Abstract:
A system and method to provide a means of communication, command and control between a mobile antenna and a satellite receiver that allows the receiver to send tuning information to the antenna and the antenna to provide feedback to the receiver when a signal has been acquired. The antenna and the receiver can share the appropriate states and stats such as diagnostics, test, GPS coordinates, etc.

Description:
TECHNICAL FIELD 
   The present invention sets forth a method for exchanging information between an antenna and a satellite receiver so that tuning information and parameters may be exchanged between them. 
   BACKGROUND 
   Satellite television has become increasingly popular due to its wide variety of programming. Current DirecTV systems employ an antenna that is fixed to a structure. The antenna is pointed once and secured into place. 
   Entertainment in automobiles such as DVD players has also become increasingly popular. It would be desirable to provide a satellite television system for a vehicle so that the wide variety of programming may be enjoyed by the rear passengers. In vehicles the antenna must continually move as the vehicle moves to maintain a connection with the satellite receiver. Current satellite receivers do not know information about the antenna and the antenna does not know information about the receiver. Therefore, the time to perform certain tasks may be increased. Currently, mobile satellite service uses standard set top boxes (IRDs). The designs of the IRDs change nearly every year. This increases the challenge for a reliable system particularly in view of the ever-changing antenna designs. 
   It would therefore be desirable to provide a method and apparatus for performing two-way communications between a receiver and an antenna so that various information may be exchanged between them. 
   SUMMARY OF THE INVENTION 
   The present invention allows a mobile antenna to communicate information as to searching, tracking and the acquisition of a good signal to a satellite receiver. Advantageously, this information will provide a minimum disruption to the user and improve the overall perceived quality of the system. 
   The invention provides a means of communication, command and control between a mobile antenna and a satellite receiver that allows the receiver to send tuning information to the antenna and the antenna to provide feedback to the receiver when a signal has been acquired. The antenna and the receiver can share the appropriate states and stats such as diagnostics, test, GPS coordinates, etc. Various mobile vehicles with satellite receivers such as cars, SUVs, boats RVs, trains and airplanes may benefit from this invention. 
   Other advantages and features of the present invention will become apparent when viewed in light of the detailed description of the preferred embodiment when taken in conjunction with the attached drawings and appended claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a system level view of a satellite broadcasting system according to the present invention. 
       FIG. 2  is a block diagrammatic view of a vehicle having a receiving system according to the present invention. 
       FIG. 3  is a flow chart illustrating a method of storing communicating between an antenna and a receiving unit according to the present invention. 
       FIG. 4  is a signaling chart illustrating a method for communicating according to the present invention. 
   

