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公开(公告)号：EP0142138A3
公开(公告)日：1986-03-05
申请号：EP84113522
申请日：1984-11-09
申请人： FUJITSU LIMITED
发明人： Ikeuchi, Satoshi , Taniguchi, Ikuo
CPC分类号： H04B1/74
摘要： @ This invention provides a line protection switching system of which reliability is improved, and the time for protection line switching is decreased. In order to increase the reliability, the service signals are sent in parallel via plurality of transmission lines (11,12 ---), using a service bit area of PCM bit frames. Unlike the prior art system, one embodiment ofthe present system switches a failed transmission line to a stand by line (1n), at a station where it detected a fault before waiting for switching of the opposite station. At the same time the switching command is sent to the opposite station. If the switching of the opposite station fails, the station commands retry of the switching. But if it fails again, the station switches the transmission line to the initial state. Since a low priority signal is transmitted through the stand by line (1n), the total system is economized.
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公开(公告)号：EP0175888A3
公开(公告)日：1987-11-11
申请号：EP85109756
申请日：1985-08-02
发明人： Cellerino, Giuliano
CPC分类号： H04L1/22 , H03L7/087 , H04L7/0083
摘要： A phase comparator is included with each incoming channel to compare the clock phase of the incoming signal and a local oscillator. The phase comparator of an on-line active unit generates a signal to control the oscillator to maintain its output in phase with the incoming signal. The generated control signal is also connected to capacitor storage in associated channel phase comparators to provide them with an initial starting control voltage when they are switched in to be the receiving channels. Thus eliminating the uncontrolled operation of the oscillator during switching interval.
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3.发明公开Microwave relay station having a common standbby channel for signals of different types of modulation 失效具有不同类型调制信号的通用通道的微波继电器站
公开(公告)号：EP0208270A3
公开(公告)日：1988-11-23
申请号：EP86109108
申请日：1986-07-03
申请人： NEC CORPORATION
IPC分类号： H04L01/22
CPC分类号： H04L27/0008 , H04L1/22
摘要： A multichannel microwave relay station has first and second channels for respectively transmitting signals of different types of modulation, such as QAM and FM modulated signals. These different types of signals rely on a common standby transmission channel that is selectively capable of transmitting the different types of signals. The type of signal currently carried by the standby channel is automatically Identified by a detector circuit (6), such as one that can auto matically distinguish differences in the frequency spectrums of the different types of signals. A selecting circuit (3) responds to the output of the detector circuit (6) by selecting between first and second transmitting means (5) in the common channel, thereby dedicating it to the identified type of signal.
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公开(公告)号：EP0180943A3
公开(公告)日：1988-07-27
申请号：EP85113982
申请日：1985-11-04
申请人： NEC CORPORATION
IPC分类号： H04L01/22
CPC分类号： H04L1/22
摘要： A channel switching system in a digital radio transmission circuit with at least one regular channel and a standby channel has a received signal supply circuit (10), signal frequency divider circuits (20, 27), signal order change circuits (21, 28), a comparator (30), a hitless signal switching circuit (31) and a frequency multiplier (35). Each channel transmits a digital multiplexed signal including a data signal of N (N is an integer of 1 or more) strings. The received signal supply circuit (10) supplies a data signal to a receiving-side regular channel through a standby channel when a corresponding transmitting-side regular channel has a circuit failure. The signal frequency divider circuits (20, 27) N frequency-divide a data signal received through a regular channel and the data signal received through the received signal supply circuit (10). The signal order change circuits (21, 27) change orders of the N signal strings in response to different signal order change signals. The comparator (30) supplies the regular or standby N signal string to the signal order change circuit (21, 27) when a noncoincidence is established, but generates a coincidence signal when a coincidence is established. The hitless signal switching circuit (31) receives the signal string from the signal order change circuit (21, 28) and generates the regular or standby channel signal string in accordance with the coincidence signal from the comparator (30). The frequency multiplier ( 3 5) multiplies an output from the hitless signal switching circuit with N.
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5.发明公开
公开(公告)号：EP0143224A3
公开(公告)日：1987-09-09
申请号：EP84110781
申请日：1984-09-10
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公开(公告)号：EP0180238A3
公开(公告)日：1986-07-02
申请号：EP85113897
申请日：1985-10-31
申请人： FUJITSU LIMITED
发明人： Sasaki, Susumu
CPC分类号： H04B7/2643 , H04B1/74
摘要： A digital radio communication system in the form of a multi-direction time division multiplex network including; a central station having one working transmitter (24) and receiver (25) and one standby transmitter (29) and receiver (30), both working and standby transmitter and receiver having a radio line terminating equipment, each transmitter and receiver having a first phase shifting circuit (21, 26) for adjusting a phase of a transmission signal and a second phase shifting circuit (22, 27) for adjusting a phase of a sampling clock signal, whereby a signal propagation delay time of the working transmitter (24) and receiver (25) is previously adjusted by the first phase shifting circuit (21) so as to become equal to that of the standby transmitter (29) and receiver (30), then, the phase of a sampling clock signal is previously adjusted between both second phase shifting circuits (22, 27) so as to be at a central position of bit width of a reception signal, and a plurality of substations, each operatively connected to the central station by time-divided digital radio signal, and each at least having a clock phase shifting circuit for adjusting a phase of a transmission signal transmitted from itself.
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