JPH02230827A - Dama communication system - Google Patents

Abstract

PURPOSE:To prevent the occurrence of the deviation of an actual internal state of a slave station from the internal state of the slave station recognized with a master station by making the internal state of the slave station coincident forcedly with the content of station information when the master station receives a signal opposed from the content of the station information from the slave station. CONSTITUTION:Suppose that an error is caused by a signal sent from a slave station 3a on a CCS line and a closing signal 33a is arrived, a master station 2 closes the state of the relay line trunk 9a of the slave station 3a and sends a closing acknowledging signal 34 to the slave station 3a. Since the relay line trunk 9a is not actually closed, a line assignment requesting signal 31 may or may not be sent. When the signal 31, is received, the master station 2 discriminates that there is any error in the closing signal 33a or the line assignment requesting signal 31. Then the master station 2 makes the state of the relay line trunk 9a idle, uses the relay line trunk 9a as the object of line assignment control and sends a release acknowledging signal 35 to the slave station 3a. Thus, the deviation between the actual internal state of the slave station and the internal state of the slave station recognized by the master station is corrected automatically.

Description

[Detailed description of the invention] [Industrial application field]

This invention provides an SC P in which one communication path is composed of one carrier wave.
C (Single Channel Per Car
DAMA (Demand A) is the second communication method based on the DAM (demand
ssign Multiple Access) communication method.

[Conventional technology]

FIG. 4 is a system configuration diagram showing the configuration of each station in the DAMA communication system, as shown in the application related to Japanese Patent Application No. 63-164663, for example. In the figure, 1 indicates a communication satellite;
2 is a master station that executes channel assignment; 3 a. 3 b
, 3c, -..., 3n are slave stations that perform mutual communication using the communication path assigned by the master station 2. Figure 5 is a frequency allocation diagram showing an example of the arrangement of carrier waves (hereinafter referred to as SCPC carriers) in a repeater (not shown) mounted on a communication satellite.
, 3b, 3c, ..., 3n, a downlink common channel signal (hereinafter CC S ; Com++
+on Channel Signaling)
SCPC carrier for line, 5 is each slave station 3a, 3b, 3c
, ... SCPC carrier for uplink CCS line that sends a line allocation request signal from 3n to master station 2, 6a, 6
b, 6c, ..., 6n are SCPC carriers for communication paths allocated by the master station 2 and used for mutual communication between the slave stations 3a, 3b, 3c, ..., 3n. . FIG. 6 is a block diagram showing an example of the device configuration of each slave station 3a, 3b, 3c, . . . 3n, where 7 indicates the exchange side, and 8a, 8b, . The relay lines 9a, 9b, . . . input from the side 7 are this relay line 8.
Trunk line trunk accommodating a, 8b, . . . , 1
0 is the slave station 3a, 3b, 3C, according to the DAMA communication method.
3n is a control device that controls the trunk trunks 9a, 9b, . . . and the SCPC for the communication path.
Carriers 6a, 6b. SCPC transceiver 11a, llb, . . . using a synthesizer and having a synthesizer
... and a CCS signal transmitter/receiver 12 that uses a CCS line SCPC. 13 is an intermediate frequency/high frequency device including an antenna. 14a and 14b are blocking switches provided in the trunk trunks 9a and 9b. Next, the operation will be explained with reference to FIGS. 4 and 6. First, when the trunk line trunk 9a of the slave station 3a is blocked, the blockage switch 14a is set to the blocked side. The control device 10 detects that the blocking switch 14a is set to the blocked state, activates the CCS signal transmitter/receiver 12, and sends a blocking signal indicating that the trunk trunk 9a is blocked using the CCS line. send it out. Next, the master station 2 receives this blocking signal and automatically deletes the information indicating that the trunk trunk 9a of the slave station 3a is not blocked from the line assignment station information. Thereafter, the master station 2, which has received a line assignment request signal from another slave station 3b via the CCS line, recognizes from the line assignment station information that the trunk line trunk 9a of the slave station 3a is blocked, Line assignment control is executed excluding this trunk line trunk 9a. On the other hand, in the slave station 3a, maintenance etc. of the trunk line trunk 9a are performed. When the maintenance etc. of the trunk line trunk 9a of the slave station 3a is completed and the blockage switch 14a is set to the non-blocked state, the control device engineer 0 detects that the blockage switch 14a is set to the non-blocked state, and The signal transmitter/receiver 12 is activated to send a release signal indicating that the trunk trunk 9a has been unblocked using the CCS line. Then,
The master station 2 receives this release signal, automatically re-registers information indicating that the trunk trunk 9a of the slave station 3a is not blocked in the line allocation station information, and relays the slave station 3a again. The line trunk 9a is added to the line allocation control target.

