US5355375A
Expired / Lapsed
US
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Hub controller for providing deterministic access to CSMA local area network
Assignee: Network Systems Corp
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Filing: 1993-03-18
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Granted: 1994-10-11
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Expires: 2013-03-18
Abstract
Abstract A method and apparatus for deterministic access to a carrier-sense-multiple-access (CSMA) or carrier-sense-multiple-access with collision detection (CSMA/CD) local area network (LAN) alters the basic indeterminate contention algorithm of the CSMA/CD protocol LAN within a hub controller. The hub controller includes media control logic that can selectively raise a pseudo carrier control signal to each port, thereby inhibiting any CSMA/CD protocol LAN transmissions by that port. In this way, the media control logic allows the hub controller to control which of the multiple ports will be allowed to contend for access to a common internal bus within the hub controller and for how long. A variety of different deterministic contention algorithms can be implemented by the hub controller, such as sequential polling, interrupt allocation, or a combination of deterministic contention algorithms with the normal CSMA/CD indeterminate contention algorithm.
Inventors
- 👤 Gary S. Christensen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:05
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/44; H04L12/40; H04L12/407; H04L12/413; H04L12/417
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
183 words
A hub controller for use with a carrier-sense-multiple access (CSMA) protocol local area network (LAN) having a plurality of user nodes each of which inhibit transmission of messages from the user node when the user node senses a carrier signal in accordance with the CSMA protocol, the hub controller comprising: a plurality of ports, each port connected to a common bus internal to the hub controller and to a user node external to the hub controller that generates and receives messages in accordance with the CSMA protocol, each port including: media a control logic means for selectively controlling whether a pseudo carrier control signal which simulates the carrier signal in accordance with the CSMA protocol is presented to the user node connected to that port; and control means operably connected to each of the media control logic means for determining which of the ports will present the pseudo carrier control signal, such that the hub controller can selectively generate the pseudo carrier control signal to each port and thereby inhibit the transmission of any messages from the user node connected to that port.
Claim 2
Dependent Claim
183 words
A hub controller for use with a carrier-sense-multiple access (CSMA) protocol local area network (LAN) having a plurality of user nodes each of which inhibit transmission of messages from the user node when the user node senses a carrier signal in accordance with the CSMA protocol, the hub controller comprising: a plurality of ports, each port connected to a common bus internal to the hub controller and to a user node external to the hub controller that generates and receives messages in accordance with the CSMA protocol, each port including: media a control logic means for selectively controlling whether a pseudo carrier control signal which simulates the carrier signal in accordance with the CSMA protocol is presented to the user node connected to that port; and control means operably connected to each of the media control logic means for determining which of the ports will present the pseudo carrier control signal, such that the hub controller can selectively generate the pseudo carrier control signal to each port and thereby inhibit the transmission of any messages from the user node connected to that port.
Claim 3
Dependent Claim
27 words
The hub controller of claim 1 wherein the control means is a microprocessor that implements a preselected deterministic contention algorithm for controlling access to the common bus.
Claim 4
Dependent Claim
20 words
The hub controller of claim 2 wherein the deterministic contention algorithm is a sequential polling of each of the ports.
Claim 5
Dependent Claim
31 words
The hub controller of claim 3 wherein a user node does not occupy a time slot on the internal bus when polled if the user node has no messages to transmit.
Claim 6
Dependent Claim
39 words
The hub controller of claim 2 wherein the deterministic contention algorithm is an interrupt allocation whereby the control means selectively generates the pseudo carrier control signal to ports in response to receiving requests for access to the common bus.
Claim 7
Dependent Claim
63 words
The hub controller of claim 2 wherein the deterministic contention algorithm assigns a predetermined portion of a transfer bandwidth of the common bus to a selected one or more of the ports on a polling basis and the remaining ports contend for access to the remaining portion of the transfer bandwidth by sensing for the carrier signal in accordance with the CSMA protocol.
Claim 8
Dependent Claim
27 words
The hub controller of claim 1 further comprising: a router means operably connected to the common bus for transmitting and receiving the messages to other hub controllers.
Claim 9
Dependent Claim
43 words
The hub controller of claim 1 further comprising: one or more additional internal common busses operably connected to each port; and selection means as part of each port for selectively determining which of the common busses will be used to transmit each message.
Claim 10
Dependent Claim
49 words
The hub controller of claim 1 wherein the media control logic means comprises an OR gate connecting a carrier signal on the internal bus and the pseudo carrier control signal front the control means to a carrier signal line on the port that is connected to the user node.
