KR0183274B1 - Reference time duplexing apparatus of satellite communication system - Google Patents

Abstract

The present invention allows each network control module (CPM) in a redundant central control station (DMP) to process the reference time, respectively, so that any base station is error-free for each base station during redundancy switching from an active state to an idle state. A reference time redundancy apparatus in a satellite communication system capable of providing time, comprising: redundant network control means for controlling request allocation call processing, reference time output means for generating a reference time, and redundant switching control A satellite communication system having a central control station having an RCL means, the network control means comprising: reference time storage means for storing a reference time, and time data storage means for temporarily storing a reference time; In the operating state, the reference time is stored in the reference time storing means, Control means for outputting to the network control means, the control means for controlling to store the reference time input from the network control means of the operating state in the time data storage means in the idle state.

Description

Reference time redundancy device in satellite communication system

1 is an overall system configuration for explaining the outline of a general satellite communication system.

FIG. 2 is a block diagram showing the configuration of the central control station 2 in FIG.

3 is a block diagram showing the configuration of the network controller 40 in FIG.

4 is a block diagram showing the configuration of a reference time redundancy device in a satellite communication system according to an embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

1: satellite 2: central control station

3A, 3B: base station 11A, 11B: switchboard

12A, 12B: Telephone 13A, 13B: Data Terminal

14A, 14B: Facsimile 21: Antenna

22: orthogonal mode converter 23: low noise amplifier

24: frequency down converter 25: intermediate frequency combination / distribution unit

26, 31: SCPC channel unit 32: frequency up converter

33: high power amplifier 40, 40 ′: network control unit

41: processor 44: program storage unit

45: base station information storage unit 46: channel information storage unit

48: Redundancy Control Logic (RCL)

60: network management system 70: processor

71: time storage unit 72: timer

73: Complementary Metal Oxide Semiconductor (CMOS)

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system using satellites. In particular, two network control modules (CPMs) in a duplicated central control station (DMP) can each process a reference time, thereby allowing an arbitrary module to go from an idle state to an idle state. The present invention relates to a reference time redundancy device in a satellite communication system that is capable of providing an error-free reference time to each base station during redundancy switching.

Recently, with the rapid development of communication technology, satellite communication, which enables subscribers who are located in remote areas to make calls through satellites, is becoming more common. Such satellite communication does not require a separate signal line for a call. Therefore, it is mainly used as a long-distance communication between countries or a communication method of a mountainous country such as Korea.

In the above-described satellite communication, there are two types of PAMA (Pre Assignment Multiple Access) method for allocating communication channels for each subscriber according to the channel allocation method and Demand Assignment Multiful Access (DAMA) method for allocating communication channels according to subscriber's request. In general, in the satellite communication system for communication between subscribers, many DAMA methods are adopted in consideration of the cost and the effectiveness of the communication channel.

1 is a block diagram showing the overall system configuration of a general satellite communication system according to the DAMA method.

In FIG. 1, reference numeral 1 is a satellite having a plurality of communication channels, 2 is a central control station for controlling the entire satellite communication system, and 3 (3A, 3B) is an exchanger (11A, 11B) or a telephone (12A, 12B). Communication function between the various terminals through data transmission and reception with the central control station 2 as well as an interface function for terminals such as data terminals 13A and 13B and facsimile 14A and 14B, such as a computer. The base station that provides.

In FIG. 1, reference numeral S denotes a service channel for transmitting and receiving control data, and T denotes a traffic channel for transmitting and receiving data or voice.

In the above-described configuration, the central control station 2 transmits a control message through a service channel in a normal state and then, based on a response message transmitted from the base station 3, that is, communication of the base station 3. It performs the polling function to check the available capacity or the communication channel. When there is a call request from a specific base station, for example, the base station 3A to a terminal having jurisdiction over the base station 3B, it is determined whether the base station 3B is in a state in which communication is possible based on the information obtained in the polling process. In the case of the communicable state, the available traffic channel T of the satellite is allocated to both base stations 3A and 3B so that both base stations 3A and 3B can directly communicate with each other.

Subsequently, when the communication between the base stations 3A and 3B is terminated and the communication termination signal is applied through the service channel S from the base station 3A, which has been requested for communication, the central control station 2 is applied to both base stations. By executing the communication termination process, the traffic channel T which has been provided to both base stations 3A and 3B is released.

