Patent US4413258A successfully refreshed from Google Patents.
US4413258A
Expired / Lapsed
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Interconnection for local area contention networks
Assignee: Unisys Corp
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Filing: 1981-12-14
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Granted: 1983-11-01
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Expires: 2001-12-14
Abstract
Abstract An interconnection circuitry for two local area contention networks which is adapted to jam the respective networks when stations on both sides of the interconnection circuitry attempt transmission. If stations on opposite sides of the interconnect circuitry begin transmitting at the same time, the interconnect circuitry operates to place a high signal on the channel of each network and all stations will detect that the data is garbled and discard it.
Inventors
- 👤 Roy F. Quick, Jr.
- 👤 John E. Spracklen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:33
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/46; H04L12/4604; H04L12/462; H04L12/4625
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
181 words
In a system of local area contention networks including a plurality of channels, each channel having a plurality of stations coupled thereto for transmission thereon, and an interconnection means for connecting said plurality of channels, each station being adapted to sense its corresponding channel for activity when it is ready to transmit, wait a random period of time and, then, begin transmission if there is still no activity on said channel, said interconnection means comprising: a pair of output drivers each coupled to one of said channels; a pair of input receivers each coupled to one of said channels; latch means to set the input receiver from one of said channels for transmission to the output driver for the other of said channels for transmission from said one channel to said other of said channels; and detection means to detect when transmission is received from the other of said channels while transmission is being received from said one of said channels and to cause each of said output drivers to place a jamming signal on the respective channels to block transmission.
Claim 2
Dependent Claim
181 words
In a system of local area contention networks including a plurality of channels, each channel having a plurality of stations coupled thereto for transmission thereon, and an interconnection means for connecting said plurality of channels, each station being adapted to sense its corresponding channel for activity when it is ready to transmit, wait a random period of time and, then, begin transmission if there is still no activity on said channel, said interconnection means comprising: a pair of output drivers each coupled to one of said channels; a pair of input receivers each coupled to one of said channels; latch means to set the input receiver from one of said channels for transmission to the output driver for the other of said channels for transmission from said one channel to said other of said channels; and detection means to detect when transmission is received from the other of said channels while transmission is being received from said one of said channels and to cause each of said output drivers to place a jamming signal on the respective channels to block transmission.
Claim 3
Dependent Claim
38 words
An interconnection means according to claim 1 wherein: said latch means is adapted to provide a time-out period when transmission has been received from one of said channels to allow the interconnection circuitry to reverse direction of transmission.
Claim 4
Dependent Claim
21 words
An interconnection means according to claim 2 wherein: said latch means includes two pairs of JK flip-flops to form gray-code counters.
Claim 5
Dependent Claim
62 words
An interconnection means according to claim 3 further including: a pair of transmission gates each coupled between the input receiver from one of said channels and the output driver to the other of said channels respectively, said transmission gates being coupled to said latch means to block reception of transmission from one channel when transmission is being received from said other channel.
Claim 6
Dependent Claim
146 words
In a system of local area contention networks including a plurality of channels, each channel having a plurality of stations coupled thereto for transmission thereon, and an interconnection means for connecting said plurality of channels, said interconnection means comprising: a pair of output drivers each coupled to one of said channels; a pair of input receivers each coupled to one of said channels; latch means to set the input receiver from one of said channels for transmission to the output driver for the other of said channels for transmission from said one channel to the said other of said channels; and detection means to detect when transmission is received from the other of said channels while transmission is being received from said one of said channels and to cause each of said output drivers to place a jamming signal on the respective channels to block transmission.
Claim 7
Dependent Claim
146 words
In a system of local area contention networks including a plurality of channels, each channel having a plurality of stations coupled thereto for transmission thereon, and an interconnection means for connecting said plurality of channels, said interconnection means comprising: a pair of output drivers each coupled to one of said channels; a pair of input receivers each coupled to one of said channels; latch means to set the input receiver from one of said channels for transmission to the output driver for the other of said channels for transmission from said one channel to the said other of said channels; and detection means to detect when transmission is received from the other of said channels while transmission is being received from said one of said channels and to cause each of said output drivers to place a jamming signal on the respective channels to block transmission.
Claim 8
Dependent Claim
38 words
An interconnection means according to claim 5 wherein: said latch means is adapted to provide a time-out period when transmission has been received from one of said channels to allow the interconnection circuitry to reverse direction of transmission.
Claim 9
Dependent Claim
21 words
An interconnection means according to claim 5 wherein: said latch means includes two pairs of JK flip-flops to form gray-code counters.
Claim 10
Dependent Claim
62 words
An interconnection means according to claim 7 further including: a pair of transmission gates each coupled between the input receiver from one of said channels and the output driver to the other of said channels respectively, said transmission gates being coupled to said latch means to block reception of transmission from one channel when transmission is being received from said other channel.
Claim 11
Dependent Claim
44 words
An interconnection means according to claim 8 further including: a pair of one-shot multivibrators, each coupled between said detection means and one of said output drivers to prevent said output driver from transmitting a new jam signal immediately after transmitting a previous jam signal.
Claim 12
Dependent Claim
45 words
An interconnection means according to claim 8 further including: a pair of optical isolators respectively coupled between the transmission gate from one channel and the output driver to the other channel to provide optical isolation between said channels which may operate at different voltage levels.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-31 | 1987-05-02 | 1987-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-31 | 1991-05-02 | 1991-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-31 | 1995-05-02 | 1995-11-01 | $7700.00 | Window Closed / Lapsed |