KR100258686B1 - Internal call setting method in satellite communication - Google Patents

Abstract

PURPOSE: A method for rapidly setting up an internal call in a satellite communication system is provided to achieve a rapid call setup by assigning a communication channel without the necessity of the subband signaling procedure to set and synchronize a modem of a calling subscriber base station and a modem of a called subscriber base station. CONSTITUTION: If a calling message from a calling subscriber base station is generated for a called subscriber base station(ST2), a processor retrieves and appoints the called subscriber base station through the translation of the calling message(ST3). The processor checks the existence of an available communication channel through a channel information storage part(ST4). In case that an available communication channel exists(ST5), the processor sends available channel information to both base stations(ST6). The processor counts time through a timer while sending a ring signal to the called subscriber base station(ST7). If an off-hook signal is received within a given time, the processor sends a message to inform the calling subscriber base station that call connection has been made, so both base stations can carry out a call through the allocated channel(ST11).

Description

Fast internal call setup in satellite communication system

The present invention relates to a method for establishing a call in a satellite communication system. In particular, a method for quickly setting up an internal call in a satellite communication system in which a call can be quickly established without a process of synchronizing a channel modem allocated in an internal communication between subscribers of a satellite communication network. It is about.

Figure 1 shows the overall system configuration of a typical demand assignment multiple access (DAMA) satellite communication system that is assigned to the communication channel according to the subscriber's request.

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 addition, 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.

That is, in the satellite communication system having the above-described configuration, the central control station 2 normally transmits a control message through the service channel, and then, based on the response message transmitted from the base station 3, each base station 3 It performs a polling function to check the state of the communication capacity or the availability of the communication channel.

If there is a call request from a subscriber of a satellite communication network, for example, from a base station 3A to another terminal 3B, the base station 3B can communicate based on the information obtained during the polling process. It is determined whether the state is, that is, the subband signaling for synchronizing the modem of the base station 3A to which the calling party belongs and the modem of the base station 3B to which the called party belongs.

The subband signaling is performed by checking the abnormal state of channel modems of both base stations 3A and 3B, and also sending a synchronization message for synchronizing both channel modems, and receiving a synchronization message signal from the subscriber base station 3A. In this case, the central control station 2 transmits a ring signal to the called subscriber base station 3B.

Subsequently, when a synchronization response message signal is received from the called party base station 3B, the central control station 2 sends a ringback tone signal to the calling party base station 3A, and transmits the available traffic channel T of the satellite to both base stations (see FIG. By allocating to 3A and 3B, both base stations 3A and 3B can directly communicate with each other.

On the other hand, the synchronization message signal transmitted from the subscriber base station 3A is to be transmitted three times in succession, the modem of the subscriber base station 3B is to wait for the synchronization message signal that is sent every time when the call is set up call setup time In addition to this delay, if there is an error in the modem of the subscriber base station 3A, the subscriber station 3B subscriber cannot communicate with the calling subscriber because the synchronization message signal is not transmitted to the destination base station 3B modem. In addition, there is inconvenience that the call service request cannot be made because communication is tied up.

Accordingly, the present invention has been made in view of the above circumstances, and in the internal communication of a satellite communication system, a communication channel is allocated without a subband signaling process of setting and synchronizing a modem of a calling party base station and a calling party base station. The purpose of the present invention is to provide a fast internal call setup method in a satellite communication system that enables quick call setup.

1 is a block diagram showing the overall system configuration of a general satellite communication system.

2 is a diagram showing the configuration of a central control station for explaining a method for quickly establishing an internal call in a satellite communication system according to the present invention;

3 is a configuration diagram showing the configuration of the network control unit 40 shown in FIG.

Figure 4 is a flow chart for explaining a quick internal call setup method in a satellite communication system according to an embodiment of the present invention.

