Abstract:
A method, apparatus, and system are disclosed for providing communication between a utility meter and a remote station via any of a plurality of RF modulation schemes and communication protocols over any of a plurality of carrier frequencies. The utility meter includes adaptive radio circuitry that is preferably programmably configured to receive and process any format of incoming signals, and generate and send any format of outgoing signals. The adaptive radio circuitry includes a DSP, filters, an analog-to-digital converter, a digital-to-analog converter, a tunable broad-band up/down converter and other processing circuitry. A main processor and memory provides control over the adaptive radio module.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to utility meters and, more particularly, to utility meters capable of communicating meter data to a remote location. 
     2. Description of the Prior Art 
     Utility meters are commonplace with regard to measuring utility or commodity consumption or usage (e.g. electricity, gas, water, and the like) for billing the consumer. Such utility meters are interposed between the source of the utility and the usage point. The utility meters are generally located proximate the area of usage of the commodity and, in the case of electricity meters, are typically mounted on a side of the structure in which the electrical energy is consumed. Because the cost of the commodity to the consumer is determined in part by usage, the metered amount of consumption of the commodity must be communicated to the utility service provider. 
     Various techniques have been developed to communicate data from utility meters that measure commodity usage at utility customer sites. Historically, meters have been read manually by human “meter readers” who traveled from meter site to meter site. In such techniques, the meter reading data may be written down by the meter reader or inputted manually into an electronic data collection device. However, manual reading has substantial labor costs and is vulnerable to transportation problems, truancy, and human error. In view of the above, various techniques have been developed to alleviate the problems. 
     One technique for remote meter data collection is to utilize hardwired electronic communications systems (such as telephone lines) to transmit meter data to remote monitor stations. Such systems, however, require dedicated line connections that can increase meter installation costs, and, for example, in the case of telephone lines, rely on the specifications and dependability of communications networks over which the utility supplier has little of not control. 
     Another technique for remote meter data collection employs radio frequency (RF) communications between meters and remote monitor stations. A problem with prior art RF communications techniques is that no standard, universal communication system has been adopted. Accordingly, different utility service providers may adopt any one of various RF communications technologies, such as Itron, Cell Net, RAMAR, etc., that utilize various frequency modulation and protocol schemes. As a result, meter manufacturers must specifically adapt meters to accommodate the RF communications schemes of particular utility service providers. In particular, manufacturers must equip each meter with a radio that is specifically adapted to communicate using the communication system employed by the utility service provider. The process of equipping separate meters with diverse radio equipment increases manufacturing and logistical costs. 
     It would thus be desirable for a utility meter to be capable of sending and/or receiving meter data within a plurality of RF communication schemes. 
     It would also be desirable for a utility meter to be capable of transmitting and/or receiving meter data and the like without requiring each meter to be specifically adapted to the particular communication scheme used by the utility service provider that purchases the meter. 
     SUMMARY OF THE INVENTION 
     The present invention, in one form, is a utility meter having an adaptive radio that provides communication between the utility meter and a remote station via any of a plurality of RF modulation schemes and communication protocols over any of a plurality of carrier frequencies. 
     According to one embodiment, a utility meter has an adaptive radio module that includes processing circuitry, memory, an analog-to-digital (A/D) converter, a digital-to-analog (D/A) converter, filters, a tunable broad band up/down converter (UDC), and an RF antenna. The adaptive radio module is preferably configured to send and/or receive data and is electronically coupled to controlling and monitoring circuitry of the meter. 
     In operation, the RF antenna receives and transmits RF waves, and is operationally connected to the UDC. For reception of communications (such as a request for data) from the remote station, the UDC scans a plurality of RF carrier frequencies for communications to the meter from the remote station. The communications may be in any one of a plurality of combinations of modulation schemes and communications protocols. Output signals from UDC are filtered, digitized by the A/D converter, and then demodulated by the processing circuits. The signal processing capabilities of a digital signal processor (DSP) provides demodulation of a plurality of modulation schemes. 
