KR100258685B1 - Transit call setting method and apparatus in satellite communication system - Google Patents

Abstract

PURPOSE: A method and an apparatus for setting up a transit call in a satellite communication system are provided to overcome the communication obstacles of a generic telephone network by offering a communication path between external generic telephone network subscribers so that they can carry out communication through a satellite communication network. CONSTITUTION: In case that a calling message is received from a satellite through an antenna(ST1), a processor translates the received calling message and searches a ROM table for a generic telephone network base station corresponding to a local number among the translated calling message(ST2). The processor reads out status information from a base station information storage part in order to check whether the searched base station is in a communication possible state(ST3). If it is judged that the base station is in the communication possible state(ST4), the processor reads modem status data from a modem information storage part in order to check whether an available modem exists. In case that there is an available modem, the processor assigns the call modem to the calling base station and the called base station(ST5). The processor checks an available communication channel through a channel information storage part. If an available communication channel exists, the processor allocates the communication channel to both base stations(ST6). The processor sets up a transit call by sending allocated communication modem and channel information to both base stations(ST7).

Description

Transient call establishment method and apparatus in satellite communication system

The present invention relates to a satellite communication system using satellites, and in particular, by providing a communication path to a general telephone network subscriber and other general telephone network subscribers through a satellite communication network to overcome communication obstacles of a general telephone network that could not be communicated locally and geographically. The present invention relates to a method and apparatus for establishing a transient call in a satellite communication system.

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, communication from land to an island without a communication line, or a communication method in a mountainous country such as Korea.

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

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.

When there is a call request from a subscriber, for example, a base station 3 to a terminal under the control of the base station 3B, it is determined whether the base station 3B is in a state capable of communication 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 receives By executing the communication termination process, the traffic channel T which has been provided to both base stations 3A and 3B is released.

On the other hand, the call setup method of the satellite communication system includes an internal call setting for connecting a call between internal subscribers and an outgoing call for connecting a call between a subscriber and a general telephone network subscriber through a satellite communication network. ), There is an incoming call setup that connects the call between the internal subscribers through the subscriber and the satellite communication network.

In addition, as described above, the satellite communication system is connected to the subscriber of the general telephone network through the switch 11, so that the subscriber of the satellite telephone network can provide a call in the subscriber network.

However, when the subscriber of the satellite communication network and the subscriber of the general telephone network makes a call request to another general telephone network that is not subscribed to the satellite communication network, it is usually executed through a general telephone network (PSTN). If the general telephone network in the area where the land network can not be installed, it requires a communication method that can communicate wirelessly. In addition, when the spaced distance is a long distance, there is a need for a method of communicating through the satellite communication.However, in the case of satellite communication, a transit call providing a communication path to an external general telephone network subscriber through a satellite communication network (Transit) call) There is a problem that the setting method is not executed.

Accordingly, the present invention has been made in view of the above circumstances, and it is possible to provide a communication path for communication between the external general telephone network subscribers through the satellite communication network, thereby overcoming the communication obstacles of the general telephone network. The purpose of the present invention is to provide a method and apparatus for establishing a transient call.

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

2 is a block diagram showing a transient call setup device in a satellite communication system according to an embodiment of the present invention.

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

4 is a flow chart for explaining the operation of the device of the configuration of FIG.

<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) 27: Trunk Interface Port (TIP)

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

26, 31: SCPC (Single Channel Per Carrier) Channel Unit

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

40: network controller 41: processor

42: Service Channel Controller (SCC)

43: Dual Port RAM 44: Program Storage

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

47: modem information storage unit 48: ROM table

50: network management system

Transient call setup method in the satellite communication system according to the present invention for realizing the above object receives and stores the information of the general telephone network subscriber and a plurality of base stations each coupled with a plurality of subscribers, based on which A satellite communication system having a central control station for controlling communication between base stations, comprising: a general telephone network call request receiving step for receiving a general telephone network call request from an arbitrary base station combined with a general telephone network, and a received general telephone network call request Search for the corresponding base station to search and designate the corresponding base station in charge of the call by translating the message, and check the corresponding base station to check whether the designated base station can communicate, and search for a modem that can communicate if the base station is in communication. Communication modem allocator And a communication channel assignment step of searching for communication channels and assigning them to both base stations, and transmitting the allocated communication channel and communication modem information to a call requesting base station and a call destination base station, and establishing a transient call. Characterized in that configured.

