Patent GB549680A successfully refreshed from Google Patents.
US3725787A
Expired / Lapsed
US
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Exigent multisatellite digital radio communications system
Assignee: International Business Machines Corp
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Filing: 1971-06-30
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Granted: 1973-04-03
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Expires: 1991-06-30
Abstract
Abstract The reliability and efficacy of traffic control in multiple station exigent radio communications is assured by a digital data communication system having accelerated polling and lockout of satellite or circumjacent subordinate station transmitting apparatus when the subordinate stations are contending for the attention of the central or base station and/or a circumjacent station is located in an area of unfavorable radio wave propagation. Duplex frequency operation with the central station continuously broadcasting messages and/or synchronizing characters, assures synchronization and resynchronization immediately on receipt of a single synchronizing character. Contention is evaluated in the central receiving apparatus by determining the level of optimum signal-to-noise ratio and measuring the r.m.s. value of distortion to establish reception parameters for controlling the mode of the radio net operation. A busy signal is then broadcast for locking out all transmission from the subordinate stations except for that one station accepted. Similarly an indication of field strength is obtained at subordinate station receiving apparatus by a threshold detector arranged to lock out the transmitting apparatus for propagation levels predetermined as unreliable and in a mobile situation to notify the operator to move the station to a better location for communication. Current flow in the second limiter stage of an FM receiver is suggested as a base measurement over a predetermined time period to prevent backlash. Confirmation, acknowledgment, and roll call are controlled by a polling character transmitted at the end of a message. Circuitry responsive to these characters is arranged for conducting an accelerated poll for effecting a single bit response from each circumjacent transmitter addressed specifically in a poll as listed in a predetermined time assignment. For the latter arrangement a shift register used for normal data processing is arranged to double as a counter for this purpose. Changeover delay is obviated by effecting transmission at a predetermined later bit time. Subordinate stations are addressed in general, in groups or as individual stations as best suits the purpose at the central station. Each character comprises identification bits and a control bit. Circuitry responsive to the latter bit is arranged to lock out the transmitter when the central receiving apparatus is busy. Overall capacity of the system is enhanced by interposing message buffer stores for each transmitting and each receiving apparatus.
Inventors
- 👤 J Featherston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:31
CPC Classifications
H; H04; H04L; H04L1/00; H04B; H04B1/00; H04B1/38; H04B1/40; H04B1/50
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
253 words
An exigent multiple circumjacent station synchronous digital radio communication system comprising, a central radio station having data handling circuitry for translating trains of digital data characters with all characters comprising a predetermined number of bits, a bit rate oscillating circuit coupled to said data handling circuitry for timing said digital data trains, transmitting apparatus coupled to said data handling circuitry and tuned for continuously radiating a digital data modulated radio wave at a given carrier frequency, and receiving apparatus coupled to said data handling circuitry and tunEd to receive a digital data modulated radio wave at a different carrier frequency, at least one subordinate radio station having receiving apparatus tuned to receive said digital data modulated radio wave of given carrier frequency, transmitting apparatus arranged for transmission of digital data modulated radio waves at said different carrier frequency, circuitry coupling said receiving apparatus to said transmitting apparatus for timing the digital data transmitted thereby, a shift register coupled to said receiving apparatus for translating said predetermined number of digital data bits at the bit rate of said oscillating circuit at said central station, a character counting circuit coupled to said receiving apparatus for counting said predetermined number and having reset and output terminals, a synchronizing character detecting circuit coupled to said shift register and having output terminals connected to said reset terminals of said counting circuit for resetting the same on said shift register containing said synchronizing character, and thereby maintaining said subordinate station in bit and character synchronization with said central station.
Claim 2
Dependent Claim
253 words
An exigent multiple circumjacent station synchronous digital radio communication system comprising, a central radio station having data handling circuitry for translating trains of digital data characters with all characters comprising a predetermined number of bits, a bit rate oscillating circuit coupled to said data handling circuitry for timing said digital data trains, transmitting apparatus coupled to said data handling circuitry and tuned for continuously radiating a digital data modulated radio wave at a given carrier frequency, and receiving apparatus coupled to said data handling circuitry and tunEd to receive a digital data modulated radio wave at a different carrier frequency, at least one subordinate radio station having receiving apparatus tuned to receive said digital data modulated radio wave of given carrier frequency, transmitting apparatus arranged for transmission of digital data modulated radio waves at said different carrier frequency, circuitry coupling said receiving apparatus to said transmitting apparatus for timing the digital data transmitted thereby, a shift register coupled to said receiving apparatus for translating said predetermined number of digital data bits at the bit rate of said oscillating circuit at said central station, a character counting circuit coupled to said receiving apparatus for counting said predetermined number and having reset and output terminals, a synchronizing character detecting circuit coupled to said shift register and having output terminals connected to said reset terminals of said counting circuit for resetting the same on said shift register containing said synchronizing character, and thereby maintaining said subordinate station in bit and character synchronization with said central station.
Claim 3
Dependent Claim
92 words
An exigent multiple circumjacent station synchronous digital radio communications system as defined in claim 1 and incorporating a further counting circuit having input terminals connected to said output terminals of said character counting circuit and having reset terminals, an operational character detecting circuit coupled to said shift register and having output terminals connected to said reset terminals of said further counting circuit for resetting the latter on said shift register containing said operational character, and thereby synchronizing said subordinate station in readiness for performing an operation, in accordance with said operational character.
Claim 4
Dependent Claim
94 words
An exigent multiple circumjacent station synchronous digital radio communications system as defined in claim 2 and wherein said further counting circuit has output terminals at each of at least a plurality of component stages, and incorporating a qualifying character detecting circuit having terminals connected to said output terminals of said further counting circuit and having output terminals, and circuitry connected to said output terminals of said qualifying character detecting circuit and interconnected with other of said apparatus for rendering the same operational only on said qualifying character being represented in said further counting circuit.
Claim 5
Dependent Claim
69 words
An exigent multiple circumjacent station synchronous digital radio communications system as defined in claim 3 and incorporating further circuitry interposed between said qualifying character detecting circuitry and said apparatus and having a connection to a predetermined stage of said further counting circuit for rendering said apparatus operational in response to detection of said qualifying character and responsive to the count in said further counting circuit reaching said predetermined stage.
Claim 6
Dependent Claim
47 words
An exigent multiple circumjacent station synchronous digital radio communications system as defined in claim 4 and incorporating a delay circuit arrangement coupled to said qualifying character detecting circuit and to said further counting circuit for delaying the response to said count by a predetermined number of counts.
Claim 7
Dependent Claim
40 words
An exigent multiple circumjacent station synchronous digital radiocommunications system as defined in claim 5 and wherein said delay circuit arrangement is connected to said further counting circuit at a stage later in said count by said predetermined number of counts.
Claim 8
Dependent Claim
47 words
An exigent multiple circumjacent station synchronous digital radio communications system as defined in claim 6 and incorporating response circuitry coupled to said transmitting apparatus and to said further circuitry and arranged for transmitting a burst of radio frequency energy in response to receipt of said qualifYing character.
Claim 9
Dependent Claim
39 words
An exigent multiple circumjacent station synchronous digital radio communications system as defined in claim 7 and incorporating gating circuitry interposed in said response circuitry and arranged for limiting said burst to a time duration within one of said counts.
Claim 10
Dependent Claim
51 words
An exigent multiple circumjacent station synchronous digital radio communications system as defined in claim 8 and incorporating propagation evaluating circuitry connected between said gating circuitry and said receiving apparatus and arranged for gating said burst in response to evaluation of radio wave energy between said central station and said subordinate station.
