KR100224562B1 - Apparatus for call restriction in a satellite communication system, and method thereof - Google Patents

Abstract

The present invention relates to an apparatus and method for making a call in a satellite communication system that can restrict a call based on a caller category set at the start-up of a system. And a central control station for managing and controlling the base station; The base station includes a system status class information storing means for storing current system status class information, a subscriber class information storing means for storing a subscriber class assigned to each subscriber line, and an outgoing call for storing subscriber number data set as a prohibition class. Prohibited information storage means and control means for performing normal call processing if the subscriber's subscriber level is higher than the system status class when the call request signal is input from any subscriber, and the system class is higher than the system status class. It features.

Description

Call Limiting Device and Method in Satellite Communication System

The present invention relates to a communication system using satellites, and more particularly, to an apparatus and method for calling a satellite communication system that can restrict a call based on a subscriber's predetermined call category in a normal operating state of the system. It is about.

Recently, with the rapid development of communication technology, satellite communication, which enables subscribers who are located at remote sites to make calls through satellites, has become increasingly common. Since such satellite communication does not require a separate signal line for a call, It is mainly used as a long distance communication between countries or as a communication method in a mountainous country such as Korea.

In the above-mentioned satellite communication, a PAMA (Pre-Assignment Multiple Access) method for allocating communication channels for each subscriber according to the channel assignment method and a DAMA (Demand Assignment Multiple Access) method for allocating communication channels according to a subscriber's request There are two methods. 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 Figure 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, 3 (3A, 3B) is a data terminal and facsimile, such as an exchange, a telephone, a computer, etc. A base station having an interface function for a terminal and providing a call function between the various terminals through data transmission and reception with the central control station 2.

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 sent from the base station 3, that is, communication It performs a polling function to check the available capacity or the utilization status of the communication channel. When there is a call request from a specific base station, for example, the base station 3A to the terminal of the base station 3B, it is determined whether the corresponding 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 21 through the antenna 21 using a polarization property of frequency. Orthogonal Mode Transducer (OMT) for separating and transmitting and receiving signals, 23 is a low-noise amplifier for low-noise amplifying 12.25 to 12.75 GkHz downlink frequency signal input through the orthogonal mode converter (22) 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. An intermediate frequency combiner / distributor (IF C / D) for combining and outputting an intermediate frequency signal applied from the SCU: 26, and 26 is an intermediate applied from the intermediate frequency combiner / distributor 25. It is a SCPC channel unit for demodulating, decoding, and outputting a frequency signal, and encoding and modulating and outputting a message output from the network controller 40 to be described later.

Here, the intermediate frequency combination / distributor 25 is employed for system scalability when using a plurality of SCPC channel units.

Further, reference numeral 27 denotes a frequency up-converter for converting an IF signal of 70 MHz applied from the IF combination / distributor 25 into an microwave of 14.0 to 14.5 GHz to generate an uplink frequency signal. And 28 are high power amplifiers (HPAs) for amplifying uplink frequency signals output from the frequency up-converter 27.

Reference numeral 40 denotes a state of each base station 3 based on a response message transmitted from the base station after transmitting a control message to each base station 3 through an arbitrary SCPC channel unit 26 _{1 to} 26 _N. Perform a polling function that checks whether a call is received from a specific base station, and determines if the other base station is in a communication state based on the information obtained in the polling process, and uses a satellite in a communication state. It is a network control unit that performs system control, such as by assigning possible traffic channels (T) and modems to both base stations to directly communicate with each other.

In addition, reference numeral 50 denotes a network management system for managing the overall network of the satellite communication system by the system administrator to manage the network control unit 40, the network management system 50 is coupled to the operator terminal 51 The operator terminal 51 operates according to a command input from an administrator who manages system operation and displays the state of the system through a predetermined display device.

3 shows the configuration of the base station 3 in FIG.

In general, the base station 3 has a configuration similar to that of the above-described central control station 2 as shown in FIG. 3, and since most of the configuration performs the same function as that of the central control station 2, it performs the same function. The detailed description is abbreviate | omitted about the structure to make.

In FIG. 3, reference numeral 70 denotes a base station controller which performs overall control of the base station, and the base station controller 70 is an arbitrary SCPC channel unit 66 _{1 to} 66 _n according to a control signal received from the central station 2. Or by allocating a communication channel so as to perform communication between subscribers, and control to transmit base station information such as a call setup state and a channel use state of the subscriber coupled to the base station 3 to the central control station 2. do.

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 periodically performs a polling operation to check the state of each base station and allocate an arbitrary communication channel based on the call request message required by the base station 3.

That is, the network controller 40 generates a TDM stream message from the packet data for checking the status of each base station, and then designates an arbitrary SCPC channel unit 26 to output the message.

Subsequently, the corresponding SCPC channel unit 26 converts the message into an intermediate frequency signal of 70 MHz by encoding and modulating the message, and outputs the intermediate frequency signal, which is combined by frequency in the IF combination / distributor 25. After that, the frequency increase converter 27 converts the frequency into an uplink frequency signal of, for example, 14.5GHz. The uplink frequency signal is output through the high power amplifier 28, the quadrature mode converter 22, and the antenna 21, and then transmitted to each base station 3 through the satellite 1 in FIG.

Then, when the base station control unit 70 of the base station 3 receives the downlink frequency signal of the TDM stream through the satellite 1, it extracts packet information from the frequency signal to the subscriber to any communication channel or SCPC channel. By allocating units, the controller can control the mutual communication or generate a response message of the S-ALOHA packet for the polling message and send it to the central control station 2.

On the other hand, the response message received by the antenna 21 from each base station 3 via the satellite 1, i.e., the downlink frequency signal of 12.25GHz, is frequency down through the orthogonal mode converter 22 and the low noise amplifier 23. It is applied to the converter 24 and converted into an intermediate frequency signal of 70 MHz, and then applied to an arbitrary SCPC channel unit 26 through the IF combination / distributor 25, demodulated and decoded, and then to the network controller 40. To be authorized.

In addition, the network controller 40 extracts packet information from the received message to generate an S-ALOHA packet, and then updates and registers a predetermined base station information storage unit based on this to hold state information for all base stations.

In addition, the network control unit 40 outputs the base station state information received from each base station 3 to the network management system 50, the network management system 50 to send the state information to the operator through a predetermined display device Will be displayed.

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

On the other hand, if there is a call request from another base station to another base station during the above-described polling operation, the network controller 40 reads the state information of the base station called from the predetermined base station information storage unit, and the base station is presently present. It is determined whether communication is possible. At this time, when it is determined that the communication is possible, the communication channel currently available is examined and the channel is allocated to the calling base station.

When the communication channel and the SCPC channel unit is allocated, the base station 3 controls the corresponding SCPC channel unit 66 _{1 to} 66 _N to perform mutual communication between subscribers.

As described above, when there is a call request from any subscriber, the base station 3 generates a series of S-ALOHA packets according to the call request, and sends it to the central control station 2, and the central control station 2 Searching for and assigning available communication channels and SCPC channel units will allow subscribers to communicate with each other.

By the way, in general, the communication channel provided by the satellite 1 is limited, and the number of subscribers who want to use this communication channel is relatively large.

Therefore, if a large number of subscribers are using the channel or requesting a new use at some point, the system may be congested, causing the system to be overloaded, causing the system to malfunction, and causing the system to go down. Will be created.

It is desirable to be able to use only a small number of subscribers rather than all subscribers not using it for a certain period of time due to excessive load on the system.

Accordingly, the present invention was created in view of the above circumstances, and the system can be down by limiting calls by determining the degree of load generated in the system based on the subscriber category set in the system. It is an object of the present invention to provide a method and a method for limiting a satellite communication system that can be prevented in advance.

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 a base station 3 in FIG.

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

FIG. 5 is an operational flowchart for explaining the operation of the apparatus of FIG. 4. FIG.

* Brief description of the main parts of the drawing

1: satellite 2: central control station

3A, 3B: base station 21, 61: antenna

22, 62: orthogonal mode converter 23, 63: low noise amplifier

24, 64: Frequency down converter 25, 65: Intermediate frequency combination / distribution

26, 66: SCPC channel unit 27, 67: frequency converter

28, 68: high power amplifier 40: network control unit

50: network management system 51: operator terminal

70, 80: base station controller 81: system status class information storage unit

82: subscriber grade information storage unit 83: outbound information storage unit

84: incoming call information storage

The method proposed in the satellite communication system according to the first aspect of the present invention for realizing the above object comprises a plurality of base stations coupled with a plurality of subscribers and a central control station for managing and controlling the base stations. In; The base station, when receiving the system status rating information, subscriber rating information, outgoing prohibition information data transmitted from the central control station, and storing them in a predetermined memory, respectively, and if the call request signal from the subscriber, the outgoing prohibition The outgoing grade determination step of determining whether the outgoing subscriber is the outgoing grade based on the information data, the grade comparing step of comparing the grades of the system status grade information data and the subscriber grade information data, and the subscriber grade has the outgoing grade. If it is not higher than the system status class, it characterized in that it comprises a step of performing a normal call processing.