In addition, in the satellite communication system according to the present invention for realizing the above object, the apparatus for establishing a transient call has a call request from any base station coupled with a trunk interface port and a general telephone network to which a switch or the like for coupling with a general telephone network subscriber is connected. If there is a communication state by translating this call request, it is determined whether the designated base station is in a communication state, and if it is in a communication state, the available traffic channels and modems of the satellite are allocated to both base stations. A processor that sets up a transient call to directly communicate with each other, a base station information storage unit for storing state information of each base station obtained by the polling operation of the processor, and a state of use of a communication channel allowed by satellites. Channel information storage unit, modem of each base station Including a ROM table, which is a satellite communication network, each base station code is stored corresponding to the modem information storage unit that stores information about the status, the area code of a general telephone network is characterized in that configured.

That is, according to the present invention having the above-described configuration, communication between subscribers of the general telephone network can be performed through the satellite communication network, so that the transient call service of the satellite communication system capable of overcoming the communication failure of the general telephone network can be executed.

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

2 is a block diagram showing a transient call setup device in a satellite communication system according to an embodiment of the present invention.

In FIG. 2, reference numeral 21 denotes an antenna for transmitting and receiving an uplink signal and a downlink signal for the satellite 1, and 22 denotes an antenna 21 using a polarization property of frequency. Orthogonal Mode Transducer (OMT) 23 for separating and transmitting and receiving signals transmitted and received through the low noise amplifier for low noise amplification of, for example, 12.25-12.75 GHz downlink frequency signals inputted through the Orthogonal Mode Converter 22 (LNA: Low Noise Amplifier), 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, 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.

Further, reference numeral 27 denotes a trunk interface port for connecting the central control station to another switch, and 31 denotes an encoding, modulation, and output of a message output from the network controller 40 to be described later. SCPC channel unit 32 is a frequency up-converter (UC) for converting a 70 MHz IF signal applied from the IF combination / distributor 25 into microwaves of 14.0 to 14.5, for example, to generate an uplink frequency signal. Is a high power amplifier (HPA) for amplifying an uplink frequency signal output from the frequency up-converter 32.

Reference numeral 40 denotes a polling function for checking 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 the SCPC channel unit 26. If there is a call request from any base station combined with a general telephone network, the call request is translated and designated to search for the base station, and the communication can be performed by determining whether the designated base station can communicate. In the case of a state, it is a network control unit which performs system control, such as by allocating an available traffic channel of a satellite and a modem to both base stations so that both base stations can directly communicate with each other.

In addition, the network controller 40, the channel modem 26, the trunk interface port 27 for transmitting and receiving the control data and MPH (Main PCM Highway BUS) for transmitting and receiving processing data, such as voice data It is coupled via the UPH (Utility PCM Highway BUS).

The configuration of the network control unit 40 is shown in FIG. 3, in FIG. 3, reference numeral 41 denotes a processor that controls the entire system and particularly controls call processing between base stations according to the present invention, and 42 denotes the SCPC. The packet information is extracted from the message applied from the channel unit 26 to generate a S-ALOHA (Slotted ALOHA) packet, and a time division multiplex (TDM) stream for the SCPC channel unit 31 is generated. Service Channel Controller (SCC) that generates and outputs messages from Streams.

In addition, 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, and 44 denotes a program storage unit in which an operation program of the processor 41 is stored. Reference numeral 45 denotes a base station information storage unit that stores state information of each base station obtained by a polling operation of the network processor 41, and 46 denotes a channel information storage unit that stores a use state of a communication channel allowed by the satellite.

Reference numeral 47 is a modem information storage unit for storing information on the modem usage status of each base station, and 48 is a ROM table in which each base station code corresponding to a local telephone network area code is stored.

In addition, reference numeral 50 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 the normal state, the network controller 40 of FIG. 3 performs a polling operation to check the state of each base station.

That is, the processor 41 of the network controller 40 writes packet data for checking the state of each base station into the dual port RAM 43, and the service channel controller 42 writes into 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 for each frequency in the IF combination / distributor 25, The frequency increasing 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 transmitted through the orthogonal 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 70 MHz, then applied to the SCPC channel unit 26 through the IF combination / distribution unit 25 is demodulated and decoded and then applied to the network control unit 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 thereon, the state information for each base station is retained. In addition, the above-described polling operation is continuously performed for each base station.

On the other hand, if there is a call request (data call) in which the data such as the telephone number together with the area code of the general telephone network from any base station connected to the general telephone network (PSTN) during the above-described polling operation (step ST1), that is, FIG. When a message indicating a call request is received from the satellite 1 through the antenna 21 of the receiver, and the corresponding packet data is input from the service channel controller 42 of the network controller 40, the processor 41 first receives the received call. The request message is translated and searched for the corresponding general telephone network base station corresponding to the area code from the translated call request message from the ROM table 48 (ST2 step).

When the designated general telephone network jurisdiction base station reads the state information from the base station information storage unit 45 to determine whether it is in a communicable state, and checks whether it is in a state where communication is possible (step ST3). In step ST4, the modem information storage unit 47 reads modem status data in units of 1 byte and checks the available modem. When there is a modem available, the call modem is allocated to both base stations (ST5). step).

In addition, the processor 41 checks the currently available communication channel from the channel information storage unit 46 and allocates to both the call request base station and both base stations of the call target when there is a communication channel (step ST6).

Accordingly, the processor 41 transmits the allocated communication modem and communication channel information to the base station that has made the call request of the general telephone network and the base station that is the target of the call request. The call is made between the terminals through the transient call is established through the satellite communication network (ST7 step).

On the other hand, if it is determined in step ST4 that the base station for the general telephone network of the call target is in a call-free state, the processor 41 transmits a message indicating that the call is incapable of calling to the originating base station of the call request (step ST8).

That is, according to the above embodiment, it is possible to realize a transient call setup method in a satellite communication system that enables communication by providing a communication path between subscribers of an external general telephone network through a satellite communication network.

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, it is possible to implement a transient call setting method in a satellite communication system that can overcome communication obstacles of a general telephone network by enabling communication between subscribers of an external general telephone network through a satellite communication network.

Claims (2)

In a satellite communication system equipped with a central control station that receives and stores information of a general telephone network subscriber and a plurality of base stations associated with a plurality of subscribers through satellites, and controls communication between arbitrary base stations based on the information. , General telephone network call request receiving step of receiving a general telephone network call request from any base station combined with the general telephone network, A corresponding base station search step of translating the received general telephone network call request message to search and designate a corresponding base station that has a target of a call; A corresponding base station inspection step of checking whether the designated base station is in a state of communication possible, A communication modem allocation step of searching for a modem that can communicate with the base station and assigning it to both base stations, A communication channel allocation step of searching for and assigning communication channels to both base stations; And a transient call setting step of transmitting the allocated communication channel and communication modem information to a call requesting base station and a call destination base station to set up a transient call. Trunk interface port to which exchanges, etc., to be combined with general telephone network subscribers are connected. When there is a call request from any base station combined with a general telephone network, the call request is translated and designated by searching for the call base station. If the designated base station is available for communication, the satellite is available. A processor that establishes a transient call so that both base stations directly communicate with each other by assigning traffic channels and modems to both base stations; A base station information storage unit for storing state information of each base station obtained by the polling operation of the processor; Channel information storage unit for storing the use state of the communication channel allowed by the satellite, Modem information storage unit for storing information about the modem usage status of each base station, Transient call setting device in a satellite communication system, characterized in that it comprises a ROM table that stores each base station code corresponding to the area code of the general telephone network.

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