Wide area communications network for remote data generating stations

Abstract

A wide area communications network communicating data from a plurality of network service modules through a plurality of remote cell nodes and intermediate data terminals to a central data terminal. The wide area communicates network collects network generated by a plurality of physical devices such as gas, water or electricity meters, located within a geographical area. The wide area communications network is a layered network have a hierarchical communications topology. The central data terminal controls network operation. Intelligence exists at all layers of the network, thereby easing the workload of the central data terminal. The intelligence attributed to each module is a function of the application of that module.

What is claimed:  
     
         20 . A data collection system comprising: 
 a) a plurality of telemetry devices, each including 
 i) a sensor configured to generate a series of successive measurements by measuring a parameter at a series of measurement times,  
 ii) a memory configured to store a plurality of measurements from said series of successive measurements, and  
 iii) a transmitter configured to transmit measurements stored in memory to a collection device at a series of transmission times, each of said transmitted measurements being transmitted at a plurality of different transmission times; and  
   b) a collection device having 
 i) a receiver configured to receive transmissions from said telemetry devices,  
 ii) a processor configured to extract said series of successive measurements from a series of received transmissions and further configured to generate a metered function of said parameter by analyzing said series of successive measurements, and  
 iii) a transmitter configured to transmit said metered function to a monitoring station.  
   
     
     
         21 . The data collection system of  claim 20  wherein the transmitter of each telemetry device is configured to generate wireless transmissions.  
     
     
         22 . The data collection system of  claim 20  wherein the sensor of each telemetry device includes: 
 a counter for storing a value,  
 means for incrementing said counter upon receipt of a trigger signal, and  
 means for storing said value from said counter in said first memory and resetting said counter at said measurement times.  
 
     
     
         23 . The data collection system of  claim 20  wherein each of said telemetry devices discards the oldest measurement stored in memory and stores in memory a new measurement from said sensor.  
     
     
         24 . The data collection system of  claim 20  wherein each of said telemetry devices further includes a timer having a predetermined time interval, wherein the expiration of said predetermined time interval causes said sensor to generate a measurement.  
     
     
         25 . The data collection system of  claim 20  wherein said collection device further includes a memory configured to store a data object representing a given telemetry device from which the collection device receives transmissions.  
     
     
         26 . The data collection system of  claim 25  wherein 
 the memory of each telemetry device is configured to store a number,  
 the given telemetry device increments said number each time a measurement is generated,  
 said stored number is transmitted by the transmitter of the given telemetry device in a current transmission,  
 the data object representing the given telemetry device includes a number transmitted in a previous transmission received from the given telemetry device; and  
 the processor of the collection device is configured to compare the number transmitted in the current transmission to the number transmitted in the previous transmission.  
 
     
     
         27 . The data collection system of  claim 25  wherein 
 each of said telemetry devices includes means for detecting a power failure,  
 the memory of each telemetry device is configured to store power failure information indicating whether each stored measurement was generated following a power failure,  
 said power failure information is transmitted by the transmitter of the given telemetry device at said transmission times, and  
 the data object representing the given telemetry device includes said transmitted power failure information received by the collection device from the given telemetry device.  
 
     
     
         28 . The data collection system of  claim 25  wherein 
 said metered function is a load profile, and  
 the data object includes the duration of a load profile period.  
 
     
     
         29 . The data collection system of  claim 25  wherein 
 said metered function is a demand profile, and  
 the data object includes a duration of a demand profile period.  
 
     
     
         30 . The data collection system of  claim 20  wherein said parameter is selected from the group consisting of electrical power, fluid flow, voltage, current, temperature, pressure, and humidity.  
     
     
         31 . The data collection system of  claim 30  wherein said parameter is electrical power.  
     
     
         32 . The data collection system of  claim 30  wherein said parameter is fluid flow.  
     
     
         33 . The data collection system of  claim 30  wherein said fluid is natural gas.  
     
     
         34 . The data collection system of  claim 30  wherein said fluid is water.  
     
