KR100205660B1 - Data call checking method and thereof method in satellite telecommunication system - Google Patents

Abstract

The present invention monitors a call path periodically in a data call communication and detects an abnormal state in a call, releases the call, and immediately notifies an operator of an abnormal state in a call of a data call, The present invention relates to a method and apparatus for monitoring a data call in a satellite communication system in which a plurality of base stations are combined with a plurality of subscribers, And a central control station for operating and controlling a plurality of base stations based on data CALL information, the system comprising: Wherein the base station comprises first and second timer means for performing a predetermined counting operation, acknowledgment message storing means for storing acknowledgment message data for monitoring a data call in communication, And transmits the acknowledgment message data to the mobile station, and releases the data call if a response message is not received from the mobile station before a predetermined time.

Description

Method and apparatus for monitoring data call in a satellite communication system

The present invention relates to a communication system using a satellite, and more particularly to a communication system using a satellite, which periodically monitors a call path during a data call communication and releases an associated data call, The present invention relates to a method and apparatus for monitoring a data call in a satellite communication system that enables a subscriber to be prevented from being disadvantaged by promptly reporting an abnormal state.

In recent years, with the rapid development of communication technology, satellite communication that enables subscribers located at a remote place to make calls through a satellite is gradually becoming common. Such satellite communication is useful for long distance communication between countries, or communication method of a mountainous country like Korea because a separate signal line is not required for communication.

The satellite communication includes a PAMA (Pre-Assignment Multiple Access) scheme in which a corresponding channel is reserved according to a channel allocation request to be used by a subscriber according to a channel allocation scheme, and a PAM And a Demand Assignment Multiple Access (DAMA) method.

In general, considering the price and effectiveness of communication channels, real-time voice communication adopts the DAMA scheme and data communication uses the PAMA scheme.

1 is a block diagram showing the overall system configuration of a satellite communication system according to the PAMA scheme.

In FIG. 1, reference numeral 1 denotes a satellite having a plurality of communication channels, reference numeral 2 denotes a central control station for controlling the entire satellite communication system, reference numerals 3A and 3B denote data terminals such as exchangers, And is a base station having an interface function with respect to the terminal and providing a call function between the various terminals through data transmission / reception with the central control station 2.

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

In the above configuration, the central control station 2 transmits a control message through the service channel S and then grasps the state of each base station 3 based on a response message transmitted from the corresponding base station 3 . That is, the base station 3 performs a polling function for checking the communication capacity of the base station 3 and the use state of the communication channel.

Meanwhile, the central control station 2 is connected with a predetermined signal for reserving the satellite channel by the operator, and is associated with a data call (DATA CALL) such as a reservation time, a subscriber number, a connection mode such as synchronous or asynchronous, When information is input, information related to the data call is stored, and based on the data, a communication channel and a communication modem (SCU) are allocated when the reservation time is reached to control communication between the base stations.

Then, when the use end time of the channel set by the operator has elapsed, the central control station 2 cancels the traffic channel T provided for both the base stations 3A and 3B by executing communication end processing for both base stations .

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

Reference numeral 21 in FIG. 2 denotes an antenna for transmitting / receiving an uplink signal and a downlink signal with the satellite 1 and reference numeral 22 denotes an antenna for transmitting / receiving an uplink signal and a downlink signal through the antenna 21 An orthogonal mode transducer (OMT) 23 for separately inputting and outputting signals to be transmitted and received, a low noise amplifier 23 for low-noise amplifying a downlink frequency signal of 12.25 to 12.75 GHz inputted through the orthogonal mode converter 22 LNA (Low Noise Amplifier), and 24 is a frequency down converter (DC) for converting a frequency signal applied through the low noise amplifier 23 to an intermediate frequency signal IF of, for example, 70 MHz.

