JPS6277724A - Line repairing method for satellite communication demmand assign equipment - Google Patents

Abstract

PURPOSE:To repair a line without interrupting an operating line by collecting the information of communication line assignment of an earth station just before an error takes place and resetting a communication line with the earth station when the system is restored into a normal operation after the error takes place. CONSTITUTION:Station control processors (SCP) 1-1-1-n have managing tables 2-1-2-n and store the line operating state of their own station, the operating frequency, or the information such as the operating time slot or inter-station connection state respectively. When a network control processor (NCP) 3 restores to the normal operation, a line request inhibition command to each SCP, each SCP reads the information just before the occurrence of an error from the managing table of its own station and sends it to the NCP 3. Then the NCP 3 reedits the management table 5 and sends the permission signal of a new line setting request without interrupting the operating line.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a line repair method for a demand assignment device in a satellite communication system.

[Technical Background of the Invention] Line assignment methods for satellite communications include a bria assignment method in which a fixed line is set in advance, and a demand assignment method in which a vacant line is allocated each time a line assignment request is made.

Satellite communication demand assignment device is a line connection device to effectively utilize the limited number of satellite lines.
When applied to the 5CPC communication method that allocates one carrier wave per communication line, an empty line is detected from among the satellite lines that are pending in response to a call request from a user terminal, and a call request is made. Set up a communication line between earth stations. Furthermore, when applied to a TDMA communication method that performs time division multiple access,
In response to a call request from a user terminal, an empty time slot among the time-divided time slots is set between earth stations.

The demand assignment method is a decentralized system in which each earth station independently determines which lines are free by referring to its own data table of line settings and usage status, and requests the use of the line. The system is divided into a control system and a centralized control system in which a central control station serving as a higher-level station of each earth station determines the usage status of the line and allocates an idle line each time a line allocation request is generated.

In the latter centralized control method, the device that performs centralized control of line allocation is generally called a network control processor (NCP), and this NCP responds to line allocation requests from each user terminal by assigning frequencies or time slots to be used. Performs work such as allocating stations and securing and setting up lines between stations. On the other hand, the station control processor (SC) is generally used to process calls at the earth station, which collectively manages user terminals of access devices such as telephones, facsimiles, computers, etc.
P), which handles overall call processing such as the above-mentioned call to request line allocation from the NCP, and incoming calls when there is a line connection request from the local station, as well as the actual call processing by the NCP. They are in charge of connecting lines using assigned frequencies or time slots.

Both SCP and NCP have management tables, and each SCP has its own line usage status, frequency used, or time slot used.

Information such as inter-office connection status is stored in this management table. On the other hand, the NCP collects the contents of the management table of each SCP in a management table and stores information such as frequency or time slot usage status and inter-station connection status. N
The CP compares this information with each SCP's line allocation request, and if there is a free line, it allocates that line to the SCP that issued the line allocation request; if there is no free line, it is impossible to allocate the line. Notify the SCP of this fact.

By the way, in such a demand assignment centralized control method, when the system is turned on and started up for the first time, all the contents of the management tables attached to both NCP and SCP are erased, so that there are no lines in use. initialize.

On the other hand, even when the NCP malfunctions for some reason during normal operation of the system and the power is turned on again to restore normal operation, initialization is performed in the same way as when the power is turned on for the first time. This is true if the NCP power is turned off and then turned on again.

This is because if the SCP is not initialized, the following inconvenience will occur. In other words, when the NCP's power is cut off, the SCP's line allocation request is not accepted by NCP3 at all, so no new line is set up or allocated. Some of the lines that were in use were terminated during the power cut, while others continued to be active. Therefore, when the NCP power is turned on again, N
If the CP and SCP are not initialized, the NCP will have no idea which line is currently being used.
If a new line allocation request is issued after the power is turned on again, interference will occur.

[Problems with the background technology] However, if the same initialization as when the power is turned on for the first time is performed when the power is turned on again after a system abnormality occurs, the NCP will not allocate lines during normal operation. It is possible for the assigned lines to continue to be used even if the NCP is in an abnormal operating state, but once the NCP returns to normal operation, all the lines are forced to be used regardless of whether they are in use or not. This results in a problem in that the serviceability of the satellite communication system deteriorates in terms of operation.

[Object of the Invention] The present invention provides a line repair method for a satellite communication demand assignment device that can prevent the line in use from being forcibly cut off when the NCP returns to normal operation after a system abnormality occurs. The purpose is to provide

[Summary of the invention] The present invention provides an
Information on the allocation and status of the communication line immediately before the occurrence of a system error stored in the R management table or the earth station management table is collected, and the communication line with the earth station is reconfigured based on this collected information. By doing so, the above objectives have been achieved.