In addition, the apparatus invoked by the satellite communication system according to the second aspect of the present invention includes a satellite communication system including a plurality of base stations each coupled with a plurality of subscribers, and a central control station for managing and controlling the base stations; The base station includes a system status class information storing means for storing current system status class information, a subscriber class information storing means for storing a subscriber class assigned to each subscriber line, and an outgoing call for storing subscriber number data set as a prohibition class. Prohibited information storage means and control means for performing normal call processing if the subscriber's subscriber level is higher than the system prohibition level and not the outgoing prohibition class when the call request signal is input from any subscriber. It is done.

That is, according to the above configuration, if a call request is received from any subscriber, the system can be prevented from being overloaded by performing a predetermined call limit operation by comparing the current status of the system with the call allowance range of the subscriber. .

On the other hand, Figure 4 is a block diagram showing the configuration of a call limiting device in a satellite communication system according to an embodiment of the present invention, with reference to the Figure will be described in detail an embodiment according to the present invention.

In FIG. 4, reference numeral 81 denotes a system state class information storage unit for storing the state class information of the current system with a predetermined flag, and the system state class information storage unit 81 is used by the base station controller 80 to be described later. The predetermined update registration operation is repeatedly performed in accordance with the control signal. This system status class indicates the load level of the system for each operation state of the system, such as the communication modem currently available, the SCPC channel unit, and whether the charging information of the subscriber transmitted from the base station is normally received.

That is, the network controller 40 periodically searches for the state of the system, and sets the system state in three steps, for example, normal, pre-overload, and overload. Each base station receiving the broadcast signal sets the system state class information storage unit 81 with a predetermined flag.

In addition, reference numeral 82 is a subscriber grade information storage unit for storing predetermined call grade information for a plurality of subscribers. The subscriber grade is similar to the system status grade for each subscriber line when the system is started. It is granted and can be changed by the operator during operation.

The subscriber class indicates the possibility that a call can be set when a call of any subscriber is converted into a grade. When a call is requested by a subscriber, the base station controller 80 to be described later is based on the subscriber grade of the subscriber. The state data of the system state grade information storage unit 81 is compared and a series of call processing is performed based on the result.

That is, if the current system status class is pre-overload and the subscriber's call request is the same pre-overload, the subscriber's request is accepted and the call processing operation is performed later, but the subscriber's rating is normal. If not, the base station controller 80 to be described later transmits a congestion sound to the subscriber without performing the call processing operation of the subscriber.

Also, reference numeral 83 is a call-inhibition information storage section for storing subscriber number information forbidding call-out. This call-inhibition information storage section 83 controls the base station controller 80 to be described later at the time of system startup. Accordingly, the subscriber number is stored, but outgoing subscriber means a subscriber who cannot send to other subscribers. For example, the out-of-call subscriber may include a complaint counter such as a police station or a fire station, and a subscriber may apply to the out-going subscriber by applying to an operator.

Further, reference numeral 84 denotes a call-inhibition information storage unit for storing subscriber number information forbidding call-in. This call-inhibition information storage unit 83 controls the base station controller 80 to be described later at the time of system startup. Accordingly, the subscriber number is stored. For example, the incoming call subscriber can be made by the subscriber's application, and when the other subscriber calls the incoming call subscriber, the base station transmits a call tone to the caller.

Further, reference numeral 80 denotes that the subscriber can perform communication between the subscribers by assigning an arbitrary SCPC channel unit 66 _{1 to} 66 _n or a communication channel, for example, when the subscriber requests a call. The system status class information and subscriber provided from the central control station 2, as well as outputting the base station information such as the call establishment state and channel usage state of the subscriber coupled to the central control station 2, On the basis of rating information and call forwarding / prohibition information, a series of call processing is performed when a subscriber requests or calls from another station.

Next, the operation of the device having the above configuration will be described using the operation flowchart of FIG. 5.

First, when the system is started, the central control station 2 searches for subscriber numbers coupled to each base station 3, and sets, for example, a do not disturb number, a do not disturb number, and a class of each subscriber by line, and stores the respective memories. In addition to storing in the broadcast to the base station.

Subsequently, as described with reference to FIGS. 2 and 3, as the polling operation is periodically performed, state information of each base station including the currently used communication channel and SCPC channel unit received from each base station 3 is received and retained. Done.