Claim 11
Dependent Claim
84 words
An exigent multiple circumjacent station synchronous digital radio communications system as defined in claim 1 and incorporating message controlling circuitry at said central station connected to said receiving apparatus and to said data handling circuitry for interposing prearranged data in said data train in response to reception of data by said receiving apparatus, and prearranged data recognition circuitry at said station connected to said receiving apparatus and to said transmitting apparatus and arranged for preventing transmission in response to reception of said prearranged data.
Claim 12
Dependent Claim
28 words
An exigent multiple circumjacent station synchronous digital radio communications system as defined in claim 10 and wherein said prearranged data recognition circuitry is connected to said shift register.
Claim 13
Dependent Claim
27 words
An exigent multiple circumjacent station synchronous digital radio communication system as defined in claim 1, and wherein said coupling circuitry comprises a digital data transition detecting circuit.
Claim 14
Dependent Claim
170 words
An exigent multiple circumjacent station synchronous radio communication system comprising, a central radio station having data handling circuitry, transmitting apparatus coupled to said data handling circuitry for continuously radiating a radio wave at a given carrier frequency and receiving apparatus tuned to receive a modulated radio wave at a different carrier frequency, and a plurality of subordinate radio stations each subordinate radio station having receiving apparatus tuned to receive said modulated radio wave of given carrier frequency, transmitting apparatus arranged for transmission of radio waves at said different carrier frequency, a detector coupled to the receiving apparatus of the subordinate station under consideration for measuring the quality of radio wave propagation between said central station and said subordinate station under consideration, an indicator coupled to said detector for indicating the quality to an observer, and circuitry connecting said detector to said transmitting apparatus for confining transmission thereby to conditions of favorable propagation only, thereby eliminating interference with subordinate station to central station communication by subordinate stations under unfavorable propagation conditions.
Claim 15
Dependent Claim
170 words
An exigent multiple circumjacent station synchronous radio communication system comprising, a central radio station having data handling circuitry, transmitting apparatus coupled to said data handling circuitry for continuously radiating a radio wave at a given carrier frequency and receiving apparatus tuned to receive a modulated radio wave at a different carrier frequency, and a plurality of subordinate radio stations each subordinate radio station having receiving apparatus tuned to receive said modulated radio wave of given carrier frequency, transmitting apparatus arranged for transmission of radio waves at said different carrier frequency, a detector coupled to the receiving apparatus of the subordinate station under consideration for measuring the quality of radio wave propagation between said central station and said subordinate station under consideration, an indicator coupled to said detector for indicating the quality to an observer, and circuitry connecting said detector to said transmitting apparatus for confining transmission thereby to conditions of favorable propagation only, thereby eliminating interference with subordinate station to central station communication by subordinate stations under unfavorable propagation conditions.
Claim 16
Dependent Claim
37 words
An exigent multiple circumjacent station synchronous radio communications system as defined in claim 13 and wherein said circuitry interconnecting said detector and said transmitting apparatus is arranged to lockout said transmitting apparatus under conditions of unfavorable propagation.
Claim 17
Dependent Claim
37 words
An exigent multiple circumjacent station synchronous radio communications system as defined in claim 13 and wherein said circuitry interconnecting said detector and said transmitting apparatus is arranged to enable said transmitting apparatus under conditions of good propagation.
Claim 18
Dependent Claim
24 words
An exigent multiple circumjacent station synchronous radio communications system as defined in claim 13 and wherein said detector is a level triggering reciproconductive circuit.
Claim 19
Dependent Claim
31 words
An exigent multiple circumjacent station synchronous radio communications system as defined in claim 13 and wherein said detector has a hysteresis characteristic thereby eliminating marginal operation under conditions of marginal propagation.