[Problem to be solved by the invention]

Since the conventional DAMA communication method is carried out as described above, errors may occur in the signals on the CCS line due to noise in the satellite line or noise from the modem of the communication satellite l, causing blockage signals, release signals, etc. If the status signals sent by the slave stations 3a to 3n indicating the status of the slave stations 3a to 3n are received by the master station 2 by mistake, incorrect information will be registered in the station information.
In particular, there was a problem in that vacant trunk trunks 9a and 9b were excluded from the control target. This invention was made in order to solve the above-mentioned problem, and it is possible to distinguish between the actual internal state of the slave station and the internal state of the slave station recognized by the master station, which is caused by an error in the signal on the CCS line. It is an object of the present invention to obtain a DAMA communication system that can automatically correct deviations or prevent the occurrence of deviations.

[Means to solve the problem]

In the DAMA communication system according to the invention described in claim (1), when a master station receives a signal such as a line allocation request signal that is inconsistent with the contents of the station information from any slave station, it sends the slave station to the slave station. The slave station transmits an instruction signal instructing the station to forcibly adjust its internal state to a predetermined state, and upon receiving this instruction signal, the slave station adjusts its internal state to match the instruction given by the instruction signal, and It is designed to send out a status signal indicating the internal status. In the DAMA communication system according to the invention described in claim (2), each slave station transmits a status signal using an arbitrary slot on the CCS line when the internal status changes, and transmits this status signal. The master station that received the confirmation signal sends a confirmation signal to the slave station, and if the slave station cannot receive this confirmation signal within a predetermined time, it uses another slot and transmits the status signal again. This is how it was done.

[Effect]

The DAMA communication method in the invention described in claim (1) is:
Due to a data error that occurred in the CCS line, after content different from the actual internal status of the slave station is registered in the station information of the master station, if a signal inconsistent with the content is received from the slave station, the forced The internal state of the slave station and the contents of the station information of the master station are completely destroyed. In addition, in the DAMA communication system according to the invention described in claim (2), the master station that receives a status signal from an arbitrary slave station sends a confirmation signal to the slave station, and the slave station receives this fl1! monitor the recognition signal.

【Example】

An embodiment of the present invention will be described below with reference to the drawings. The system configuration and slave station configuration of the DAMA communication system according to the present invention are the same as those shown in FIGS. 4 and 6. However, the control device 10 has additional functions for realizing this method. FIG. 1 is an explanatory diagram for explaining the operation of a DAMA communication system according to an embodiment of the present invention. In the figure, the left side shows the internal state of the slave station 3a, and the right side shows how the station information of the master station 2 changes. Furthermore, a CCS line using a satellite line is shown between the slave station 3a and the master station 2, and the arrows between them indicate each signal on the CCS line. Next, the operation will be explained. First, a signal sent by the slave station 3a or other slave stations 3b to 3n causes an error in the CCS line, and the master station 2 receives a blockage signal 33a indicating that the trunk trunk 9a of the slave station 3a is blocked. Suppose we have reached it. Then, the master station blocks the status of the trunk line trunk 9a of the slave station 3a in the station information, sends a blockage confirmation signal 34 to the slave station 3a, and thereafter excludes it from line allocation control. In reality, the trunk trunk 9a is not blocked, so the line assignment request signal 31 that uses the trunk trunk 9a of the slave station 3a may be sent. This signal 31
When the master station 2 receives the blockage signal 3, the master station receives the previously received blockage signal 3.
3a or the line allocation request signal 31 is judged to have an error. Therefore, in order to resolve the contradictory situation, the master station 2 sends an instruction signal 32 to change the internal state of the slave station 3a to a state where the trunk line trunk 9a is empty. Upon receiving this instruction signal 32, the slave station 3a sets its internal state to the state where the trunk trunk 9a is vacant, and sends a release signal 331j to the master station 2 indicating that the trunk trunk 9a is vacant. The master station 2 makes the status of the trunk line trunk 9a of the slave station 3a in the station information vacant, adds the trunk trunk 9a to the line allocation control target, and sends a cancellation confirmation signal 35 to the slave station 3a. Note that when the trunk line trunk 9a is actually blocked before receiving the instruction signal 32 (actually, the line allocation request signal 3
1 is an error), the slave station 3a may send out the blocking signal 33a again after the above operation. Further, in the above embodiment, the discrepancy between the actual internal state of the slave station 3a and the contents of the station information of the master station 2 is detected by a line allocation request signal using the trunk trunk 9a whose station information is blocked. However, as shown in FIG. 2, when the trunk trunk 9a of the trunk line is actually blocked, the slave station 3a
The blockage signal 33a is sent out multiple times (twice in the figure) from the master station 2, and the blockage confirmation signal 34 is sent out only when the blockage signal 33a is received a specified number of times, thereby compensating for errors in the blockage signal 33a. Good too. In this case, if the master station 2 receives the blockage signal 33a a predetermined number of times within a certain period of time T1 after receiving the first blockage signal 33a, the master station 2 updates the station information. FIG. 3 is an explanatory diagram for explaining the operation of the DAMA communication system according to another embodiment of the present invention. In the figure, the upper side shows the state of the signal on the downlink CCS line, and 20 is a reference burst located at the beginning of each frame. The lower part shows the state of each slot on the uplink CCS line, and shows a plurality of slots 21 to 2 whose start timing is determined based on the reception timing of the reference burst 20.
It is divided into 4 parts. Each slave station 3a to 3n uses an arbitrary slot, for example, the n-th slot 23, to send a blockage signal 33a when there is a change in the internal state, for example, when the trunk trunk 9a is blocked.
Send out. Then, this blockage signal 33a is sent from the master station 2.
When the confirmation signal for the block cannot be received within the predetermined time T2, the blockage signal 33a is retransmitted using the n+m slot 24 delayed by a random number of slots. In this way, even if an error occurs in the blockage signal 33a or confirmation signal on the satellite line, or even if the blockage signal 33a collides with another signal, the master station can reliably change the internal state of the slave station 3a. 2 can be notified. Here, the predetermined time T2 is determined in consideration of the delay time due to the satellite line and the signal processing time of the repeater and each station. Also in this case, the blockage signal 33a may be sent a plurality of times, and the station information may be updated if the blockage signal 33a is received a specified number of times within a predetermined time at the master station 2. Note that the blockage signal 33a and the release signal 33b are defined in the claims (
This is an example of the status signal described in 1) and (2), and the line allocation request signal 31 is also an example of the signal. The status signal may be any signal other than the blocking signal 33a and release signal 33b as long as it is related to the internal status of the slave stations 3a to 3n, and the signal may be a request for processing from the slave stations 3a to 3n to the master station 2. If the signal is, line allocation request signal 3
It may be other than 1.

