Data link extension for data communication networks
First Claim
1. A communication network comprising:
- a communication medium,a plurality of using units interfaced to the medium for communicating thereacross; and
an interface arrangement coupling a using unit located any distance away from the medium to the medium for communications, the interface arrangement comprisingbuffering means located at the medium and having storage capacity for temporarily storing communications of the using unit for transmission on the medium,control means coupled between the buffering means and the medium for communicating stored communications on the medium on behalf of the using unit according to the communication protocol of the medium,transferring means coupled between the using unit and the buffering means for transmitting communications of the using unit to the buffering means for transmission on the medium, the transferring means responsive to receipt of a first signal for pausing transmission of the communications to the buffering means, andsignaling means responsive to the buffering means for sending the first signal to the transferring means when unfilled storage capacity of the buffering means decreases to a minimum at least adequate to store without overflowing communications receivable from the transferring means before the transferring means receive and respond to the first signal.
1 Assignment
0 Petitions
Accused Products
Abstract
In a data communication network (100) wherein using units (104-111) contend for access to the network communication bus (160), data links (101-103) interface using units located remotely from the bus to the bus for communication such that the distances between the using units and the bus are rendered functionally transparent from the viewpoint of the bus. A data link (102) includes a network interface circuit (117) connected to and located near the using unit (108) for buffering communications passing between the using unit and the bus, a data transfer controller circuit (151) connected to and located near the bus for communicating on the bus on behalf of the using unit according to the communication protocol of the bus, a local fiber optic extension circuit (141) connected to and located near the data transfer controller circuit for emulating thereto the network interface circuit, a remote fiber optic extension circuit (125) connected to and located near the network interface circuit for emulating thereto the data transfer controller circuit, and an optical fiber link (131) connecting the fiber optic extension circuits.
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Citations
33 Claims
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1. A communication network comprising:
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a communication medium, a plurality of using units interfaced to the medium for communicating thereacross; and an interface arrangement coupling a using unit located any distance away from the medium to the medium for communications, the interface arrangement comprising buffering means located at the medium and having storage capacity for temporarily storing communications of the using unit for transmission on the medium, control means coupled between the buffering means and the medium for communicating stored communications on the medium on behalf of the using unit according to the communication protocol of the medium, transferring means coupled between the using unit and the buffering means for transmitting communications of the using unit to the buffering means for transmission on the medium, the transferring means responsive to receipt of a first signal for pausing transmission of the communications to the buffering means, and signaling means responsive to the buffering means for sending the first signal to the transferring means when unfilled storage capacity of the buffering means decreases to a minimum at least adequate to store without overflowing communications receivable from the transferring means before the transferring means receive and respond to the first signal. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A communication network comprising:
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a communication medium; a plurality of using units interfaced to the medium for communicating thereacross; and an interface comprising a medium interface arrangement and a using unit interface arrangement together coupling a using unit located any distance away from the medium to the medium to interface the using unit to the medium for communicating thereacross, the using unit interface arrangement located at the using unit and connected to the using unit and to the medium interface arrangement for transmitting communications received from the using unit to the medium interface arrangement, the using unit interface arrangement responsive to receipt of a first signal from the medium interface arrangement for pausing transmission of the communications to the medium interface arrangement, and further responsive to receipt of a second signal for resuming paused transmission of the communications to the medium interface arrangement, the medium interface arrangement located at and connected to the medium for transmitting on the medium communications received from the using unit interface arrangement, the medium interface arrangement comprising buffering means having storage capacity for temporarily storing the communications received from the using unit interface arrangement, control means coupled between the buffering means and the medium for communicating stored communications on the medium on behalf of the using unit according to the communication protocol of the medium, signaling means responsive to the buffering means for sending the first signal to the using unit interface arrangement when unfilled storage capacity of the buffering means decreases to a minimum at least adequate to store without overflowing communications receivable from the using unit interface arrangement before the using unit interface arrangement receives and responds to the first signal and for sending the second signal to the using unit interface arrangement when the unfilled storage capacity increases to a minimum at least adequate to store without overflowing communications receivable from the using unit interface arrangement before the using unit interface arrangement receives and responds to a subsequently-sent first signal. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. A communication network comprising:
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(A) a communication medium; (B) a plurality of using units interfaced to the medium for communicating thereacross; and (C) an interface for coupling a using unit located any distance away from the medium to the medium for communicating thereacross, the interface including (1) means for conducting communications and signals, (2) a first transmitting unit located at the using unit and connected between the using unit and the conducting means for transmitting on the conducting means communications including communications received from the using unit, the first transmitting unit responsive to receipt on the conducting means of a first signal for pausing the transmission of the communications received from the using unit and transmitting on the conducting means a third signal indicating the pause, and further responsive to receipt on the conducting means of a second signal for resuming paused transmission of the communications received from the using unit and transmitting on the conducting means a fourth signal indicating the resumption, (3) a first receiving unit located at the using unit and connected between the using unit and the conducting means for transferring to the using unit communications received on the conducting means, the first receiving unit further connected to the first transmitting unit and responsive to receipt on the conducting means of the first or the second signal for transferring the received signal to the first transmitting unit, (4) a second receiving unit located at the medium and coupled to the conducting means for temporarily storing communications received on the conducting means from the first transmitting unit, the second receiving unit responsive to receipt on the conducting means of the third signal for ceasing to store received communications and further responsive to receipt on the conducting means of the fourth signal for resuming to store received communications, the second