US4835731A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Processor-to-processor communications protocol for a public service trunking system
Assignee: MA Com Private Radio Systems Canada Corp
•
Filing: 1987-08-14
•
Granted: 1989-05-30
•
Expires: 2007-08-14
Abstract
Abstract A downlink between a communications dispatch console and a digitally trunked radio repeater system site controller efficiently transfers message data between the site controller and the console over a standard 9.2 kilobit per second landline. A downlink trunking card identical in structure to trunking cards used in the preferred embodiment system for RF channel signal processing interfaces the site controller with the landline link. A similar trunking card on the other side of the landline link interfaces the dispatch console processor with the landline link. Message protocol and format is translated between the site controller and the landline link and between the landline link and the dispatch console. Data buffering at each end of the landline link maximizes data transfer rate over the landline, and in addition, a priority scheme insures that more important messages are transmitted over the downlink before less important messages. Retransmit-until-acknowledged protocol is used to insure reliable message transfer--and also to permit receiving units along the downlink to slow down transmitting units in order to avoid message traffic blockage.
Inventors
- 👤 Dimitri M. Nazarenko
- 👤 Houston H. Hughes, III
- 👤 Robert T. Gordon
- 👤 David L. Hattey
- 👤 Bruno Yurman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:46
CPC Classifications
H; H04; H04W; H04W84/00; H04W84/02; H04W84/04; H04W84/08; H04L; H04L1/00; H04L1/12; H04L1/16; H04L1/1607; H04L1/1614; H04L1/18; H04L1/1867; H04L1/1887; H04W4/00; H04W4/06; H04W4/10; H04W76/00; H04W76/40; H04W76/45
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
103 words
In a digitally trunked radio frequency repeater system of the type including plural RF repeater transceivers communicating via radio frequency channels with mobile radio transceivers, said repeater transceivers being controlled by a site controller which communicates control information with a dispatch console over a downlink, a method of operating said system comprising: communicating digital control signals between said repeater RF transceivers and said mobile radio transceivers via said radio frequency channels using a synchronous serial communications protocol; and communicating digital control signals between said site controller and said dispatch console over a telephone line data link using said same synchronous serial communications protocol.
Claim 2
Dependent Claim
103 words
In a digitally trunked radio frequency repeater system of the type including plural RF repeater transceivers communicating via radio frequency channels with mobile radio transceivers, said repeater transceivers being controlled by a site controller which communicates control information with a dispatch console over a downlink, a method of operating said system comprising: communicating digital control signals between said repeater RF transceivers and said mobile radio transceivers via said radio frequency channels using a synchronous serial communications protocol; and communicating digital control signals between said site controller and said dispatch console over a telephone line data link using said same synchronous serial communications protocol.
Claim 3
Dependent Claim
103 words
In a digitally trunked radio frequency repeater system of the type including plural RF repeater transceivers communicating via radio frequency channels with mobile radio transceivers, said repeater transceivers being controlled by a site controller which communicates control information with a dispatch console over a downlink, an improvement comprising: means for communicating digital control signals between said repeater RF transceivers and said mobile radio transceivers via said radio frequency channels using a synchronous serial communications protocol; and means for communicating digital control signals between said site controller and said dispatch console over a telephone line data link using said same synchronous serial communications protocol.
Claim 4
Dependent Claim
103 words
In a digitally trunked radio frequency repeater system of the type including plural RF repeater transceivers communicating via radio frequency channels with mobile radio transceivers, said repeater transceivers being controlled by a site controller which communicates control information with a dispatch console over a downlink, an improvement comprising: means for communicating digital control signals between said repeater RF transceivers and said mobile radio transceivers via said radio frequency channels using a synchronous serial communications protocol; and means for communicating digital control signals between said site controller and said dispatch console over a telephone line data link using said same synchronous serial communications protocol.
Claim 5
Dependent Claim
143 words
In a digitally trunked radio frequency repeater system, a method of communicating digital control signals between an RF repeater site controller and a telephone switch over a digital signal downlink, said method including: (1) communicating distinct first and second site controller messages between said site controller and a downlink trunking card module over a high-speed data link connecting said site controller to said downlink trunking card module; (2) communicating distinct first and second console messages between said switch and a switch trunking card module over a further high-speed data link connecting said switch trunking card module to said switch; and (3) communicating single messages corresponding to said first and second console message and single messages corresponding to said first and second site controller messages between said downlink trunking card module and said switch trunking card module over a lower speed landline communications link.
