System and method for radio disconnect and channel access for digitized speech trunked radio systems
First Claim
1. A digital communications system including a plurality of portable/mobile transceivers, where a controller assigns an available one of a plurality of working communications channels to a transceiver requesting a working channel over a control channel, each transceiver comprising:
- an encoder for digitally encoding speech signals input to one of said transceivers;
a transmitter for transmitting digitally encoded speech signals;
a receiver for receiving digitized speech signals;
a decoder for decoding the received speech signals;
a data processor connected to the encoder, transmitter, decoder, and receiver for minimizing time delays occurring between a time when an operator of the transceiver ends a transmission over a current working channel and a time when the current working channel is disconnected.
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Accused Products
Abstract
In half-duplex, trunked digitized voice communications between mobile transceivers, the present invention minimizes time delays occurring after one transceiver ends a transmission and before other transceiver communications may commence. A disconnect signal is transmitted from the currently transmitting transceiver during a time frame immediately following indication that a current communication has ended. Channel access time delays are minimized by permitting speech input to a transmitting transceiver immediately upon receipt of a working communications channel. The present invention has particular applicability in trunked TDMA radio communication systems.
74 Citations
30 Claims
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1. A digital communications system including a plurality of portable/mobile transceivers, where a controller assigns an available one of a plurality of working communications channels to a transceiver requesting a working channel over a control channel, each transceiver comprising:
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an encoder for digitally encoding speech signals input to one of said transceivers; a transmitter for transmitting digitally encoded speech signals; a receiver for receiving digitized speech signals; a decoder for decoding the received speech signals;
a data processor connected to the encoder, transmitter, decoder, and receiver for minimizing time delays occurring between a time when an operator of the transceiver ends a transmission over a current working channel and a time when the current working channel is disconnected. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A digital communications system including a plurality of mobile transceivers, where a controller assigns an available one of a plurality of working communications channels to a transceiver requesting a working channel over a control channel, each transceiver comprising:
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means for digitally encoding and transmitting speech signals input to one of said transceivers; means for receiving and decoding transmitted digitized speech signals; means, connected to the means for digitally encoding and transmitting and to the means for receiving and decoding, for minimizing time delays occurring between a time when an operator of the transceiver ends a transmission over a current working channel and a time when the current working channel is disconnected, said means for encoding and transmitting capturing speech in consecutive speech frames; and means for processing and buffering speech captured in a current speech frame during the next speech frame such that said means for encoding and transmitting transmits the processed and buffered speech during a speech frame following said next speech frame.
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9. A digital communications system including a plurality of mobile transceivers, where a controller assigns an available one of a plurality of working communications channels to a transceiver requesting a working channel over a control channel, each transceiver comprising:
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means for digitally encoding and transmitting speech signals input to one of said transceivers; means for receiving and decoding transmitted digitized speech signals; and means, connected to the means for digitally encoding and transmitting and to the means for receiving and decoding, for minimizing time delays occurring between a time when an operator of the transceiver ends a transmission over a current working channel and a time when the current working channel is disconnected, wherein said means for minimizing includes; means for detecting the status of a transmission switch of said one transceiver; means for transmitting a disconnect signal from said one transceiver during a disconnect time frame after detecting change in the status of said transmission switch; and means for preventing processing and transmission of speech information received during said disconnect time frame.
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10. A half-duplex trunked digital communications system for providing communications between a plurality of mobile transceivers, each transceiver comprising:
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means for digitally encoding and transmitting speech signals input to one of said transceivers; means for receiving and decoding transmitted digitized speech signals; and means, connected to the means for digitally encoding and transmitting and to the means for receiving and decoding, for minimizing time delays occurring after one transceiver ends a transmission and before another transceiver communication may commence including; means for detecting the status of a transmission switch of said one transceiver; means for transmitting a disconnect signal from said one transceiver during a disconnect time frame after detecting change in the status of said transmission switch; and means for preventing processing and transmission of speech information received during said disconnect time frame; wherein said system is a time division multiple access (TDMA) communications system, each speech frame being divided into plural time slots such that said disconnect signal is transmitted during a first time slot in said disconnect time frame.
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11. A digital communications system including a plurality of mobile transceivers, where a controller assigns an available one of a plurality of working communications channels to a transceiver requesting a working channel over a control channel, each transceiver comprising:
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means for digitally encoding and transmitting speech signals input to one of said transceivers; means for receiving and decoding transmitted digitized speech signals; and means, connected to the means for digitally encoding and transmitting and to the means for receiving and decoding, for minimizing time delays occurring between a time when an operator of the transceiver ends a transmission over a current working channel and a time when the current working channel is disconnected; means for initiating an access to a communications channel; means for generating an alert signal immediately upon receiving a communication channel assignment; means for permitting transceiver speech input and for simultaneously performing channel set up tasks relating to speech transmission; and means for processing and buffering speech received during a speech frame following receipt of said communications channel assignment.
