Abstract:
A digital TV (DTV) incorporates a TV white space device capable of operating on plural TV frequencies and responsive to the DTV processor to send a signal to an interfering white space device nearby the DTV that is interfering with a TV channel being presented on the TV. The signal sent from the TV white space device to the interfering white space device alters operation of the interfering white space device so as to reduce if not eliminate the interference.

Description:
FIELD OF THE INVENTION 
     The present application relates generally to the active suppression, by a TV, of white space device interference. 
     BACKGROUND OF THE INVENTION 
     Various proposals have advanced the concept of using unallocated channels within the TV frequency bands, often referred to as “white spaces”, that are a result of the Federal Communication Commission&#39;s channel allocation scheme. A device intended to use such unallocated or unassigned channels is referred to as a white-space device (WSD). These (currently) unlicensed devices are proposed to provide services such as wireless broadband Internet access, and have been defended based on a projected capability to detect the presence of existing signals, such as TV stations and other wireless users, and to then avoid the use of active channels. 
     Thus, a principal premise of white spaces devices is that through some technique that either by a geographical data base in conjunction with GPS or through channel detection (spectrum sensing) determines that a channel or a number of channels are occupied by incumbent broadcast stations. Through such techniques it is envisioned that a white spaces device will be able to detect and use an unused channel. However, as understood herein, even with such techniques white space devices may nevertheless cause interference with nearby digital and legacy TVs (DTVs), including causing, at the DTV, freeze frames, pixilation, and even a complete loss of picture. 
     SUMMARY OF THE INVENTION 
     A digital TV (DTV) includes a TV processor communicating with a TV tuner and a TV display controlled by the TV processor to present video signals received from the TV tune. Through the tuner and demodulator, the TV processor is programmed to detect interference from a white space device and to cause a suppression signal to be transmitted to the white space device to suppress the interference. 
     In example embodiments a TV chassis holds the TV display and an (internal) TV white space device (establishing a transceiver) is supported by the TV chassis. The TV white space device is responsive to the TV processor to transmit the suppression signal. The suppression signal may include information identifying at least one channel actually or potentially interfered with by the white space device and/or a geographic location of the DTV. The suppression signal transmitted by the TV white space device alternatively may be a non-data interference signal on an interfered-with channel to cause other white space devices to navigate transmission away from the interfered-with channel. 
     If desired, the TV white space device can receive, over a wide area data network, audio/video content for presentation thereof on the TV display. Also, the TV white space device may receive software updates for the TV processor over a wide area data network. In some embodiments the TV white space device is caused to transmit the suppression signal only when the TV displays a terrestrial broadcast signal, and otherwise never transmits the suppression signal. In other embodiments the suppression signal may be transmitted when interference is sensed only when receiving a terrestrial broadcast signal and/or a cable TV signal. The suppression signal may be transmitted only when interference is sensed on a currently tuned-to channel. 
     In another aspect, a method includes providing a digital TV (DTV) and programming the DTV to modify operation of an interfering white space device operating on or near an interfered-with TV channel and thereby actively protect channels of DTV interest. 
     In another aspect, an apparatus includes a TV chassis and a digital TV (DTV) tuner supported on the chassis. A display is supported on the chassis for presenting video from the DTV tuner. A TV white space device is supported on the chassis and is capable of operating on plural TV frequencies. 
     The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of an example system in accordance with present principles; and 
         FIG. 2  is a flow chart of example logic that may be employed by the system of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  shows a digital TV (DTV)  10  that has a TV chassis  12  holding a TV processor  14  accessing a TV computer-readable medium  16  such as but not limited to disk-based or solid state storage. The medium  16  may contain logic executable by the TV processor  14  in accordance with disclosure below. A DTV tuner  18 , which may be in the chassis  12  or in a separate set-top box, receives TV signals from one or more TV signal sources including, e.g., a terrestrial broadcast signal source, and the TV processor  14  causes TV signals from a selected channel received by the tuner  18  to be presented on a TV display  20 . 
     In accordance with present principles, the DTV  10  can alter operation of a nearby white space device (WSD) to reduce if not eliminate interference from the nearby WSD. In the example embodiment shown in  FIG. 1 , a TV WSD  22  is provided on the chassis  12  for this purpose. As shown, the TV WSD  22  includes a TV WSD processor  24  accessing a TV WSD computer readable medium  26  such as disk-based or solid state storage. The TV WSD  22  also includes a TV WSD transceiver  28  controlled by the TV WSD processor  24  in accordance with disclosure below. The TV WSD transceiver  28 , which may communicate with a wide area data network using, e.g., WiFi principles, operates in the TV frequency band and may transmit on multiple TV frequencies, with the TV WSD processor  24  controlling which frequency is being used by the TV WSD transceiver  28 . It is to be understood that in some embodiments the TV WSD processor  24  may act in conceit with the TV processor  14  to undertake present principles, or the TV WSD processor  24  may be eliminated altogether and its functions undertaken by the TV processor  14 . 
