US4564838A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Data communication network and method of communication
Assignee: NCR Voyix Corp
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Filing: 1982-10-27
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Granted: 1986-01-14
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Expires: 2002-10-27
Abstract
Abstract A local area network has a plurality of data stations 1 each connected to a common data channel 2 via a receiver 5, a transmitter 6 and a directional coupler 7, wherein, in order to resolve contention for the channel and at the same time providing each station with statistically an equal chance of gaining use of the channel, each station contends for use of the channel by transmitting, when the channel is free, transmission request signals in a sequence of consecutive time periods wherein in each time period the station either transmits a request or does not transmit a request according to a predetermined code. If in any time period a data station 1 transmits a request but detects no transmitted request by other stations, the station is permitted use of the channel 2. If the station 1 does not transmit in any time period and another station transmits a request, then the station aborts contention.
Inventors
- 👤 Gerardus F. Boulogne
- 👤 Bernardus P. J. van Berkel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:01
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/40; H04L12/407; G; G06; G06F; G06F13/00; G06F13/14; G06F13/36; G06F13/368; G06F13/374
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
244 words
A data communication network comprising: a plurality of data stations; a common data channel connecting said data stations; each one of said data stations having a transmitter and a receiver, wherein each said data station includes channel contention means coupled to the associated said transmitter and receiver for initiating transmission request signals in a sequence of consecutive time periods in each of which a said data station either transmits or does not transmit a transmission request signal according to a predetermined code assigned to that said data station; said channel contention means further including contention resolving means for determining during said sequence whether another one of said data stations is transmitting a said transmission request signal while a first one of said data stations is not transmitting such a said transmission request signal; and said contention resolving means including means for aborting a contention for said common data channel by said first one of said data stations when said contention resolving means determines that any other one of said data stations is transmitting; said channel contention means for each said data station including means for generating transmission request signals according to said predetermined code which is cyclic and unique to the associated said data station, and also including means for commencing a succeeding channel contention at a point in the associated cycle of said predetermined code determined by the point in said cycle at which a previous contention for said common data channel ceased.
Claim 2
Dependent Claim
244 words
A data communication network comprising: a plurality of data stations; a common data channel connecting said data stations; each one of said data stations having a transmitter and a receiver, wherein each said data station includes channel contention means coupled to the associated said transmitter and receiver for initiating transmission request signals in a sequence of consecutive time periods in each of which a said data station either transmits or does not transmit a transmission request signal according to a predetermined code assigned to that said data station; said channel contention means further including contention resolving means for determining during said sequence whether another one of said data stations is transmitting a said transmission request signal while a first one of said data stations is not transmitting such a said transmission request signal; and said contention resolving means including means for aborting a contention for said common data channel by said first one of said data stations when said contention resolving means determines that any other one of said data stations is transmitting; said channel contention means for each said data station including means for generating transmission request signals according to said predetermined code which is cyclic and unique to the associated said data station, and also including means for commencing a succeeding channel contention at a point in the associated cycle of said predetermined code determined by the point in said cycle at which a previous contention for said common data channel ceased.
Claim 3
Dependent Claim
135 words
The network as claimed in claim 1, wherein at least one of said data stations, hereinafter referred to as a second data station, has a directional coupler connecting the associated said transmitter and receiver of said second data station to said common data channel to enable the associated said receiver to monitor said common data channel for transmission request signals transmitted by other said data stations at the same time as said transmitter of said second data station makes transmissions; and wherein said contention resolving means of said second data station includes means for determining in a said time period whether said second data station is the only one of said data stations to transmit a transmission request signal, in which case use of said common data channel by said second data station is permitted.
Claim 4
Dependent Claim
108 words
The network as claimed in claim 1, wherein said contention resolving means of at least one said data stations, hereinafter referred to as a second data station, includes means for determining over a predetermined time of channel contention whether a said transmission request signal from another said data station occurs in a said time period in which said second data station does not transmit a transmission request signal, said network being such that if such transmission by another said data station does occur, channel contention by said second data station is aborted, but that, if not, use of said data channel by said second data station is permitted.
Claim 5
Dependent Claim
83 words
The network as claimed in claim 1, wherein said channel contention means for each said data station includes means for detecting a period of silence in which no data transmissions take place on said data channel greater than a maximum period of silence occurring in any transmission request assigned to said data stations according to said predetermined code and for providing a silence signal in response thereto, said channel contention means being responsive to said silence signal to initiate a channel contention sequence.
