US3921137A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semi static time division multiplex slot assignment
Assignee: International Business Machines Corp
•
Filing: 1974-06-25
•
Granted: 1975-11-18
•
Expires: 1994-06-25
Abstract
Abstract A plurality of time division multiplexed time slots circulate on a loop communication link, some of said time slots being permanently assigned to terminals connected to the loop and others being temporarily assigned to terminals such as on an every third or every fifth slot basis by an extra slot count command. One use of a write echo command allows even permanently assigned time slots to be temporarily utilized by a terminal having a very high data rate.
Inventors
- 👤 Jr Carl Meade Mcclearn
- 👤 Thomas Alva Edison Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:34
CPC Classifications
H; H04; H04L; H04L5/00; H04L5/22; H04L12/00; H04L12/28; H04L12/42; H04L12/423
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
147 words
A data transmission system comprising: a central controller; a plurality of remote terminals; means providing a loop signal path between said central controller and each of said remote terminals in a multiplexed sequence of time slots, at least one different time slot being associated with each of said remote terminals; control means at said central controller for transmitting a load slot count command and a slot count from said central controller to a remote terminal; command decode means at said remote terminal for storing said slot count in response to said load slot count command; comparator means at said remote terminal for comparing a number of slots counted by a slot counter with said stored slot count and actuating said terminal to transmit and receive in a slot whenever the slots counted is equal to said stored slot count; whereby said slot is associated with said terminal.
Claim 2
Dependent Claim
147 words
A data transmission system comprising: a central controller; a plurality of remote terminals; means providing a loop signal path between said central controller and each of said remote terminals in a multiplexed sequence of time slots, at least one different time slot being associated with each of said remote terminals; control means at said central controller for transmitting a load slot count command and a slot count from said central controller to a remote terminal; command decode means at said remote terminal for storing said slot count in response to said load slot count command; comparator means at said remote terminal for comparing a number of slots counted by a slot counter with said stored slot count and actuating said terminal to transmit and receive in a slot whenever the slots counted is equal to said stored slot count; whereby said slot is associated with said terminal.
Claim 3
Dependent Claim
24 words
A data transmission system of claim 1 wherein said slot counter restarts counting following each of said time slots associated with said remote terminal.
Claim 4
Dependent Claim
68 words
The data transmission systems of claim 1 wherein said control means at said central controller transmits a plurality of frames of time slots, the number of time slots in each frame being in excess of the number of remote stations connected to said means for providing a loop signal Path, each time slot further comprising a modifier bit position for identifying the following information bytes as a command.
Claim 5
Dependent Claim
23 words
The data transmission system of claim 3 wherein each of said command bytes includes a device type identifier field and a command field.
Claim 6
Dependent Claim
47 words
The data transmission system of claim 1 wherein said load slot count command is duplicated in a time slot and said remote terminal further comprising compartor means for comparing first and second commands in said time slot and actuating said command decode means upon a true comparison.
Claim 7
Dependent Claim
81 words
The data transmission system of claim 1 wherein said command decode means at a first remote terminal is responsive to a write echo command to a non-existant device type at said first terminal to allow following information bits in information slots assigned to said first remote terminal to be echoed without change on said loop signal path; whereby said extra slot register in a second remote terminal may control said second terminal to utilize information echoed by said first remote terminal.
Claim 8
Dependent Claim
131 words
A terminal for communication over a loop signal path with a central controller in a multiplexed sequence of time slots, at least one time slot being associated with said terminal, wherein the improvement comprises: extra slot storage means at said terminal for receiving a slot count from said central controller; command decode means at said terminal for storing a slot count in said extra slot storage means in response to a load slot count command received from said central controller; comparator means at said terminal for comparing a number of slots counted by a slot counter with said stored slot count and actuating said terminal to transmit and receive in a slot whenever the slots counted is equal to said stored slot count; whereby said slot is associated with said terminal.
Claim 9
Dependent Claim
131 words
A terminal for communication over a loop signal path with a central controller in a multiplexed sequence of time slots, at least one time slot being associated with said terminal, wherein the improvement comprises: extra slot storage means at said terminal for receiving a slot count from said central controller; command decode means at said terminal for storing a slot count in said extra slot storage means in response to a load slot count command received from said central controller; comparator means at said terminal for comparing a number of slots counted by a slot counter with said stored slot count and actuating said terminal to transmit and receive in a slot whenever the slots counted is equal to said stored slot count; whereby said slot is associated with said terminal.
Claim 10
Dependent Claim
21 words
The terminal of claim 7 wherein said slot counter restarts counting following each of said time slots associated with said terminal.
Claim 11
Dependent Claim
30 words
The terminal of claim 7 wherein said command decode means is responsive to a modifier bit position of a time slot for identifying the following information bytes as a command.
Claim 12
Dependent Claim
21 words
The terminal of claim 9 wherein each of said command bytes includes a device type identifier field and a command field.
Claim 13
Dependent Claim
45 words
The terminal of claim 7 wherein said load slot count command is duplicated in said associated time slot and said terminal further comprises comparing means for comparing first and second commands in said time slot and actuating said command decode means upon a true comparison.
Claim 14
Dependent Claim
70 words
The terminal of claim 7 wherein said command decode means is responsive to a write echo command to a non-existent device type at said terminal, to allow following information bits in information slots assigned to said terminal to be echoed without change on said loop signal path; whereby an extra slot storage means in a second terminal may control said second terminal to utilize information echoed by said first terminal.
References Cited (Backward Citations)
US3483329A
Cited
US3544976A
Cited
US3644678A
Cited
US3639904A
Cited
US3632881A
Cited
US3796835A
Cited
US3732374A
Cited
US3705267A
Cited
US3751597A
Cited
US3845472A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |