System for wireless collection of data from a plurality of remote data collection units such as portable bar code readers
First Claim
1. A system for collecting data messages from a plurality of data collection units at a base station comprising:
- a means for individually polling, at a certain rate, certain of said individual units from said base station on each of a plurality of successive polling cycles, to determine which of said certain of said individual units have data messages available to transmit to said base station, wherein each cycle has a duration; and
a means in said base station for receiving poll response messages from certain of said individual units after they are polled representing that certain of said individual units have data messages which are available for transmission to said base station, anda means in said base station for changing the rate of polling, anda means for changing the duration of said cycles depending upon the poll response messages received from said units.
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Accused Products
Abstract
In order to collect data messages at a base station which is in radio communications with portable data collection terminals, such as bar code readers, that may move between different locations, all remote from the base station, a set of successive polling messages are broadcast from the base station addressed to different individual remote units during successive polling cycles. Increases in speed of polling cycles are obtained by eliminating from the polling cycle messages addressed to remote units which are turned off, or are inactive for a time since the unit recently sent data to the base station. During the last polling cycle in a set, the base station transmits acknowledgment of the collection of valid data to all of the units which have transmitted data. The time required for data collection depends upon the activity of the units and complex error and collision avoidance codes are not required. The system is also adapted for use with polarization diversity radio transmission whereby the one of a pair of antennas disposed at the base station in polarization diversity relationship (orthogonal to each other) can be selected for transmission for each units next poll depending upon which of the antennas received the strongest poll response signal from that unit on the previous cycle of polling signals.
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Citations
46 Claims
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1. A system for collecting data messages from a plurality of data collection units at a base station comprising:
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a means for individually polling, at a certain rate, certain of said individual units from said base station on each of a plurality of successive polling cycles, to determine which of said certain of said individual units have data messages available to transmit to said base station, wherein each cycle has a duration; and a means in said base station for receiving poll response messages from certain of said individual units after they are polled representing that certain of said individual units have data messages which are available for transmission to said base station, and a means in said base station for changing the rate of polling, and a means for changing the duration of said cycles depending upon the poll response messages received from said units. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of collecting data messages at a base station from a plurality of remote portable data collection units, which base station and units have wireless transmitting and receiving capability, said method comprising steps of:
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broadcasting at a certain rate, from said base station a plurality of successive cycles of successive poll messages, to determine which individual units have data messages to transmit to said base station, wherein each individual poll message is addressed to a different individual, and said rate consists of the frequency with which a poll message addressed to an individual unit is broadcast during an interval of time and wherein each cycle has a duration; collecting at a certain speed and time, by said base station, a cycle of successive poll response messages sent from certain of said individual units in response to said poll messages, indicating that said certain of said individual units have data messages to transmit to said base station during a subsequent cycle, and changing the rate at which said poll messages are broadcast from said base station and changing the duration of said cycles in accordance with said poll response messages thereby minimizing the time for collection of said poll response messages at said base station. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A method of collecting data messages at a base station from a plurality of remote portable bar code scanner units which comprises steps of:
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individually polling, at a certain rate, certain of said individual remote portable bar code scanner units on each of a plurality of successive polling cycles, wherein each cycle has a duration, and receiving poll response messages from certain of said individual remote portable bar code scanner units after each is polled, said poll response messages representing that the certain of said individual remote portable bar code scanner units have data messages which are available for transmission to said base station, and changing the rate of polling and changing the duration of said cycles depending upon the poll response messages received from said remote portable bar code scanner units. - View Dependent Claims (14, 15, 16, 17)
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18. A method of collecting data messages at a base station from a plurality of remote portable data collection units by wireless communication between said base station and said units which comprises the steps of:
