EP0054077A1 — Method of transmitting information between statio…

Claim 1

Independent Claim 156 words

Method of transmitting information between stations attached to a unidirectional transmission ring, access to the ring for sending addressed information being given to stations, without frame synchronization, by a circulating frame header and a token indication, characterized in that for allowing both non-periodic transmission of asynchronously furnished data packets as well as periodic transmission of synchronously furnished data blocks: - a particularly marked frame header for circuit-switched transmission is released as CS frame header by a CS monitor station in periodic intervals, - a CS frame header and a free token indication enable only previously authorized stations to send a block of synchronous data, ; - a non-marked frame header with a free token indication, ; enabling any station to transmit a packet of asynchronous data is released by the CS monitor station as PS frame header after all blocks of synchronous. data due to be sent within a periodic interval from authorized stations were transmitted.

Claim 2

Dependent Claim 156 words

Method of transmitting information between stations attached to a unidirectional transmission ring, access to the ring for sending addressed information being given to stations, without frame synchronization, by a circulating frame header and a token indication, characterized in that for allowing both non-periodic transmission of asynchronously furnished data packets as well as periodic transmission of synchronously furnished data blocks: - a particularly marked frame header for circuit-switched transmission is released as CS frame header by a CS monitor station in periodic intervals, - a CS frame header and a free token indication enable only previously authorized stations to send a block of synchronous data, ; - a non-marked frame header with a free token indication, ; enabling any station to transmit a packet of asynchronous data is released by the CS monitor station as PS frame header after all blocks of synchronous. data due to be sent within a periodic interval from authorized stations were transmitted.

Claim 3

Dependent Claim 114 words

Method in accordance with claim 1, characterized in that - each CS frame header is followed by a given number of uniform CS slots, each CS slot comprising a token indication, an address field, and a data block field, - the given number corresponds to the number.of currently authorized stations, - each authorized station seizes the first CS slot having a free token indication, converts it to non-token, and inserts the destination address and its data block into the respective fields, - the CS monitor station releases a PS frame header with a free token indication to the ring after it received and retransmitted the CS frame including the given number of CS slots.

Claim 4

Dependent Claim 126 words

Method in accordance with claim 1, characterized in that - in each frame header a particular CS priority indicator is provided; - the CS monitor station generates a CS interval time signal pulse in regular intervals, and sets the priority indicator in each first PS frame header that passes the station after a CS interval time signal pulse; - any station, when it had access to the ring and transmitted an asynchronous data packet, issues a new non-marked PS frame header with free token indication after receiving back a PS frame header in which the CS priority indicator was not set, but issues no new frame header and transmits only idling characters after receiving back a PS,frame header in which the CS priority indicator was set.

Claim 5

Dependent Claim 114 words

Method in accordance with claim 2, characterized in that - if a CS frame header is received back the first time by the CS monitor station before it transmitted an end delimiter for the same CS frame, the CS frame header and the contents of the following CS slots is buffered in the CS monitor station, - the frame header, followed by CS slots, are released from the buffer to the ring for a second round after first transmission of the frame's end delimiter; and - a new PS header with free token indication is released by the CS monitor unit when it transmitted the CS frame including an end delimiter a second time.

Claim 6

Dependent Claim 42 words

Method according to claim 1, characterized in that the CS interval time is an integer multiple of the period of the synchronous data to be transmitted, such that each CS data block contains a plurality of successive samples of the synchronous information.

Claim 7

Dependent Claim 118 words

Method according to claim 1, characterized in that - the CS monitor station keeps a first number N(max) representing the maximum allowed number of authorized stations, and keeps a second number N(aut) representing the number of currently authorized stations; - any station that wants to transmit synchronous data in,CS frames sends an authorization request to the CS monitor station; - the CS monitor station, for each received request, and if the second number is still less than the first number, sends an authorization grant message to the respective requesting station and updates the second number accordingly; and - authorized stations utilize the transmission capacity in the regularly issued CS frames without any involvement of the CS monitor station.

Claim 8

Dependent Claim 136 words

Method in accordance with claim 1, characterized in that - a free token indication is contained in each CS frame header released by the CS monitor station; - any authorized station that has a block of synchronous data to be transmitted and receives a CS frame header with a free token indication converts it to non-token, inserts a destination address in the CS frame header and transmits its data block followed by an end delimiter on the ring, and subsequently releases a new start delimiter and CS frame header with free token indication on the ring; and - the CS monitor station, upon receiving a CS frame header with a free token indication, replaces the CS frame header by a non-marked PS frame header and releases the latter with a free token indication on the ring.

