EP0790714A2
Expired / Lapsed
EP
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Handset signalling time slot assignment plan for satellite mobile communication
Assignee: The AT&T MVPD Group LLC
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Filing: 1997-02-06
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Granted: —
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Expires: 2017-02-06
Abstract
Abstract A mobile, satellite-based communication system (20) includes a defined signaling arrangement developed from an analysis of factors including movement of mobile terminals (28), movement of the satellite (22), beam discrepancies and duration of the call to the mobile terminal (28) to set up a frame assignment plan for time division multiple access (TDMA) carriers and identifying permissible frame offset which can be accommodated throughout the entire transmission. As a result, timing and frequency references from a mobile to mobile command may be provided from a reference source (24) along with receive and transmit data communications without losing the command signals or the communication information and providing highly efficient use of each carriers time slots for receiving/transmitting communication signals. Similarly, the signaling arrangement permits an efficient frame structure and a time slot assignment plan that does not require enhanced equipment at the mobile terminal (28). Moreover, the signaling frame assignment is applicable to multibeam satellite-based mobile communication systems for use with communications between mobile terminals (28) and gateways (24, 20) as well as between mobile terminals (28).
Inventors
- 👤 James D. Thompson
- 👤 Mohammad Soleimani
- 👤 Jeffrey E. Outwater
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 11:45
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/14; H04B7/15; H04B7/185; H04B7/1853; H04B7/18539; H04W; H04W72/00; H04W72/04; H04W72/044; H04W72/0446; H04W84/00; H04W84/02; H04W84/04; H04W84/06
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
207 words
A method for achieving high efficiency frame structures in a time division multiple access (TDMA) communication signal having a plurality of frames (38) for a satellite telecommunication system (20) with mobile terminals (28), comprising: including at least one terminal command (MMC) portion (48), a receive signal portion (50) and a transmit signal portion (52), in each frame (38); selecting a number of MMC portions (48) by determining a frame offset; determining a guard time portion (46); determining allowable communication slot (44) assignments as a function of frame offset for each possible MMC portion (48) location including generating a communication slot assignment table to receive signals and transmit signals; selecting the communication slot assignment that permits continuous use of an MMC slot throughout a predetermined degree of frame offset; selecting the minimum number and location of MMC portions (48) required for high frame efficiency; and generating a TDMA communication signal with said minimum number of terminal command (MMC) portions (48) on a first carrier (34), said at least one receive signal portion (50) and said at least one transmit signal portion (52) selected according to said communication slot assignment table transmitted on at least one second carrier (35) corresponding in number to the number of mobile terminals (28).
Claim 2
Dependent Claim
26 words
The method of claim 1, characterized in that said determining a frame offset comprises quantifying the position of a mobile terminal (28) in a beam (30).
Claim 3
Dependent Claim
40 words
The method of claim 2, characterized in that said quantifying step comprises determining the difference in transmission times from each of two mobile terminals (28) and multiplying it to define a time slot portion of frame offset for the signal.
Claim 4
Independent Claim
24 words
The method of any of claims 1 - 3, characterized in that said determining a frame offset comprises quantifying the beam center pointing error.
Claim 5
Independent Claim
23 words
The method of any of claims 1 - 4, characterized in that said determining a frame offset comprises quantifying the beam identification error.
Claim 6
Independent Claim
30 words
The method of any of claims 1 - 5, characterized in that said determining a frame offset comprises quantifying the mobile terminal position in a coverage area including multiple beams.
Claim 7
Independent Claim
29 words
The method of any of claims 1 - 6, characterized in that said determining a frame offset comprises quantifying an inclination offset change over a period of one day.
Claim 8
Independent Claim
27 words
The method of any of claims 1 - 7, characterized in that said determining a guard time (46) comprises guantifying the movement of the mobile terminal (28).
Claim 9
Dependent Claim
22 words
The method of claim 8, characterized in that said quantifying is determined as a selected velocity for a selected duration of time.
Claim 10
Independent Claim
23 words
The method of any of claims 1 - 9, characterized in that said determining a guard time (46) comprises quantifying a satellite movement.
Claim 11
Independent Claim
28 words
The method of any of claims 1 - 10, characterized in that said determining a guard time (46) comprises examining the retune time of a mobile terminal (28).
Claim 12
Independent Claim
31 words
The method of any of claims 1 - 11, characterized in that said determining a guard time (46) comprises examining the transmit to receive switching time of a mobile terminal (28).
Claim 13
Dependent Claim
131 words
A TDMA carrier frame design providing a frequency and timing reference for time division multiple access (TDMA) communication with mobile terminals (28) by a communication signal used in a satellite communication system (20), comprising: a terminal command (MMC) time portion (48) derived from a gateway timing reference source (24) and delivered on a first carrier (34) from said satellite (22); a guard time (46) at each edge of said MMC time portion (48); a receive time portion (50) on a second carrier (34) separated from adjacent time portions corresponding to said MMC time slot portion (48) by at least one guard time (46); and a transmit time portion (52) separated from adjacent receive time portions (50) and MMC portions (48) in a frame (38) by at least one guard time (46).
Claim 14
Dependent Claim
27 words
The design of claim 13, characterized in that said MMC time portion (48) is an updater for assisting frequency and timing synchronization at the mobile terminal (28).
Claim 15
Dependent Claim
21 words
The design of claim 13 or 14, characterized in that said satellite communication system (20) comprises a satellite in geostationary orbit.
Claim 16
Dependent Claim
21 words
The design of claim 13 or 14, characterized in that said satellite communication system (20) comprises a satellite in geosynchronous orbit.
Claim 17
Dependent Claim
139 words
A mobile terminal to mobile terminal communication system with a plurality of time division multiple access (TDMA) carriers (34, 35) in a geographic coverage area, comprising: a frame structure (38) including at least one control signal time (48), at least one transmit communication time (52) and at least one receive communication time (50), a plurality of terminals (28) having digital processing (DSP) capacity for switching between transmit and receive functions and tuning capability for multiple carriers (34) for each at least one transmit communication time (52), receive communication time (50) and control signal time (48), and a time slot assignment plan for spacing transmit communication slots, receive communication slots and control communication slots relative to each other to achieve 100% frame efficiency for a plurality of used terminals (28) located at at least one location in said coverage area.
Claim 18
Dependent Claim
38 words
The system of claim 17, characterized in that said system includes a plurality of beams (30) and said at least one position of said used terminals (28) comprises a plurality of positions in one of said beams (30).
Claim 19
Dependent Claim
22 words
The system of claim 18, characterized in that said at least one position comprises a plurality of positions in any beam (30).
Claim 20
Independent Claim
41 words
The system of any of claims 17 - 19, characterized in that said system includes a satellite (22) between said terminals (28), and said at least one position includes relative displacement between at least one terminal (28) and said satellite (22).
References Cited (Backward Citations)
No citation records indexed.
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