[Embodiment of the Invention] FIG. 1 is a diagram showing an embodiment of a satellite communication system to which the present invention is applied, in which a plurality of SCPs set on the earth 1
-1. 1-2. -1-n shows a configuration in which satellite communication is performed via the NCP3. In the figure, each SCP 1-1 to 1n has a management table 2-1.
2-2. ..., 2-n, and each station stores information such as its own line usage status, frequency used, time slot used, connection status between stations, etc. in this management table. -1 to 4-n and the communication satellite 6. On the other hand, the NCP 3 stores the management table 2 of each SCp 1-1 to 1-n in the management table 5.
-1 to 2-n are collected and information such as frequency or time slot usage status and connection status between two stations is stored. NCP3 uses this information and each 5CPI-1 to 1-
SCP 1-1 compares the line allocation request of n, and if there is a free line, it is allocated to the SCP that issued the line allocation request, and if there is no free line, it is impossible to allocate the line. ~1-n will be notified.

Figure 2 shows the NC for SCPs 1-1 to 1-n that continue to use the line even during abnormal operation of NCP 3.
It is a figure which shows the management table reproduction|regeneration procedure after P,3 restoration.

In the figure, first, when NCP3 returns to normal operation,
A signal S1 is sent to each of the 5CPI-1 to 1-n to notify that the white color has been restored, and a line request prohibition command is sent indicating that new requests cannot be accepted for a while because the management table 5 of the NCP 3 will be reproduced from now on. In contrast, each scp
When i-i to 1-n receive the signal 81, they read the line usage status of their own stations from the management tables 2-1 to 2-n,
This is transmitted to NCP 3 by signal S2.

Then, the NCP 3 updates the management table 5 based on the line usage information sent and received from each SCP 1-1 to 1-n.
Reorganize. Once this reorganization is complete,
At this point, the contents of the management tables of NCP 3 and SCPs 1-1 to 1-n completely match, so each SCP
A new line setting request permission signal S3 is transmitted to CPs 1 to 1 to 1-n.

As described above, according to this embodiment, when the NCP 3 returns to normal operation, the SCP management tables 2-1 to 2-
The contents of management table 5 are collected to restore the contents of management table 5 to the state before the system abnormality occurred, and after this restoration, the communication line is reconfigured, so communication is interrupted from before the system abnormality occurs until normal operation is restored. The line in this state can continue communication without being disconnected midway.

Note that the present invention is not limited to the above embodiments. For example, in the 5CPC communication system, a random access memory or magnetic disk with a backup power source is used as the management table 5 of the NCP 3, and information on the line usage status held by the NCP 3 is transmitted at appropriate time intervals during normal system operation. Make it memorize and once NCP
If NCP 3 enters an abnormal operating state, when returning to normal operating state, retrieve the final information during normal operation of NCP 3 from the above management table, and return the line to the state before the system error occurred based on this information. It may be possible to repair it.

By doing this, since it was not possible to allocate a new line while NCP 3 was out of order, the set line would be assigned to NCP 3.
Compared to the situation before the failure in No. 3, although the number of lines may be reduced due to call termination, the number of new lines is not increased, so the same effect as in the above-described embodiment can be obtained.

Further, although the embodiments described above have all been related to the 5CPC communication method, the present invention is not limited to this communication method. The same concept as described above can be applied to the TDMA communication system as well. However, 5
In the CPC communication system, line allocation is about frequencies, whereas in the TDMA communication system, it is information about time zones, that is, which time slots are used by which stations and by which lines. In addition, in 6), there are communication methods that use the demand assignment centralized control method.
Various modifications can be made without departing from the spirit of the invention.

[Effects of the Invention] As detailed above, according to the present invention, after a system abnormality occurs during normal operation of the NCP, when the NCP returns to normal operation, the NCP management table or the earth station management table The system collects information on the communication line allocation status immediately before the system error occurred, and reconfigures the communication line with the earth station based on this collected information, without interrupting the line in use. It can be used continuously and can be operated as if the user were not aware of the effects of an abnormality in the NCP, thereby improving serviceability.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing a management table repair procedure. 1-1~1-n...Station" Nhiror Processor, ? -1 to 2-n... Management table, 3... Network control processor, 5... Management table, 6... Communication satellite.

Claims (1)

[Scope of Claims] Detecting whether or not there is an idle communication line among a predetermined number of communication circuits based on information on the allocation status of communication circuits stored in a management table for a call from an earth station; In a satellite communication demand assigning device that allocates an idle communication line to the earth station that has issued the call, if there is an idle communication line, this is stored in the management table or the management table of the earth station when normal operation is restored after a system abnormality occurs. A method for repairing a line in a satellite communication demand assignment device, characterized by collecting information on the allocation status of a communication line immediately before a system abnormality occurs, and resetting a communication line with an earth station based on this collected information.