network  102  for general dialing and can thus no longer connect to service center  108 . 
     Even if the telecommunication apparatus within vehicle  100  has been deactivated and the cellular telephone therein been deregistered from wireless network  102  both can still be used to establish a connection to a Public Safety Answering Point (PSAP). Connecting to a PSAP is independent of a subscription with the service provider or the underlying wireless network  102 . This is, especially in the United States, to comply with federal law mandating free access to a PSAP for all devices used to access a commercial mobile radio service (CMRS). 
     Referring now to  FIG.  2 A  there is shown wireless telecommunication apparatus  200  in vehicle  100 . The telecommunication apparatus  200  communicates voice and data through an antenna  206  with wireless network  102  and through wireless network  102  with public switched telephone network  104 . The telecommunication apparatus  200  may provide “hands-free” voice communication through a microphone  202  and speaker  204 . The telecommunication apparatus may include a GPS or similar navigation apparatus (not shown) which receives signals through a GPS antenna (not shown) from global positioning satellites and derives therefrom position data (e.g., the longitude and latitude and/or the speed and heading) of the apparatus. The telecommunication apparatus  200  may convert the GPS position information into a transmissible form for subsequent transmission from vehicle  100  to service center  108  or Public Safety Answering Point  106 . Communication between the telecommunication apparatus  200  and service center  108  or PSAP  106  may be voice communication utilizing microphone  202  and speaker  204  and/or data communication the data comprising e.g. GPS location information. 
     Connected to the telecommunication apparatus  200  are one or more buttons  208  and status indicator  210 . Buttons  208  provide a simple user interface for an operator, e.g. the driver or passenger in vehicle  100 , to interact with the telecommunication apparatus  200 . The buttons  208  may e.g. include a dedicated emergency call button. If the emergency call button is pressed telecommunication apparatus  200  establishes voice and/or data communication with service center  108 . Status indicator  210 , which may e.g. be one or more light emitting diodes or any other form of display, provides feedback to the vehicle operator as to the status of the telecommunication apparatus  200 . Telecommunication apparatus  200  is also connected to vehicle data bus  212  to exchange messages with other electronic modules within vehicle  100  as required. 
     Telecommunication apparatus  200  may provide general dialing capability, e.g. to a telephone  110 ,  112  within the public switched telephone network  104  or to a wireless telephone  114  through wireless network  102  or any other wireless network. To facilitate dialing telecommunication apparatus  200  may include a voice recognition and activation apparatus, which responds to predetermined spoken data via microphone  202  to perform predetermined functions. It accesses a plurality of voice models stored within telecommunication apparatus  200 . Each voice model includes data permitting recognition of a spoken word or phrase. The voice recognition apparatus compares received spoken data with the voice models in order to recognize those words and phrases which are defined and for performing predetermined actions in response thereto. Some voice models represent commands, such as “menu,” “store,” “dial,” “call,” etc. Other voice models represent the digits required for telephone dialing: “one,” “two,” etc. For example, the apparatus may be programmed to recognize the phrase “Dial 9-1-1 Dial” and respond by placing a call to a Public Safety Answering Point. General dialing capability may be initiated by the word “Dial” followed by the number, digit by digit. 
     Telecommunication apparatus  200  may also be configured to allow dialing utilizing a keypad which may be connected directly to communication apparatus  200  or indirectly connected to another module which communicates with telecommunication apparatus  200  through the vehicle data bus  212 . In an exemplary embodiment navigation system  218  comprises a touch screen display  220  which displays a virtual telephone keypad  222 . An operator may enter a telephone number he wishes to dial on the virtual keypad  222 . After the telephone number has been entered navigation system  218  transmits a telephone dial command message on the vehicle data bus  212  including the telephone number to be dialed. Telecommunication apparatus  200  responsive to receiving the telephone dial command message establishes voice and/or data communication with the desired telephone number. 
     Quicker and easier access to dialing 911 and establishing voice and/or data communication with a Public Safety Answering Point is provided by emergency call apparatus  214 , which is connected to vehicle data bus  212  and to one or more buttons  216 . Buttons  216  may include an emergency call push button switch which when pressed causes emergency call apparatus  214  to transmit a telephone dial command message including a telephone number to be dialed on vehicle data bus  212 . Telecommunication apparatus  200  responsive to receiving the telephone dial command message establishes voice communication with the requested telephone number, e.g. 911. Emergency call apparatus  214  and its operation are described in more detail with reference to  FIGS.  5  through  9    below. 
     As is shown in  FIG.  2 B  vehicles equipped with an embedded telecommunication apparatus  200  are typically also equipped with buttons  208 , one of which may be an emergency call button to initiate an emergency call to service center  108 . Buttons  208  and telecommunication apparatus  200  do not serve any useful purpose if the owner or lessor of vehicle  100  does not register with the mobile application service provider. The existing buttons  208  and the telecommunication apparatus  200  may however be used when retrofitting vehicle  100  with an emergency call apparatus  214  at some time after vehicle built. 