     In one form, the DSP is operable to be self-configurable to effectuate any one of a plurality of demodulation schemes and any one of a plurality of communication protocols. Transmissions of communications from the utility meter to the remote station are conversely accomplished in any of a plurality of modulation schemes and any one of a plurality of communications protocols. 
     The present invention, in another form, provides a method of providing communication between a utility meter and a remote station via an adaptive radio that communicates with a remote station via any of a plurality of RF modulation schemes and communications protocols over any of a plurality of carrier frequencies. 
     As a result, the present utility meter with an adaptive radio provides communications between the utility meter and a remote station via any of a plurality of RF modulation schemes and communications protocols over any of a plurality of carrier frequencies. The use of the adaptive radio reduces, if not eliminates, the need to specially configure each meter for the specific RF communication techniques employed by the system in which the meter is used. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein: 
     FIG. 1 is a front perspective view of a utility (electricity) meter having an adaptive radio therein in accordance with the principles of the present invention; 
     FIG. 2 is a block diagram of the utility meter of FIG. 1 particularly showing the adaptive radio module in communication with processor board  24 ; 
     FIG. 3 is a flowchart of general DSP operation for incoming signals; and 
     FIG. 4 is a flowchart of general DSP operation for outgoing signals. 
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one preferred embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference now to FIG. 1 there is depicted a utility meter  10 . While utility meter  10  is depicted in FIG. 1 as an electricity or watt-hour meter, it should be appreciated that the present invention is not limited to electricity meters, but is applicable to all types of utility meters and thus hereafter will be termed “meter.” Meter  10  is mounted to a wall  12  that is typically the outside of a residence or other building but may be any structure at any location. Meter  10  includes a cover  14  typically made from glass or a suitable plastic. The cover  14  is secured to a base plate  16  that is attached to the wall  12  and houses the various components typical of an electricity meter. 
     Particularly, the meter  10  depicted in FIG. 1 is a rotating disk type electricity meter characterized by a rotating disk  18 , dial face plate  20  on which is mounted several dials that visually indicate the total kilowatt-hours of electricity that has been used, and other components typical of an electricity meter as is known in the art. The meter  10  has a processing unit  22  that is in communication with the various components of the meter  10  so as to receive information regarding usage and electricity supply characteristics/parameters from the various components. According to an aspect of the present invention, the processing unit  22  includes processor board  24  and adaptive radio module or circuitry  26  that is in communication with the processor board  24 . The adaptive radio circuitry  26  may be a separate module that is adapted to interface with a processing unit of a utility meter, or as part of a processing unit of a utility meter. 
     As is known in the art, the several dials on faceplate  20  indicate accumulated watt-hours of electricity used. The meter-reader typically reads the dials on the faceplate  20  in order to determine the amount of energy consumed by the customer. Other parameters for various statistics may also be gathered by the meter  10 . In this regard, the processing unit  22  can perform the necessary data processing to obtain or calculate any such parameters. Since the processing unit  22  is electronic, it should be appreciated that faceplate  20  may be an electronic display such as an LCD display or the like rather than the analog dials. 
     It should also be appreciated that the utility meter  10  may as well be an electronic or solid state (digital) type utility meter as is known in the art in addition to the analog utility meter as depicted in FIG.  1 . In the case of a solid state meter, the processor board  24  of the processing unit  22  would typically be part of a main processing unit or controller board that is typically a part of an electronic meter. The adaptive radio module  26  is then in communication with the processing unit or controller board. One example of an electronic meter which may be employed is the meter  10  described in U.S. patent application Ser. No. 08/690,973 which is assigned to the assignee of the present invention and specifically incorporated herein by reference. 
     With reference to FIG. 2, there is shown a block diagram of the adaptive radio module  26  and at least a portion of the processor board  24  of processing unit  22 . Processor board  24  includes a microprocessor (“μP”)  28  that is in communication with memory  30  via data communication line  32 . It should be understood that the term data communication line, or any similar term may encompass all types of data and/or communication links that enables the transfer of such data/communications from one device to another device. 