【Effect of the invention】

As described above, according to the invention described in claim (1), the DAM
In communication method A, when the master station receives a signal from the slave station that contradicts the contents of the station information, the internal state of the slave station is forced to match the contents of the station information. term (
2) According to the invention described above, the DAMA communication system uses a confirmation signal for the status signal, and if this confirmation signal cannot be received, the status signal is retransmitted using another slot, so that the It is possible to obtain a highly reliable method that can prevent the occurrence of a discrepancy between the actual internal state of the station and the internal state of the slave station recognized by the master station.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram for explaining a DAMA communication system according to a first embodiment of the invention, and FIG. 2 is an explanatory diagram for explaining a DAMA communication system according to a second embodiment of the invention. FIG. 3 is an explanatory diagram for explaining the DAMA communication method according to the third embodiment of the present invention, and FIG. 4 is an explanatory diagram for explaining the DAMA communication method according to the present invention and the conventional DAMA communication method. FIG. 5 is a frequency allocation diagram showing an example of the arrangement of SCPC carriers in a repeater mounted on a communication satellite, and FIG. 6 is an example of the device configuration of a slave station according to the present invention and a conventional slave station. Block diagram showing. 3l is a line allocation request signal (signal), 32 is an instruction signal,
33a is a blockage signal (state signal), and 33b is a release signal (state signal). In addition, in the figures, the same symbols indicate the same or equivalent parts. (2 others) Figure Zixun (3a) T!L station (2) Figure 1. Display of the incident Hei Ling 41 Patent Application No. 1-50102 2. Name of the invention DAMA communication method 3. Make amendments Relationship with the incident

Claims (2)

[Claims] (1) One communication path is composed of one carrier wave, and a large number of carrier waves are arranged in a repeater mounted on a communication satellite, and a common signal line selected from the large number of carrier waves is used to communicate with multiple base stations. performs call connection control with the slave stations of the plurality of slave stations, and allocates the communication path to the slave station that has requested line allocation among the plurality of slave stations and the slave station with which the slave station communicates; In a DAMA communication system of a centralized control type of the master station, the master station receives a status signal regarding the internal state of the slave station from the slave station and updates station information about the slave station owned by the master station. When the slave station sends a signal with contradictory content to the master station, the master station sends a signal with contradictory content to the slave station using the common signal line. , transmits an instruction signal to forcibly set the internal state of the slave station to a predetermined internal state, and upon receiving this instruction signal, the slave station forcibly adjusts its internal state to the instruction by the instruction signal, and A DAMA communication system, characterized in that a status signal indicating an internal status after the internal status is transmitted to the master station. (2) One communication path is composed of one carrier wave, and a large number of carrier waves are arranged in a repeater mounted on a communication satellite, and a common signal line selected from the large number of carrier waves is used to communicate with multiple base stations. The master station performs call connection control with the slave stations, and allocates the communication path to the slave station that has requested a line allocation among the plurality of slave stations and the slave station that is the communication partner, and the master station , in a DAMA communication system of a centralized control type of a master station, in which the master station receives a status signal regarding the internal state of the slave station from the slave station and updates station information regarding the slave station owned by the master station, the slave station receives the common channel signal. The master station sends out the status signal using an arbitrary slot of the frame used on the line, and the master station that receives the status signal sends out a confirmation signal using the common line signal line. A DAMA communication system characterized in that if a slave station that has sent a status signal does not receive the confirmation signal within a predetermined time, it uses another slot to transmit the status signal again.