     
         35 . A method of collecting data comprising the steps of: 
 a) generating a series of successive measurements by measuring a parameter with a telemetry device at a series of measurement times;    b) storing a plurality of said measurements in said telemetry device;    c) transmitting said stored measurements to a collection device at a series of transmission times;    d) extracting said series of successive measurements from a series of said transmissions with said collection device;    e) generating a metered function of said parameter with said collection device by analyzing said series of successive measurements; and    f) transmitting said metered function to a monitoring station.    
     
     
         36 . The method of  claim 35  further comprising the steps of: 
 storing an old number in said collection device,  
 generating a new number in said telemetry device each time a measurement is generated,  
 transmitting said new number with stored measurements, and  
 comparing said old number to said new number at said collection device to determine which measurements are new measurements which were not previously received by said collection device and whether there are missing measurements.  
 
     
     
         37 . The method of  claim 35  wherein said transmissions are wireless transmissions.  
     
     
         38 . The method of  claim 36  further comprising the step of storing said old number in said telemetry device, and wherein the step of generating said new number includes incrementing said old number.  
     
     
         39 . The method of  claim 38  further comprising the step of determining the measurement times for new measurements received by said collection device.  
     
     
         40 . The method of  claim 39  further comprising the steps of: 
 storing information in said telemetry device indicating whether a power failure occurred between successive measurements,  
 transmitting said information to said collection device, and  
 using said information to determine whether there are new measurements for which the measurement time cannot be determined.  
 
     
     
         41 . The method of  claim 40  further comprising the step of performing a recovery operation for missing measurements or new measurements for which the measurement time cannot be determined.  
     
     
         42 . The method of  claim 35  further comprising the step of waiting an alignment time following a measurement to transmit said stored measurements.  
     
     
         43 . The method of  claim 42  wherein said alignment time is selected randomly.  
     
     
         44 . The method of  claim 42  wherein said transmission occurs following an integer number of measurements.  
     
     
         45 . The method of  claim 35  wherein said parameter is selected from the group consisting of electrical power, fluid flow, voltage, current, temperature, pressure, and humidity.  
     
     
         46 . The method of  claim 45  wherein said parameter is electrical power.  
     
     
         47 . The method of  claim 45  wherein said parameter is fluid flow.  
     
     
         48 . The method of  claim 45  wherein said fluid is natural gas.  
     
     
         49 . The method of  claim 45  wherein said fluid is water.  
     
     
         50 . A network for collecting data generated by a plurality of sensors, comprising: 
 a) a plurality of data generating devices, each including 
 i) a sensor configured to generate measurements by measuring a parameter,  
 ii) a memory configured to store said measurements, and  
 iii) a transmitter configured to transmit at a plurality of transmission times measurements stored in memory to an intermediate device; and  
   b) a plurality of intermediate devices, there being fewer intermediate devices than data generating devices, each of said intermediate devices including 
 i) a receiver configured to receive transmissions from a subset of said plurality of data generating devices,  
 ii) a processor configured to extract said measurements from said transmissions and further configured to generate a metered function of said parameter by analyzing said measurements, and  
 iii) a transmitter to transmit said metered function; and  
   c) a central station configured to receive said transmitted metered functions from said plurality of intermediate devices.    
     
     
         51 . A method of collecting data comprising the steps of: 
 a) generating measurements by measuring a parameter with a sensor;    b) storing a plurality of said measurements in a memory;    c) transmitting said stored measurements to an intermediate device;    d) extracting said measurements from said transmissions with said intermediate device;    e) generating a metered function of said parameter with said intermediate device by analyzing said measurements; and    f) transmitting said metered function to a central station.    
     
     
         52 . A data collection system, comprising: 
 a plurality of sensors each of which has a meter configured to sample a parameter value at discrete measurement times and a transmitter configured to transmit data measured by the meter; and    a collector having a receiver configured to receive data transmitted by the plurality of sensors, a processor configured to generate a summary profile of data received by the receiver from the plurality of sensors, and a transmitter configured to transmit the summary profile to a monitoring station, wherein each sensor periodically transmits a plurality of data measurements during a current data collection period and, with each transmission, each sensor transmits redundant data measurements corresponding to a prior transmission, and the collector is configured to reduce the occurrence of usage profile errors based upon the redundant data measurements contained in a received transmission.