     An exemplary method of retrofitting vehicle  100  is show in  FIG.  2 C . Vehicle  100  is retrofitted by adding emergency call apparatus  214 . The electrical connection between buttons  208  and telecommunication apparatus  200  is removed and instead buttons  208  are rewired and connected to emergency call apparatus  214 . Optionally the vehicle data bus connection between telecommunication apparatus  200  and vehicle data bus  212  may be disconnected and instead re-routed into the emergency call apparatus  214 . A new connection is made between the emergency call apparatus  214  and vehicle data bus  212 . Further, emergency call apparatus  214  is connected to vehicle battery and vehicle ground to power emergency call apparatus  214 . 
     To enable the rewiring of buttons  208  the electrical interface between buttons  216  and emergency call apparatus  214  may be identical to the electrical interface between buttons  208  and telecommunication apparatus  200 . Using an identical interface, e.g. the same resistor values in case of resistor coded switches, provides that an emergency call button  208  which is connected to and used in combination with telecommunication apparatus  200  before the retrofit can be rewired and used in combination with emergency call apparatus  214  after the retrofit. This simplifies the process of retrofitting vehicle  100  which may have originally been equipped with telecommunication apparatus  200  and buttons  208  but not emergency call apparatus  214  and buttons  216 . 
     Referring now to  FIG.  3   , there is shown a block diagram illustrating an exemplary vehicle communication system  300  including the telecommunication apparatus  200 , an airbag control apparatus  302 , the emergency call apparatus  214  and the navigation system  218 . As is shown, each system is in communication with the vehicle&#39;s data bus  212 , which may be a Class  2  or CAN vehicle data bus or any other suitable bus known in the art for electronic data communication. 
       FIG.  4    illustrates an alternative embodiment of the vehicle communication system  400 . In this embodiment telecommunication apparatus  200  is in communication with vehicle data bus  212  using an indirect connection made trough emergency call apparatus  214 , as will be explained in more detail with respect to  FIG.  6    and  FIG.  7   . 
       FIG.  5    is a block diagram illustrating an exemplary emergency call apparatus  214 . Control processor  500 , which may take the form of a programmed digital computer or a custom digital processor, is operatively connected to push button switch  216 . Push button switch  216  may be an emergency call button located within easy reach of the driver and labeled prominently, e.g. with a Red Cross icon or the letters “SOS”. Push button switch  216  is designed to be easily found and operated by the driver or passenger of vehicle  100  even under stress. Push button switch  216  may be any suitable device that translates a human operator&#39;s intention into a signal that can be detected by control processor  500 , including e.g. a momentary push button switch, a toggle switch, a rocker switch, a rotary switch or a virtual button on a touch screen display. Control processor  500  is connected to the vehicle data bus  212  through a vehicle data bus interface  504  using an electrical terminal  508 . Control processor  500  and vehicle data bus interface  504  are powered by power supply  506 . Power supply  506  is connected to the vehicle&#39;s power distribution system through vehicle battery terminal  512  and vehicle ground terminal  510 . While emergency call apparatus  214  is shown as a stand alone unit it should be appreciated that it may also be integrated within another electronic control module in which case control processor  500 , power supply  506  and vehicle data bus interface  504  may be shared with other functions. 
       FIG.  6    is an alternative embodiment showing an emergency call apparatus  610  which may be used in the vehicle communication system  400  shown in  FIG.  4   . In this example the telecommunication apparatus  200  is connected to the vehicle data bus  212  indirectly through emergency call apparatus  610 . Electrical terminal  600  connects the emergency call apparatus  610  to the telecommunication communication apparatus  200 . Electrical terminal  602  connects the emergency call apparatus  610  to vehicle data bus  212  and through that to all other electronic modules communicating through vehicle data bus  212 . Control processor  500  electronically controls switch  606 , which may e.g. be an electromechanical relay with coil  604 , or any other suitable switching device. Switch  606  is normally closed, creating a short circuit between electrical terminals  600  and  602 . In case of a crash the vehicle communication system  400  may be damaged, e.g. may deformation to the vehicle&#39;s sheet metal have caused a wire of vehicle data bus  212  to be shortened to vehicle ground or battery, making communication on vehicle data bus  212  impossible. Control processor  500  is configured to detect such damage to the communication system by monitoring its vehicle data bus interface  504 . If damage to the communication system is detected control processor  500  restores communication with the telecommunication device  200  by opening switch  606  and thereby disconnecting the damaged part of the vehicle communication system  400  from vehicle data bus interface  504 . In its open position switch  606  may cause vehicle data bus interface  504  to be connected to a network termination element  608 , simulating a network termination usually present in the now disconnected vehicle communication system. Network termination may consist of a pull-up or pull-down resistor or any other electronic circuit known in the art of electronic communication for terminating communication networks. 
