JPS60212040A - Ss-tdma line control system - Google Patents

Abstract

PURPOSE:To attain switching and rearrangement without inconvenience even when any number of frames of a control relinquishes by transmitting the final notice of execution of changeover to all earth stations for many number of times from a reference station to each station through a control line and allowing the reception side to apply majority decision and decide the switching to a new pattern and rearrangement of a burst. CONSTITUTION:The reference station transmits simultaneously a transmission start control signal 23 n times and each earth station establishes the normal reception through the reception of x times among the n times and prepares for the reception of a burst rearrangement data transmitted afterward. The station receiving the transmission end control signal 25 from the corresponding station compares all the burst rearrangement data or an old burst arrangement data with a burst rearrangement data, rewrites only the modified part, stores the result to a temporary memory and transmits the reception end control signal 26 to the reference station. When the reference station confirms the end of preparation of the said earth station, a switching command signal 29 of the switch pattern is transmitted to a satellite and commands the execution of data burst rearrangement to the earth station by using a line control window of all basic frames of the next line control frame.

Description

Detailed Description of the Invention (Technical Field) The present invention is based on the 88-TDMA system, and uses a line control frame consisting of an integral multiple of the basic frame synchronized between the satellite and the earth station, and is capable of controlling a matrix switch. The present invention relates to a line control system that switches switch patterns or rearranges data bursts during communication without affecting calls.

(Background technology) A certain area on the earth is irradiated with multiple beams from a satellite, and communication between earth stations within each beam area is performed by time division multiple access via a matrix switch on the satellite88
- In the TDMA system, switching the switch pattern which is the connection mode of the matrix switch and controlling the rearrangement of data bursts including calls in progress are performed. A ha lump bias 1f denunciation ÷ 1 den -
++L II) It becomes possible to set a w-m-notch switch pattern, which is an effective means for efficiently using the satellite line. When changing the switch pattern of the matrix switch or rearranging data bursts for active calls, it is important to ensure that the specified line is controlled without system down and that active calls are controlled without momentary interruption. Desirable from the perspective of maintaining quality.

Conventionally, as this type of control technology, Intelsat System's uninterrupted data burst relocation control method has been announced. As a control procedure, the reference station sends and receives new data burst configuration data to and from the earth station via the control line while the line control frames between the satellite and the earth station are synchronized, completing preparations. Next, the reference station confirms that all earth stations applicable to switching are ready, and transmits the time reading information for simultaneous switching via the control line, starting from the basic frame at the time when the time reading information becomes 0. Perform data burst relocation. These control procedures use the microwave band as the radio frequency, guaranteeing high transmission quality, and are effective in rare cases where inconveniences such as loss of control signals occur. When using this method, it may not be possible to maintain high transmission quality, and data burst relocation control or matrix switch switch pattern switching control may fail due to disappearance of time reading information.

(Problems to be solved by the invention) In order to solve these drawbacks, the present invention performs switch pattern switching and data burst relocation control in units of line control frames, and sends control signals to the reference station across all basic frames of the line control frames. sent many times from
The earth station receives it from the majority decision delay, and performs IJ switch pattern switching and data burst relocation control at a timing after a predetermined line control frame from the received line control frame. The drawings will be explained in detail.

(Structure and operation of the invention) FIG. 1 is a conceptual diagram of the SS-TDMA system, showing the relationship between the internal structure of a communication satellite and the corresponding earth station.

In FIG. 1, a multi-beam antenna (1) onboard a satellite generates - for example, four beams (2);
Each beam (2) has four limited beam areas (
31 (distinguished as A, BIC and D)'. This antenna (1) also receives radio waves radiated from earth stations (4) within each beam area. Radio waves from the earth station (4) in each beam area A, B, C, and D received by this antenna (1) are transmitted to four receivers (5) (RIA, RB) corresponding to each beam area. , R
, C, RD). On the other hand, the power that should be irradiated from the antenna (1) to each beam area is the same as that of the four transmitters (6) (TA,
T.B., T.C.

Supplied by TD). In order to connect the outputs of these (5) and the input of the transmitter (6), a matrix switch (power) is provided, which is controlled by the control circuit α0. Matrix switch (switch pattern data and control information for controlling power) are transmitted and received via a line control station (9) and an intra-satellite line control transmitter (8).