<Explanation of symbols for main parts of drawing>

1: satellite 2: central control station

3: base station S: service channel

T: Traffic channel 11A, 11B: Switch

12A, 12B: Computer 13A, 13B: Terminal

14A, 14B: Facsimile 21: Antenna

22: Orthogonal Mode Converter (OMT) 23: Low Noise Amplifier (LNA)

24: frequency down converter (DC)

25: Intermediate frequency combiner / distributor (IF C / D: IF Combiner / Distributer)

26: SCPC (Single Channel Per Carrier) Channel Unit

27: Telephone Data Card

32: Frequency Up Converter (UC) 33: High Power Amplifier (HPA)

40: network controller 41: processor

42: Service Channel Controller (SCC)

43: dual port RAM 45: base station information storage unit

46: channel information storage unit 47: timer

50: network management system

In the satellite communication system according to the present invention for realizing the above object, a rapid internal call setup method controls a call so as to make a call by allocating a transponder channel usable between a calling party base station with a call request and a called party base station of a call destination. In a satellite communication system equipped with a central control station, a call request receiving step for receiving a destination number and a number translation request message from a calling party base station, and a called base station designation step for designating a called party base station by translating the received number. A channel assignment step of allocating an available channel of the transponder between the retrieved called subscriber base station and the called subscriber base station, an incoming signal sending step of transmitting an incoming signal to the called subscriber base station, and a time coefficient for counting a predetermined time after sending the incoming signal Step, while counting the predetermined time Call execution step to make a call between the two base stations through the assigned channel when the pre-hook signal is received, Call termination step to recover the transponder channel allocated between both base stations when receiving the message data about the call termination from the subscriber base station Characterized in that configured to include.

Further, if the off-hook signal is not received even after a predetermined time elapses after sending the incoming signal to the called party base station, the communication error signal sending step of sending a signal relating to the communication error to the calling party base station further comprises It features.

According to the present invention having the above-described configuration, in the internal communication of the satellite communication system, when there is a call request from the calling party base station, the central control station can use the transponder between the calling party base station and the calling party base station without subband signaling. You will assign channels so that calls can be made immediately.

Therefore, the communication call setup time is shortened, and when there is no response from the called subscriber base station even after a predetermined time elapses, it is possible to determine an abnormal state of the channel modem.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Figure 2 shows the configuration of a central control station for explaining a quick internal call setup method in a satellite communication system according to the present invention.

In FIG. 2, reference numeral 21 is an antenna for transmitting and receiving an uplink signal and a downlink signal with respect to satellites 1: 1, and 22 is a signal transmitted and received through the antenna 21 using a polarization property of frequency. Orthogonal Mode Transducer (OMT) 23 for separating and inputting and outputting a low noise amplifier (LNA) for low noise amplifying a downlink frequency signal of 12.25 to 12.75 GHz, for example, inputted through the Orthogonal Mode Transducer 22. Amplifier 24 denotes 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, the 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 ( IF C / D: IF Combiner / Distributer (IF C / D) which combines and outputs the intermediate frequency signal applied from SCU: 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.

Reference numeral 27 denotes a telephone data card (hereinafter referred to as a TDC) for connecting terminals such as a telephone 12, a data terminal 13, a facsimile 14, and the like as shown in FIG. Is an SCPC channel unit for encoding and modulating and outputting a message output from the network controller 40 to be described later, and 32 is a microwave signal of 14.0 to 14.5, for example, an IF signal of 70 MHz applied from the IF combination / distributor 25. An up-converter (UC), 33, which converts to an uplink frequency signal to generate an uplink frequency signal, is a high power amplifier (HPA) that amplifies an uplink frequency signal output from the frequency up-converter 32.

Reference numeral 40 denotes a base station 3B that manages a call connection target through number translation when there is a call request from an arbitrary base station 3A, and is used between the call connection target base station and the call request base station. It is a network control unit that executes a call control function in which both base stations can directly perform communication through this allocated communication channel by allocating a possible transponder channel.

4 is a configuration diagram schematically illustrating the configuration of the network controller 40 described above. In FIG. 4, reference numeral 41 denotes a processor that controls the entire system and particularly controls call processing between base stations according to the present invention. In addition to extracting packet information (Packet Information) from the message authorized from the SCPC channel unit 26 generates a S-ALOHA (Slotted ALOHA) packet, and the TDM (Time Division Multiplex) for the SCPC channel unit 31 Service Channel Controller (SCC) that generates and outputs messages from streams.

Further, reference numeral 43 denotes 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 41. Denotes a channel information storage unit for storing the state of use of the communication channel allowed by the satellite, and 47 denotes a timer for counting a predetermined time.