       FIG.  7    shows another alternative embodiment of emergency call apparatus  710 . In this example control processor  500  communicates with telecommunication apparatus  200  through vehicle data bus interface  504  and electrical terminal  600 . It is also communicates with other electronic modules connected to the vehicle data bus  212  through a second vehicle data bus interface  700  and electrical terminal  602 . Vehicle data bus interface  504  and vehicle data bus  700  are electrically insulated from each other so that damage to the vehicle data bus  212  does not affect the ability of control processor  500  to communicate with the telecommunication device  200  through vehicle data bus interface  504 . During normal operation control processor  500  is configured to act as bidirectional gateway between vehicle data bus interface  504  and vehicle data bus  700 . Control processor  500  re-transmits any messages it receives from vehicle data bus interface  504  through vehicle data bus interface  700  and any messages it receives from vehicle data bus interface  700  through vehicle data bus interface  504 , thereby functionally connecting telecommunication apparatus  200  with vehicle data bus  212 . 
       FIG.  8    is a flow diagram illustrating an exemplary method  800  that may be implemented in process controller  500 . Process controller  500  is configured to detect a trigger condition in block  802 . The trigger condition may be a manual operator request to initiate an emergency call, e.g. by pressing emergency call push button switch  216 . The trigger condition may also be the receipt of a predetermined message or a combination of predetermined messages on vehicle data bus  212 . The predetermined message or messages may e.g. reflect that the airbag control apparatus  302  has inflated an airbag in vehicle  100 . Other suitable messages that may act as a trigger for automatic emergency calling include a message from an object detection apparatus indicating that vehicle  100  was involved in a collision, a message indicating vehicle deceleration above a predetermined threshold or any other message or combination of messages which indicate that vehicle  100  was involved in a severe accident which may have caused the occupants within vehicle  100  to be injured and no longer be able to manually initiate an emergency call. 
     If the trigger condition in block  802  is detected then in step  804  process controller  500  sends a telephone dial command message to the telecommunication apparatus  200 . The telephone dial command consists of or is part of a predetermined message on the vehicle data bus containing a telephone number to be dialed. Telecommunication apparatus  200  is configured to receive the telephone dial command and responsive thereto establish voice and/or data communication through wireless network  102  and PSTN  104  with the desired telephone number. For emergency use in the United States the telephone number requested in step  804  will typically be “911” to establish communication with a PSAP. 
     As described earlier with respect to  FIG.  2 B  and  FIG.  2 C  emergency call apparatus  214  may be retrofitted into a vehicle  100  at some time after the vehicle has been built. In case of a retrofit telecommunication apparatus  200  may not haven been designed for use with the emergency call apparatus  214 . In particular, telecommunication apparatus  200  may not have been configured to receive a telephone dial command message on vehicle data bus  212  that is originating from emergency call apparatus  214 . Telecommunication apparatus  200  may however have been configured to receive telephone dial command messages on vehicle data bus  212  that are originating from other devices, for example navigation system  218 . To operate under these circumstances emergency call apparatus  214  may be configured to mimic the telephone dial command message originating e.g. from navigation system  218 . To mimic the dial command message emergency call apparatus  214  uses the same message identifier segment that has been assigned to navigation system  218  when transmitting its telephone dial command message. By sharing the same message identifier segment a telephone dial command message originating from emergency call apparatus  214  and a telephone dial command message originating from navigation system  218  become indistinguishable for the telecommunication apparatus  200 . Telecommunication apparatus  200  hence responds properly to a telephone dial command message originating from emergency call apparatus  214  even though it may not have been designed for this purpose. While emergency call apparatus  214  shares the same message identifier segment with navigation system  218  it should be understood that vehicle  100  need not necessarily be equipped with navigation system  218 . It is sufficient if telecommunication apparatus  200  is configured to respond to telephone dial command messages on the vehicle data  212  bus irrespective of whether the potential transmitter of such a message is actually present in the vehicle. 
     Table 1 illustrates the structure of an exemplary vehicle data bus message. As illustrated the message consist of an identifier segment, which in case of CAN messages may e.g. be 11 or 29 bits long, and a data segment carrying the message payload, which may be up to 8 bytes long. To avoid message collision vehicle communication networks usually use unique identifier segments for each transmitting module, if the same message is originating from more than one module. Modules connected to the communication network are configured to respond to predetermined messages which are distinguished from other messages by their identifier segments. 
     
