US3564147A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Local routing channel sharing system and method for communications via a satellite relay
Assignee: International Telecommunications Satellite Organization
•
Filing: 1968-04-05
•
Granted: 1971-02-16
•
Expires: 1988-04-05
Abstract
Abstract A demand assigned multiple access system provides for the sharing of satellite circuits by a large number of terrestrial users. Demand assignment of satellite circuits is especially useful and efficient to the developing nations as compared to preassignment of satellite circuits, since they have a low number of call minutes per day. Terrestrial transmissions are FDM multiplexed through the satellite on a single channel or carrier, and since no carriers are preassigned between specific terrestrial locations, any ground station may select any one of the carriers available in the entire system, provided that carrier is not presently in use. A common TDM channel is used at all terrestrial locations for maintaining a record of the carriers used and requested by all locations.
Inventors
- 👤 John G Puente
- 👤 Richard B Mcclure
- 👤 George D Dill
- 👤 Eugene R Cacciamani
- 👤 Andrew M Walker
- 👤 William G Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:30
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/14; H04B7/15; H04B7/185; H04B7/18528; H04B7/204; H04B7/2043; H04J; H04J4/00
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
140 words
A method of providing communication between stations through a relay via selected channels from a pool of FDM channels available on a demand assigned basis to all stations in a group of stations, comprising, at one station, the steps of: a. periodically transmitting bursts of FDM channel routing information via a TDM channel common to all stations in said pool, said routing information including information about FDM channels used by and requested by said one station, b. receiving via said TDM channel, bursts of channel routing information from all operating stations in said pool, c. storing the availability condition of said pool of channels and updating said storage in accordance with the information received via said TDM channel, and d. selecting an available FDM channel for transmission to and an available FDM channel for reception from a selected remote station.
Claim 2
Independent Claim
140 words
A method of providing communication between stations through a relay via selected channels from a pool of FDM channels available on a demand assigned basis to all stations in a group of stations, comprising, at one station, the steps of: a. periodically transmitting bursts of FDM channel routing information via a TDM channel common to all stations in said pool, said routing information including information about FDM channels used by and requested by said one station, b. receiving via said TDM channel, bursts of channel routing information from all operating stations in said pool, c. storing the availability condition of said pool of channels and updating said storage in accordance with the information received via said TDM channel, and d. selecting an available FDM channel for transmission to and an available FDM channel for reception from a selected remote station.
Claim 3
Dependent Claim
104 words
The method as claimed in claim 1 wherein the step of selecting an available FDM channel for transmission to said selected remote station comprises: a. sending a request for a channel presently stored as being available and an identification of said selected remote station as the addressee via said transmitted burst, b. receiving and detecting said last mentioned burst containing said request and addressee information, c. checking the availability of said requested channel at the time of detection of said request, and d. seizing said requested channel after said checking step if said requested channel is available at the time of said checking step.
Claim 4
Dependent Claim
56 words
The method as claimed in claim 2 wherein said step of selecting an available FDM channel for reception comprises: a. detecting information in a TDM burst from said selected remote station that confirms receipt of said request information and names a second available channel, and b. receiving and extracting information carried by said second available channel.
Claim 5
Dependent Claim
30 words
The method as claimed in claim 2 wherein said relay is a satellite relay and wherein the step of seizing said requested channel comprises, transmitting data via said requested channel.
Claim 6
Dependent Claim
27 words
The method as claimed in claim 4 wherein the step of selecting an available FDM channel for reception comprises detecting information received on said latter FDM channel.
Claim 7
Dependent Claim
79 words
The method as claimed in claim 1 wherein the step of selecting comprises: a. detecting in a TDM burst received from said selected remote station information of a request for a channel naming said one station as the addressee, b. checking the availability of said requested channel at the time of detection of said request, c. detecting information transmitted via said requested channel if available at the time of checking, and d. transmitting information via a different available channel.
Claim 8
Dependent Claim
80 words
The method as claimed in claim 5 further comprising the steps of: a. detecting in a TDM burst from an initiating remote station information of a request for a channel naming said one station as the addressee, b. checking the availability of said requested channel at the time of detection of said request, c. detecting information received via said latter mentioned requested FDM channel if available at the time of checking, and d. transmitting information via a different available channel.