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broadcasting from said base station a first cycle of successive poll messages, wherein each poll message is addressed to a different individual remote unit, said poll messages being spaced in time from each other by first intervals, transmitting during said first intervals, from each individual remote unit, in response to said first cycle of successive poll messages, a second cycle of poll response messages, wherein each poll response message identifies a different individual unit and whether or not data messages are ready for transmission to said base station therefrom, and broadcasting from said base station to said individual units a third cycle of successive poll messages which are separated by second intervals, wherein said third cycle of poll messages are addressed only to those individual units from which the poll response messages during said second cycle represented that said units were ready to transmit said data messages to said base station, and wherein during said second intervals in said third cycle, said individual units which received said poll messages transmit their data messages to said base station, where they are collected. - View Dependent Claims (19, 20, 21, 22, 23, 24)
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25. A system for collecting data messages at a base station from a plurality of remote portable wireless data collection units, which comprises:
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means for providing wireless transmitting and receiving capability in said base station and said units, means for broadcasting from said base station, at a certain rate, utilizing the wireless transmitting means thereof, a plurality of successive cycles of successive poll messages, to determine which individual units have data messages to transmit to said base station, wherein each individual poll message is addressed to a said individual unit, and said rate consists of the frequency with which a poll message addressed to an individual unit is broadcast during an interval of time, and wherein each cycle has a duration; means for collecting at said base station, at a certain speed and time, utilizing the wireless receiving means thereof, a cycle of successive poll response messages sent from certain individual units in response to said poll messages indicating that said certain of said individual units have data messages to transmit to said base station during a subsequent cycle, and means in said base station for changing the rate at which said poll messages are broadcast from said base station and changing the duration of said cycles in accordance with said poll response messages thereby maximizing the speed and minimizing the time for collection of said poll response message at said base station. - View Dependent Claims (26, 27, 28, 29, 30, 31)
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32. A system for collecting data messages at a base station from a plurality of remote portable data collection units, comprising:
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wireless communications capability between said base station and said remote portable data collection units, means for broadcasting, at a certain rate, from said base station a first cycle of a plurality of successive individual poll messages, wherein each individual poll message is addressed to a different individual remote portable data collection unit, said poll messages being spaced in time from each other by first intervals, means for transmitting poll response messages from said remote portable data collection units, in response to said first cycle of a plurality of successive poll messages, wherein each said poll response message identifies a certain one of said individual units and whether or not a data message is ready for transmission to said base station from said unit, and each poll response message for each individual unit is transmitted during the first interval, following the poll message addressed to that individual unit during said first cycle, and means for broadcasting from said base station a third cycle of successive poll messages, which are separated by second intervals, and wherein said third cycle poll messages are only broadcast to an individual unit if the poll response message received by the base station for that individual unit on said third cycle represented that said unit was ready to transmit data messages to said base station, and wherein said second interval provides an interval for transmission of said data messages from said units between said polling messages of said third cycle. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39)
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40. A method of collecting data messages at a base station from a plurality of remote portable data collection units, which base station and units have wireless transmitting and receiving capability, said method comprising the steps of:
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(a) broadcasting from said base station a first plurality of successive poll messages in a sequence, wherein each individual poll message is addressed to a different individual unit, to determine which units have data messages available to transmit to said base station; (b) responsive to said broadcasting of said first plurality of successive poll messages, collecting at said base station, poll response messages sent from each individual unit that has a data message available for transmission to said base station; (c) broadcasting from said base station a second plurality of successive poll messages to each individual unit which responded with a poll response message in step (b), to prompt those units to each transmit a data message to said base station; (d) responsive to said broadcasting of said second plurality of successive poll messages, collecting at said base station, data messages sent from each individual unit that had a data message available for said base station, said data messages being sent from each individual unit in response to each poll message broadcast in the step (c), repeating steps (a)-(c) successively; and altering the polling sequence of said step (a) so as to alter the time it takes to complete steps (a) through (c). - View Dependent Claims (41, 42, 43, 44, 46)
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45. A bar code data acquisition system comprising:
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a plurality of remote portable bar code scanner units, each unit having wireless transmission and receiving communications capability; and a base station having wireless transmission and receiving communications capability for communication with said plurality of remote portable bar code scanner units, said base station includes a pair of antennas in polarization diversity relationship to one another, and a pair of receiving channels wherein one receiving channel connects to one of said pair of antennas and the other receiving channel connects to the other of said pair of antennas; wherein said base station connects one of said pair of antennas to transmit to said remote portable bar code scanner units.
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Specification