Reference numeral 25 denotes a frequency division multiplexer for separating and outputting an intermediate frequency signal IF applied from the frequency down converter 24 to a plurality of intermediate frequency signals and outputting a single channel per channel (SCPC) channel unit (IF C / D: IF Combiner / Distributor) 26 for outputting an intermediate frequency signal applied from the intermediate frequency combining / distributing unit 25, Demodulates, decodes and outputs the frequency signal, and encodes and modulates a message output from the network control unit 40, which will be described later, and outputs the message.

Here, the intermediate frequency combining / distributing unit 25 is employed for system scalability when a plurality of SCPC channel units are used, and the number of the SCPC channel units 26 is generally 32. [

Reference numeral 27 denotes a frequency up-converter (UC) for converting an IF signal of 70 MHz applied from the IF combining / distributing unit 25 into a microwave of, for example, 14.0 to 14.5 GHz to generate an uplink frequency signal. And 28 is a high power amplifier (HPA) for amplifying an uplink frequency signal output from the frequency up converter 27.

Reference numeral 40 indicates a state of each base station 3 based on a response message transmitted from the corresponding base station after transmitting a control message to each base station 3 through arbitrary SCPC channel units 261 to 26N And a polling function to perform the polling function. The network controller 40 allocates the available traffic channel T and the modem when a channel allocation command according to the data call CALL is input from the network management system 50 to be described later, So that the system control can be performed.

Reference numeral 50 denotes a network management system for the system manager to manage the overall network of the satellite communication system by managing the network control unit 40. The network management system 50 controls the network controller 40 based on the data call information input by the operator to perform communication between the base stations.

3 is a functional block diagram showing the configuration of the network control unit 40 and the network management system 50. [

Reference numeral 41 denotes a network processor for controlling and controlling a series of data call operations when a predetermined control signal for a data call is input from the network management processor 51 to be described later, A reference numeral 43 denotes a data call information storage unit for storing data call related information input from the network management system 50;

Reference numeral 51 denotes a network management processor for controlling a data call function such as execution control of a channel reservation operation set by an operator, reference numeral 52 denotes a network communication interface between a satellite communication system and an operator An information exchange device, that is, a man-machine interface (MMI) for an operator to confirm information from the system and input operation commands of the system.

Reference numeral 53 denotes a terminal server for transmitting and receiving a signal to and from the network processor 41 of the network control unit 40. This is a terminal server based on a communication protocol of the RS-232C and the network control unit 40, To communicate with each other.

Reference numeral 54 denotes a data call real-time processing unit for outputting a predetermined signal to the network management processor 51 when a reservation time or a reservation end time is reached based on a series of data call data input by the operator, The data call real-time processing unit 54 itself has a timer for counting a predetermined time. Reference numeral 55 denotes a data call execution unit for performing a series of data call operations in accordance with a control signal input from the network management processor 51. [

Reference numeral 56 denotes a data call storage unit for storing data call information input according to the operation of the operator according to the control of the network management processor 51. Reference numeral 57 denotes a channel reservation time input from the operator, And a data call reservation unit for temporarily storing data call related information such as a subscriber number and a communication speed. The data call reservation unit 57 is provided for the reference when the network management processor 51 determines that the data call data input from the operator is correct data.

5, reference numeral 61 denotes an antenna for transmitting and receiving an uplink signal and a downlink signal to and from the satellite 1. The base station 3 of FIG. And 62 is an Orthogonal Mode Transducer (OMT) for separating and inputting / outputting a signal transmitted / received through the antenna 61 using the polarization characteristic of the frequency.

Reference numeral 63 denotes a low noise amplifying unit for low-noise amplifying the downlink frequency signal inputted through the orthogonal mode converting unit 62 and converting the downlink frequency signal into an intermediate frequency signal IF of, for example, 70 MHz, And a frequency converter for combining and outputting intermediate frequency signals applied from a single channel per channel (SCPC) channel unit (SCPC) 64, which will be described later. The frequency converter 63 converts an intermediate frequency signal (IF) signal of 70 MHz into a microwave of 14.0 to 14.5 GHz, for example, to generate an uplink frequency signal, and then outputs the generated uplink frequency signal through the antenna.

