EP0584904A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A system and method for radio disconnect and channel access for digitised speech trunked radio systems
Assignee: Ericsson Inc
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Filing: 1993-05-18
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Granted: —
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Expires: 2013-05-18
Abstract
Abstract In half-duplex, trunked digitised voice communications between mobile transceivers, the present invention minimises 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 (#4) immediately following indication that a current communication has ended. Channel access time delays are minimised 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.
Inventors
- 👤 Ross W. Lampe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 13:52
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/14; H04B7/15; H04B7/204; H04B7/212; H04W; H04W84/00; H04W84/02; H04W84/04; H04W84/08; H04W4/00; H04W4/06; H04W4/10; H04W76/00; H04W76/40; H04W76/45
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
86 words
A half-duplex trunked digital communications system for providing communication between a plurality of transceivers, each transceiver comprising: means (10, 12) for transmitting and receiving speech signals; means (24) for encoding speech to speech signals and decoding speech signals to speech characterised by means (14, 28) for minimising time delays occurring after one transceiver ends a first transmission and before another transceiver commences a further transmission and for minimising time delays occurring after one transceiver is activated to commence a transmission and before the transmission can begin.
Claim 2
Dependent Claim
36 words
A system according to claim 1, in which said means for minimising includes: means for transmitting a disconnect signal from said one transceiver during a time frame immediately following indication that the first transmission has ended.
Claim 3
Dependent Claim
29 words
A system according to claim 1 or 2, in which said means for minimising includes: switch means operable by a user for indicating an end to said first transmission.
Claim 4
Independent Claim
71 words
A system according to any one of claims 1 to 3, in which said encoding and decoding means includes means (22) for capturing speech in consecutive speech frames, said system further comprising: means (24, 30) for processing and buffering speech captured in a first speech frame during the second subsequent speech frame such that said transmitting and receiving means transmits said processed and buffered speech during a third subsequent speech frame.
Claim 5
Dependent Claim
65 words
A system according to claim 4 when dependent on claim 3, in which said means for minimising includes: means for detecting the status of the switch means; means for generating a disconnect signal from said one transceiver during a disconnect time frame immediately after detecting change in said switch status; and means for preventing processing and transmission of speech captured during said disconnect time frame.
Claim 6
Independent Claim
54 words
A system according to any one of the preceding claims further comprising: means for initiating an access to a communications channel; means for generating an alert signal immediately upon receiving a communications channel assignment; and means for permitting transceiver speech input and for simultaneously performing channel set up tasks relating to speech signal transmission.
Claim 7
Dependent Claim
35 words
A system according to claim 6 when dependent on claim 4, in which said means for processing and buffering speech permits speech received during a speech frame immediately following receipt of said communications channel assignment.
Claim 8
Independent Claim
34 words
A system according to any one of the preceding claims, in which said system is a time division multiple access (TDMA) communications system, each speech frame being divided into a number of time slots.
Claim 9
Independent Claim
59 words
A method for minimising channel disconnect delays in a half-duplex radio system including plural mobile transceivers for processing speech in consecutive time frames, comprising: (a) detecting completion of a transceiver transmission in a first time frame; (b) transmitting a disconnect signal during a second subsequent time frame: and (c) prohibiting transmission of speech captured in said first time frame.
Claim 10
Dependent Claim
33 words
A method according to claim 9, further comprising before said step (a): capturing speech in consecutive time frames, and processing and storing speech in time frames immediately following the time frame of capture.
Claim 11
Dependent Claim
50 words
A method according to claim 9 or 10, in which 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 (b) during a first available assigned time slot in said second time frame.
Claim 12
Independent Claim
94 words
A method for minimising channel access delays in a half-duplex radio system including plural mobile transceivers for processing speech in consecutive time frames, comprising: (a) receiving a working channel assignment via a control channel during a first time frame; (b) immediately thereafter, 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 immediately following time frame.
Claim 13
Dependent Claim
26 words
A method according to claim 12, further comprising before step (a): depressing a transceiver transmit switch; and generating a channel access request over said control channel.
Claim 14
Dependent Claim
38 words
A method according to claim 12 or 13, in which said system is a time division multiple access system such that said working channel defines a particular frequency and one of plural time slots in a time frame.
References Cited (Backward Citations)
No citation records indexed.
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