Claim 6
Dependent Claim
53 words
The network as claimed in claim 1, wherein each said data station includes means for overriding said channel contention means of the associated said data station in response to a direct access signal from the associated said data station for directly enabling data transmission and data reception by the associated said data station.
Claim 7
Dependent Claim
105 words
The network as claimed in claim 1, in which each said transmission request signal comprises a pulse burst of predetermined duration, and in which the minimum bit length of a data transmission is greater than the length of said pulse burst, each said data station having means to prevent receipt of a simulated data transmission formed by overlapping transmission request signals received from more than one of said data stations, and also to enable receipt of a data transmission when a received pulse burst has a length less than a predetermined value which is not greater than the minimum bit length of a data transmission.
Claim 8
Independent Claim
228 words
A method of communicating in a data communication network on a common data channel between data stations, wherein one of said data stations wishing to transmit data, hereinafter referred to as a said first data station, performs the steps of: monitoring said common data channel, hereinafter called channel, to ascertain whether data transmissions from other said data stations are currently taking place on said channel; contending for use of the said channel by ascertaining that data transmissions on said channel have ceased; initiating transmission of transmission request signal during a sequence of consecutive time periods in each of which said first data station either transmits of does not transmit a transmission request signal on said channel according to a predetermined code assigned to said first data station; monitoring said channel during said sequence; and aborting contention for use of the channel if said first data station finds that another said data station is transmitting a transmission request signal while said first data station is not transmitting such a signal wherein said predetermined code is a cyclic code, and wherein, when a channel contention of said first data station ceases, said step of initiating transmission of transmission request signals is effected by said first data station by beginning the next succeeding channel contention at a position in the code determined by the position at which channel contention previously ceased.
Claim 9
Independent Claim
228 words
A method of communicating in a data communication network on a common data channel between data stations, wherein one of said data stations wishing to transmit data, hereinafter referred to as a said first data station, performs the steps of: monitoring said common data channel, hereinafter called channel, to ascertain whether data transmissions from other said data stations are currently taking place on said channel; contending for use of the said channel by ascertaining that data transmissions on said channel have ceased; initiating transmission of transmission request signal during a sequence of consecutive time periods in each of which said first data station either transmits of does not transmit a transmission request signal on said channel according to a predetermined code assigned to said first data station; monitoring said channel during said sequence; and aborting contention for use of the channel if said first data station finds that another said data station is transmitting a transmission request signal while said first data station is not transmitting such a signal wherein said predetermined code is a cyclic code, and wherein, when a channel contention of said first data station ceases, said step of initiating transmission of transmission request signals is effected by said first data station by beginning the next succeeding channel contention at a position in the code determined by the position at which channel contention previously ceased.
Claim 10
Dependent Claim
45 words
The method as claimed in claim 7, wherein a said transmission request signal is effected by maintaining a pulse burst of a predetermined duration and thereafter maintaining a period of silence equal to or greater than twice the longest propagation delay associated with said channel.
Claim 11
Dependent Claim
62 words
The method as claimed in claim 8, wherein each said data station initiates contention for use of said channel by following the cessation of data transmissions on said channel or by following a period of silence on said channel of a duration greater than the maximum period a silence occurring in any of the transmission request codes assigned to said data stations.
Claim 12
Dependent Claim
114 words
The method as claimed in claim 9 wherein at least one said data station, hereinafter called second data station, is able to detect transmission request signals from other said data stations at the same time as said second data station is transmitting a transmission request signal, and wherein said second data station contends for use of said channel by monitoring said channel in each said time period to determine whether said second data station itself is the only said data station transmitting, whereupon said second data station is permitted use of the channel, or whether another said data station is transmitting but said second data station itself is not transmitting, whereupon contention is aborted.
Claim 13
Dependent Claim
119 words
The method as claimed in claim 10 wherein at least one said data station, hereinafter called third data station, is unable to discriminate transmission request signals from other said data stations from transmission request signals transmitted by said third data station, and wherein said third data station contends for use of said channel by transmitting transmission request signals for a predetermined time; determining whether transmission request signals from other said data stations occur during any of the said time periods occurring in said predetermined time in which said third data station does not itself transmit a transmission request signal; and aborting contention when such transmission request signals from other said data stations occur, but otherwise using said data channel.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-01-13 | 1989-07-15 | 1990-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-01-13 | 1993-07-15 | 1994-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-01-13 | 1997-07-15 | 1998-01-14 | $7700.00 | Window Closed / Lapsed |