Modular, Portable Data Processing Terminal for Use in a Radio Frequency Communication Network
First Claim
1. A portable data collection terminal comprising:
- a base module comprising a first processing unit and a first storage element that stores base module communication software;
a selected one of a plurality of communication modules, each communication module comprising a second processing unit, a second storage element that stores communication module software, and at least one of a plurality of radio transceivers, each of the plurality of radio transceivers having different operating characteristics; and
wherein the second processing unit, using the communication module software, isolates the first processing unit, which uses the base module communication software, from differences in the operating characteristics of the plurality of radio transceivers.
3 Assignments
0 Petitions
Accused Products
Abstract
Modular, portable data collection terminals are disclosed for use in mixed wireless and hard-wired RF communication networks, wherein various radio transmitter modules and associated antennas may be selectively added to a base terminal unit to solve networking problems associated with specific types of business environments. Modularity exists in both the hardware (splitting data collection and processing control circuitry from radio transceiver control circuitry) and software (splitting transceiver specific, lower level communication protocol from generic, higher level communication protocol). The control circuitry, including associated microprocessors devices, interact to selectively activate communication circuits to perform necessary communication or data processing functions and enter and remain in a power-saving dormant state during other times. To support such dormant or “sleeping” states, a series of communication protocols provide for channel access to the communication network.
43 Citations
20 Claims
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1. A portable data collection terminal comprising:
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a base module comprising a first processing unit and a first storage element that stores base module communication software;
a selected one of a plurality of communication modules, each communication module comprising a second processing unit, a second storage element that stores communication module software, and at least one of a plurality of radio transceivers, each of the plurality of radio transceivers having different operating characteristics; and
wherein the second processing unit, using the communication module software, isolates the first processing unit, which uses the base module communication software, from differences in the operating characteristics of the plurality of radio transceivers. - View Dependent Claims (2, 3)
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4. A portable data collection terminal comprising:
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a first processing unit capable of operating per a first set of communication software routines;
a selected one of a plurality of radio transceivers, each of the plurality having different operating characteristics; and
a second processing unit capable of isolating the first processing unit from differences in the operating characteristics of the plurality of radio transceivers. - View Dependent Claims (5, 6, 7, 8)
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9. In an RF communications network having a communication channel, an access point and a portable data collection terminal, wherein the portable data collection terminal having a transceiver which may be selectively powered up or down to conserve energy, a method used by the portable data collection terminal for gaining access to the communication network, comprising the steps:
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(a) powering up the transceiver;
(b) sensing the communication channel for a first predetermined time;
(c) if during the sensing of the communication channel the channel remained clear, transmitting to the access point; and
(d) if during the sensing of the communication channel the did not remain clear, waiting for a second predetermined time, and branching to step (b). - View Dependent Claims (10)
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11. In an RF communications network having a communication channel, an access point and a portable data collection terminal, wherein the portable data collection terminal having a transceiver which may be selectively powered up or down to conserve energy, a method used by the portable data collection terminal for gaining access to the communication network, comprising the steps:
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(a) powering up the transceiver;
(b) resetting a retry count;
(c) sensing the communication channel for a first predetermined time;
(c) if during the sensing of the communication channel the channel remained clear, transmitting to the access point, else, if the channel did not remain clear, incrementing a retry count; and
(e) if the retry count is less than a threshold value, branching to step (C), else, powering down the transmitter for a period of time before branching back to step (a).
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12. In a local area communications network having a communication channel, a host computer, an access point, and a portable data collection terminal, wherein the portable data collection terminal has the capability to enter a sleep mode when not transmitting or receiving, and the access point periodically transmit SYNC messages, a method used by the portable data collection terminal for gaining access to the communication network, comprising the steps:
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(a) waking up when data is available for transmission to the host computer;
(b) waiting for a first predetermined time in order to receive a SYNC message from the access point;
(c) sensing the communications channel for a second predetermined time to determine if the channel is busy;
(d) transmitting a request for poll to the access point if the channel is clear for the second predetermined time; and
(e) if the channel is busy during the second predetermined time, repeating step (b). - View Dependent Claims (13, 14)
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15. A method used by a sending device for beginning a data exchange over an RF communication link with a polling device, wherein the polling device has an interpoll gap time, comprising the steps of:
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(a) identifying that the RF communication link is clear throughout a period which is at least as long as the interpoll gap time; and
(b) transmitting a request for poll frame. - View Dependent Claims (16, 17)
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18. In a communication network having a first and second subnetwork, a portable data collection terminal comprising:
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a base processing unit capable of operating per a first set of communication software routines;
a first selected one of a plurality of radio transceivers, each having different operating characteristics;
a second selected one of a plurality of radio transceivers, each having different operating characteristics; and
a communication process capable of isolating the base processing unit from differences in the operating characteristics of the first and second radio transceiver - View Dependent Claims (19, 20)
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Specification