The channel information storage section 46 has a storage area corresponding to the number of communication channels allowable by the satellite, and each storage area has a binary value of " 0 " or " 1 " depending on whether a communication channel corresponding thereto is used. The data will be saved. The binary data is changed and set by the processor 41 according to the use state of the communication channel.

On the other hand, the reference numeral 50 in FIG. 2 is a network management system for the system administrator to manage the network control unit 40 to manage the overall network of the satellite communication system.

Next, the operation of the satellite communication system having the above configuration will be described with reference to the flowchart shown in FIG. 4.

In a normal state, the network control unit 40 performs a polling operation to check the state of each base station. The processor 41 of the network control unit 40 supplies packet data for checking the state of each base station. The service channel controller 42 reads the packet data written in the dual port RAM 43, generates a message of the TDM stream, and outputs the message 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. The up-converter 32 converts the uplink frequency signal of, for example, 14.5 GHz. 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.

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 applied to the orthogonal mode converter 22 and converted into an intermediate frequency signal of 70 MHz. Then, it is applied to the SCPC channel unit 26 through the IF combination / distributor 25, demodulated and decoded, and then applied to the network controller 40.

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 polling operation is continuously performed for each base station (step ST1).

On the other hand, if there is a call request for the called party base station which receives the destination number and the number translation request message from any calling base station during the above-mentioned polling operation (step ST2), The received number data is translated to search for and designate a corresponding subscriber base station (step ST3).

When the busy state of the communication channel is "1", it is checked whether there is an available communication channel written as "0" in the channel information storage unit 46 (step ST4). If there exists, this channel information is transmitted to both base stations, thereby allocating communication channels to both base stations (ST5 to ST6).

In addition, the processor 41 transmits an incoming signal, for example, a ring signal, to the called subscriber base station and counts the time through the timer 47 (step ST7).

If the off-hook signal is not received even after a predetermined time has elapsed by sending the incoming signal to the called party base station, the processor 41 sends a signal (business tone signal) indicating a call to the calling party base station or a signal indicating a communication error. Transmission is performed (ST8 to ST10 steps).

On the other hand, the receiving subscriber base station receiving the incoming signal transmits the incoming signal to the subscriber terminal of the corresponding number through its available modem so that the link is formed when the subscriber is off-hook.

Therefore, when an off-hook signal is received while transmitting an incoming signal to the called party base station and counting a predetermined time, the processor 41 sends a signal indicating that a call connection is made to the calling party base station, so that both base stations allocate the allocated channel. The call is made through (ST11 step).

Thereafter, when a communication termination message is transmitted from the subscriber base station (step ST12), the processor 41 transmits a message indicating that the communication is terminated for both base stations where the communication has been performed, and corresponds to the channel information storage unit 46. The communication end process is executed by setting the area to "0" again (step ST13).

That is, according to the embodiment, when there is a call request from the subscriber base station in the satellite communication system, the central control station allocates a communication channel immediately available without a subband signaling process for searching and synchronizing the communication modems of both base stations. Can be made.

In addition, this invention is not limited to the said Example, It can variously deform and implement within the range which does not deviate from the technical summary of this invention.

As described above, according to the present invention, when there is a call request from the calling party base station, the call setup time can be shortened by allowing the call to be made immediately without the subband signaling process, and in the satellite communication system which can check the communication modem state. A fast internal call setup method can be realized.

Claims (2)

In the satellite communication system provided with a central control station for controlling a call can be made by allocating a transponder channel usable between the calling party base station having a call request and the called party base station of the call target, A call request reception step of receiving a destination number and a number translation request message from a calling party base station, A destination base station designation step of translating the received number to designate a corresponding subscriber base station; A channel assignment step of allocating an available channel of the transponder between the retrieved called base station and the called base station; An incoming signal transmission step of transmitting an incoming signal to the called subscriber base station; A time counting step of counting a predetermined time after sending the incoming signal, If the off-hook signal is received while counting a predetermined time, the call execution step to make a call between both base stations through the assigned channel, And a call termination step of recovering a transponder channel allocated between both base stations when receiving message data about call termination from a calling party base station. The method of claim 1, And if the off-hook signal is not received even after a predetermined time has elapsed after sending the incoming signal to the called party base station, the method further comprises a communication error signal sending step of sending a signal relating to a communication error to the calling party base station. Fast internal call setup in a satellite communication system.

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