   DETAILED DESCRIPTION 
   In the following figures the same reference numerals will be used for the same views. The following figures are described with respect to a mobile satellite television system. However, those skilled in the art will recognize the teachings of the present invention may be applied to various types of mobile reception including land-based type systems. 
   Referring now to  FIG. 1 , a satellite television broadcasting system  10  is illustrated. The satellite television broadcasting system  10  includes a network operations center  12  that generates wireless signals through a transmitting antenna  14  which are received by a receiving antenna  16  of a satellite  18 . The wireless signals, for example, may be digital. A transmitting antenna  20  generates signals directed to various receiving systems including stationary systems such as those in the home as well as mobile receiving systems  22 . The wireless signals may have various types of information associated with them including location information. The wireless signals may also have various video and audio information associated therewith. As illustrated, the mobile receiving system  22  is disposed within an automotive vehicle  24 . A receiving antenna  26  receives the wireless signals from the satellite  18  and processes the signals in a mobile receiving unit  28 . The mobile receiving unit  28  will be further described below. 
   The system  10  may also receive location signals from a GPS system  30  that includes a first satellite  32 A and a second satellite  32 B. Although only two satellites are shown, a typical GPS system includes several satellites, several of which may be in view at any particular time. Triangulation techniques may be used to determine the elevation, latitude and longitude of the system. A locating system may also include cellular towers  34 A and  34 B that may be used by the mobile receiving system  22  to determine a location. Cellular phones typically include a GPS locating system. As the vehicle  24  moves about, the exact coordinates in latitude and longitude may be used to determine the proper designated marketing area for local television and broadcasting. 
   The present invention may also be used for displaying various wireless information on a personal mobile device  36  such as a laptop computer  38 , a personal digital assistant  39 , and a cellular telephone  40 . It should be noted that these devices and the automotive-based devices may also receive wireless signals having various types of information associated therewith from the cellular towers  34 A and  34 B. Other types of information may be broadcast from various other types of broadcasting areas such as an antenna  42  on a building  44 . The building  44  may be various types of buildings such as a store and the wireless information transmitted from the antenna  42  may be advertising information. All of the wireless signals preferably include location information transmitted therewith. As will be described below, the information may be coded digitally into the signals. Thus, by reviewing the location information, signals appropriate for the location of the mobile devices may be displayed on the various devices. 
   Referring now to  FIG. 2 , a receiving system  22  is illustrated in further detail. Antenna  26  may be various types of antennas including a moving or rotating antenna which is used to track the relative movement of the satellite or other transponding devices with respect to the vehicle. The antenna  26  may be a single antenna used for satellite television reception, or a number of antennas such as one for receiving television signals and one coupled to a GPS location receiver  50 . The antenna  26  may also be an electronic antenna. As will be further described below, the antenna  26  may have? two-way communicate information to the mobile receiving unit  28 . The two-way communication principles set forth herein may also be applied to stationary antennas. 
   The antenna  26  may include a control module  27  that controls the communication with the receiving unit  28 . The control module  27  may also control the movement of the antenna  26  as the vehicle moves. During operation, the control module  27  generates various types of signals such as information regarding the antenna, timing information and the like as will be described below. 
   The mobile receiver unit  28  is coupled to antenna  26  with a two-way communication channel such as a wire or a wireless system. The mobile receiving unit  28  may also include a location receiver  52  integrated therein. The location receiver  52  may be a GPS receiver. In a preferred embodiment, only one location receiver  50 ,  52  may be provided in the system. However, the location receiver  50 ,  52  may be part of the vehicle  24  or may be part of the mobile receiving system  22 ,  36 . The controller  60  may be coupled directly to location receiver  52  and/or location receiver  50 . The mobile receiving unit  28  includes a display  54 . The display  54  may be incorporated into the device  36  or within the vehicle  24 . The display  54  may include output drivers  56  used for generating the desired audio and video outputs suitable for the particular display  54 . 
   A controller  60  may be a general processor such as a microprocessor. The controller  60  may be used to coordinate and control the various functions of the receiving unit  28 . These functions may include a tuner  64 , a demodulator  66 , a forward error correction decoder  68  and any buffers and other functions. The tuner  64  receives the signal or data from the individual channel. The demodulator  66  demodulates the signal or data to form a demodulated signal or data. The decoder  68  decodes the demodulated signal to form decoded data or a decoded signal. The controller  60  may be similar to that found in current DirecTV set top boxes which employ a chip-based multifunctional controller. 