Claim 6
Dependent Claim
143 words
In a digitally trunked radio frequency repeater system, a method of communicating digital control signals between an RF repeater site controller and a telephone switch over a digital signal downlink, said method including: (1) communicating distinct first and second site controller messages between said site controller and a downlink trunking card module over a high-speed data link connecting said site controller to said downlink trunking card module; (2) communicating distinct first and second console messages between said switch and a switch trunking card module over a further high-speed data link connecting said switch trunking card module to said switch; and (3) communicating single messages corresponding to said first and second console message and single messages corresponding to said first and second site controller messages between said downlink trunking card module and said switch trunking card module over a lower speed landline communications link.
Claim 7
Dependent Claim
261 words
A digitally trunked radio frequency repeater system of the type which communicates over radio frequency channels with mobile radio transceivers under the control of a dispatch console, said system comprising: plural RF repeater transceiver means for communicating via said radio frequency channels with said mobile radio transceivers, said plural repeater transceiver means each including an RF trunking card associated therewith; downlink means for communicating control signals between said dispatch console and a site controller means, said downlink means including a downlink trunking card; a switch trunking card associated with said dispatch console; site controller means connected to said plural RF trunking cards and to said downlink trunking card for controlling said trunking cards; first serial data link means connected between said site controller means and said downlink trunking card for communicating digital signals in a first protocol between said site controller means and said downlink trunking card; said downlink trunking card including means for translating said digital signals between said first protocol and a second protocol different from said first protocol; second serial data link means connected between said downlink trunking card and said switch trunking card for communicating said digital signals in said second protocol between said downlink trunking card and said switch trunking card; said switch trunking card including means for translating digital signals between said second protocol and a third protocol different from said second protocol; and third serial data link means connected between said switch trunking card and said dispatch console for communicating said third protocol digital signals between said switch trunking card and said dispatch console.
Claim 8
Dependent Claim
261 words
A digitally trunked radio frequency repeater system of the type which communicates over radio frequency channels with mobile radio transceivers under the control of a dispatch console, said system comprising: plural RF repeater transceiver means for communicating via said radio frequency channels with said mobile radio transceivers, said plural repeater transceiver means each including an RF trunking card associated therewith; downlink means for communicating control signals between said dispatch console and a site controller means, said downlink means including a downlink trunking card; a switch trunking card associated with said dispatch console; site controller means connected to said plural RF trunking cards and to said downlink trunking card for controlling said trunking cards; first serial data link means connected between said site controller means and said downlink trunking card for communicating digital signals in a first protocol between said site controller means and said downlink trunking card; said downlink trunking card including means for translating said digital signals between said first protocol and a second protocol different from said first protocol; second serial data link means connected between said downlink trunking card and said switch trunking card for communicating said digital signals in said second protocol between said downlink trunking card and said switch trunking card; said switch trunking card including means for translating digital signals between said second protocol and a third protocol different from said second protocol; and third serial data link means connected between said switch trunking card and said dispatch console for communicating said third protocol digital signals between said switch trunking card and said dispatch console.
Claim 9
Dependent Claim
100 words
A system as in claim 4 wherein at least one of said first, second and third serial data link means includes means for transmitting/receiving digital signals in the following protocol: a frame start character having a value of "AA" hex; a message identification byte which specifies an operational code and a number N of data bytes to follow said identification byte; a variable number N of message data bytes following said identification byte, said variable number being dependent on the value of said identification byte; and a further byte indicating the end of message and also specifying error checking/correction information.
Claim 10
Dependent Claim
44 words
A system as in claim 4 wherein: said plural repeater transceiver means each include means for communicating digitally encoded radio frequency signals with said mobile radio transceivers via said radio frequency channels using a synchronous serial communications protocol substantially identical to said second protocol.
Claim 11
Dependent Claim
93 words
A system as in claim 4 wherein: said first serial data link means includes means for communicating distinct first and second site controller messages to said downlink trunking card; said third serial data link means includes means for communicating distinct first and second console messages with said dispatch console; and said downlink trunking card and said switch trunking card include means for communicating single messages corresponding to said first and second console messages and single messages corresponding to said first and second site controller messages therebetween over said second serial data link means.
Claim 12
Dependent Claim
115 words
A system as in claim 4 wherein: said first serial data link means includes means for transmitting distinct first and second site controller messages from said site controller means to said downlink trunking card; said downlink trunking card includes means for packing said first and second messages into a single message; said second link means includes means for transmitting said single message to said switch trunking card; said switch trunking card includes means for unpacking said single message into distinct first and second console messages corresponding to said first and second site controller messages; and said third serial data link means includes means for transmitting said first and second console messages to said dispatch console.