The satellite reference frequency is generated from the vcxo (11).

Conventionally, the synchronization burst that serves as the reference for synchronization of the earth station is transmitted from the reference station (4a), but here, a synchronization burst generation circuit a is installed in the satellite, and the synchronization burst is transmitted from the satellite in broadcast mode. Assuming the case of sending.

Figure 2 is a TDMA frame hierarchy diagram, and shows the basic frame (which is the repetition period of the matrix switch connection mode).
= TDMA frame monthly field) v-b length is tms (15
), and let n times tms (n number of earth stations) be the synchronous control frame αa, which is the repetition period of TDMA synchronous control. Frame α9, which is made up of N times the synchronous control frame Nagasumi η, is a line control frame used for switching control of the switch pattern of a matrix switch or data burst relocation control of a call in progress, and its frame length Tc
Ql needs to have a length that does not cause any inconvenience in terms of control during the daytime round trip delay. The basic frame consists of a control line window (21) and a communication window (21) for transmitting a synchronization burst, which is a reference for TDMA synchronization, from a satellite in broadcast mode. .

Figure 3 shows the synchronized burst generated from the synchronous burst generation circuit inside the satellite.
Basic frame (L synchronization window a) in Figure 2
This is an example of a configuration of a reference burst (2) to be transmitted to all earth stations including the reference station (4a).Each earth station determines the transmission and reception timing based on the detection time of the unique word (UW) of the received synchronization burst.Line As a method of synchronizing the line control frame used for control between the satellite and the ground station, notification is made by changing the synchronization burst pattern on the satellite every line control frame period TC.The earth station notifies the satellite of the UW pattern change frequency. There are methods such as detecting this and synchronizing the line control frame of the local station.

FIG. 4 shows an embodiment of the present invention, in which data of a new switch pattern is transmitted between the reference station (4a) and the satellite to the line control station (9).
After transmitting and receiving data via the transceiver (8) on the satellite, the reference station transmits and receives data burst relocation data to and from each earth station via a line control window. First, the transmission start control signal (23) is transmitted n times at the same time, and each earth station considers the reception to be normal when it receives it X times out of n times (n≧X), and prepares to receive the burst relocation data that will be transmitted afterwards. The control signals of (c), (261, @, (c) and 31) are also transmitted using the same method.The reference station transmits the new burst relocation data (24) while checking with the relevant station for errors. When the transmission and reception of data (goods) is completed, the reference station transmits the transmission completion control signal (251) all at once.After receiving the transmission start control signal (2nd stage), the earth station that does not receive the data (24J) 24) Please judge by yourself that the station is not related to the switching of the switch pattern, and do not execute the subsequent processing.

The station that receives the transmission completion control signal (251) compares all of the burst relocation data or the old burst relocation data with the burst relocation data, rewrites only the changed parts (different data), and stores it in temporary memory. It stores and transmits a reception completion control signal (26) to the reference station.When the reference station receives the reception completion control signal (26) from the corresponding station, it simultaneously transmits an execution preparation signal (27).

When the corresponding earth station receives the execution preparation control signal (27), it transfers the burst relocation data stored in the primary memory into a standby state in the secondary memory, which has a dual configuration of the θ system and 1 system. One memory memorizes the ready control signal (to)
Send. When the reference station confirms that the corresponding earth station is ready, it sends a switch pattern switching command signal to the satellite and executes data burst relocation to the earth station in the line control window of all basic frames of the next Tcn+1 line control frame. Sends an execution command control signal (to) to command.