In addition, based on the status information of each base station to determine the degree of load on the current system and stores the result in a predetermined memory as one of the system status class of normal, pre-overload, overload, and each base station Will be broadcast.

When the base station controller 80 of the base station 3 receives the system status message and the subscriber class message from the central control station 2, the system status class information storage unit 81 and the subscriber class information storage unit ( 82).

Subsequently, the base station control unit 80 stores the system state class information storage unit 81, the subscriber class information storage unit 82, the outgoing call information storage unit 83, and the incoming call avoidance information storage unit 84 as described above. If there is a call request signal from any subscriber in the state where the data is stored (step ST1), the calling party number is extracted, and then the information about the subscriber number is retrieved by referring to the storage units 81, 82, and 83. (ST2 step).

That is, the base station controller 80 first determines whether the calling subscriber is the calling prohibition class by referring to the data of the calling prohibition information storage unit 83 (step ST3). Congestion Tone is sent to the user (ST4 step).

On the other hand, if the originating subscriber is not the originating prohibition grade, the system status class information storage unit 81 is searched for the current system status level and the subscriber class information storage unit 82 is referred to. The subscriber's grade is determined (ST5, ST6).

Subsequently, the base station controller 80 compares the system class and the subscriber class searched in the step (ST7 step). If the subscriber class is higher than the system class, the base station controller 80 generates a predetermined S-ALOHA packet according to the central control. By sending to the station 2, normal call processing is executed (ST8 step).

That is, according to the above embodiment, it is possible to control the overload of the system by comparing the calling party's subscriber rating and the current system status rating and performing call processing based on the result.

On the other hand, when the base station 3 receives the incoming signal from the central control station 2, the base station 3 extracts the called party number from the called signal and then refers to the data of the do not disturb information storage unit 84 to stop the incoming caller number. Determine if it is a grade.

Thus, if the called party is called, the call will be sent to the central station 2, and the central station 2 will then send a call to the calling base station. The request signal is ignored. However, if the called party is not the incoming call ban class, normal call processing is performed.

On the other hand, the subscriber can set his own subscriber class arbitrarily. At this time, the base station 3 performs call processing based on the subscriber class. However, subscribers may not upgrade their rating.

For example, a subscriber first presses a special key (*) commonly used in a telephone to adjust his / her subscriber grade, and then presses a grade change code (eg, 22) to restrict a call. You can change the subscriber's rating by pressing the rating you want to change and then pressing the special key (*).

That is, according to the above embodiment, when a call request is received from a certain subscriber, the system can be prevented from being overloaded by performing a predetermined call limit operation by comparing the current status of the system with the call permission range of the subscriber.

In addition, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the technical gist of the present invention.

As described above, according to the present invention, it is possible to realize an apparatus and method called by a satellite communication system that can control the overload of the system by restricting the call based on the caller category set at the start of the system. have.

Claims (5)

A satellite communication system comprising a plurality of base stations each coupled with a plurality of subscribers, and a central control station for managing and controlling the base stations; The base station, A data storage step of storing system state rating information, subscriber rating information, and outgoing call information data transmitted from the central control station in a predetermined memory, respectively; When the call request signal is received from the subscriber, the call prohibition rating judgment step of determining whether the call out subscriber is a call prohibition class based on the call prohibition information data, A rating comparison step of comparing the ratings of the system status rating information data and the subscriber rating information data; And if the subscriber class is not a prohibition class and is higher than the system status class, executing normal call processing. The method of claim 1, Calling method in a satellite communication system characterized in that it comprises a congestion sound transmitting step of transmitting a congestion sound to the calling subscriber if the calling subscriber is outgoing call grade. The method of claim 1, If the subscriber class is lower than the system status class, the call limiting method in the satellite communication system characterized in that it comprises a congestion sound transmitting step for transmitting a congestion sound to the subscriber. A satellite communication system comprising a plurality of base stations each coupled with a plurality of subscribers, and a central control station for managing and controlling the base stations; The base station, System status rating information storage means for storing current system status rating information; Subscriber grade information storage means for storing subscriber grades granted for each subscriber line, Outgoing call information storage means for storing the subscriber number data set to the call prohibition class, and Satellite communication system comprising a control means for performing normal call processing if the call request signal from any subscriber is not the calling party's subscriber class or the call prohibition class but higher than the system status class. Call limiting device. The method of claim 4, wherein It further comprises a call forwarding information storage means for storing the subscriber number data set to call forwarding grade, And the control means controls to perform a series of call processing based on the do not disturb information data when a call signal is received.