Abstract:
A satellite digital broadcast systems transmits signals from a geosynchronous satellite to a plurality of geographically dispersed receivers. Each receiver measures a receive signal level and transmits a value representing the level to a data center. The data center analyses data received from a plurality of receivers in order to determine a size, shape, and velocity of propagation of an obstruction. The data center then predicts which receivers will experience signal disruptions based on the obstruction and the velocity of propagation of the obstruction. The data center transmits instructions to receivers that will be affected by the obstruction.

Description:
BACKGROUND 
       [0001]    The present disclosure relates generally to satellite digital broadcast systems, and more particularly to determining obstructions using satellite television receive signals. 
         [0002]    Satellite digital broadcast systems use a geosynchronous satellite to transmit radio frequency signals to multiple receivers. Signals transmitted by the satellite can be disrupted by several types of obstructions including atmospheric conditions (e.g., rain storms and magnetic storms), vehicles (e.g., aircraft), etc. The disruptions caused by these obstructions can cause scheduled broadcasts to be interrupted. These interruptions can irritate viewers who expect to view broadcasts without disruption. 
       SUMMARY 
       [0003]    In one embodiment, a method of operating a data center includes receiving data from a plurality of receivers. An obstruction and a velocity of propagation of the obstruction are determined based on the data. A particular receiver that will be affected by the obstruction is identified based on the velocity of propagation of the obstruction. In one embodiment, the data includes a value of a first signal receive level detected at a first time and a value of a second signal receive level detected at a second time. In one embodiment, a size and a shape of the obstruction are determined and can be updated based on new data from the plurality of receivers. The size, shape, and velocity of propagation of the obstruction can be used to determine a particular receiver that will be affected by the obstruction. 
         [0004]    In one embodiment, the data center transmits alternate path data to the particular receiver. The alternate path data indicates an alternate signal path to obtain a signal and a time at which the particular receiver should use the alternate signal path. In one embodiment, the alternate path data indicates a time at which the particular receiver should discontinue use of the alternate signal path. In one embodiment, the time at which the particular receiver should use the alternate signal path is based on the obstruction. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  depicts a satellite digital broadcast system according to an embodiment; 
           [0006]      FIG. 2  depicts details of the components of the satellite digital broadcast system according to an embodiment; 
           [0007]      FIG. 3  depicts satellite digital broadcast system during a particular atmospheric event; 
           [0008]      FIG. 4  depicts satellite digital broadcast system disrupted by an obstruction; 
           [0009]      FIG. 5  a plurality of receivers distributed in a geographic area; 
           [0010]      FIG. 6  depicts a method for operating a data center according to an embodiment; and 
           [0011]      FIG. 7  depicts a high-level block diagram of a computer that can be used to implement components of the satellite digital broadcast system. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]      FIG. 1  depicts a satellite digital broadcast system (DBS) system  100  including a satellite  102  for transmitting a wireless signal to multiple receivers  200 ,  300 ,  400 . Satellite DBS  100  can be used to provide content to users associated with receivers. As such, anyone who wants to receive content via the satellite DBS  100  can have a receiver installed in their location. Therefore, any number of receivers can be located in various geographic areas. The signal from satellite  102  as received by a receiver (such as receiver  200 ) can provide information about the signal propagation path between satellite  102  and the receiver. Reception of signals from satellite  102  by receivers  200 ,  300 ,  400  can be disrupted by various factors such as atmospheric conditions (e.g., rain storms, clouds, magnetic storms, etc.) and/or physical objects (e.g., planes, blimps, etc.). Signal disruption, in one embodiment, means that the strength of a received signal is lower than expected. A signal receive level (e.g. signal strength) of signals received by each of receivers  200 ,  300 ,  400  is measured and a value is stored locally in the respective receiver. This data can be transmitted to a data center  500  for analysis. The analysis can be used to determine a geographic area that has signal receive levels lower than expected. Based on the lower than expected signal receive levels, geographic area affected, and changes in signal receive levels and geographic areas affected over time, it can be determined what other receivers may experience lower than expected signal receive levels in the future. For example, a disturbance, such as a rain storm, may be affecting receivers in a specific geographic area. Based on data received over time, it can be determined what other receivers may be affected based on a velocity of propagation of the obstruction causing the disturbance determined by data center  500 . Actions can then be taken in advance of the signal disturbance with respect to receivers that may be affected by the disturbance in the future. For example, it may be determined that one or more of receivers  200 ,  300 ,  400  will be affected by a signal disturbance. In response, a receiver that will be affected can be programmed to obtain signals via methods other than signals that would have been received from satellite  102 . 