     As shown in  FIG. 1 , one or more potentially interfering WSD  30  maybe sufficiently near the TV  10  to cause interference on a TV channel actually being used or potentially being displayed by the TV  10 . The WSD  30  typically includes a WSD processor  32  accessing a WSD computer readable medium  34  such as disk-based or solid state storage. The WSD  30  also includes a WSD transceiver  36  controlled by the WSD processor  32 . The WSD transceiver  36  operates in the TV frequency band and may transmit on multiple TV frequencies, with the WSD processor  32  controlling which frequency is being used by the WSD transceiver  36 . 
     When the TV  10  is connected to a terrestrial antenna or signal source, the TV is capable of determining the presence of terrestrial broadcast signals, typically done through channel scanning during set-up. The TV medium  16  stores the frequencies (physical channel numbers) and other channel data of the receivable channels. 
       FIG. 2  shows that at decision diamond  38 , if it is determined that the TV  10  is having difficulty receiving a cable or broadcast signal that was previously receivable it may move to decision diamond  40  to determine if the reception difficulty is from interference that is characteristic of the transmission signature of a white space device, e.g., the WSD  30 . If both tests are positive the logic moves to block  42  to suppress the interfering signal from the WSD  30 . If desired, the logic of  FIG. 2  may be implemented only when the TV seeks to present TV signals from a terrestrial signal; otherwise, e.g., when the TV is presenting satellite signals, the logic need not be invoked. In other embodiments  FIG. 2  may be implemented when the TV receives TV signals over a cable. 
     An example protocol for suppressing interference caused by, e.g., the WSD  30  is for the TV processor  14  to cause the TV WSD  22  to actively transmit a suppression signal to the interfering WSD  30 . The suppression signal may include information identifying the interfered channel or indeed all of the channels, and in some cases only all of the terrestrial broadcast channels, detected by the TV as being available during the above-mentioned scan. Using this information the interfering WSD  30  can alter its operation to use a channel sufficiently removed (e.g., by three or more channel numbers) from the interfered-with channel or sufficiently removed from any channel detected in the set-up scan to reduce if not eliminate interference with the TV  10 . 
     In addition to or in lieu of identifying the interfered-with channel, the suppression signal may include information pertaining to the geographic location of the TV as might be received from, e.g., a global position satellite (GPS) receiver on the TV. Using the geographic information the WSD  30  can access its storage medium  34  to correlate the geographic position of the TV to a channel map. Using the channel map the interfering WSD  30  can alter its operation to use a channel sufficiently removed (e.g., by three or more channel numbers) from any channel on the map to reduce if not eliminate interference with the TV  10 . 
     Yet again, the suppression signal may simply be a noise signal generated by the TV WSD  22  on the same frequency as the one being used by the interfering WSD  30 , which, based on the signal from the TV WSD  22 , determines that the channel is occupied, forcing the interfering WSD  30  to navigate transmission away from that channel. In any case, it may now be appreciated that the above logic allows the TV  10  to actively protect the channels of interest and not have reception of channels interfered by white space devices  30 . 
     In addition, the TV WSD  22  may be used for additional functions. Non-limiting examples of such additional functions include receiving video or other content for presentation on the TV  10 , receiving software updates for the TV processor  14 , etc. 
     In some implementations, the suppression signal from the TV WSD may bear characteristics such as fields identifying itself as “from a TV” so that if it is detected by other TVs nearby, the other TVs can activate their WSDs and propagate the message to the interfering WSD. This improves the likelihood that the interfering WSD receives the suppression signal. A time-out period, message sequence number, or other feature may be provided in such implementations to prevent looping the message among the cluster of TVs. For example, a TV might propagate a suppression signal once only within any five minute period, or it might propagate a suppression signal having a particular message sequence number only once. 
     While the particular ACTIVE SUPPRESSION BY TV OF WHITE SPACE DEVICE INTERFERENCE is herein shown and described in detail, it is to be understood that the subject matter which is encompassed by the present invention is limited only by the claims.