Reference numeral 64 denotes an SCPC channel unit for demodulating, decoding, and outputting an intermediate frequency signal applied from the frequency converting unit 63, and for outputting a message to be described later, which is output from the base station controlling unit 60, to be.

Reference numeral 60 denotes a base station control unit for allocating arbitrary SCPC channel units 261 to 26N according to a control signal received from the central control station 2 to control direct communication between subscribers.

Next, the operation of the PAMA satellite communication system having the above-described configuration will be described with reference to the operation flow chart of FIG.

First, when data related to a data call is input by the operator, the network management processor 51 temporarily stores the data in the data call reservation unit 57 (ST41 and ST42). The data related to the data call includes a channel reservation time, an end time, an incoming / outgoing subscriber number, a communication channel number, a communication modem (SCU), and the like.

Then, the network management processor 51 determines whether or not the input channel reservation time is in the future (ST43). If the reservation time is in the future, the network management processor 51 determines whether the inputted calling subscriber number and called subscriber number exist normally (ST44).

If the input data call related data is in the future and the subscriber number normally exists, the data call reserving unit 57 re-stores the data in the data call storage unit 56 in step ST45.

Thereafter, the network management processor 51 searches for a signal input from the data call real-time processing unit 54. [ At this time, the data call real-time processing unit 54 continuously checks whether the reserved time is reached (ST46). When the reserved call time is reached, the network call processor 51 outputs a predetermined result signal.

The network management processor 51 searches for available satellite channels when a predetermined result signal is input from the data call real-time processing unit 54 and broadcasts the available satellite channels to the base station 3 and allocates the SCPC channel unit 64 (ST47 , Step 48). Then, the base station 3 controls data communication between the subscribers through the communication channel and the SCPC channel unit 64 allocated from the central control station 2.

On the other hand, the data call real-time processing unit 54 continuously judges whether or not the reserved channel is the end time. The network management processor 51 receives the result signal of the predetermined level from the data call real- The control command is output to the network controller 40 to release the set call (steps ST49 and ST50). Then, the network control unit 40 outputs a data call release signal to the base station 3. When the base station 3 receives the call release signal, the network control unit 40 outputs a communication end signal to the subscriber to terminate the communication through the data call do.

On the other hand, if there is no available communication channel in step ST47, the network management processor 51 sets a reservation failure state (FAIL) for the channel reservation operation, and the operator re-inputs the data (Step ST51).

That is, as described above, in the channel reservation assignment method (PAMA), when the operator inputs a reservation time such as a channel use start time and an end time for a certain channel and reserves the reservation, the processor allocates the corresponding channel when the reservation time comes The subscriber can perform the data communication, and the data call is automatically released when the end time comes.

Meanwhile, after the data call is established, the central control station 2 does not participate in the data communication between the subscribers until the end time of the data call, and direct communication between the base stations is performed. That is, both base stations perform data communication without passing through the central control station 2 through the communication channel and the SCPC channel unit allocated from the central control station 2.

After the data channel is reserved after the communication channel is reserved and the data call is established, the data call continuously maintained until the end time is maintained, and an abnormal state, a data line abnormal state, an allocated communication modem (SCU) An error occurs in the call path due to various factors such as an error of the data link, and thus the established data call is maintained even if an error occurs in the data transmitted and received.

This causes a disadvantage that a user is charged even when the user can not perform data transmission / reception due to various communication conditions.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a data call communication system and a data call method in which when a data call communication is periodically monitored, The present invention provides a method and apparatus for monitoring a data call in a satellite communication system that enables a subscriber to be informed of an abnormal state immediately.

1 is a general system configuration diagram for explaining an outline of a general satellite communication system;

Fig. 2 is a functional block diagram showing the configuration of the central control station 2 in Fig. 1. Fig.

3 is a functional block diagram showing the configuration of the network control unit 40 and the network management system 50 in Fig.

FIG. 4 is an operation flow chart for explaining a reservation allocation method (PAMA) of a satellite channel; FIG.

5 is a block diagram showing the configuration of the base station 3 in Fig.