FIG. 5 is a time chart showing the operation from the time when the reference station shown in FIG. 4 sends a switch pattern changeover command signal to the satellite to the time when the switch pattern of the matrix switch is changed and the data burst relocation of the earth station is completed. On the satellite, the switch pattern switching command signal (Tc after the third line control frame from the line control frame Ten in which the second signal was received)
Switching to the new switch pattern (34) starts from the first basic frame of the n+3 frame. Therefore, the old switch pattern (c) is operated up to the line control frame of Tcn+2. The reference station transmits the execution command signal (30) N x n times in the next Tcn+1 line control frame after transmitting the switch pattern change command signal to the satellite. On the other hand, the earth station transmits y times (to) of the NXn execution command signals (to) transmitted by the reference station.
y ≦ N The system switches from there to the secondary memory of the system storing the burst relocation data and performs communication according to the burst relocation data stored therein. At the earth station, the transmitting side is switched first, and the receiving side is round) IJ Tsubu delay (τ) (switching after three times, and the switching completion signal Oυ is sent to the reference station. The timing of switching the switch pattern on the satellite is determined by the earth station transmitting side. There will be a delay of τ/2 from the switching.The line control frame used for switching control is synchronized between the satellite and the earth station, and is always in the state of Tcn=Tcn.

As mentioned above, in matrix switch/switch pattern switching and burst relocation control, switching execution is controlled in units of line control frames that are synchronized between the satellite and the earth station, and the final The notification is sent in broadcast mode across all the basic frames constituting the line control frame, and the earth station detects a command signal to execute switching by majority decision, and from the line control frame in which the control signal was detected, it sends the notification to the specified line control frame. By switching from the first basic frame to the new switch pattern and rearranging data bursts, system operation can be improved.
Switching control is also possible without affecting the call in progress.

(Effects of the Invention) As explained above, according to the present invention, the final notification of execution of switching to all earth stations is sent from the reference station to the count information (Example 9.
8.7...0), the control line is sent to each station, and switching (or traffic relocation) is determined by receiving the information of count O. On the receiving side, switching to a new pattern and rearranging bursts are determined by majority decision, so there is an advantage that even if some frames of control signals disappear due to deterioration of transmission quality, switching and rearrangement can be performed without any inconvenience.

In the embodiment of the present invention, the control signal is transmitted from the satellite, but even if the reference burst generator cannot be mounted on the satellite, the synchronized burst can be transmitted from the reference station using the same method as when transmitting from the satellite. The same control is possible by sending.

Further, the same control method can also be used to control only burst relocation.

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram of 88-TDMA system, Figure 2 is TDM
FIG. 3 is an example of the structure of a reference burst, FIG. 4 is an embodiment of the present invention, and FIG. 5 is an example of the operation of the present invention. 1...Multi-beam antenna, 2...Beam, 3.
...Beam area, 4...Earth station, 4a...Reference station,
5... Receiver, 6... Transmitter, 7... Matrix switch, 8... Telemeter command transceiver,
9... Earth station for telemeter command, 10... Control circuit, 11... VCXO, 12... Synchronous burst generation circuit, 13... Basic frame, 14... Synchronous control frame, 15... ...Line control frame, 16...
Basic frame length, 17...Synchronization control frame length, 18
...°Line control frame length, 19...Synchronization window, addition...Control line window, 21...Communication window, head...Reference burst, Ru...Transmission start control signal, ...Data, 5...Transmission completion control signal, addition...Reception completion control signal, 27...Execution preparation control signal, column...Preparation completion control signal, 29...Command signal, 30. ... Execution command control signal, 31 ... Completion control signal, 32 ... Round trip delay time, 33
... Old switch pattern, 34... New switch pattern. Patent applicant Nippon Telegraph and Telephone Public Corporation Patent application agent Megumi Yamamoto - #lclosen -I

Claims (1)

[Claims] In the 88-TDMA method, a predetermined area on the earth is irradiated with multiple beams from a satellite, and communication between earth stations within each beam area is performed by time division multiple access via a matrix switch on the satellite. Using line control frames consisting of integral multiples of the basic frame that is synchronized between the satellite and all earth stations, line control is performed when control commands are detected during matrix switch switch pattern switching and earth station data burst relocation control. All basic frames of the line control frame after the frame, synchronization bursts sent from the reference station in broadcast mode using the synchronization window of the frame, control signals are sent to all earth stations simultaneously over the basic frame many times, and each earth station An 88-TDMA line characterized in that a control signal is detected by majority decision, and the switch pattern of the matrix switch is changed and the data burst is rearranged from a predetermined line control frame from the end of the line control frame in which the control signal has been received. control method.