receiving unit comprising (i) buffering means coupled to the conducting means and having storage capacity for temporarily storing the received communications, (ii) means responsive to the buffering means for determining whether unfilled storage capacity of the buffering means has decreased or increased to a predetermined minimum level at least equal to an amount of communications transmittable by the first transmitting unit in twice signal travel time over the conducting means between the first transmitting unit and the second receiving unit, and generating the first or the second signal upon determination of decrease or increase, respectively, to the predetermined level, (5) a second transmitting unit located at the medium and coupled to the conducting means for transmitting on the conducting means to the first receiving unit communications received on the medium, the second transmitting unit further connected to the determining means of the second receiving unit and responsive to generation of the first or the second signal for transmitting the generated signal on the conducting means to the first receiving unit; (6) medium transmission control means located at the medium and coupled between the second receiving unit and the medium for transmitting communications stored in the buffering means on the medium in accordance with the communication protocol of the medium; and (7) medium reception control means located at the medium and coupled between the second transmitting unit and the medium for receiving on the medium communications for the using unit and transferring the received communications to the second transmitting unit. - View Dependent Claims (15)
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16. An interface arrangement for a communication network having a communication medium and a plurality of using units interfaced to the medium for communicating thereacross, for coupling a using unit located any distance away from the medium to the medium for communications, the interface arrangement comprising:
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buffering means for being located at the medium and having storage capacity for temporarily storing communications of the using unit for transmission on the medium; transferring means, coupled to the buffering means and for coupling to the using unit, for transmitting communications received from the using unit to the buffering means for transmission on the medium, the transferring means responsive to receipt of a first signal for pausing transmission of the communications to the buffering means; and signaling means responsive to the buffering means for sending the first signal to the transferring means when unfilled storage capacity of the buffering means decreases to a minimum at least adequate to store without overflowing communications receivable from the transferring means before the transferring means receive and respond to the first signal. - View Dependent Claims (17, 18, 19, 20, 21, 22)
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23. An interface arrangement for a communication network having a communication medium and a plurality of using units interfaced to the medium for communicating thereacross, for coupling a using unit located any distance away from the medium to the medium for communicating thereacross, the interface arrangement comprising:
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a medium interface portion and a using unit interface portion, the using unit interface portion for being locate at the using unit and being connected to the using unit and to the medium interface portion for transmitting communications received from the using unit to the medium interface portion, the using unit interface portion responsive to receipt of a first signal from the medium interface portion for pausing transmission of the communications to the medium interface portion, and further responsive to receipt of a second signal for resuming paused transmission of the communications to the medium interface portion, the medium interface portion for being located at and connected to the medium for transmitting to the medium communications received from the using unit interface portion, the medium interface portion comprising buffering means having storage capacity for temporarily storing the communications received from the using unit interface portion, and signaling means responsive to the buffering means for sending the first signal to the using unit interface portion when unfilled storage capacity of the buffering means decreases to a minimum at least adequate to store without overflowing communications receivable from the using unit interface portion before the using unit interface portion receives and responds to the first signal and for sending the second signal to the using unit interface portion when the unfilled storage capacity increases to a minimum at least adequate to store without overflowing communications receivable from the using unit interface portion before the using unit interface portion receives and responds to a subsequently-sent first signal. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30)
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31. An interface arrangement for a communication network having a communication medium and a plurality of using units interfaced to the medium for communicating thereacross, for coupling a using unit located any distance away from the medium to the medium for communicating thereacross, the interface arrangement comprising:
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means for conducting communications and signals; a first transmitting unit, for being located at the using unit and being connected between the using unit and the conducting means, for transmitting on the conducting means communications including communications received from the using unit, the first transmitting unit responsive to receipt on the conducting means of a first signal for pausing the transmission of the communications received from the using unit and transmitting on the conducting means a third signal indicating the pause, and further responsive to receipt on the conducting means of a second signal for resuming paused transmission of the communications received from the using unit and transmitting on the conducting means a fourth signal indicating the resumption; a first receiving unit, for being located at the using unit and being connected between the using unit and the conducting means, for transferring to the using unit communications received on the conducting means, the first receiving unit further connected to the first transmitting unit and responsive to receipt on the conducting means of the first or the second signal for transferring the received signal to the first transmitting unit; a second receiving unit, for being located at the medium and coupled to the conducting means, for temporarily storing communications received on the conducting means from the first transmitting unit, the second receiving unit responsive to receipt on the conducting means of the third signal for ceasing to store received communications and further responsive to receipt on the conducting means of the fourth signal for resuming to store received communications, the second receiving unit comprising buffering means coupled to the conducting means and having storage capacity for temporarily storing the received communications, and means responsive to the buffering means for determining whether unfilled storage capacity of the buffering means has decreased or increased to a predetermined minimum level at least equal to an amount of communications transmittable by the first transmitting unit in twice signal travel time over the conducting means between the first transmitting unit and the second receiving unit, and generating the first or the second signal upon determination of decrease or increase, respectively, to the predetermined level; and a second transmitting unit, for being located at the medium and coupled to the conducting means, for transmitting on the conducting means to the first receiving unit communications received from the medium, the second transmitting unit further connected to the determining means of the second receiving unit and responsive to generation of the first or the second signal for transmitting the generated signal on the conducting means to the first receiving unit. - View Dependent Claims (32, 33)
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Specification