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12. A digital communications system including a plurality of mobile transceivers, where a controller assigns an available one of a plurality of working communications channels to a transceiver requesting a working channel over a control channel, each transceiver comprising:
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means for digitally encoding and transmitting speech signals input to one of said transceivers; means for receiving and decoding transmitted digitized speech signals; and means, connected to the means for digitally encoding and transmitting and to the means for receiving and decoding, for minimizing time delays occurring between a time when an operator of the transceiver ends a transmission over a current working channel and a time when the current working channel is disconnected; means for initiating an access to a communications channel; means for generating an alert signal immediately upon receiving a communication channel assignment; and means for permitting transceiver speech input and for simultaneously performing channel set up tasks relating to speech transmission, wherein said communications system is a time division multiple access system where speech is captured in consecutive speech frames and transceived during assigned time slots in speech frames subsequent to capture. - View Dependent Claims (13)
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14. A method for minimizing channel disconnect delays in a radio system including plural mobile transceivers for processing speech over an assigned one of a plurality of working channels captured in consecutive time frames, comprising the steps of:
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(a) detecting completion of a transceiver transmission over the assigned working channel in a first time frame; (b) transmitting a disconnect signal over the assigned working channel during a second following time frame; and (c) prohibiting transmission of speech over the assigned working channel captured in said first time frame. - View Dependent Claims (15, 16, 17, 18, 19)
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20. A method for minimizing channel disconnect delays in a half-duplex radio system including plural mobile transceivers for processing speech in consecutive time frames, comprising:
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(a) capturing speech in consecutive time frames; (b) processing and storing speech in time frames immediately following the time frame of capture; (c) detecting completion of a transceiver transmission in a first time frame, (d) transmitting a disconnect signal during a second following time frame, wherein time frames are divided into a series of time slots, each time slot providing a separate communications channel, and said disconnect signal is transmitted in said step (d) during a first available assigned time slot in said second time frame.
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21. A method for minimizing channel access delays in a radio system where each of plural mobile transceivers performs the steps comprising:
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(a) receiving a working channel assignment via a control channel during a first time frame on the assigned working channel; (b) generating an alert signal to a transceiver user and permitting receipt of speech input from said user; and (c) processing and transmitting speech received in consecutive time frames such that speech received during said first time frame is not transmitted over the assigned working channel unless there is time remaining in said first time frame to process speech received during said first time frame before a second, following time frame begins. - View Dependent Claims (22, 23, 24)
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25. A method for minimizing channel access delays in a half-duplex radio system including plural mobile transceivers for processing speech in consecutive time frames, comprising:
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receiving a working channel assignment via a control channel during a first time frame; generating an alert signal to a transceiver user and permitting receipt of speech input from said user; and processing and transmitting speech received in consecutive time frames such that speech received during said first time frame is not transmitted unless there is sufficient time to process speech received during the first time frame before a second following time frame begins; wherein simultaneous with the alert signal generating step, said method further comprises the steps of; initially performing transceiver speech processing functions, and thereafter performing functions relating to tasks other than speech processing.
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26. A method for minimizing channel access delays in a half-duplex radio system including plural mobile transceivers for processing speech in consecutive time frames, comprising:
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(a) receiving a working channel assignment via a control channel during a first time frame; (b) generating an alert signal to a transceiver user and permitting receipt of speech input from said user; and (c) processing and transmitting speech received in consecutive time frames whereby speech received during said first time frame is not transmitted unless there is sufficient processing time before a second following time frame; further comprising the steps of; (d) capturing speech received in a second time frame following said first frame; (e) processing and buffering second time frame speech in a third consecutive time frame; (f) transmitting speech processed and buffered in said third time frame in a fourth consecutive time frame.
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27. In a radio communications system, a method of controlling digital communications between radios where a controller assigns an available one of plural working radio channels to a radio requesting a working channel over a control channel, with the radio performing the steps of:
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(a) receiving information to be transmitted; (b) transmitting the received information over an assigned working channel; (c) detecting when an operator indicates completion of a communication; and (d) transmitting a disconnect signal before all of the received information is transmitted. - View Dependent Claims (28, 29, 30)
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Specification