         [0013]      FIG. 2  depicts components of satellite DBS  100 . As shown in  FIG. 2 , receiver  200  includes a satellite signal receiving dish  202  (referred to as dish) for receiving signals from satellite  102  (shown in  FIG. 1 ). Dish  202  transmits received signals to signal receiver  206  via radio frequency (RF) signal switch and distribution device  204 . Signal receiver  206  outputs a signal to a display such as a television (not shown). Signal receiver  206  is also in communication with alternate signal device  600 . In one embodiment, alternate signal device  600  is associated with an entity that transmits signals from satellite  102  to receivers  200 ,  300 ,  400 . For example, a content provider that transmits content from a satellite to a plurality of receivers may also be in communication with the receivers using an alternate signal device connected to the receivers via the internet. Receivers  200 ,  300 ,  400  communicate with alternate signal device  600  to transmit and receive various data such as control data and operation data. Alternate signal device  600  can be used to provide broadcast signals normally transmitted from satellite  102  in order to provide a signal to a receiver when signals from satellite  102  are disrupted. Signal receiver  206  is also in communication with Ethernet transport  208 . Ethernet transport  208  is in communication with data center  500 . In one embodiment, receiver  200  communicates with data center  500  using out of band communications. For example, in band communication between receiver  200  and data center  500  can include control data and operation data. Out of band communication between receiver  200  and data center  500  can include other data, such as a broadcast signal that would normally be transmitted to receiver  200  via satellite (such as satellite  102 ). Indicator  210  depicts a signal receive level of receiver  200  using an arbitrary scale of one to five with five being the highest. Indicator  210  is depicted in  FIG. 2  to identify a signal receive level of receiver  200 . Indicator  210  may be omitted from receiver  200  in one embodiment. Receivers  300  and  400  have similar components numbered in a similar manner. 
         [0014]    Data center  500  includes a controller  502  that is in communication with receiver database  504  and atmospheric information database  506 . Receiver database  504 , in one embodiment, stores information pertaining to receivers, such as receivers  200 ,  300 ,  400 . The information stored pertaining to a particular receiver can include an indication of a location of the particular receiver and signal receive levels of the particular receiver over time. In one embodiment, the geographic location of receivers  200 ,  300 ,  400  is determined at the time of installation of the receiver. Receiver location information can then be stored in receiver database  504 . Atmospheric database  506  stores information pertaining to atmospheric conditions and information pertaining to possible obstructions (e.g., flight routes of aircraft, etc.). In one embodiment, information stored in atmospheric database  506  is obtained from external data sources such as National Oceanic and Atmospheric Administration (NOAA) database  508  and/or external database  510 . External database  510  can be a database associated with one or more data sources such as the Federal Aviation Administration (FAA) or National Aeronautics and Space Administration (NASA). In one embodiment, data pertaining to obstructions identified by data center  500  can be transmitted to NOAA database  508  and/or external database  510 . 
         [0015]      FIG. 3  depicts satellite DBS  100  during a particular atmospheric event. As shown in  FIG. 3 , differences in atmospheric conditions present between satellite  102  and each of receivers  200 ,  300 ,  400 , can cause disturbances in signal receive levels of signals transmitted from satellite  102  and received by each of receivers  200 ,  300 ,  400 . As shown in  FIG. 3 , signals transmitted from satellite  102  and received by receiver  200  are affected by cloud  700  which is shown located in the signal path between satellite  102  and receiver  200 . Obstruction of a signal from satellite by cloud  700  causes the signal receive level of receiver  200  to be  4  as shown by indicator  210 . As such, signals received by receiver  200  are being affected by atmospheric conditions. Signals transmitted from satellite  102  and received by receiver  300  are affected by clouds  702  and  704  which are shown located in the signal path between satellite  102  and receiver  300 . Obstruction of a signal by clouds  702  and  704  causes the signal receive level of receiver  300  to be  2 . 4  as shown by indicator  310 . As such, signals received by receiver  300  are being affected by atmospheric conditions. Signals transmitted from satellite  102  and received by receiver  400  are affected by clouds  702 ,  704 ,  708 , and  710 . It should be noted that cloud  708  is not producing rain, but the condition of cloud  708  is changing so that cloud  708  may soon begin producing rain. Cloud  710  is producing rain. The level of disruption of signals can be affected by the state of a particular cloud. Obstruction of a signal from satellite  102  by clouds  702 ,  704 ,  708 , and  710  causes the signal receive level of receiver  400  to be 1.4 as shown by indicator  410 . 
         [0016]    In this example, clouds  700 ,  702 ,  704 ,  708 , and  710  are moving in a direction from receiver  400  toward receiver  200 . As such, atmospheric conditions affecting receipt of signals by receiver  400  may affect receipt of signals by receivers  300  and  200  in the future. Similarly, atmospheric conditions moving toward receiver  400  as detected by additional receivers (not shown) can affect receiver  400  in the future. Also, atmospheric conditions affecting receipt of signals by receiver  200  can affect receipt of signals by receivers (not shown) that are down wind of receiver  200  in the future. 
         [0017]      FIG. 4  depicts signals transmitted from satellite  102  for receipt by receivers  200 ,  300 ,  400  disrupted by an obstruction. In this example, the obstruction is an airplane  800  shown flying in a direction from receiver  400  toward receiver  200 . Airplane  800  is depicted transmitting signals which can also disrupt receipt of signals from satellite  102  by receivers  200 ,  300 ,  400 . Signals transmitted from satellite  102  to receiver  200  are affected minimally by airplane  800  and the signals transmitted by airplane  800 . As such, receiver  200  has a signal receive level of 4 on an arbitrary scale of 1 to 5 with 5 being the highest. Signals transmitted from satellite  102  to receiver  300  are somewhat affected by airplane  800  and signals transmitted by airplane  800 . As such, receiver  300  has a signal receive level of 2.4. Signals transmitted from satellite  102  to receiver  400  are significantly affected by airplane  800  and signals transmitted by airplane  800 . As such, receiver  400  has a signal receive level of 1.4. The signal disruption experienced by various receivers will change as airplane  800  travels. 
         [0018]    As described above, signals can be disrupted by obstructions such as atmospheric conditions and/or physical objects such as aircraft. The obstructions described in  FIGS. 3 and 4  causing signal disruption were moving. Data center  500  can use signal receive level data received from multiple receivers in order to determine a propagation velocity of an obstruction. The propagation velocity can then be used to determine what additional receivers will be affected by the obstruction. 
         [0019]    Signals can be disrupted by other obstructions as well. For example, a device broadcasting a signal can interfere with a signal transmitted by satellite  102  for receipt by one of receivers  200 ,  300 ,  400 . If the device broadcasts a signal with a certain schedule, this schedule can be determined and this information can be used to instruct receivers when to use alternate signal paths to obtain signals so as to avoid the disruption of signals. A device broadcasting a signal may be located in a ground vehicle that is moving. For example, a vehicle may be travelling along a road broadcasting a signal that can interfere with signals for receipt by receivers  200 ,  300 ,  400 . 
         [0020]      FIG. 5  depicts geographic area  902 , which is the contiguous United States in this example.  FIG. 5  depicts satellite  102  transmitting signals for receipt by receivers  900 . The accuracy of detection of obstructions, such as atmospheric conditions and/or objects, is based on number and location of receivers in a particular geographic area. In general, the greater number of receivers in a geographic area, the greater the accuracy of detection of the obstruction. 