2 is a block diagram showing the configuration of the central control station 2 described above.

In FIG. 2, reference numeral 21 is an antenna for transmitting / receiving an satellite 1, an uplink signal, and a downlink signal, and 22 is an antenna 22 using frequency polarization characteristics. Orthogonal Mode Transducer (OMT) 23 for separating and transmitting and receiving signals transmitted and received through a low noise amplifier for low noise amplification Low Noise Amplifier (LNA), 24 is a frequency down converter (DC) for converting a frequency signal applied through the low noise amplifier 23 into an intermediate frequency signal IF of 70 MHz, for example.

In addition, reference numeral 25 separates and outputs the intermediate frequency signal IF applied from the frequency down converter 24 into a plurality of intermediate frequency signals, and also describes a Single Channel Per Carrier (SCP) channel unit to be described later. SCU: an intermediate frequency combiner / distributor (IF C / D: IF combiner / distributer) which combines and outputs an intermediate frequency signal applied from 31), and 26 is an intermediate applied from this intermediate frequency combiner / distributer 25 An SCPC channel unit that demodulates, decodes, and outputs a frequency signal, wherein the intermediate frequency combination / distributor 25 is employed for system scalability when using a plurality of SCPC channel units.

Further, reference numeral 31 denotes an SCPC channel unit for encoding, modulating and outputting a message output from the network controller 40 to be described later, and 32 denotes an IF signal of 70 MHz applied from the IF combination / distributor 25. For example, a frequency upconverter (UC) for converting the microwave into a microwave of 14.0 to 14.5 GHz to generate an uplink frequency signal, 33 is a high output amplifier for amplifying the uplink frequency signal output from the frequency upconverter 32 ( HPA: High Power Amplifier.

And, reference numeral 40 is a polling function that checks the state of each base station 3 based on a response message transmitted from the base station 3 after transmitting a control message to each base station 3 through the SCPC channel unit 26. In addition to performing a call request, when there is a call request, the network control unit performs system control such as allowing both base stations to directly communicate with each other based on the information obtained during the polling process.

In addition, reference numeral 60 is a network management system for a system administrator to manage the network control unit 40 to manage the overall network of the satellite communication system, which is largely composed of a VAX computer system, a terminal, and a printer, in particular, each base station It generates a reference time that is essential for data communication.

Here, the SCUs 26 and 31 and the network controller 40 are collectively called a DMA (DAMA Management Processor), and a network management system for executing the system operation and network management function is called a DOP (DAMA Operation Processor). do.

On the other hand, Figure 3 is a schematic diagram showing the configuration of the above-described network control unit 40, reference numeral 41 in the drawing controls the entire system, and in particular to control the same time between the central control station and the base station. Processor 42, extracts packet information from the message authorized by the SCPC channel unit 26 to generate a slotted ALOHA (S-ALOHA) packet, and a TDM for the SCPC channel unit 31; (Time Division Multiplex) A service channel controller (SCC) that generates and outputs a message of a stream.

Further, reference numeral 43 is a dual port RAM, which is provided for data transmission and reception between the processor 41 and the service channel controller 42.

Reference numeral 44 is a program storage unit for storing the operation program of the processor 44, and 45 is a base station information storage unit for storing state information of each base station obtained by the polling operation of the network processor 40. Is a channel information storage unit for storing the state of use of the communication channel allowed by the satellite, and 48 is an RCL that performs redundancy control for the Common Processor Module (CPM), system bus, etc. according to the duplication of the DMPs 26, 31, and 40. to be.

Next, the operation of the satellite communication system having the above configuration will be described.

In the normal state, the network controller 40 of FIG. 2 performs a polling operation to check the state of each base station.

That is, the processor 41 of the network control unit 40 writes packet data for checking the state of each base station in the dual port RAM 43, and the service channel controller 42 writes in the dual port RAM 43. After reading the written packet data, the TDM stream generates a message and outputs it to the SCPC channel unit 31.