       
         
           
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Identifier Segment 
                 Data Segment 
               
               
                   
                 11 bit or 29 bit 
                 0 to 8 bytes 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 Example 
                 0x0CF00400 
                 39 
                 31 
                 31 
                 23 
                 FF 
                 FF 
                 FF 
                 FF 
               
               
                   
               
            
           
         
       
     
     To avoid the unlikely but possible collision of two telephone dial command messages issued simultaneously by both the navigation system  218  and the emergency call apparatus  214  the emergency call apparatus  214  may in a vehicle communication system configuration  400  actively prevent such collision. Accordingly control processor  500  in an embodiment as shown in  FIG.  6    may in a first step open switch  606  so that the navigation system  218  is no longer connected to the telecommunication apparatus  200  before control processor  500  in a second step transmits its telephone dial command message to the telecommunication apparatus  200 . Control processor  500  in an embodiment as shown in  FIG.  7    may selectively suppress forwarding a telephone dial command received from the navigation system  218  through vehicle data bus interface  700  while transmitting its own telephone dial command through vehicle data bus interface  504 . 
       FIG.  9    is a flow diagram showing an alternative exemplary embodiment of the method illustrated in  FIG.  8   . This embodiment is suitable for example for vehicles in which the emergency call apparatus  214  is integrated with the navigation system  218  and where the navigation system  218  is connected to a display. If in step  802  a trigger condition, e.g. an airbag deployment, is detected the emergency call apparatus displays or causes to be displayed an emergency screen  1000  comprising a prominent user interface to activate an emergency call. If in step  904  an emergency call is requested the emergency call apparatus in step  804  sends a telephone dial command to telecommunication apparatus  200 . 
     Finally, an exemplary emergency screen  1000  as may e.g. be used within a touch screen navigation display is shown in  FIG.  10   . Emergency screen  1000  comprises virtual button  1002  to call PSAP  106  and virtual button  1004  to call service center  108 . 
     While the invention has been described with reference to a preferred embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.