     The memory  30  may be in addition to any memory on or integral with the microprocessor  28  and can comprise any known memory devices such as RAM, ROM, EEPROM, or the like. The memory  30  stores instructions that are executed by the microprocessor  28 . The instructions or logic may comprise a software program or subroutine for control or regulation of the various aspects of the present invention as well as the utility meter in general. 
     Arrow  70  emanating from the microprocessor  28  represents connection and/or communication with other typical components of a processing unit for a utility meter. For example, arrow  70  may represent a connection to electronic energy consumption measurement circuits, not shown, that perform measurements and generate the energy consumption within the meter. Such circuits are well-known and may include voltage and current sensors, analog to digital converters, and digital signal processing circuitry. In addition, arrow  70  may represent a communications port for connection to peripherals, modems and the like. Power for the processing unit  22  is supplied by known power means in a manner known in the art. 
     Generally, the present adaptive radio module  26  is configured and operable to receive RF signals comprising one or a plurality of frequencies within a band or bands of frequencies. The various frequencies are particular or common to those used for RF communications. Adaptive radio module  26  includes a tunable broad band up/down converter  34  that is in communication with an antenna  36 . 
     The antenna  36  is adapted to send and receive broad band RF signals as is known in the art. The antenna  36  may be part of the module board or a separate structure. If the antenna  36  is a separate structure, it may be disposed within the meter housing or outside thereof. The choice of location of the antenna  36  is dependent upon various factors such as location, terrain, and expected frequencies that will be used. 
     The broad band up/down converter  34  is tunable through external control such as that provided by the microprocessor  28  via the communication line  66  and/or the DSP  42  via the communication line  72 . Depending on the instructions performed by the microprocessor  28  and/or the DSP  42  the broad band up/down converter  34  can tune a wide range of RF signals received by the antenna  36  such as those typically used for communications. Moreover, the broad band up/down converter  34  is further operable to downconvert the RF signals to intermediate frequency (IF) signals that are more easily processed. As well, the broad-band up/down converter  34  can process IF signals generated by the present adaptive radio module  26  and upconvert the IF signals to appropriate RF signals for transmission by the antenna  36 . Preferably, the DSP  42  is operable to tune the broad-band up/down converter  34  in both the receive and transmit modes. 
     The broad band up/down converter  34  is in communication with a filter  38  via communication line  50  such that IF signals generated by the broad band up/down converter  34  are provided to the filter  38 . The filter  38  is preferably a band-pass type filter tuned for the various downconverted IF signals received from the broad-band up/down converter  34  and has a low Q (energy in/energy out) and an anti-aliasing function. The filter  38  is in communication via communication line  52  with an analog-to-digital (A/D) converter  40  for digitizing the IF signals passed by the filter  38 . 
     The A/D converter  40  samples the incoming analog IF signals outputted from the filter  38  preferably above the Nyquist sampling rate for passband bandwidth. The output digital signal from the A/D converter  40  is sent to a preferably programmable digital signal processor (DSP)  42  via communication line  54 . The A/D converter  40  is adapted to capture all intermediate frequencies and all types of modulations in the IF bandwidth. 
     The DSP  42  receives the output signals from the A/D converter  40  and processes them in accordance with instructions stored in the memory  44 . The instructions include various algorithms necessary for demodulating the various known modulation schemes and protocol schemes. 
     For example, the memory  44  may include algorithms that allow the DSP  42  to perform modulation and demodulation using Frequency Shift Keying (“FSK”) techniques, Quadrature Amplitude Modulation (“QAM”) techniques, Quadrature Phase Shift Keying (“QPSK”), and others. Likewise, the memory  44  may include algorithms that allow the DSP  42  to communicate demodulated digital signals using Manchester encoding protocols, Hamming protocols, and other well-known communication and/or error correction protocols (e.g. Reed-Solomon). Such algorithms would be known to those in the art. 
     The DSP  42  also controls the various frequencies and/or channels being received and processed by the adaptive radio module  26  and any additional filtering as necessary. The received and demodulated signals are communicated to the microprocessor  28  via communication line  64  to be used, stored, and/or processed by the processing unit  22 . The incoming signals may include instructions (e.g. software), polling, and the like. The memory  44  is in addition to any memory integral with the DSP  42  and may be any type of memory such as RAM or ROM. 