FIG. 6 is a block diagram showing a configuration of a data call monitoring apparatus in a satellite communication system according to a first embodiment of the present invention; FIG.

FIG. 7 is an operation flow chart for explaining the operation of the apparatus having the configuration of FIG. 6; FIG.

* A brief description of the main parts of the drawing

1: satellite 2: central control station

3A: base station 21: antenna

22: orthogonal mode converter 23: low noise amplifier

24: frequency down converter 25: intermediate frequency combination /

26: SCPC channel unit 27: frequency up converter

28: high power amplifier 40: network controller

41: network processor 42: program storage unit

43: Data call information storage unit 50: Network management system

51: Network Management Processor 52: Man-Machine Interface (MMI)

53: Terminal server 54: Data call real-time processing unit

55: data call execution unit 56: data call storage unit

57: Data call reservation unit 60, 70:

63: frequency conversion unit 64: SCPC channel unit

71: counter 72: first timer

73: second timer 74: confirmation message storage section

A method for monitoring a data call in a satellite communication system according to a first aspect of the present invention for realizing the above object is a method for monitoring a data call by using a plurality of base stations combined with a plurality of subscribers, A satellite communication system having a central control station for operating and controlling a plurality of base stations based on data CALL information, the system comprising: A data call information input step of the operator inputting data call information, a confirmation message transmission step of transmitting a confirmation message to the mobile station after the data call is set up, a response message waiting to receive a response message to the confirmation message transmitted to the mobile station And releasing the data call if the response message is not received for a predetermined period of time in the response message receiving step and sending a call release message including the charging information to the central control station .

In addition, if the response message is not received for a predetermined time in the response message receiving step, the process proceeds to the acknowledgment message sending step and the following operations are repeatedly performed for a predetermined number of times.

According to a second aspect of the present invention, in a satellite communication system, a data call monitoring apparatus includes a plurality of base stations coupled with a plurality of subscribers, and a data call (DATA CALL And a central control station for operating and controlling a plurality of base stations based on the information of the plurality of base stations; Wherein the base station comprises first and second timer means for performing a predetermined counting operation, acknowledgment message storing means for storing acknowledgment message data for monitoring a data call in communication, And transmits the acknowledgment message data to the mobile station, and releases the data call if a response message is not received from the mobile station before a predetermined time.

Further, the control means may send a confirmation message again if a response message is not received after a predetermined time from the game station after transmitting the confirmation message, and repeat the confirmation message sending operation a predetermined number of times.

Therefore, according to the above-described method, if a data call in communication is continuously monitored, if the communication path is abnormal, the call is immediately released and the operator is notified of the data call, thereby preventing disadvantages of the subscriber.

Embodiments according to the present invention will now be described with reference to the accompanying drawings.

FIG. 6 is a block diagram showing a configuration of a data call monitoring apparatus in a satellite communication system according to an embodiment of the present invention. In FIG. 6, components performing the same functions as those of FIG. 4 are denoted by the same reference numerals, do.

In FIG. 6, reference numeral 71 denotes a counter for performing a predetermined counting operation, reference numerals 72 and 73 denote first and second timers for counting a predetermined time and outputting a resultant signal when a predetermined time is reached, And a confirmation message storage unit for storing confirmation message data to be transmitted from the originating station to the receiving station in order to inspect the communication path currently being communicated by the processor 60 to be described later.

In addition, reference numeral 70 denotes a unit for reading confirmation message data from the confirmation message storage unit 73 every time a signal obtained by counting a predetermined value from the first timer 72 is input when a data call is formed, To the base station via the base station.

Next, the operation of the apparatus having the above-described configuration will be described with reference to the operation flow chart of Fig.

First, when the data call information is inputted from the operator through the man-machine interface 52, the network management system 50 of the central control station 2 stores the data call information in the data call information storage unit 56. Thereafter, when the start time of an arbitrary data call is reached, data call information is output to the network control unit 40. The network control unit 40 generates a TDM stream message for data call setup and broadcasts to the corresponding base station 3 do.

Then, the base station 3 controls and controls communication between subscribers through the SCPC channel unit included in the data call information received from the central control station 2. [

Then, when the communication path is formed as described above (ST1), the base station control unit 70 drives and controls the first timer 72 to count the time (ST2). When the first timer 72 counts a predetermined value, the resultant signal of a predetermined level is output. When a result signal of a predetermined level is input from the first timer 72 (ST3 The confirmation message is read out from the confirmation message storage unit 74, and the confirmation message is transmitted to the partner station through the arbitrary SCPC channel unit 64 (ST4).

In addition, the base station control unit 70 increases the count value of the counter 71 by '1' (ST5).

On the other hand, after transmitting the confirmation message to the base station, the base station control unit 70 drives and controls the second timer 73 to count a predetermined time and to continuously search whether a response message to the confirmation message is received from the base station (Step ST6), the counted data of the counter 71 is cleared, and the process proceeds to step ST2, and the following steps (ST7).

On the other hand, if the response message is not received from the game station until the second timer 73 counts the predetermined time in step ST6 (ST8), the base station control unit 70 determines that the current count value (Step ST9). If the present counted value exceeds the set value, the caller sends a ringing tone to the subscriber of the local station and the corresponding station (Step ST10).

That is, if the acknowledgment message sent out to the mobile station exceeds the predetermined number, it is regarded as an abnormal state of the voice call and the corresponding call is released.

Then, the base station control unit 70 transmits a call release message including billing information such as a start time and an end time for the call to the central control station 2 (ST11).

On the other hand, if it is determined in step ST9 that the current counted value does not exceed the predetermined count value, the process proceeds to step ST2 to perform the following operation.

That is, according to the above embodiment, when the acknowledgment message is not received while monitoring the call path by transmitting / receiving the acknowledgment / response message through the data call in communication, the disadvantage of the subscriber can be minimized by canceling the call immediately.

The present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the technical scope of the present invention.

As described above, according to the present invention, when a call is periodically monitored during a data call communication and an abnormal state is detected, a call is released and an operator is immediately notified of an abnormal state of the call The present invention can realize a data call monitoring method and apparatus in a satellite communication system that can prevent a disadvantage of a subscriber.

Claims (6)

There is provided a satellite communication system including a plurality of base stations coupled to a plurality of subscribers, and a central control station for operating and controlling a plurality of base stations based on data call information input by a system operator, the system comprising: A data call information input step in which an operator inputs data call information, Transmitting an acknowledgment message to the mobile station after the data call is established, A response message reception step of awaiting reception of a response message to an acknowledgment message transmitted to a partner station; And transmitting a call release message including the charging information to the central control station when the response message is not received in the response message reception step for a predetermined time period. A method for monitoring data calls in a communication system. The method according to claim 1, If the response message is not received for a predetermined time in the response message receiving step, the process proceeds to the acknowledgment message sending step and the following operations are repeatedly performed for a predetermined number of times. The method according to claim 1, If the response message is received within a predetermined time in the response message receiving step, the process proceeds to the acknowledgment message transmitting step and repeats the following operation. There is provided a satellite communication system including a plurality of base stations coupled to a plurality of subscribers, and a central control station for operating and controlling a plurality of base stations based on data call information input by a system operator, the system comprising: The base station comprises first and second timer means for performing a predetermined counting operation, A confirmation message storage means for storing confirmation message data for monitoring a data call in communication, And a control means for reading the confirmation message data and sending it out to a mobile station when a predetermined time has elapsed after the data call is set and releasing the data call if a response message is not received from the mobile station before a predetermined time The data call monitoring device in the satellite communication system. 5. The method of claim 4, Wherein the control unit sends a confirmation message again when a response message is not received after a predetermined time from the game station after transmitting the confirmation message and repeats the confirmation message transmission operation a predetermined number of times. Monitoring device. 5. The method of claim 4, Wherein the control unit repeatedly transmits an acknowledgment message when a response message is received a predetermined time before the receiving station after transmitting the acknowledgment message.