   The controller  60  may include or be coupled to a local bus  70 . The local bus  70  may be used to couple a dynamic memory  72  such as RAM which changes often and whose contents may be lost upon the interruption of power or boot up. The bus  70  may also be coupled to a non-volatile memory  74 . The non-volatile memory may be an in-circuit programmable type memory. One example of a non-volatile memory is an EEPROM. One specific type of EEPROM is flash memory. Flash memory is suitable since it is sectored into blocks of data segments that may be individually erased and rewritten. 
   Other memory devices  76  may also be coupled to local bus  70 . The other memory devices may include other types of dynamic memory, non-volatile memory, or may include such devices such as a digital video recorder. The display  54  may be changed under the control of controller  60  in response to the data in the dynamic memory  72  or non-volatile memory  74 . 
   The controller  60  may also be coupled to a user interface  80 . User interface  80  may be various types of user interfaces such as a keyboard, push buttons, a touch screen, a voice activated interface, or the like. User interface  80  may be used to select a channel, select various information, change the volume, change the display appearance, or other functions. The user interface  80  is illustrated as part of the mobile receiving unit. However, should the unit be incorporated into a vehicle, the user interface  80  may be located external to the mobile receiving unit such as dial buttons, voice activated system, or the like incorporated into the vehicle and interface with the mobile receiving unit. 
   A remote control  86  may be used as one type of interface device. The remote control  86  provides various data to the controller  60 . 
   A conditional access module card  82  (CAM) may also be incorporated into the mobile receiving unit. Access cards such as a conditional access module (CAM) cards are typically found in DirecTV units. The access card  82  may provide conditional access to various channels and wireless signals generated by the system. Not having an access card or not having an up-to-date access card  66  may prevent the user from receiving or displaying various wireless content from the system. 
   An external data port  84  may be coupled to the controller  60  for transmitting or receiving information from a device. The receiving device is illustrated having a data port  84  that is coupled to antenna  26 . The data port  84  provides two-way communication between the antenna  26  and the controller  60  through a two-way communication line  85 . The connection between the data port  84  and the antenna  26  may be one of a number of types of connections including an RS 232 type connection, a USB connection, a wired connection, a wireless connection or the like. A dedicated port from controller  60  may be used to communicate in addition to other data ports. 
   In  FIG. 3 , step  210  starts the two-way communication system. Handshaking techniques are implemented to ensure proper communications are sent and received. In step  212  a command parser is reset. In step  214 , a command prefix is sent from the receiver box to the antenna (or vice-versa). In step  216 , the command parser attaches to a data port and sends the command which corresponds to the parser being in use. The command sent provides an alert that the receiving unit is going to send the antenna some information. In step  218 , if a contention is not detected, step  220  is executed. A contention is detected when both the receiver unit and the antenna are trying to communicate at exactly the same time. If no contention is detected, a determination of a positive response has been received. If a positive response has been received and the ACK_CMD response is provided, the antenna is acknowledging the command from the receiver unit. In step  224 , it may be possible to send a multiple byte command. If a multiple byte command has been sent in step  224 , the system proceeds to step  226 . In step  226 , it is determined whether the correct number of parameters has been sent for the particular command. In step  230 , if the response has been received (ACK_PARAMS) the parameters have been properly received by the antenna. In step  224 , if a multiple byte command is not provided, or after step  230 , step  232  allows the system to execute the desired command. In step  234 , it is determined whether the command has been completed successfully. If the command has been completed successfully, a response acknowledging this is provided from the antenna. This response may take the form of an acknowledge function OK command (ACK_FCNOK), and thus the parser is freed in step  236 . Referring back to step  234 , if the command has not been successfully completed, step  238  is executed in which a no acknowledge signal (NACK_FCNOK). 
   In step  228 , if the parameters have not been acknowledged, a no acknowledge parameter signal is provided (NACK_PARAMS) and step  240  is generated. If a positive response has not been received and a no acknowledge parameter is provided in step  224  or the command is not successfully completed and a no acknowledge function is generated in step  238 , step  212  is again executed. 
   It should be noted that at any time a response such as an acknowledge reset in step  250 , a data error in step  252 , or a command buffer overflow in step  254  may be received by either device. In either case, the system jumps from where it is in the program loop and resets the command parser in step  212 . 
   Referring back to step  218 , if a contention has been detected, step  260  is executed. In step  260 , the response command prefix and command may be received. To indicate a contention, a response of no acknowledge busy (NACK_BUSY) may be provided in  262  or in step  264  a no acknowledge busy response (NACK_BUSY) may be received. In step  266 , a wait for a random backoff time may be performed while another try is made at generating a communication. By waiting a random time, the two devices will likely not try to communicate simultaneously. After step  266 , step  212  is executed in which the command parser is reset. 
   Referring now to  FIG. 4 , a communication diagram of the handshaking between the module antenna and receiver is set forth. As an overview, there are three main states: boot-up, program guide acquisition, and channel tuning. A summary of each is set forth below: 
   Boot up 
   