Then, the SCPC channel unit 31 converts the message into an intermediate frequency signal of 70 MHz by encoding and modulating the message, and outputs the intermediate frequency signal. The intermediate frequency signal is combined by frequency in the IF combination / distributor 25 and then frequency. Increment conversion section 32 is converted to an uplink frequency signal of, for example, 14.5GHz. The uplink frequency signal is output through the high power amplifier 33, the quadrature mode converter 22, and the antenna 21, and then transmitted to each base station 3 through the satellite 1 in FIG. .

Meanwhile, the response message received from the base station 3 through the satellite 1 to the antenna 21, that is, the downlink frequency signal of 12.25 GHz is transmitted through the quadrature mode converter 22 and the low noise amplifier 23 to the frequency down converter. It is applied to (24) is converted into an intermediate frequency signal of 70MHz, and then applied to the SCPC channel unit 26 through the IF combination / distribution unit 25, demodulated and decoded and then applied to the network controller 40.

In addition, the network controller 40 extracts packet information from the message to which the service channel controller 42 is applied to generate an S-ALOHA packet, and then writes the packet information into the dual port RAM 43. By reading the packet data from the port RAM 43 and updating and registering the base station information storage unit 45 based on this, the state information for each base station is retained.

In addition, the above-described polling operation is continuously performed for each base station.

In addition, the network controller 40 is configured to be fully redundant to provide a smooth communication of the entire satellite communication network system. That is, the network controller 40 is composed of two modules that perform the same function. For example, if one network controller 40 is executing an operation (ACTIVE), the other is idle (STAND-BY). If a malfunction occurs in the network control unit 40 in the operating state, the module in the idle state becomes an operating state according to a predetermined control signal, and the module in the operating state is transferred to the idle state.

In addition, in the communication system using satellite communication as described above, the central control station 2 counts the reference time by itself and transmits it to each base station 3, and polls to check the state of the base station 3 as well. Each base station 3 performs mutual communication such as outputting a corresponding response message according to the polling message to the central control station 2.

At this time, when a transfer signal is output from the redundancy control logic (RCL) to the network control module (CPM) that counts the reference time in the operating state, the network control module (CPM) is in a dormant state, and the other network in the dormant state. The control module (CPM) is in operation to perform overall network management. If the new operation network control module (CPM) does not count the reference time by itself, the reference time from the existing operation network control module (CPM) is obtained. Even if it is received, a time difference occurs during the time required during the transfer, so that problems such as reliability of call transmission / reception data, call setup, and teardown or billing processing cannot be handled without error in the communication of each base station 3A, 3B. .

Accordingly, the present invention was created in view of the above circumstances, and by allowing two network control modules (CPMs) in a redundant central control station (DMP) to process reference times, respectively, an arbitrary module is in an idle state. It is an object of the present invention to provide a reference time redundancy device in a satellite communication system capable of providing an error-free reference time to each base station during redundancy switching to a furnace.

In order to achieve the above object, a reference time duplication apparatus in a satellite communication system according to an embodiment of the present invention includes redundant network control means for controlling request allocation call processing, reference time output means for generating a reference time, and duplication. A satellite communication system having a central control station having an RCL means for executing switching control, the network control means comprising: reference time storage means for storing a reference time, and time data storage for temporarily storing a reference time Means for storing the reference time in the reference time storing means and outputting the reference time to the network control means in the idle state, and in the idle state the reference time input from the network control means in the operating state. And control means for controlling to store in the visual data storage means. Characterized in that configured.

That is, according to the present invention having the above-described configuration, the redundant network module (CPM) in the central control station 2 can independently process the reference time to provide an error-free reference time for each base station in the redundant switching process. do.

Hereinafter, an embodiment according to the present invention will be described with reference to the drawings.

FIG. 4 is a block diagram showing a reference time redundancy apparatus in a satellite communication system according to an embodiment of the present invention. In FIG. 4, parts having substantially the same functions as those of FIG. 3 are denoted by the same reference numerals. Omit.

In FIG. 4, reference numeral 71 denotes a time storage unit for storing a reference time periodically input from a network controller (not shown) which is in an ACTIVE state according to a predetermined control signal, and reference numeral 72 denotes a predetermined control signal. In the idle state, the time data stored in the time storage unit 71 is counted. In the operating state, a timer for counting the time data stored in the CMOS 73 to be described later, and 73 is a sleep state (StandBy). In operation C, it is a CMOS (Clementary Metal Oxide Semiconductor) for storing the time data stored in the time storage unit 71 according to a predetermined control signal.