Claim 9

Dependent Claim 120 words

Method according to claim 7, characterized in that for duplex communication of synchronous data blocks between two stations, - only the calling station is an authorized station, - the calling station inserts a CS data block together with the called station's address into a passing available CS frame; - a called station, upon detecting its address in a destination address field, copies the data block from, and inserts its own data block for transmission into, the information field of the respective CS frame without changing the associated destination address; and - a calling station, upon detecting the corresponding called station's address, in a CS frame destination address field, copies the data block from the information field of that CS frame.

Claim 10

Dependent Claim 132 words

Method according to claim 2, characterized in that - for duplex communication of synchronous data blocks between two stations, only the calling station is an authorized station; - the calling station inserts a CS data block together with the called station's address as destination address into an available CS slot in a passing CS frame; - a called station upon detecting its address in a destination address field in a passing CS slot, copies the data block from, and inserts its own data block for transmission into, the information field of the respective CS slot without changing the associated destination address; and - a calling station upon detecting the corresponding called station's address in a CS slot's destination address field, copies the data from the information field of the respective CS slot.

Claim 11

Dependent Claim 215 words

Method of exchanging asynchronous data packets as well as synchronous data blocks in frames between stations attached to a unidirectional transmission ring, which includes for each said station the steps of: - recognizing a circulating frame header, testing a first control bit (TK) in said header, and setting said first control bit to a first binary value (1) if the station has an asynchronous data packet to be transmitted, and - transmitting said data packet if said first control bit had a second binary value (0), and releasing a new frame header including a first control bit having said given first binary value; characterized by the following additional steps: - in each said station testing a second control bit (P1) in said frame header, and preventing issuance of a new frame header after transmission of said data packet if said second control bit had a first binary value (1); and - in a particular circuit-switch monitor station: - issuing a timing signal at periodic intervals, - setting said second control bit to said first binary value in the next frame header received after each said periodic timing signal, and - issuing a frame header in which a third control bit (CS) is set to a first binary value (1) after receiving a frame end delimiter.

Claim 12

Dependent Claim 215 words

Method of exchanging asynchronous data packets as well as synchronous data blocks in frames between stations attached to a unidirectional transmission ring, which includes for each said station the steps of: - recognizing a circulating frame header, testing a first control bit (TK) in said header, and setting said first control bit to a first binary value (1) if the station has an asynchronous data packet to be transmitted, and - transmitting said data packet if said first control bit had a second binary value (0), and releasing a new frame header including a first control bit having said given first binary value; characterized by the following additional steps: - in each said station testing a second control bit (P1) in said frame header, and preventing issuance of a new frame header after transmission of said data packet if said second control bit had a first binary value (1); and - in a particular circuit-switch monitor station: - issuing a timing signal at periodic intervals, - setting said second control bit to said first binary value in the next frame header received after each said periodic timing signal, and - issuing a frame header in which a third control bit (CS) is set to a first binary value (1) after receiving a frame end delimiter.

Claim 13

Dependent Claim 147 words

Method in accordance with claim 10, characterized by following steps in each said station: - testing said third control bit (CS) in each frame header, - preventing conversion of said first control bit (TK) and transmission of data if said station has only an asynchronous data packet to be transmitted and said third control bit (CS) had said first binary value (1), - setting said first control bit (TK) to said first binary value (1) if said station has a synchronous data block to be transmitted and said third control bit (CS) had said first binary value (1), and - transmitting said synchronous data block if said first control bit (TK) had said second binary value (0), and releasing a new frame header including a first control bit (TK) having said second binary value (0) and a third control bit (CS) having said first binary value (1).

Claim 14

Dependent Claim 68 words

Method in accordance with claim 11, characterized in that - said circuit-switch monitor station releases, after receipt of a frame header in which said second control bit (TK) had said second binary value (0) and said third control bit (CS) had said first binary value (1), a new frame header including a first, second and third control bit (TK, P1, CS) each having said second binary value (0).

Method of transmitting information between stations attached to a unidirectional transmission ring

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