       
       
         
           Once the receiver comes out of reset and starts executing, it will wait for capabilities and other information from the antenna. 
           Upon reception of AntennaInfo, the receiver checks the antenna capabilities and enables two-way communications with the antenna.
 
Program Guide Acquisition—Boot Stage
 
           During Program Guide Acquisition boot, the receiver tunes to different transponders and possibly different satellites. The receiver will make use of the ReportDesiredTuningInfo to indicate to the antenna the required satellite and transponder. This process is the same as when tuning to a video channel (see Channel Tuning below).
 
Channel Tuning
 
           When tuning to a channel, the receiver will make use of the ReportDesiredTuningInfo to indicate to the antenna the required satellite and transponder. 
           The antenna receives the command and sends back a status/state response. It scans for the appropriate satellite. 
           The receiver waits for a status that indicates the antenna has completed its process to track the appropriate satellite. 
           The receiver acquires further information from the satellite to confirm that the antenna is tracking correctly and sends back ReportActualTuningInfo. 
           The receiver and antenna exchange status/state information until the next channel change. 
         
       
     
  
   In  FIG. 4 , a boot-up phase of the system is illustrated. The left side illustrates the receiving device or IRD and the right illustrates an antenna. During boot up the IRD may send a request antenna information request to the antenna or the antenna may send its information to the receiver box without prompting. The receiving device generating a request is provided in box  300  and transmits the request antenna information signal in step  302  to the antenna  304 . The antenna may respond with antenna information in step  306 . In box  308 , the receiving device may request or send various tuning information such as it desires to receive the automatic program guide (APG) or it may be desired to tune to a new channel. This is illustrated in step  310 , report desired tuning info. In box  312 , the antenna may search for the particular satellite or the like. In box  314  the antenna may send a status state in step  316  to the receiving device in step  318 . In step  320 , the antenna may also provide tracking information or the like with a send status state signal in step  322  to the receiving device in step  324 . In step  326 , the receiving device may report actual tuning information in step  328  to the antenna  330  in which the desired tuning information is tracked. This may be due to a channel change or the like. This may be performed when a successful tuning to a particular channel is performed. Every once in a while the antenna may provide information in step  340  by providing a send status state signal  342  to the IRD  344 . This may be performed every once in a while such as every 30 seconds, or every time a status changes. 
   A list of various commands is provided in Table 1. The “get” commands are commands that the antenna or receiver generates to request information. The report commands are commands that provide information to the other device. Thus, as can be seen, two-way communication between a receiver and an antenna is provided in the present invention. This allows the tuner or receiving device to have information as to the status of the antenna. The antenna also has information regarding the status of the receiving device. 
   
     
       
             
             
           
         
             
               TABLE 1 
             
             
                 
             
             
               Command 
               Description 
             
             
                 
             
           
           
             
               GetDesiredTuninginfo 
               Command signal generated by the antenna. 
             
             
                 
               The receiver responds with desired (not 
             
             
                 
               tuned yet) tuning information. 
             
             
               GetActualTuninginfo 
               Command signal generated by the antenna. 
             
             
                 
               The receiver responds with the actual 
             
             
                 
               tuning information. 
             
             
               SetAntennainfo 
               This command signal sets the antenna 
             
             
                 
               information within the receiver which 
             
             
                 
               allows the receiver to enable/disable 
             
             
                 
               related features. 
             
             
               ReportAntennaState 
               The antenna provided status information 
             
             
                 
               signal to the receiver. 
             
             
               GetReceiverStatus 
               This command signal gets the state of the 
             
             
                 
               receiver. 
             
             
               GetCurPrograminfo 
               This command signal retrieves the pro- 
             
             
                 
               gramming information associated with the 
             
             
                 
               current channel. 
             
             
               Getreceiverinfo 
               This command signal gets information about 
             
             
                 
               the receiver. 
             
             
               ReportGPSLocation 
               This command signal informs the receiver 
             
             
                 
               of the current GPS location. 
             
             
               ReportDesiredTuninginfo 
               Command signal generated by the receiver 
             
             
                 
               any time there is a channel change. 
             
             
                 
               Desired tuning information is provided 
             
             
                 
               with command. 
             
             
               ReportActualTuninginfo 
               Command signal generated by the receiver 
             
             
                 
               any time there is a channel change and 
             
             
                 
               the receiver has tuned successfully to a 
             
             
                 
               channel. 
             
             
               GetAntennaDiagnostic 
               Command signal generated by the receiver 
             
             
                 
               to retrieve and display antenna diagnostics 
             
             
                 
               information. 
             
             
               GetAntennaInfo 
               Command signal generated by the receiver 
             
             
                 
               to retrieve and display antenna information. 
             
             
                 
             
           
        
       
     
   
   While particular embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the appended claims.