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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：GB2319696B
公开(公告)日：2001-08-01
申请号：GB9624105
申请日：1996-11-20
Applicant: INTERNAT MOBILE SATELLITE ORGA , INMARSAT TWO COMPANY , INMARSAT LTD
Inventor： CHAMBERS PAUL , CHAMBERS CHARLES , BJOERNSTROEM GUNNAR ARVID
Abstract: In a mobile communications system 10, a message is sent to a mobile terminal 16 which transmits an acknowledgement signal if the message is received. If the system 10 does not detect an acknowledgement signal, it transmits a high margin notification signal to the mobile terminal 16 to notify the terminal that an attempt was made to send the message. When the mobile terminal 16 has received a notification signal and subsequently comes within range of lower margin signals from the system, it sends a registration signal to the system. The system may then retransmit the message to the mobile terminal 16.
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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：GB2306827B
公开(公告)日：2000-05-31
申请号：GB9521777
申请日：1995-10-24
Applicant: INT MOBILE SATELLITE ORG , INMARSAT TWO COMPANY , INMARSAT LTD
Inventor： KINAL GEORGE V , NAGLE JAMES R , SODDU CLAUDIO , RYAN FINTAN R , NAGLE JAMES R
IPC: G01C23/00 , G01S1/00 , G01S5/00 , G01S5/06 , G01S5/10 , G01S5/14 , G01S19/02 , G01S19/04 , G01S19/07 , G01S19/11 , G01S19/38 , G01S19/41 , G01S19/48 , H04B7/19
Abstract: A satellite radiodetermination system comprises global navigation service (GNSS) satellites 2 such as GPS satellites, which generate GNSS ranging signals Rn, geostationary satellites 6 which retransmit ranging signals Rg generated at a navigation land earth station (NLES) 8, including augmentation data A, and medium earth orbit (MEO) satellites 10 which generate ranging signals Rm including regional augmentation data RA transmitted from a satellite access node (SAN) 14. The regional augmentation data RA is supplied by regional augmentation systems 21a, 21b. A navigation receiver 11 receives the ranging signals Rg, Rm, Rn and calculates ionospheric delay values for those ranging signals which are provided on dual frequencies. Using these ionospheric delay values, and optionally the regional augmentation data RA and the augmentation data A, the navigation receiver estimates ionospheric delay values for those ranging signals which are provided on single frequencies. The navigation receiver uses the ranging signals, corrected for ionospheric delay and errors indicated by the augmentation data A and regional augmentation data RA, to calculate position and time accurately.
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公开(公告)号：GB2343594A
公开(公告)日：2000-05-10
申请号：GB9822145
申请日：1998-10-09
Applicant: INT MOBILE SATELLITE ORG , INMARSAT TWO COMPANY , INMARSAT LTD
Inventor： HOWARD CHRIS FRANK , CHRISTODOULIDES LOUIS MIMIS , FEBVRE PAUL , MUDGE DAVID DENIS
Abstract: A medium access control (MAC) layer protocol, preferably in a mobile satellite communication system, groups upper data link layer (UDLL) connections (MC) onto bearer connections (BC), which are assigned to shared access bearers (SAB). The connection data (MAC SDU) is formatted into packets (MAC PDU) including a header (MH) identifying the connection to which the packet belongs. The connection packets are formatted into packets (bearer connection PDU) including a bearer connection header (BH) identifying the bearer connection to which the packet belongs. The allocation of connections to bearer connections and bearer connections to bearers is dynamically varied according to the quality of service requirements of the connections.
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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：GB2347828B
公开(公告)日：2004-05-19
申请号：GB9905182
申请日：1999-03-05
Applicant: INTERNAT MOBILE SATELLITE ORGA , INMARSAT TWO COMPANY , INMARSAT LTD
Inventor： FEBVRE PAUL , JONES EDWARD ARTHUR , FINES PANAGIOTIS , MUDGE DAVID DENIS
Abstract: To demodulate the received bursts correctly, the timing of reception of the bursts is predicted by a receive timing controller (29) which receives the frame timing control information from the frame timing function (14) and parameters of the satellite (4) from the hardware adaptation layer HAL (10). These parameters define the position of the satellite and of its beams and allow the timing of arrival of data bursts from the mobile access node to satellite access node to be predicted. An independent claim is also included for a wireless link signal comprising a data burst including in temporal sequence, a method of receiving signal over a wireless link.
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公开(公告)号：GB2347824B
公开(公告)日：2004-03-03
申请号：GB9905181
申请日：1999-03-05
Applicant: INTERNAT MOBILE SATELLITE ORGA , INMARSAT TWO COMPANY , INMARSAT LTD
Inventor： FEBVRE PAUL , MUDGE DAVID DENIS
Abstract: In a bandwidth allocation protocol for a mobile communications network, the network stores associations between forward and return frequency channels, so that when a mobile receiving a forward frequency channel request return capacity, the network preferentially assigns return bandwidth to the mobile in one or more of the associated return channels.
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公开(公告)号：GB2335827B
公开(公告)日：2003-05-28
申请号：GB9804640
申请日：1998-03-04
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. 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：GB2315962B
公开(公告)日：2001-07-04
申请号：GB9616042
申请日：1996-07-31
Applicant: INTERNAT MOBILE SATELLITE ORGA , INMARSAT TWO COMPANY , INMARSAT LTD
Inventor： KAWAI NOBUYUKI , WONG HOK SHUEN , MCTIFFIN MICHAEL JOHN , RANDALL DAVID
Abstract: Data relating to the status of users 12 in a mobile communications system is broadcast via satellite 8 from a network register 4 to local registers 10 in an HDLC format. Each of the local registers 10 requests retransmission of any HDLC frames which are incorrectly received. The network register 4 records the earliest transmitted frame not yet acknowledged by all of the local registers and inhibits transmission of new frames if they fall outside a transmission window relative to the earliest transmitted frame. The network register 4 polls the local registers 10 for retransmission requests and the local registers 10 also send unsolicited requests to the network register 4 . The network register 4 only retransmits a frame once if multiple requests for that frame are transmitted within a predetermined period. When a new local register 10 enters the broadcast reception group, the network register 4 informs the new local register 10 which new frame will next be transmitted. The number of bits used for frame sequence numbers is greater than that defined in the HDLC protocols.
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