Patent EP0228629A2 successfully refreshed from Google Patents.
EP0228629A2
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Time-division multiplexing communication system
Assignee: Hitachi Ltd
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Filing: 1986-12-10
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Granted: —
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Expires: 2006-12-10
Abstract
Abstract Disclosed is a communication system in which a plurality of terminal devices (2, 3) connected to a loop transmission line (1) perform data transmission/reception in a time-division multiplexing manner by using a communication frame (100) circulating the transmission line, the communication frame being constituted by a plurality of sub-frames (FO - F7), each of the sub-frames being constituted by a plurality of time slots (SO - S7), each of the terminal devices being arranged to perform data transmission/reception by using a designated time slot in a designated sub-frame. All the sub-frames in the communication frame are allotted to a terminal device of a high capability of data transmission, while only the limited number of sub-frames are allotted to a terminal device of a low capability of data transmission. A plurality of low speed terminal devices, to which sub-frames different from each other have been respectively allotted, commonly use the time slot of the same number, so that each of the time slots in the communication frame can be effectively utilized.
Inventors
- 👤 Yasuhiro Takahashi
- 👤 Kunio Hiyama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 21:37
CPC Classifications
H; H04; H04J; H04J3/00; H04J3/16; H04J3/1605; H04J3/1623; H04J3/1647; H04L; H04L12/00; H04L12/28; H04L12/42; H04L12/427; H04L12/43
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
262 words
A communication system in which a plurality of terminal devices (3, 4, 5, 6) connected respectively through node devices (2, 3) to a loop transmission line (1) perform data transmission/reception in a time-division multiplexing manner by using a communication frame (100) constituted by a plurality of sub-frames (FO - F7) and circulating said transmission line, each of said sub-frames being constituted by a plurality of time slots (SO - S7), wherein each of said node devices comprises: first means (18, 19) for storing a first parameter for specifying at least one of said plurality of sub-frames allotted to said node device concerned; second means (20) for storing a second parameter for specifying at least one of said plurality of time slots of one sub-frame allotted to said node device concerned; third means (12) for receiving said communication frame from said loop transmission line; fourth means (21, 22) for identifying one of the time slots corresponding to said second parameter in one of the sub-frames corresponding to said first parameter in said communication frame being received by said third means; fifth means (23, 25, 30, 31, 32) for extracting data of said time slot identified by said fourth means from said communication frame received by said third means and for transferring the extracted data to said terminal device connected to said node device concerned; and sixth means (28, 27, 24, 11) for inserting data received from said terminal device into said time slot identified by said fourth means in said communication frame and for sending said communication frame onto said loop transmission line.
Claim 2
Dependent Claim
262 words
A communication system in which a plurality of terminal devices (3, 4, 5, 6) connected respectively through node devices (2, 3) to a loop transmission line (1) perform data transmission/reception in a time-division multiplexing manner by using a communication frame (100) constituted by a plurality of sub-frames (FO - F7) and circulating said transmission line, each of said sub-frames being constituted by a plurality of time slots (SO - S7), wherein each of said node devices comprises: first means (18, 19) for storing a first parameter for specifying at least one of said plurality of sub-frames allotted to said node device concerned; second means (20) for storing a second parameter for specifying at least one of said plurality of time slots of one sub-frame allotted to said node device concerned; third means (12) for receiving said communication frame from said loop transmission line; fourth means (21, 22) for identifying one of the time slots corresponding to said second parameter in one of the sub-frames corresponding to said first parameter in said communication frame being received by said third means; fifth means (23, 25, 30, 31, 32) for extracting data of said time slot identified by said fourth means from said communication frame received by said third means and for transferring the extracted data to said terminal device connected to said node device concerned; and sixth means (28, 27, 24, 11) for inserting data received from said terminal device into said time slot identified by said fourth means in said communication frame and for sending said communication frame onto said loop transmission line.
Claim 3
Dependent Claim
153 words
A communication system according to Claim 1, in which said fourth means (21, 22) comprises: first counter means (15) for counting the number of sub-frames received by said third means, said first counter means being arranged to be preset to an initial value thereof every time said third means receives a head portion of each communication frame; second counter means (16) for counting the number of time-slots received by said third means, said second counter means being arranged to be reset to an initial value thereof every time said third means receives a head portion of each sub-frame; and means (21) for producing a time-slot identification signal when a count value of said first counter means (15) has a predetermined relation with said first parameter stored in said first means (18, 19) and a count value of said second counter means (16) coincides with said second parameter stored in said second means (20).
Claim 4
Dependent Claim
92 words
A communication system according to Claim 1, in which said sixth means comprises means (26) for adding information indicating validity of contents of a time slot to which reception data from said terminal device is inserted, to a predetermined bit position in said time slot; and said fifth means is arranged to transfer, to said terminal device, reception data extracted from a time slot extracted from said communication frame, when information indicating validity of contents of said extracted time slot is included at a predetermined bit position of said extracted time slot.
References Cited (Backward Citations)
No citation records indexed.
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