         [0021]      FIG. 5  depicts obstruction  902  that is affecting signal receive levels of receivers  900  shown located within the boundaries of obstruction  902 . A size and a shape of obstruction  902 , in one embodiment, are determined based on the geographic location of adjacent receivers whose signal receive levels are lower than expected. The accuracy of the determination of the size and shape of obstruction  902  depends on the density of receivers in the geographic area that is being affected by obstruction  902 . More receivers in a geographic area results in a more accurate determination of the size and shape of obstruction  902 . Based on a number of adjacent receivers having lower than expected signal receive levels, it can be determined that the signals transmitted to the adjacent receivers are being disrupted. In one embodiment, receivers that have normal signal receive levels that are adjacent to receivers that have lower than expected signal receive levels define the shape of the obstruction. The geographic locations of the adjacent receivers experiencing lower than expected signal receive levels can be used to determine the size of the obstruction. 
         [0022]    As an obstruction moves, signal receive levels of receivers change. For example, for an obstruction moving from east to west, receivers located west of the obstruction will have normal signal receive levels that will change to lower than expected signal receive levels as the obstruction moves. For the same obstruction, receivers located near the east boundary of the obstruction will have lower than expected signal receive levels that will change to normal signal receive levels as the obstruction moves. Based on the times that the signal receive levels change and the locations of the receivers experiencing signal receive level changes, the speed of the obstruction can be determined. Based on the geographic locations of receivers that experience changes in signal receive levels, the direction of movement of the obstruction can be determined. The velocity of propagation of the obstruction is determined based on the speed and direction of movement of the obstruction. Based on the velocity of propagation of the obstruction, receivers that are located in the path of the obstruction can be identified. The identified receivers can then be instructed to switch to an alternate signal path in anticipation of disruption of signal receive levels that may be caused by the obstruction. The receivers can be instructed to switch to an alternate signal path in advance of an anticipated disruption in order to allow the receiver time to buffer signals. 
         [0023]    It should be noted that although  FIG. 5  depicts a particular number of receivers located in contiguous United States, the number of receivers actually in use is generally much higher. 
         [0024]    Satellite DBS  100  shown in  FIG. 2  operates as follows. Signals received by dish  202  of receiver  200  are measured to determine a signal receive level. This signal receive level information is stored locally in receiver  200 . In one embodiment, the signal receive level information is stored with a timestamp indicating a date and a time associated with a particular signal receive level. The signal receive level information is similarly collected by receivers  300  and  400 . Each of receivers  200 ,  300 ,  400  transmit signal receive level information and associated time stamps to data center  500 . Data center  500  stores and analyzes data received from receivers. In one embodiment, data center  500  analyzes data from receivers in order to determine a geographic area experiencing signal disruption. In one embodiment, data center  500  determines an obstruction based on signal disruption of one or more receivers in a particular geographic area. Based on changes in signal disruption of particular receivers, data center  500  can determine that an obstruction causing signal disruption is moving. Data center  500  can also determine a velocity of propagation (also referred to as propagation velocity) of an obstruction based on changes in signal receive levels of receivers. The velocity of propagation of the obstruction can then be used to identify receivers that may be affected by the obstruction (e.g., receivers that are in the path of the obstruction). Data center  500  can transmit instructions to receivers that may be affected by the obstruction. 
         [0025]    In one embodiment, information from NOAA database  508  and external database  510  are used to provide information to atmospheric information database  506 . Controller  502 , in one embodiment, can use the information in atmospheric information database  506  to identify obstructions that are causing disruption of signals. The information in receiver database  504  can be used in conjunction with the information in atmospheric database  506  in order to generate or modify predictions as to what receivers may be affected by obstructions. For example, information pertaining to a storm system that will be moving into an area can be used to predict when certain receivers will experience signal disruptions. When certain receivers initially begin to be affected by an obstruction, the prediction based on information from the atmospheric information database  506  can be confirmed and receivers in the path of the obstruction can be instructed to use an alternate signal path. 
         [0026]      FIG. 6  depicts a method  600  for determining an obstruction according to one embodiment. At step  602 , data is received by data center  500  from a plurality of receivers (e.g., receivers  200 ,  300 ,  400 ). In one embodiment, the data comprises a value of a first signal receive level detected by one of the plurality of receivers at a first time and a value of a second signal receive level detected by the one of the plurality of receivers at a second time. At step  604 , the data is used to determine an obstruction causing disruption of signals received by a subset of the plurality of receivers. In one embodiment, the determining the obstruction includes determining a size and a shape of the obstruction. At step  606 , a velocity of propagation of the obstruction is determined based on the data. At step  608 , a particular receiver that will be affected by the obstruction is identified (e.g., a particular receiver that will experience signals disrupted by the obstruction). In one embodiment, this identification is based on the size, shape, and velocity of propagation of the obstruction. For example, a width of the obstruction perpendicular to the velocity of propagation of the obstruction may be determined. This information may then be used to determine that a particular receiver is located in the path of the obstruction. At step  610 , alternate path data is transmitted to the particular receiver. In one embodiment, the alternate path data indicates an alternate signal path that the particular receiver is to use to obtain a signal. For example, the alternate signal path data can indicate that the particular receiver is to obtain signals from alternate signal device  600  shown in  FIG. 2 . The alternate path data also indicates a time at which the particular receiver should use the alternate signal path. In one embodiment, the time at which the particular receiver is to use the alternate signal path is based on the size and shape of the obstruction and the velocity of propagation of the obstruction. The alternate path data, in one embodiment, also includes a time at which the particular receiver should discontinue use of the alternate signal path. At step  612 , the size, shape, and velocity of propagation of the obstruction are updated based on new data received from the plurality of receivers. For example, receivers  200 ,  300 ,  400  can be configured to transmit data periodically. The determined size, shape, and velocity of propagation of the obstruction can be modified based on new data received from the receivers. Data can be transmitted from receivers  200 ,  300 ,  400  based on other triggers such as a change in a signal receive level exceeding a threshold, every X number of hours, minutes, or seconds, etc. 
         [0027]    In one embodiment, based on characteristics of the receive signal&#39;s continuous power level at the receiver, many atmospheric conditions can be identified. The atmospheric conditions of the four layers of the Earth&#39;s upper atmosphere can be mapped. Disturbances in the Earth&#39;s magnetosphere, thermosphere, mesosphere, stratosphere, and troposphere have specific fluctuation patterns that can be used to detail the signal propagation path from satellite  102  to one or more receivers (e.g., receivers  200 ,  300 ,  400 ). 
         [0028]    Satellite  102 , data center  500 , receivers  200 ,  300 ,  400  (and the components associated with the receivers), controller  502 , receiver database  504 , atmospheric information database  506 , NOAA database  508 , external database  510 , and alternate signal device  600  can each be implemented using a computer. A high-level block diagram of such a computer is illustrated in  FIG. 7 . Computer  702  contains a processor  704  which controls the overall operation of the computer  702  by executing computer program instructions which define such operation. The computer program instructions may be stored in a storage device  712 , or other computer readable medium (e.g., magnetic disk, CD ROM, etc.), and loaded into memory  710  when execution of the computer program instructions is desired. Thus, the method steps of  FIG. 6  can be defined by the computer program instructions stored in the memory  710  and/or storage  712  and controlled by the processor  704  executing the computer program instructions. For example, the computer program instructions can be implemented as computer executable code programmed by one skilled in the art to perform an algorithm defined by the method steps of  FIG. 6 . Accordingly, by executing the computer program instructions, the processor  704  executes an algorithm defined by the method steps of  FIG. 6 . The computer  702  also includes one or more network interfaces  706  for communicating with other devices via a network. The computer  702  also includes input/output devices  708  that enable user interaction with the computer  702  (e.g., display, keyboard, mouse, speakers, buttons, etc.) One skilled in the art will recognize that an implementation of an actual computer could contain other components as well, and that  FIG. 7  is a high level representation of some of the components of such a computer for illustrative purposes. 
         [0029]    The foregoing Detailed Description is to be understood as being in every respect illustrative and exemplary, but not restrictive, and the scope of the inventive concept disclosed herein is not to be determined from the Detailed Description, but rather from the claims as interpreted according to the full breadth permitted by the patent laws. It is to be understood that the embodiments shown and described herein are only illustrative of the principles of the inventive concept and that various modifications may be implemented by those skilled in the art without departing from the scope and spirit of the inventive concept. Those skilled in the art could implement various other feature combinations without departing from the scope and spirit of the inventive concept.