Reference numeral 70 denotes a processor that executes the control of the device as a whole, which is a function of the processor 41 described in FIG. 3, that is, a call such that a communication can be executed directly when there is a call request from any base station. When the redundancy switching signal is input from the RCL 48 in the idle state StandBy, the control function is switched to the active state to execute the overall control function of the apparatus. At this time, the processor 70 stores the reference time in the CMOS 73 to read the reference time from the time storage 71 and broadcasts the reference time to each base station.

Here, the network control unit (not shown) in the operating state is composed of the same device as that shown in FIG. 4, and when a redundant switching signal is input from, for example, the RCL 48 at any part of the system, The reference time input from the processor 70 which is a later operating state is stored in a time storage (not shown) in a non-illustrated time storage, and when the operation state is changed again, the reference time of the time storage part is stored in a non-illustrated CMOS. After storing, the reference time is broadcast to each base station 3 based on the stored information.

At this time, when the idle processor 70 receives an alternating signal from the RCL 48, the processor 70 switches its state to an operating state and stores the visual data of the time storage unit 71 in the CMOS 73 to store the reference signal. By continuously counting the times, network control according to the redundant transfer operation is executed.

Next, the operation of the apparatus in the above configuration will be described.

First, in the case of an active state among the redundant network controllers, the processor (not shown) in the operating state stores the reference time input from the network management system 60 in a CMOS not shown and stores the reference time. By broadcasting to each base station, the time of the entire network is matched and the reference time is output to the idle processor 70 at, for example, one second intervals.

In addition, when the redundant switching signal is input from the RCL 48, the processor in the operating state switches its state to the idle state, and then, for example, 1 second from the processor 70 (the former idle state processor) in the subsequent operating state. The reference time input at intervals is stored in a time storage not shown.

Meanwhile, when the reference time is input from the processor in the operating state, the processor 70 in the idle state stores the reference time in the time storage unit 71 and drives the timer 72 to control the counting operation with respect to the reference time. Thus, the time data of the time storage unit 71 is updated and stored.

Thereafter, when the redundant switching signal is input from the RCL 48, the processor 70 switches its state from an idle state to an operating state and reads reference time data stored in the time storage unit 71. The reference time is stored in the CMOS 73, and then the reference time is periodically broadcast to each base station 3. As shown in FIG. In addition, the processor 70 drives and controls the timer 73 to count the time data stored in the CMOS 73 by itself.

That is, according to the embodiment, when one module is in the operating state in the redundant network control module in the central control station 2, the other module is in the idle state and is switched to the operating state according to the switching signal of the RCL 48. Once the module is activated, the module performs the same function as the module in the previous operating state, and the module switched to the idle state operates in the same manner.

In addition, since each module independently processes the reference time, and if a malfunction occurs in any module in the operating state, the reference time without error is broadcasted to each base station at the time of redundancy switching based on the reference time in the idle state. The function can be performed consistently.

On the other hand, the present invention is not limited to the above embodiments and can be implemented in various modifications without departing from the technical rights of the present invention.

As described above, according to the present invention, two network control modules (CPMs) in a redundant central control station (DMP) can each process a reference time, so that when an arbitrary module is switched from the idle state to the idle state, A reference time redundancy device in a satellite communication system capable of providing an error-free reference time to each base station can be realized.

Claims (3)

10. A satellite communication system comprising a centralized control station having redundant network control means for controlling request allocation call processing and the like, a reference time output means for generating a reference time, and an RCL means for performing redundant transfer control. The control means comprises a reference time storage means for storing the reference time, and time data storage means for temporarily storing the reference time, and in the operating state, the reference time is stored in the reference time storage means and is in a rest state. And control means for outputting to the network control means of the control means, and controlling to store the reference time input from the network control means of the operation state in the time data storage means in the idle state. Reference vision redundancy device. The apparatus of claim 1, further comprising a timer means for executing a predetermined counting operation, wherein said control means controls to drive-control said timer means to update and store time data of said reference time storage means in an operation state. And updating and storing the time data of the time data storage means in the idle state. The reference time redundancy of the satellite communication system according to claim 1, wherein the control means controls to switch to an idle state in an operating state and to an operating state in an idle state when the redundant switching signal is input from the RCL means. Device.