Patent US6401801B1 successfully refreshed from Google Patents.
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EP0303407A2
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Crosstalk reduction in unshielded twisted-pair lines
Assignee: HP Inc
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Filing: 1988-08-05
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Granted: —
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Expires: 2008-08-05
Abstract
Abstract A method of reducing crosstalk in unshielded twisted-pair (TP) lines interconnecting transceiver Hub and Pod elements of an IEEE 802.3 network is disclosed. Each element is connected by a four-wire full-duplex pair of unshielded TP wires which are prone to crosstalk noise induced by proximity to other TP wires. The crosstalk noise is reduced by (i) the collision protocol, and (ii) employing different drive levels in the Hub and the Pod. By having the Pod transmit at a higher voltage level then the Hub, the signal-to-crosstalk noise ratio at the Hub is optimized, allowing for highly reliable communications at up to 10 million bits per second. A collision protocol specified by the IEEE 802.3 standard further reduces crosstalk noise at the Hub.
Inventors
- 👤 Fred G. Huang
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 03:31
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/44; H04B; H04B3/00; H04B3/02; H04B3/32
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
89 words
A network including a first transceiver and one or more second transceivers, said first transceiver receiving from at least one of said second transceivers a sequence of signals and retransmitting said sequence to other said second transceivers, characterised in that the second transceivers are connected to said first transceiver by unshielded twisted-pair wires, and in that said second transceiver transmits said sequence at a predetermined second voltage level, said first transceiver retransmitting said sequence at a predetermined first voltage level having a predetermined relationship to said second voltage level.
Claim 2
Dependent Claim
89 words
A network including a first transceiver and one or more second transceivers, said first transceiver receiving from at least one of said second transceivers a sequence of signals and retransmitting said sequence to other said second transceivers, characterised in that the second transceivers are connected to said first transceiver by unshielded twisted-pair wires, and in that said second transceiver transmits said sequence at a predetermined second voltage level, said first transceiver retransmitting said sequence at a predetermined first voltage level having a predetermined relationship to said second voltage level.
Claim 3
Dependent Claim
61 words
A network according to claim 1 wherein said predetermined relationship between said first and second voltage levels is given by the formula: where P_TSECOND and P_TFIRST is the power transmitted by said second transceiver and said first transceiver, respectively, and where where C_CTMP and C_CTIP is the coefficient of multipair crosstalk coefficients at said first transceiver and said second transceiver, respectively.
Claim 4
Dependent Claim
18 words
A network according to claim 1 wherein said second predetermined voltage level exceeds said firt predetermined voltage level.
Claim 5
Dependent Claim
75 words
Method of reducing crosstalk in a network which comprises a first transceiver and one or more second transceivers, each connected to the first, and in which the first transceiver receives a sequence of signals from one second transceiver and retransmits the sequence to another second transceiver, characterised in that the second transceiver transmits at a second voltage level, and the first transceiver retransmits at a first voltage level having a predetermined relationship to the second.
Claim 6
Dependent Claim
75 words
Method of reducing crosstalk in a network which comprises a first transceiver and one or more second transceivers, each connected to the first, and in which the first transceiver receives a sequence of signals from one second transceiver and retransmits the sequence to another second transceiver, characterised in that the second transceiver transmits at a second voltage level, and the first transceiver retransmits at a first voltage level having a predetermined relationship to the second.
Claim 7
Dependent Claim
66 words
A crosstalk reducing method according to claim 4 wherein said first and second transceivers each employ a collision detection technique having a predetermined collision threshold, said method further including the step of ceasing said retransmission upon i) completion of said signals comprising said sequence, or ii) reception by said first transceiver of signals from at least two said second transceives whereby said collision threshold is exceeded.
References Cited (Backward Citations)
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