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公开(公告)号：GB2335828B
公开(公告)日：2003-08-20
申请号：GB9804639
申请日：1998-03-04
Applicant: INTERNAT MOBILE SATELLITE ORGA , INMARSAT TWO COMPANY , INMARSAT LTD
Inventor： CHRISTODOULIDES LOUIS MIMIS , FELDMAN HOWARD RAY , TRACHMAN EYAL , WONG SIU WAH , WONG HOK SHUEN
Abstract: A set of formats and protocols is proposed for a satellite communications system. In these formats, a pilot signal (PS) is inserted after every 25 or 29 data symbols. The formats consist of SCPC frames (F) which may contain either data (D) and in-band signalling information (SU), or only signalling information (SU). In either case, the contents of each frame (F) are error-correction coded before transmission with the same coding rate. Each data frame (F) carries the data content of an integral number of input user data frames (M), each of which comprises four subframes. Different symbol transmission rates are used for different input data rates, the symbol transmission rates being selected so that their different synchronising clock rates can easily be obtained from a common clock. Data bursts may be preceded by a constant power level preamble (P). The formats and protocols satisfy the requirements of a high data rate satellite communications system.
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公开(公告)号：GB2315951B
公开(公告)日：2001-01-31
申请号：GB9616041
申请日：1996-07-31
Applicant: INTERNAT MOBILE SATELLITE ORGA , INMARSAT TWO COMPANY , INMARSAT LTD
Inventor： MCHUGH THOMAS FRANCIS HAROLD , FELDMAN HOWARD RAY
Abstract: A data interface apparatus (10) provides an interface between an analog communications link (a2) and a digital communications link (d2). Analog dialling codes on the analog communications link (a2) are converted to control codes for controlling a digital communications interface (12) attached to the digital communications link (a2) for providing access to a digital communications network (16, 18, 20).Access to the digital communications link (a2) is selectively enabled by the data interface apparatus (10) in response to a password encoded as an analog dialling sequence on the analog communications link (a2)The data interface apparatus (10) delays call set-up with a modem (6) connected to the analog communications link (a1,a2) so as to synchronize completion of call set-up with another call set-up procedure performed on a remote analog link (a3,a4) connected to the digital communications network (16, 18, 20).
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公开(公告)号：DE69606038T2
公开(公告)日：2001-01-25
申请号：DE69606038
申请日：1996-06-14
Applicant: INMARSAT LTD
Inventor： OBRADORS JOAN , FELDMAN HOWARD RAY , REMAEL FRANCOIS-ARNAUD
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公开(公告)号：GB2337663B
公开(公告)日：2000-02-16
申请号：GB9920083
申请日：1995-03-31
Applicant: INMARSAT LTD
IPC: H04B7/15 , H04B7/185 , H04L29/08 , H04L1/18 , H04L12/54 , H04L12/861 , H04L29/06 , H04M11/00 , H04M11/06 , H04L12/56 , H04Q11/04
Abstract: An interface (4;12) between a data terminal (2;18) and a digital communications link (6,8,10) implements protocols and frame formats designed to reduce delays in a data communication with a remote terminal (18;2). The interface (4;12) overcomes the need to send or receive an HDLC SABME or UA control signal, and allows data to be sent over the digital communications link (6,8,10) as soon as the communication parameters are established. In a non-ARQ (error correction) mode, the interface (4;12) sends control signals and data over the communications link (6,8,10) in frames subdivided into many small subframes of fixed length, each subframe having a length code. The interface (12), when arranged for connection to the data terminal (18) through a telephone network (14), encodes call progress signals from the telephone network (14) for sending over the digital communications link (6,8,10). The interface (4;12) encodes and decodes interrupt signals for sending between the data terminal (2;18) and the digital communications link (6,8,10) when an interrupt signal is detected.
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公开(公告)号：GB2337665A
公开(公告)日：1999-11-24
申请号：GB9920087
申请日：1995-03-31
Applicant: INMARSAT LTD
IPC: H04B7/15 , H04L29/08 , H04B7/185 , H04L1/18 , H04L12/54 , H04L12/861 , H04L29/06 , H04M11/00 , H04M11/06 , H04L29/10
Abstract: A data buffer interface between a data terminal and a digital radio frequency communications comprising a buffer for storing data for transmission from the data terminal to the digital communications link wherein an interrupt from the terminal causes clearance of the buffer and an interrupt to be sent to the link.