Claim 11
Dependent Claim
25 words
The hub controller of claim 1 wherein the CSMA protocol is the American National Standards Institute (ANSI)/Institute for Electrical and Electronics Engineering (IEEE) 802.3 protocol.
Claim 12
Independent Claim
203 words
A method for selectively controlling access to a hub controller that interconnects a plurality of user nodes operating on a carrier-sense-multiple-access (CSMA) protocol local area network (LAN) having a plurality of user nodes each of which inhibit transmission of messages from the user node when the user node senses a carrier signal in accordance with the CSMA protocol to a common internal bus within the hub controller, the hub controller including a computer processor, the method comprising the computer-implemented steps of: selectively inhibiting transmission of any messages in accordance with the CSMA protocol from selected user nodes according to a preselected deterministic contention algorithm by selectively generating a pseudo carrier control signal that simulates the carrier signal to each of the selected user nodes to prevent those user nodes from initiating transmission of any messages in accordance with the CSMA protocol; and selectively allowing transmission of messages in accordance with the CSMA protocol from selected user nodes according to the preselected deterministic contention algorithm by selectively not generating the pseudo carrier control signal to each of the selected user nodes, such that the computer processor implements the deterministic contention algorithm without any modifications to the CSMA protocol as implemented within the user nodes.
Claim 13
Independent Claim
203 words
A method for selectively controlling access to a hub controller that interconnects a plurality of user nodes operating on a carrier-sense-multiple-access (CSMA) protocol local area network (LAN) having a plurality of user nodes each of which inhibit transmission of messages from the user node when the user node senses a carrier signal in accordance with the CSMA protocol to a common internal bus within the hub controller, the hub controller including a computer processor, the method comprising the computer-implemented steps of: selectively inhibiting transmission of any messages in accordance with the CSMA protocol from selected user nodes according to a preselected deterministic contention algorithm by selectively generating a pseudo carrier control signal that simulates the carrier signal to each of the selected user nodes to prevent those user nodes from initiating transmission of any messages in accordance with the CSMA protocol; and selectively allowing transmission of messages in accordance with the CSMA protocol from selected user nodes according to the preselected deterministic contention algorithm by selectively not generating the pseudo carrier control signal to each of the selected user nodes, such that the computer processor implements the deterministic contention algorithm without any modifications to the CSMA protocol as implemented within the user nodes.
Claim 14
Dependent Claim
19 words
The method of claim 11 wherein the deterministic contention algorithm is a sequential polling of each of the ports.
Claim 15
Dependent Claim
30 words
The method of claim 12 wherein a user nodes does not occupy a time slot on the internal bus when polled if the user node has no signals to transmit.
Claim 16
Dependent Claim
42 words
The method of claim 11 wherein the deterministic contention algorithm is an interrupt allocation whereby the computer processor of the hub controller selectively generates the pseudo carrier control signal to ports in response to receiving requests for access to the common bus.
Claim 17
Dependent Claim
62 words
The method of claim 11 wherein the deterministic contention algorithm assigns a predetermined portion of a transfer bandwidth of the common bits to a selected one or more of the ports on a polling basis and the remaining ports contend for access to the remaining portion of the transfer bandwidth by sensing for the carrier signal in accordance with the CSMA protocol
Claim 18
Dependent Claim
46 words
The method of claim 11 wherein the carrier signal is selectively raised by O-Ring a carrier signal on the internal bus with the pseudo carrier control signal from the computer processor to generate a carrier signal on the port that is connected to the user node.
Claim 19
Dependent Claim
24 words
The method of claim 11 wherein the CSMA protocol is the American National Standards Institute (ANSI)/Institute for Electrical and Electronics Engineering (IEEE) 802.3 protocol.
References Cited (Backward Citations)
US4479228A
Cited
US4649548A
Cited
US4584575A
Cited
US4500990A
Cited
US4536838A
Cited
US4825435A
Cited
US4692919A
Cited
US4901348A
Cited
US4740956A
Cited
US4819229A
Cited
US4750171A
Cited
US4787082A
Cited
US4766402A
Cited
US4853950A
Cited
US4924461A
Cited
US5088032A
Cited
EP0344035A1
Cited
US5012467A
Cited
US5161192A
Cited
US5130983A
Cited
US5029164A
Cited
US5175732A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-10-10 | 1998-04-11 | 1998-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-10 | 2002-04-11 | 2002-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-10 | 2006-04-11 | 2006-10-11 | $7700.00 | Window Closed / Lapsed |