Claim 9
Dependent Claim
36 words
The method as claimed in claim 7 further comprising the step of sending via said transmitted TDM burst information confirming the acceptance of said last mentioned request and naming said initiating remote station as the addressee.
Claim 10
Dependent Claim
59 words
The method as claimed in claim 8 wherein the step of transmitting information via an FDM channel comprises: a. generating a carrier frequency corresponding to said FDM channel, b. modulating said carrier frequency with said information to form a modulated carrier, and c. up-converting said modulated carrier frequency to a modulated frequency in a range detectable by said relay.
Claim 11
Dependent Claim
59 words
The method as claimed in claim 9 wherein the step of detecting information received via an FDM channel comprises: a. receiving modulated frequencies in the range relayed by said relay, b. down converting said latter frequencies into carrier frequencies corresponding to said FDM channels, and c. extracting the modulated information from the carrier frequency corresponding to said FDM channel.
Claim 12
Dependent Claim
67 words
The method as claimed in claim 10 wherein the step of extracting the modulated information from said carrier frequency comprises: a. generating a mixer frequency differing from said carrier frequency by a predetermined difference frequency, b. mixing said mixer frequency with the said down converted carrier frequencies to form mixer component frequencies, and c. demodulating the mixer component frequency that is equal to said predetermined frequency difference.
Claim 13
Dependent Claim
74 words
The method as claimed in claim 11 wherein the step of modulating a carrier frequency with information to form a modulated carrier comprises: a. generating a digital representation of said information forming a train of digital data, b. periodically inserting in said train of digital data a unique code word representing a sync word, and c. phase shift key (PSK) modulating said carrier frequency with said train of digital data including said sync word.
Claim 14
Dependent Claim
80 words
The method of claimed in claim 12 wherein the step of demodulating the mixer component frequency corresponding to said difference frequency comprises: a. phase shift key (PSK) demodulating said difference frequency to form demodulated digital data, b. detecting a unique code word corresponding to said sync word in said demodulated data, c. converting the information in said demodulated digital data back into its original form, and d. synchronizing the conversion in accordance with the time of detection of sync words.
Claim 15
Dependent Claim
66 words
The method as claimed in claim 1 wherein the step of transmitting bursts comprises: a. periodically generating channel routing information, b. detecting a received TDM burst from a master station, c. synchronizing the time of transmission of said transmitted burst in accordance with the time of detection of said master station TDM burst, and d. transmitting said periodically generated routing information via said transmitted TDM burst.
Claim 16
Dependent Claim
92 words
The method as claimed in claim 14 wherein the step of synchronizing the time of transmission comprises: a. generating, in response to the detection of said master station TDM burst, a signal occuring at a time representing the proper time of arrival of said one station''s own TDM burst, b. detecting the time of receipt of said one station''s own TDM burst, and c. varying the burst transmission time in accordance with the difference between the proper time of arrival and the actual time of arrival of said one station''s TDM burst.
Claim 17
Dependent Claim
66 words
The method as claimed in claim 13 wherein the step of transmitting bursts comprises: a. periodically generating channel routing information, b. detecting a received TDM burst from a master station, c. synchronizing the time of transmission of said transmitted burst in accordance with the time of detection of said master station TDM burst, and d. transmitting said periodically generated routing information via said transmitted TDM burst.
Claim 18
Dependent Claim
92 words
The method as claimed in claim 16 wherein the step of synchronizing the time of transmission comprises: a. generating, in response to the detection of said master station TDM burst, a signal occurring at a time representing the proper time of arrival of said one station''s own TDM burst, b. detecting the time of receipt of said one station''s own TDM burst, and c. varying the burst transmission time in accordance with the difference between the proper time of arrival and the actual time of arrival of said one station''s TDM burst.
References Cited (Backward Citations)
US3261922A
Cited
US3363180A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-15 | 1974-08-17 | 1975-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-15 | 1978-08-17 | 1979-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-15 | 1982-08-17 | 1983-02-16 | $7700.00 | Window Closed / Lapsed |