Abstract:
A monitoring receiver accepts program preferences from an operator. When active, the receiver automatically monitors alternate frequencies for programming that matches the program preferences, alerts the operator when a match is found, and may switch to a preferred program.

Description:
PRIORITY CLAIM 
     This application claims the benefit of European Patent Application No. 03003126.4, filed Feb. 13, 2003, in the European Patent Office. The entire disclosure of that application is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The invention relates to a receiver and more particularly to a receiver that searches for a signal bearing desired content, while receiving selected content from a different signal. 
     2. Related Art 
     A receiver may include a tuner for selecting a specific frequency, channel, or program desired by an operator. An operator may tune a television or radio receiver to select a television program or radio station. The tuner receives the incoming signals and converts them to perceptible forms. 
     In some cases, however, desired programming is not always available. Mobile receivers are particularly susceptible to inconsistent availability of transmitted signals due to interference, fading, or other adverse conditions. A mobile television or telephone, for example, may experience a varying level of signal availability from a signal source. 
       FIG. 1  shows a transmitting station  102 , a transmission region  104 , and a vehicle  106  traveling along a path  108 . The station  102  transmits programming of sufficient strength for the vehicle  106  to receive the programming from within the transmission region  104 . The transmission region  104  may not have a smooth oval or circular shape as illustrated in  FIG. 1  due to differences in geographical terrain, transmitter characteristics, environmental characteristics, and so on. Rather, the transition region  104  may vary in size and shape over time, further weakening the availability and integrity of a transmitted program. 
     In  FIG. 1 , the vehicle  106  cannot receive a desired program. As a result, the driver may be forced to select a different program transmitted from a different source, even though the driver may not want to listen to or watch another program. The iterative tuning and returning process may be unpleasant for the driver. Even when the driver successfully finds a desired program at an acceptable quality level, the driver may miss significant portions of the program due to the time and effort the driver must spend tuning that program. Additionally, each time a driver retunes a receiver, the driver may be distracted from traffic and road conditions which may create a safety hazard. 
     Therefore a need exists for a receiver that addresses the potential problems described above and others previously experienced. 
     SUMMARY 
     The invention provides a receiver that minimizes or substantially eliminates the process of tuning and returning a receiver to find desired programming. The receiver accepts program preferences or other selection information from the operator. When active, the receiver automatically monitors alternate frequencies for programming that matches the program preferences. Although one receiver may receive non-preferred programming, another receiver may scan alternate frequencies to determine the availability of programming that is of greater interest to the operator. When the receiver determines that a more preferred program is available, the receiver may alert the operator, and automatically tune the receiver to preferred programming. Alternatively, the receiver may prompt the operator to manually tune the receiver. 
     The receiver may include a selected program receiver, a program monitoring receiver, and a memory that stores program designation data. The selected program receiver employs a tuner to generate a program output signal for a currently selected program (which may be a disfavored program). The program monitoring receiver employs a tuner and comparison circuitry or logic to locate preferred programming. The program monitoring receiver may locate a designated program that matches program designation data. When the program monitoring receiver locates the designated program, it may employ signaling circuitry or logic to generate a designated program location signal. The location signal may alert an operator to the availability of the designated program at another frequency. 
     The receiver operates by reading program designation data from a memory and receiving, with the selected program receiver, a currently selected program. As the selected program receiver converts the selected program signal into a perceptible form, the program monitoring receiver locates a designated program that matches program designation data. When the designated program is available, the receiver advises the operator of its availability, automatically directs the selected program receiver to switch to the designated program, or may advise the operator of its availability and ask the operator if a switch should be made. 
     The receiver may include a first program receiver and a second program receiver. The receiver also may include a memory that stores program designation data, and a controller that directs the operation of the first and second program receivers. The controller causes the first receiver to receive and convert the signal into a perceptible form while the second receiver scans other frequencies to locate a designated program that matches a portion of the designation data. When desired programming is found, the second receiver receives the desired incoming signals and converts the incoming signals to perceptible forms, such as sound or light. The first receiver then scans a frequency range to locate a designated program. Accordingly, when the second receiver locates the designated program, the controller directs the first receiver to locate a subsequent designated program, while the second receiver continues to receive and process the designated program. 
     In operation, the controller directs the first program receiver to obtain and convert an incoming signal into a perceptible form. The controller also directs the second program receiver to search for a designated program matching the program designation data. During the search, the first program receiver obtains and presents the first program to the operator. When the second program receiver locates a designated program, the second program receiver ends its locating function and receives and converts the designated program to a perceptible form. The first program receiver then scans a frequency range to locate a next designated program. 