     The DSP  42  is also adapted to generate IF signals from base-band signals received through the microprocessor  28 . As well, the DSP  42  may generate IF signals from instructions from the microprocessor  28 . Such base-band signals could include information such as watt-hours used, voltage and current information, diagnostic information, and the like for transmission by the adaptive radio module  26 . The information signals to be transmitted may be in response to polling (received signals) or as a regular or scheduled transmission. 
     A digital-to-analog (D/A) converter  46  is in communication with the DSP  42  via communication line  62  for converting digital IF signals from the DSP  42  into IF analog signals. The D/A converter  46  is in communication with a filter  48  via communication line  60 . The filter  48  is preferably a band-pass type filter tuned for the various generated analog IF frequencies received from the D/A converter  46  and has a low Q (energy in/energy out) and an anti-aliasing function. The filter  48  is in communication with the broad-band up/down converter  34  via communication line  58  that upconverts the analog IF signal received from the filter  48  into RF signals for transmission by the antenna  36 . 
     The DSP  42  is adapted to allow multiple and/or simultaneous receipt and/or transmission of RF signals/channels depending on the communication line or bus used for communication between the various components. The various modulation schemes and communications protocols used for the received signals and the signals to be transmitted are stored as known algorithms and used by the DSP  42  for signal processing. Additional or any type of modulation scheme and/or communication protocol may be stored in memory  44  and accessible by the DSP  42  and received by the adaptive radio module  26  through an RF transmission. 
     In the context of receiving RF signals, the tunable broad band up/down converter  34  can convert a whole band or bands of RF signals, but does not demodulate the incoming RF signals. In the context of sending RF signals, the tunable broad band up/down converter  34  can convert a whole band or bands of RF signals, but does not modulate the outgoing RF signal. The DSP  42  performs all IF modulation and demodulation in accordance with the selected modulation and protocol schemes. Of course, the modulation and protocol schemes of an incoming RF signal is fixed by the transmitter, but is deciphered by the present adaptive radio module  26 . The modulation and protocol scheme for transmission may be any one of the many modulation and protocol schemes. Transmission and reception schemes do not have to be the same. The DSP  42  also performs filtering to channel and frequency, and allows multiple simultaneous radio communication channels. 
     FIGS. 3 and 4 illustrate in further detail operation of the adaptive radio module  26 , particularly the DSP  42 , in an exemplary implementation of the present invention. FIG. 3 shows a signal receiving routine of the adaptive radio module  26 . FIG. 4 shows a signal transmitting routine of the adaptive radio module  26 . It should be understood that the adaptive radio module  26  only transmits information when polled through a received transmission or when scheduled, such as at various set and/or random intervals. 
     In connection with FIGS. 3 and 4, it is noted that the DSP  42  (and more particularly, the memory  44 ) is preferably programmed with information regarding a plurality of RF communication schemes known to be in use by various utility service providers. Such information preferably includes the combination of modulation/demodulation algorithms and communication protocols associated with each RF communication scheme. Such information may further include, for each RF communication scheme, i) the channel frequencies used in the RF communication scheme, and ii) data protocols employed by the communication scheme. 
     With reference now to FIG. 3, there is shown flowchart  73  generally showing operation of the DSP  42  in a signal receiving mode. In step  74 , the DSP  42  causes the up/down converter  34  to tune to a frequency or channel of a plurality of various possible radio frequencies or channels via communication line  72 . The choice of what frequency to tune may be dependent upon the modulation scheme/communication protocol. In particular, the various modulation schemes and associated communication protocols are stored in the memory  44  associated with the DSP  42 . Each modulation scheme/communication protocol and may be defined as a System. In step  74 , the DSP  42  chooses “System 1” and tunes to a frequency used by that particular System. The signal is converted into a digital intermediate frequency (IF) signal by the up/down converter  34 , filtered by filter  38  and digitized by the A/D converter  40 . In step  76 , the now digital IF signal is received by the DSP  42  for processing. The DSP  42  attempts to demodulate the digital IF signal according the modulation characteristics of System 1, step  78 , and then determines if the demodulation is successful, step  80 . Successful demodulation causes the DSP  42  to use or apply the communication protocol for System 1 to the signals, and continue to keep the converter  34  tuned to the particular frequency and demodulate the signals, step  82 . The DSP  42  further checks to determine whether the demodulated, protocol decoded signal contains intelligible data, step  84 . If the signal does not contain intelligible data, the program goes to step  88 . If the signal does contain intelligible data, that data is provided to the microprocessor  28 , step  86 . If intelligible data is found, the adaptive radio  26  thereafter applies the relevant modulation scheme and communication protocol to the incoming data/signal. 