Claim 13
Dependent Claim
120 words
A system as in claim 4 wherein: said third serial data link means includes means for transmitting distinct first and second console messages over said switch trunking card; said switch trunking card includes means for packing said first and second messages into a single message; and said second serial data link means includes means for transmitting said single message from said switch trunking card module to said downlink trunking card; said downlink trunking card includes means for unpacking said single message into distinct first and second site controller messages corresponding to said first and second console messages; and said first serial data link means includes means for transmitting said first and second site controller messages to said site controller means.
Claim 14
Dependent Claim
36 words
A system as in claim 4 wherein: said first serial data link means includes means for transmitting and receiving messages between said site controller means and said downlink trunking card module in a first format including:
Claim 15
Dependent Claim
4 words
(a1) start frame byte,
Claim 16
Dependent Claim
4 words
(a1) start frame byte,
Claim 17
Dependent Claim
4 words
(a2) operational code byte,
Claim 18
Dependent Claim
4 words
(a2) operational code byte,
Claim 19
Dependent Claim
9 words
(a3) a variable number N of data bytes, and
Claim 20
Dependent Claim
9 words
(a3) a variable number N of data bytes, and
Claim 21
Dependent Claim
30 words
(a4) a checksum byte; said downlink trunking card includes means for converting said messages transmitted over said first serial data link between said first format and the following second format:
Claim 22
Dependent Claim
30 words
(a4) a checksum byte; said downlink trunking card includes means for converting said messages transmitted over said first serial data link between said first format and the following second format:
Claim 23
Dependent Claim
4 words
(b1) Barker code bytes,
Claim 24
Dependent Claim
4 words
(b1) Barker code bytes,
Claim 25
Dependent Claim
5 words
(b2) said operational code byte,
Claim 26
Dependent Claim
5 words
(b2) said operational code byte,
Claim 27
Dependent Claim
5 words
(b3) a packet begin character,
Claim 28
Dependent Claim
5 words
(b3) a packet begin character,
Claim 29
Dependent Claim
9 words
(b4) said variable number N of data bytes, and
Claim 30
Dependent Claim
9 words
(b4) said variable number N of data bytes, and
Claim 31
Dependent Claim
12 words
(b5) at least one checksum byte different from said first-mentioned checksum byte;
Claim 32
Dependent Claim
12 words
(b5) at least one checksum byte different from said first-mentioned checksum byte;
Claim 33
Dependent Claim
45 words
said second serial data link means includes means for transmitting and receiving messages in said second format between said downlink trunking card and said switch trunking card; said switch trunking card includes means for converting messages between said second format and the following third format:
Claim 34
Dependent Claim
45 words
said second serial data link means includes means for transmitting and receiving messages in said second format between said downlink trunking card and said switch trunking card; said switch trunking card includes means for converting messages between said second format and the following third format:
Claim 35
Dependent Claim
10 words
(d1) a MID code corresponding to said operational code byte,
Claim 36
Dependent Claim
10 words
(d1) a MID code corresponding to said operational code byte,
Claim 37
Dependent Claim
12 words
(d2) a TLY byte specifying the number of data bytes to follow,
Claim 38
Dependent Claim
12 words
(d2) a TLY byte specifying the number of data bytes to follow,
Claim 39
Dependent Claim
13 words
(d3) source and destination bytes indicating the source and destination of said message,
Claim 40
Dependent Claim
13 words
(d3) source and destination bytes indicating the source and destination of said message,
Claim 41
Dependent Claim
9 words
(d4) said variable number N of data bytes, and
Claim 42
Dependent Claim
9 words
(d4) said variable number N of data bytes, and
Claim 43
Dependent Claim
31 words
(d5) a further checksum byte different from said first-mentioned and second-mentioned checksum bytes; and said third serial data link means includes means for transmitting and receiving messages in said third format.
Claim 44
Dependent Claim
31 words
(d5) a further checksum byte different from said first-mentioned and second-mentioned checksum bytes; and said third serial data link means includes means for transmitting and receiving messages in said third format.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-29 | 1992-11-28 | 1993-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-29 | 1996-11-28 | 1997-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-29 | 2000-11-28 | 2001-05-30 | $7700.00 | Window Closed / Lapsed |