     Other systems, methods, features and advantages of the invention will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the following claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like referenced numerals designate corresponding parts throughout the different views. 
         FIG. 1  is an example depiction signal availability with respect to a mobile receiver. 
         FIG. 2  is an example of a monitoring receiver and a selected program receiver. 
         FIG. 3  is an example of two receivers that locate or receive a designated program. 
         FIG. 4  is an example of a communication device. 
         FIG. 5  is an example of a flow diagram for process that a receiver may implement to receive or locate a designate program. 
         FIG. 6  is an example of a flow diagram for a process that a receiver may implement to interchange reception and location operation. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 2  shows an exemplary receiver  200  having an input terminal  202 , an output terminal  204 , and an input interface  206 . The receiver  200  includes a selected program receiver  208 , a program monitoring receiver  210 , signaling circuitry  212 , and a signaling output  244 . 
     The selected program receiver  208  includes a program tuner  218 , signal recovery circuitry  220 , and a program output  222 . The program monitoring receiver  210  includes a monitoring tuner  224 , data recovery circuitry or logic  226 , and comparison circuitry or logic  228 . As shown in  FIG. 2 , a controller  232  and a program memory  234  may be a unitary part of or interfaced to the monitoring tuner  224 . The program memory  234  may include a monitoring program  236 . 
     A designation memory  216  stores program designation data. The designation memory  216  may retain program preference data  238  and a program code list  240 . The designation memory  216  also may store program selection characteristic data  242 . 
     The output terminal  204  may deliver programming to an output device. Any output device may be used. The output device may be one or more speakers that receive an incoming program signal and convert the program signal to sound. The output device also may be a video device or display such as a television including a cathode ray tube or liquid crystal display. The video device may display audio/visual data encoded in a program output signal. Alternatively, the output device may convert an incoming signal into any perceptible form, such as sound or light. 
     The receiver  200  may receive many different types of signals. The receiver  200  may be an AM/FM receiver that selects a frequency and converts the audio programming encoded in that frequency to sound. The receiver  200  may be part of an automobile audio system or part of a home audio system. 
     The receiver  200  may be interfaced to or a unitary part of a television set. The receiver  200  may select and output audio/visual programming for a display. For discussion purposes, the receiver  200  is described in the context of a vehicle radio even though the receiver  200  is not limited to radio or television applications. Rather, the receiver  200  may be part of any application where multiple programs or information channels are present across a frequency spectrum, and where an operator desires an automated location of a preferred program. 
     The input terminal  202  provides a connection for an input signal that may bear programming of interest. The input terminal  202  may be an AM/FM or television antenna connector, for example. The input terminal  202  also may be a cable television connector, or another type of signal input connector. 
     An operator may control the receiver  200  through the input interface  206 . The input interface  206  may be one or more depressible keys. The input interface  206  may vary widely in implementation, however, and also may include a touch pad or touch screen input, memory cards, disks, a voice recognition input, a trackball, a mouse, a remote control input, translating or rotating buttons or knobs, a graphical user interface, selectable icons, or other input devices. Furthermore, one or more separate devices may be used in combination. 
     In the selected program receiver  208 , the program tuner  218  selects an FM frequency. The signal recovery circuitry  220  processes the selected frequency, deriving a program output signal. The program output signal may be processed by a mixer, a demodulator, and/or an amplifier that receives incoming signals and extracts information from those signals. The selected program receiver  208  provides the operator with a selected FM channel that may be heard through an output device connected to the output terminal  204 . 
     The program monitoring receiver  210  receives and processes other incoming signals while the selected program receiver  208  provides the operator with a currently selected FM channel. The program monitoring receiver  210  may locate a designated program within the FM band that is different from the selected FM channel. 
     The controller  232  may control the monitoring receiver  210 . The controller  232  executes a monitoring program  236  retained in the memory  234 . The controller  232  may monitor and control the tasks implemented through a monitoring program  236 . 
     The program monitoring receiver  210  may employ a monitoring tuner  224  that may select a signal within any frequency band. In the FM band, the data recovery circuitry  226  extracts identifying data from each selected FM channel. The data recovery circuitry  226  may include a Radio Data Service (RDS) decoder. The monitoring receiver  210  may store frequency, channel number, and signal strength of each FM channel and/or other signal parameters as the monitoring receiver checks the FM channel for designated programming. 