     Unsuccessful demodulation of the signal using System 1, as determined in step  80  causes the DSP  42  to determine whether there are other frequencies available for possible demodulating using System 1, step  88 . If it is determined that there are additional frequencies to try, there is a return to step  74  using one of those frequencies. If it is determined by the DSP  42  in step  88  that there are no additional frequencies, the DSP  42  causes the up/down converter  34  to tune to a frequency or channel of the plurality of frequencies or channels used by System 2, step  90 . 
     In step  90 , the received signal is converted into a digital intermediate frequency (IF) signal by the up/down converter  34 , filtered by filter  38  and digitized by the A/D converter  40 . In step  92 , the digital IF signal is received by the DSP  42  for processing. The DSP  42  attempts to demodulate the digital IF signal according the modulation characteristics of System 2, step  94 , and then determines if the demodulation is successful, step  96 . Successful demodulation causes the DSP  42  to use or apply the communication protocol for System 2 to the signals, and continue to keep the converter  34  tuned to the particular frequency and demodulate the signals, step  98 . The DSP  42  further checks to determine whether the demodulated, protocol typed signal contains intelligible data, step  100 . If the signal does not contain intelligible data, there is a return to step  102 . If the signal does contain intelligible data, that data is provided to the microprocessor  28 , step  86 . 
     Unsuccessful demodulation of the signal using System 2, as determined in step  96  causes the DSP  42  to determine whether there are other frequencies available for possible demodulating using System 2, step  102 . If it is determined that there are additional frequencies to try, steps  90  through  96  are repeated. If it is determined by the DSP  42  in step  102  that there are no additional frequencies, the DSP  42  causes the up/down converter  34  to tune to a frequency or channel of the plurality of frequencies or channels used by other Systems. The number of demodulation attempts is governed by whether demodulation is successful and/or the total number of Systems (i.e. modulation schemes/communication protocols) are stored. 
     It should be understood that the various modulation/demodulation schemes or algorithms are stored in memory  44 , and thus the number of attempts to demodulate the incoming signal by the DSP  42  depends on the number of stored modulation/demodulation schemes and/or algorithms or Systems. 
     Thus, as discussed above in connection with FIG. 3, the adaptive radio module  26  is self-configurable in the receiving mode to identify the modulation scheme and communication protocol used by the network in which the meter  10  is installed. Since it is unlikely that there would be several different types of modulation schemes and communications protocols being transmitted to the meter  10  at any one time, the adaptive radio module  26  maintains the up/down converter  34  tuned to the particular frequency/channel until 1) no intelligent data is thereafter received (as periodically determined), 2) the frequency/channel is changed by incoming data, or 3) a periodic check determines a change. 
     Typically, a utility company will use only a single modulation scheme and communication protocol from a plurality of available modulation schemes and communications protocols. Therefore it is not necessary for the DSP  42  to continuously scan the various frequencies once a particular signal has been successfully demodulated and protocol typed and determined to contain data for the meter  10 . However, several cases warrant continuous determination of an intelligent signal. In a first case, if several signals are being transmitted for reception by the meter  10  on different frequencies or channels, the DSP  42  would control the up/down converter  34  via communication line  72  to tune to the particular frequencies for processing. In a second case, if several signals are being transmitted in different modulation schemes and/or communications protocols, the DSP  42  would concurrently provide the demodulated and protocol typed signal to the microprocessor  28  for processing. As well, various “frequency hopping” or “frequency skipping” transmission schemes (e.g. spread spectrum) may also be employed which would be recognized by the DSP  42  and action taken accordingly. 