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Patent Agency Ranking
公开(公告)号：GB2300540B
公开(公告)日：1999-10-20
申请号：GB9506759
申请日：1995-03-31
Applicant: INT MOBILE SATELLITE ORG , INMARSAT TWO COMPANY , INMARSAT LTD
IPC: H04B7/15 , H04B7/185 , H04L29/08 , H04L1/18 , H04L12/54 , H04L12/861 , H04L29/06 , H04M11/00 , H04M11/06 , H04L29/10 , H04L12/46
Abstract: An interface (4;12) between a data terminal (2;18) and a digital communications link (6,8,10) implements protocols and frame formats designed to reduce delays in a data communication with a remote terminal (18;2). The interface (4;12) overcomes the need to send or receive an HDLC SABME or UA control signal, and allows data to be sent over the digital communications link (6,8,10) as soon as the communication parameters are established. In a non-ARQ (error correction) mode, the interface (4;12) sends control signals and data over the communications link (6,8,10) in frames subdivided into many small subframes of fixed length, each subframe having a length code. The interface (12), when arranged for connection to the data terminal (18) through a telephone network (14), encodes call progress signals from the telephone network (14) for sending over the digital communications link (6,8,10). The interface (4;12) encodes and decodes interrupt signals for sending between the data terminal (2;18) and the digital communications link (6,8,10) when an interrupt signal is detected.
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公开(公告)号：GB2336508B
公开(公告)日：2003-05-28
申请号：GB9904575
申请日：1999-02-26
Applicant: INTERNAT MOBILE SATELLITE ORGA , INMARSAT TWO COMPANY , INMARSAT LTD
Inventor： FELDMAN HOWARD RAY , WONG SIU WAH
Abstract: In a radio communications system in which data is transmitted on a modulated radio frequency carrier, the carrier is switched off when no data is available for transmission. If repeated signalling information is required to be transmitted, only a predetermined number of repeats are transmitted before the carrier is switched off. In one embodiment a bit sequence at the end of a first data block is compared with multiple sequences from a second block and if all sequences are equal, transmission of the second block is inhibited. In another embodiment data input for transmission is compared with a predetermined bit sequence. If a match is found for any relative bit alignment, this indicates an idle state (absence of user data) and the carrier is switched off. When more user data is received the carrier is switched on and frames are transmitted in synchronisation with the timing of frames transmitted before carrier deactivation. After carrier reactivation a constant power preamble may be transmitted to assist in level control in the transmitter. In a satellite SCPC system satellite power efficiency is improved and mobile earth station battery power is saved.
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公开(公告)号：GB2350519A
公开(公告)日：2000-11-29
申请号：GB0020720
申请日：1996-07-31
Applicant: INMARSAT LTD
Inventor： MCHUGH THOMAS FRANCIS HAROLD , FELDMAN HOWARD RAY
Abstract: A data interface apparatus (10) provides an interface between an analog communications link (a 2 ) and a digital communications link (d 2 ). Analog dialling codes on the analog communications link (a 2 ) are converted to control codes for controlling a digital communications interface (12) attached to the digital communications link (a 2 ) for providing access to a digital communications network (16, 18, 20). The data interface apparatus (10) delays call set-up with a modem (6) connected to the analog communications link (a 1 ,a 2 ) so as to synchronize completion of call set-up with another call set-up procedure performed on a remote analog link (a 3 ,a 4 ) connected to the digital communications network (16, 18, 20).
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公开(公告)号：GB2336508A8
公开(公告)日：1999-12-07
申请号：GB9904575
申请日：1999-02-26
Applicant: INMARSAT LTD
Inventor： FELDMAN HOWARD RAY , WONG SIU WAH
Abstract: In a radio communications system in which data is transmitted on a modulated radio frequency carrier, the carrier is switched off when no data is available for transmission. If repeated signalling information is required to be transmitted, only a predetermined number of repeats are transmitted before the carrier is switched off. In one embodiment a bit sequence at the end of a first data block is compared with multiple sequences from a second block and if all sequences are equal, transmission of the second block is inhibited. In another embodiment data input for transmission is compared with a predetermined bit sequence. If a match is found for any relative bit alignment, this indicates an idle state (absence of user data) and the carrier is switched off. When more user data is received the carrier is switched on and frames are transmitted in synchronisation with the timing of frames transmitted before carrier deactivation. After carrier reactivation a constant power preamble may be transmitted to assist in level control in the transmitter. In a satellite SCPC system satellite power efficiency is improved and mobile earth station battery power is saved.
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公开(公告)号：GB2337664B
公开(公告)日：2000-02-16
申请号：GB9920085
申请日：1995-03-31
Applicant: INMARSAT LTD
IPC: H04B7/15 , H04L29/08 , H04B7/185 , H04L1/18 , H04L12/54 , H04L12/861 , H04L29/06 , H04M11/00 , H04M11/06 , H04J3/12
Abstract: An interface (4;12) between a data terminal (2;18) and a digital communications link (6,8,10) implements protocols and frame formats designed to reduce delays in a data communication with a remote terminal (18;2). The interface (4;12) overcomes the need to send or receive an HDLC SABME or UA control signal, and allows data to be sent over the digital communications link (6,8,10) as soon as the communication parameters are established. In a non-ARQ (error correction) mode, the interface (4;12) sends control signals and data over the communications link (6,8,10) in frames subdivided into many small subframes of fixed length, each subframe having a length code. The interface (12), when arranged for connection to the data terminal (18) through a telephone network (14), encodes call progress signals from the telephone network (14) for sending over the digital communications link (6,8,10). The interface (4;12) encodes and decodes interrupt signals for sending between the data terminal (2;18) and the digital communications link (6,8,10) when an interrupt signal is detected.
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