     The comparison circuitry  228 , in turn, determines if the identifying data matches all or part of the program designation data stored in the designation memory  216 . When the identifying data matches, the program monitoring receiver  210  drives a match signal on the comparison output  230 . The match signal alerts the operator that a preferred program is available on another frequency channel. 
     The monitoring receiver  210  may periodically sweep a pre-selected frequency range (e.g., all or part of the FM band) for a designated program. The monitoring receiver  210  may sweep the frequency range once per minute, every five minutes, every 30 minutes, every hour, or according to any other timing schedule. Alternatively, the monitoring receiver  210  may randomly check one or more frequencies to look for a designated program or check a frequency or frequency range according to a pre-determined channel list. The monitoring receiver  210  may search for designated programs on a periodic basis, when instructed through the input interface  206 , on a random basis, or according to any other schedule. 
     Identifying data from the FM channel may include Channel ID (CID) data, RDS data, Autofahrer Rundfunk Information (ARI) data, and other identifying information encoded within the FM signal. The identifying data may be a program code or other data that reveals the identity of the program, radio station, artist, genre, recording, or other characteristic currently present or transmitting in the FM band. The identifying information may include, from RDS data, the PS Name data, the PI Code data, and the RadioText data. The PS Name data provides an 8 digit alphanumeric program label (e.g., “_JAZZFM_”, “SWR 3”), the PI Code provides a station identifying code that the receiver may search for when signal strength fades, and the RadioText data provides descriptive text information, for example, an artist name or recording name. 
     The program designation data stored in the designation memory  216  may represent operator preferred programming. For example, the program preference data  238  may specify one or more preferred frequencies (e.g., 101.3, 107.5, and 95.7 FM). Alternatively, the program preference data  238  may specify one or more preferred channel numbers. Alternatively or additionally, the program preference data  238  may include preferred program codes. The program codes may represent PS Name data, PI Code data, or RadioText data, or any other preference setting information. The operator may set the program code to “JAZZ” to specify that Jazz music is preferred. The operator may add RadioText data entries of “SongName1”, “SongName2”, and “NewsProgram1” to designate the transmission of SongName1, SongName2, or NewsProgram1 as preferred programs. 
     Similarly, the program designation data may include a program code list  240  stored in the receiver  200 . The receiver  200  may be pre-programmed with the program code list  240 , to program the receiver  200  to operate in a pre-determined geographical area based on radio stations assigned to that geographical area. The program code list  240  may include one or more program codes. Through the operator interface  206 , the operator may select one or more preferred programming codes. The selected codes may be used as operator designated program codes that the receiver  200  uses to receive incoming signals. 
     The program designation data may include program selection characteristic data  242 . The characteristic data  242  may capture the characteristics of the programming that an operator prefers. The receiver  200  may track the amount of time that the operator spends listening to any given frequency, channel, artist, program type, or other program characteristic. The tracked data may be stored in the designation memory  216  for comparisons when the monitoring receiver  210  attempts to locate preferred programming. The receiver  200  may compare the identifying information from an FM channel against the characteristic data  242 . In such a comparison, the receiver  200  may determine whether the identifying data corresponds to a program that the operator has spent more than a pre-selected threshold of time listening to, and that, therefore, may be a designated program. 
     Alternatively, the characteristic data  242  may include a program selection count. The program selection count may represent a number of times that an operator has chosen a particular frequency, channel, artist, program type, or other program characteristic. The program selection count may be stored in the designation memory  216  for comparisons with the identifying information. When the selection count exceeds a pre-selected threshold, the receiver  200  may use the corresponding program as a designated program. 
     Alone or in conjunction with the program designation data described above, the signal strength of the FM channel may be evaluated. When preferred programming is available on another FM channel, if the strength of the FM channel is below a pre-set threshold, the receiver  200  may determine that the preferred programming is not available. Alternatively, the receiver  200  may indicate to the operator that the preferred programming is available, and indicate the strength of an incoming signal through an operator interface. An operator may generate an activation signal that instructs the receiver  200  to switch to the located preferred programming. 
     When the receiver  200  finds designated programming, the receiver  200  employs the signaling circuitry  212  to alert the operator to the designated signal using a designated program location signal. The signaling circuitry  212  may be visual circuitry such as a dashboard indicator, a panel light, a display driver that displays text, an icon displayed on an LCD screen, or other circuitry or logic that provides a visual indicator. The signaling circuitry  212  also may be an audio circuit that generates audible announcement such as a tone, chime or voice alert. The location signal may convey characteristics of the preferred programming, including an artist&#39;s name, song name, information type (e.g., “news” or “traffic information”), or any other characteristics. 
     The combining circuitry  214  may combine the location signal with the program output signal received by the selected program receiver  208 . The combining circuitry  214  may combine the location signal with the program signal heard by an operator to alert the operator to the availability of a preferred program. The combining circuitry may add in an audible announcement “Preferred program SWR 3 is now available,” into the audio stream for example. 
     In an alternative, the combining circuitry  214  may combine the location signal with a video output signal. The combining circuitry  214  may be an LCD that may display text characters or graphics through a video signal to indicate a designated program is available. The text or graphics may appear on an LCD display. 
     The operator may employ an operator interface  206  that indicates that the receiver  200  should switch to a preferred program that the monitoring receiver  210  located. The operator may push a selection button that produces a signal that activates the receiver  200 . In response to the activation signal, the receiver  200  may retune the selected program receiver  208  to the designated programming located by the monitoring receiver  210 . 
     Alternatively, the monitoring receiver  210  may communicate a station change command to the selected program receiver  208  through the comparison output  230 . In this alternative, the selected program receiver  208  may automatically select the preferred programming when a command is received from the monitoring receiver  210 . The operator may select an automatic switching through the input interface  206 . 
     In some circumstances, the selected program receiver  208  may be turned OFF. Nevertheless, the monitoring receiver  210  may continue to search for preferred programming. The comparison output  230  also may include a power control signal or command that activates the output selected program receiver  208 . After powering up, the selected program receiver  208  may automatically tune to the preferred programming located by the monitoring receiver  210 . 
     The selected program receiver  208  may operate concurrently with the monitoring receiver  210 . The receiver  200  may locate preferred programming while the receiver  200  receives and presents a different program to the operator. As shown in  FIG. 2 , the selected program receiver  208  receives the selected program, while the monitoring receiver  210  sweeps through a frequency range to locate designated programs that match the program designation data. The selected program receiver  208  may present the selected program to the operator in the “foreground” while the monitoring receiver  210  locates preferred programming in the “background”. Furthermore, the monitoring receiver  210  may operate while the selected program receiver  208  or the receiver&#39;s outputs  200  are switched OFF. 
     The program designation data may include optional priority specifiers. The priority specifiers may include “high”, “medium”, and “low”, or may specify a numeric value such as an integer between 1 for a high priority and 10 for a low priority. The priority specifiers may govern the order in which the monitoring receiver  210  presents located programming to the operator. A designated program with a higher priority that is available may be made available to the operator before a designated program with a lower priority is made available. 
       FIG. 3  shows another exemplary implementation of a receiver  300 . The receiver  300  includes an input terminal  202 , an output terminal  204 , and an input interface  206 . The receiver  300  also includes a first receiver  302 , a second receiver  304 , a controller  306 , signaling circuitry  212 , a switch  308 , and a memory  310 . 
     The memory  310  stores a monitoring program  312 . Designation data stored in the memory  310  also may include the program preference data  238 , program code list  240 , and program selection characteristic data  242 . Alternatively, the designation data may be stored in a separate memory (e.g., onboard the controller  306 ). 
     The first receiver  302  includes a tuner  314 , signal recovery circuitry  316 , and data recovery circuitry  318 . The first receiver also includes a first program output  320 . The first program output  320  is connected to the switch  308 . Similarly, the second receiver  304  includes a tuner  322 , signal recovery circuitry  324 , and data recovery circuitry  326 . The second receiver  304  includes a second program output  328  that is connected to the switch  308 . The first receiver  302  and second receiver  304  may be implemented in a similar manner. 
     The controller  306  includes a signaling control output  330  and a switch control output  332 . In addition, the controller  306  directs operation of the first receiver  302  through the first receiver control outputs  334 . The controller  306  directs operation of the second receiver  304  through the second receiver control outputs  336 . 
     The output terminal  204  delivers selected programming to an output device. The output device may comprise many devices. The output device may be a speaker system that converts a program output signal to an acoustic or visual signal. 
     The receiver  300  may receive many different types of signals. The receiver  300  may be an AM/FM receiver that selects and outputs audio programming or may be a television receiver. The receiver  300  described below is configured to receive FM signals within a vehicle. The receiver  300  also may receive many other signals. 
     The input terminal  202  provides a connection for an input signal encoded with multiple programming channels. The input terminal  202  may be an FM antenna. At different times, each FM channel may encode programming of interest. 
     The first receiver  302  and second receiver  304  may assume interchangeable operations. The first receiver  302  and the second receiver  304  may perform a selected program operation or a location operation. When the first receiver  302  performs the selected program operation, the first receiver  302  employs the first tuner  314  to tune to a currently selected FM frequency. The signal recovery circuitry  316  processes the selected FM frequency to derive a program output signal for the program output  320 . The signal recovery circuitry  316  may include a mixer, a demodulator, and an amplifier to receive incoming radio signals and convert them to perceptible forms. 
     By performing the selected program operation, the first receiver  302  receives incoming signals and converts them to a perceptible form. While processing the incoming signals, the second receiver  304  may perform a location operation. The second receiver  304  may employ a second tuner  322  to locate alternative programming. 
     The first receiver  302  and the second receiver  304  operate under the direction of the controller  306 . The controller  306  executes the monitoring program  312  retained in the memory  310 . The controller  306  may communicate with the first receiver  302  over the control outputs  334  and with the second receiver  304  over the control outputs  336 . The control outputs  334  and  336  may carry commands for the receivers  302  and  304 . The commands may include tuning commands to direct the receivers  302  and  304  to tune to a particular frequency or a channel or data commands that direct the receivers to extract data from an incoming radio signal. 
     While the first receiver  302  engages in selected program operations, the second receiver  304  may engage in monitoring operations to evaluate any frequency. For each selected FM channel, the data recovery circuitry  326  may extract identifying data from the FM channel. The data recovery circuitry  326  may be a Radio Data Service (RDS) decoder. Similarly, the second receiver  304  may store signal parameters including frequency, channel number, and a signal strength indicator of each FM channel as it evaluates the FM channel for designated programming. 
     Under the direction of the controller  306 , the second receiver  304  communicates the identifying data to the controller  306 . The controller  306  may then determine whether the identifying data matches all or part of the program designation data. The controller  306  may read all or part of the designation data including the program preference data  238 , program code list  240 , and program selection characteristic data  242  and match the identifying data to the designation data. 
     The receiver  300  may sweep a pre-selected frequency range to check each channel in the frequency range for a designated program periodically or randomly. The receiver performing the location operation may sweep the frequency range at predetermined intervals, or according to a frequency list of one or more frequencies for the presence of the designated program. The receiver performing a location operation may search for designated programs on a periodic basis, when instructed through the input interface  206 , on a random basis, or based on any programmed schedule. 
     The receiver  300  may instruct the receivers  302  and  304  to decode the same identifying data employed by the receiver  200 . Accordingly, the controller  306  may receive RDS data, ARI data, or any other identifying data from the receivers  302  and  304 . The controller  306  may determine the availability of a designated program by matching the identifying data against the types of program designation data. The controller  306  may match the identifying data to the program preference data  238 , program code list  240 , and/or the selection characteristic data  242 , with or without reference to a signal strength. 
     When the controller  306  finds preferred programming, the controller  306  activates the signaling circuitry  212  to alert the operator through the signaling control output  330 . The signaling circuitry may generate a designated program location signal that may take a visual or audible form. The controller  306  may activate video signaling circuitry such as an LCD controller to display text or graphics. Similarly, the controller  306  may activate audio signaling circuitry such as an audio circuit that generates an audible announcement, such as a tone, or a voice alert. The receiver  300  may further be a unitary part of or interface with the combining circuitry  214  that merges the location signal with the program output. The location signal may convey characteristics of the preferred programming, including an artist name, song name, information type (e.g., “news” or “traffic information”), and/or other characteristics. 
     While the receiver  302  engages in selected program operations, the controller  306  directs the switch  308  to pass the program signal on the first program output  320 . The switch  308  may operate under the control of the switch control output  332  to select between the first program output  320  and the second program output  328 . The switch  308  may be an analog multiplexer or another type of switch. 
     When directed by the controller  306 , the first and second receivers  302  and  304  may reverse operations. The first receiver  302  receives a selected program, and the second receiver  304  first locates designated programs. When the second receiver  304  locates a designated program, the controller  306  may direct the second receiver  304  to receive the designate program, and direct the first receiver  302  to locate alternative designated programs. 
     The first receiver  302  then searches for a subsequent designated program, while the second receiver  304  continues to receive the designated program. The controller  306  may set a switch to pass the designated program to the second program output  328 . 
     In one implementation, the controller  306  switches the receiver operations automatically. Alternatively, the controller  306  may issue a request authorization to switch programs through an operator interface  206 . The controller  306  also may direct a selected program receiver to tune to the designated program, and maintain the other receiver as a location receiver. 
     As FM channel reception varies, the first receiver  302 , now switched to location operation, may find a different preferred program. In response, the controller  306  may switch the receiver operations again. The first receiver  302  may become the selected program receiver, and the second receiver  304  may become the location receiver. In each instance, the controller  306  directs the switch  308  to pass the program signal obtained by the selected program receiver. 
       FIG. 4  shows an exemplary communication device  400  that may incorporate one or both of the receivers  200  or  300  shown in  FIG. 2  or  FIG. 3 . The communication device  400  includes a receiver section  402 , an input connector  202 , and an output connector  204 . An operator input interface  206  provides operator input to the receiver section  402 . In addition, an antenna  404  connects to the input connector  202 , and audio/visual circuitry  406  connects to the output connector  204 . 
     The communication device  400  may be a television set, or any other visual and/or audio device. When part of a television set, the communication device  400  generates video and audio data sourced to the audio/visual circuitry  406 . The audio/visual circuitry  206  may be a display, and may include speakers or a separate audio output. When part of an AM/FM radio, the communication device  400  generates audio data sourced to the audio/visual circuitry  406 . The circuitry  406  may include one or more speakers. 
     The communication device  400  is not limited to any particular device. The communication device  400  may comprise a personal data assistant, a citizens&#39; band radio, or other any other personal electronic communication device. 
       FIG. 5  is a flow diagram  500  of the acts that may be encompassed within the monitoring program  236 . The controller  232  reads program designation data from the designation memory  216  (Act  502 ). The program designation data may include program preference data  238 , program code list  240 , and program selection characteristic data  242 . As the selected program receiver  208  receives and converts the incoming signals to a perceptible form, the controller  232  tunes the monitoring receiver  210  through a frequency band to obtain identifying data (Act  504 ). 
     At each designated frequency, the controller  232  determines whether identifying data matches the program designation data (Act  506 ). The controller  232  may find a match from the comparison circuitry  228 , or may perform the comparison under programmed control. When the controller  232  determines that the designated program is available, the controller  232  automatically switches the selected program receiver  208  to the designated program (Act  508 ). Alternatively, the controller  232  may first request an authorization to the switch. 
       FIG. 6  is a flow diagram  600  of further acts that may be encompassed within the monitoring program  312 . The controller  306  directs a first receiver to operate in a selected program mode and directs a second receiver to operate in a location mode (Act  602 ). The controller  232  sets a switch  308  to pass the output signal from the selected program receiver (Act  604 ). The controller  306  directs the selected program receiver to obtain and present the currently selected program to the operator (Act  606 ). 
     In addition, the controller  306  may direct the location receiver to tune to multiple frequencies and obtain corresponding identification data (Act  608 ). The controller  306  may direct the second program receiver  304  to scan one or more frequencies to locate a designated program. At each frequency, the controller  306  determines whether the identifying data matches the program designation data (Act  610 ). 
     When the controller  306  determines that the designated program is available, the controller  232  reverses the location operation and the selected program operation between the receivers (Act  612 ). The controller  232  directs the prior location receiver operate as the selected program receiver to receive incoming signals and convert them to perceptible form. Accordingly, the controller  232  sets the switch  308  to pass the output signal from the new selected program receiver. 
     The implementations are not limited to the particular forms described above. Any suitable implementation can be used. Although selected features of the implementations are stored in the memory  234  and  310 , all or part of systems and methods may be received, stored in, or read from other machine-readable media. Secondary storage devices also may be used such as hard disks, floppy disks, and CD-ROMs, ROM or RAM including DRAM, SRAM, Flash or other types of memory. The monitoring programs  236  and  312  may be a single program, separate programs, or distributed across several memories and processors. 
     Many other variations are also possible. For example, the controller  232  or controller  306  may be a processor, microcontroller, application specific integrated circuit (ASIC), discrete logic, or a combination of other types of logic or circuits. The controllers  232  and  306  may be associated with different circuitry or logic blocks than those shown in the Figures. Similarly, the memory  234  and  310  may be DRAM, SRAM, Flash or any other type of memory. As another example, the monitoring programs  236  and  312  may be a single program, separate programs, or a distributed program across several memories and processors. 
     While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.