     It is further preferable in the case where the adaptive radio module  26  locates a signal, successfully demodulates the signal and determines its protocol, then self-configures to utilize the successful demodulation scheme/communication protocol, that the adaptive radio module  26  is operable to periodically check the modulation scheme and communication protocol being used against the incoming signal. The check may be performed monthly, for example, in order to determine if the adaptive radio module  26  needs to be reconfigured or regularly as during signal reception. As well, if there are no current intelligent signals being received by the meter  10 , the adaptive radio module  26  may enter a continuous scan mode for any such signals. Such periodic transmission may be scheduled and thus the adaptive radio module  26  may only tune or scan at a predetermined time for a predetermined time period. 
     With reference now to FIG. 4, there is shown flowchart  105  generally showing operation of the DSP  42  in a signal transmitting mode. The DSP  42  generates data, or compiles and/or receives data from the microprocessor  28  to be transmitted, step  106 . The data is typically commodity usage information in various forms, but may include meter performance data, operating characteristics and the like. Once the data has been compiled by the DSP  42 , a modulation scheme and communications protocol are selected and applied to the data, step  108 . The selection of the modulation scheme and communications protocol may be 1) arbitrary, 2) according to the modulation scheme and communications protocol of any incoming data, or 3) according to other criteria. The DSP  42  selects the modulation scheme and communications protocol from those stored in memory  44 . 
     After modulation and protocol selection, step  108 , the DSP  42  generates digital IF signals accordingly, step  110 , that are converted into analog IF signals by D/A converter  46 , filtered by filter  48 , and received by up/down converter  34 . Thereafter, the DSP  42  causes the up/down converter  34  to upconvert the analog IF signals into analog RF signals for transmission, step  112 . The choice of which frequency or channel on which to transmit may be 1) arbitrary, 2) according to the frequency/channel of any incoming signal, or 3) according to other criteria. The DSP  42  may select the frequency/channel from those stored in memory  44 . 
     The DSP  42  is operable to receive multiple channels/frequencies of variously modulated, protocol coded signals while generating and transmitting multiple channels/frequencies of variously modulated and protocol decoded signals. As well, transmission of signals may be accomplished during a time when there are no incoming signals. 
     It is further more noted that the adaptive radio  26  may be adapted to new modulation schemes and communication protocols by reprogramming the memory  44  with the appropriate algorithms. As a result, the adaptive radio  26  need not be replaced to accommodate new data transmission schemes. The present adaptive radio  26  is operable to allow the change of the communications bandwidths, frequencies, and modulation schemes that can be received and transmitted by merely modifying the software/firmware thereof. Thus, a single meter incorporating the present adaptive radio  26  may be manufactured and used in any location with any communication system. 
     It should also be appreciated that the algorithm of FIG. 3 may not necessarily be implemented by the DSP  42 . If the adaptive radio  26  is programmed to receive a particular one of the various modulation schemes/communications protocols, it is not necessary to determine the modulation scheme and communications protocol being used. This information may be preprogrammed into the memory  44  or may be sent to the adaptive radio  26 . In this case, the a priori nature of knowing the modulation scheme/communications protocol obviates the need for the algorithm of FIG.  3 . Of course, the modulation scheme and communications protocol may be changed due to the adaptive/configurable nature of the present adaptive radio  26 . 
     While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims. 
     For example, while the exemplary embodiment of the adaptive radio described above includes a digital signal processor, it is noted that the phrase “digital signal processor” shall encompass other types of processors and/or combinations of discrete circuitry and processing circuitry may be adapted to carry out the salient operations described above in connection with the digital signal processor. Moreover, it is noted that the RF receiver circuitry is in no way limited to the configuration of the broad-band up/down converter, filter, antenna and A/D conversion circuitry described above. Any RF receiver circuitry operable to receive broadband RF signals and provide digitized IF signals to the processing circuitry of the adaptive radio may be used as the RF receiver circuitry of the adaptive radio.