Claim 20
Dependent Claim
152 words
Circuitry for controlling the operation of a subordinate two-way communications radio station from a like central radio station having means for transmitting messages including a predetermined message start signal and a predetermined index character signal transmitted periodically when said central station is idle with respect to traffic therefrom, comprising demodulated data input terminals at the output of a radio receiver at a subordinate radio station, a data bit clocking circuit coupled to said input terminals, a shift register coupled to said input terminals and shifted by said bit clocking circuit for examining the demodulated data one character length at a time, start and identification character recognition circuitry coupled to said shift register for delivering character clocking and polling initiating pulses, character clocking and polling controlling circuitry responsive to data passing through said shift register, and station identification circuitry coupled to said polling central circuitry for effecting operation of said subordinate radio station.
Claim 21
Dependent Claim
152 words
Circuitry for controlling the operation of a subordinate two-way communications radio station from a like central radio station having means for transmitting messages including a predetermined message start signal and a predetermined index character signal transmitted periodically when said central station is idle with respect to traffic therefrom, comprising demodulated data input terminals at the output of a radio receiver at a subordinate radio station, a data bit clocking circuit coupled to said input terminals, a shift register coupled to said input terminals and shifted by said bit clocking circuit for examining the demodulated data one character length at a time, start and identification character recognition circuitry coupled to said shift register for delivering character clocking and polling initiating pulses, character clocking and polling controlling circuitry responsive to data passing through said shift register, and station identification circuitry coupled to said polling central circuitry for effecting operation of said subordinate radio station.
Claim 22
Dependent Claim
273 words
Circuitry for controlling the operation and response of a subordinate two-way communication radio station from a central two-way communication radio station having means for periodically transmitting messages having a message start signal and a predetermined index character when said central station is idle with respect to traffic transmitted therefrom, comprising, demodulated data input terminals at the output of the radio receiver at a subordinate station, a receiver bit clocking circuit having input terminals connected to said data input terminals and output terminals, a shift register having input terminals connected to said bit clocking circuit output terminals, data output terminals and stage output terminals, a character divider circuit having input terminals coupled to said bit clocking circuit ouput terminals, character clocking circuit output terminals and reset pulse input terminals, a further divider circuit having input terminals coupled to said character clocking output terminals, stage output terminals, and reset input terminals, a start character recognition circuit having stage input terminals coupled to said stage output terminals connected to said character divider reset terminals, and stage output terminals, an index character recognition circuit having stage input terminals individually coupled to said stage output terminals of said start character recognition circuit and output terminals coupled to said reset terminals of said further divider circuit, a subordinate station identification circuit individual to said subordinate station; and a comparing circuit having input terminals coupled to said further dividing circuit stages, input terminals coupled to said identification circuit and output terminals at which a signal is developed for effecting the operation of said subordinate radio station to said central radio station on recognition of the identification of said subordiante station.
Claim 23
Dependent Claim
273 words
Circuitry for controlling the operation and response of a subordinate two-way communication radio station from a central two-way communication radio station having means for periodically transmitting messages having a message start signal and a predetermined index character when said central station is idle with respect to traffic transmitted therefrom, comprising, demodulated data input terminals at the output of the radio receiver at a subordinate station, a receiver bit clocking circuit having input terminals connected to said data input terminals and output terminals, a shift register having input terminals connected to said bit clocking circuit output terminals, data output terminals and stage output terminals, a character divider circuit having input terminals coupled to said bit clocking circuit ouput terminals, character clocking circuit output terminals and reset pulse input terminals, a further divider circuit having input terminals coupled to said character clocking output terminals, stage output terminals, and reset input terminals, a start character recognition circuit having stage input terminals coupled to said stage output terminals connected to said character divider reset terminals, and stage output terminals, an index character recognition circuit having stage input terminals individually coupled to said stage output terminals of said start character recognition circuit and output terminals coupled to said reset terminals of said further divider circuit, a subordinate station identification circuit individual to said subordinate station; and a comparing circuit having input terminals coupled to said further dividing circuit stages, input terminals coupled to said identification circuit and output terminals at which a signal is developed for effecting the operation of said subordinate radio station to said central radio station on recognition of the identification of said subordiante station.
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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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |