KR100205643B1 - Two channel adjacent assigning method and thereof device in satellite telecommunication system - Google Patents

Abstract

According to the present invention, in allocating a transmission (TX) channel and a reception (RX) channel necessary for two-way voice communication, a satellite communication system is configured to allocate two adjacent channels among a pair of available channels except for a service channel. The present invention relates to a two-channel adjacent allocation method and apparatus for bidirectional voice communication in which two channels are available, except for a service channel, in which two adjacent channels are paired to form a pair of channels, and an effective channel usable for a call request of an arbitrary subscriber. The channel frequency information for each channel of the indexed effective channel pair is searched out from the memory, and the allocated channel information is transmitted to the base station based on the allocated channel information.

Description

Two-Channel Adjacent Assignment Method for Bidirectional Voice Communication in Satellite Communication System

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

2 is a diagram illustrating a channel division state of a satellite transponder mounted in the satellite 1 shown in FIG.

3 is a block diagram showing in detail the configuration of the central control station 2 according to the present invention.

4 is a block diagram showing the configuration of a network controller 40 in a satellite communication system according to an embodiment of the present invention.

5 is a memory map diagram of the channel information storage section 46 shown in FIG.

FIG. 6 is a flow chart illustrating the channel assignment process of the device of FIG.

7 is a diagram illustrating a state in which a communication channel is allocated by a channel allocation method according to the present invention.

* Explanation of symbols for main parts of the drawings

1: satellite 2: central control station

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

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

14A, 14B: Facsimile 21: Antenna

22: orthogonal mode converter 23: low noise amplifier

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

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

33: high power amplifier 40: network control unit

41: processor 42: service channel controller

43: dual port RAM 46: channel information storage unit

44: program storage unit 48: channel frequency information storage unit

50: network management system

The present invention relates to a satellite communication system, and in particular, in assigning a transmission (TX) channel and a reception (RX) channel required for two-way voice communication, one adjacent channel is selected from the remaining available channels except for the service channel. The present invention relates to a two-channel neighbor allocation method and apparatus for bidirectional voice communication of a satellite communication system arranged to be allocated in pairs.

In general, voice communication using satellite refers to providing a two-way communication service so that voice calls can be made between two remote subscribers through a stationary satellite mounted at an altitude of 36000 km. Fig. 1 shows the overall system configuration of the Demand Assignment Multiple Access (DAMA) satellite communication system, which is configured to allocate a communication channel on demand.

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 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. A base station that provides functionality.

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 periodically transmits a control message through a time division multiplex (TDM) type service channel, and is then transmitted from the base station 3 in a slotted aloha (S / A) type. Based on the analysis of the response message, the polling function is performed to check the state of each base station 3, that is, the available capacity of the communication channel or 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. When the communication state is available, the available traffic channels T of the satellites are allocated to both base stations 3A and 3B so that the base stations 3A and 3B can directly communicate with each other.

Thereafter, when the communication between the base stations 3A and 3B is terminated and the communication termination signal is applied from the base station 3A through the service channel S, the central control station 2 receives the By executing communication channel processing, the traffic channel T provided to both base stations 3A and 3B is released.

On the other hand, the number of radio resources that can be provided by the satellite system, that is, the communication channel is related to the specifications of the satellite transponder mounted on the satellite 1, Figure 2 is a communication channel provided by the satellite repeater In the following description, a channel division state of a satellite repeater (transponder) having a bandwidth of 36 MHz is illustrated.

The channel allocation illustrated in FIG. 2 is a case in which TDM channels and S / A channels are used one by one and each is allocated to both edges of available frequency bands. The control data transmitted from the central control station 2 to the base station 3 is transmitted in a TDM method having a frequency band of 83.2 KHz, while the control transmitted from the base station 3 side to the central control station 2. Data is transmitted by S / A method having a frequency band of 41.6 KHz. Therefore, in consideration of this, as shown in FIG. 2, three channels (90 KHz) among 1200 communication channels divided by 30 KHz units are TDM service channels (S), and at least two channels (60 KHz) are S /. The service channel S of the A method is fixedly assigned to each other, and the rest of the service channel S is used as the traffic channel T.

On the other hand, two-way voice communication requires two channels, a transmission channel TX and a reception channel RX, and the central control station 2 receives a call request from a certain subscriber. It is necessary to efficiently select two channels and allocate them as a transmission channel TX and a reception channel RX required for communication between two subscribers.

The present invention was created in view of the above circumstances, and in assigning a transmission (TX) channel and a reception (RX) channel required for two-way voice communication, two adjacent channels among the remaining available channels except for the service channel are allocated. It is an object of the present invention to provide a method and apparatus for adjoining two channels for two-way voice communication of a satellite communication system so that faster channel allocation can be performed by assigning pairs of two pairs.

Two-channel adjacent allocation method for two-way voice communication of the satellite communication system according to the first aspect of the present invention for realizing the above object is to communicate between any base station by combining a plurality of base stations each with a plurality of subscribers via satellite In a satellite communication system capable of performing the following steps, a channel pair forming step of pairing available channels except for service channels by two adjacent channels to form a channel pair, and an effective channel pair usable for a call request of an arbitrary subscriber. A valid channel pair search step for searching, a channel frequency information read step for reading channel frequency information for each channel of the effective channel pair indexed in the effective channel search step, and assigned on the basis of the read channel frequency information And a channel assignment step of allocating channel information by transmitting the channel information to both stations. It shall be.

In addition, the two-channel adjacent allocation device for the two-way voice communication of the satellite communication system according to the second aspect of the present invention, a plurality of base stations each coupled with a plurality of subscribers, satellites for providing a communication channel between each base station, and call A satellite communication system having a central control station for assigning and controlling a call channel usable for a base station on demand, said central control station controlling the whole system and in particular controlling means for controlling call processing between base stations; Base station information storage means for storing the state information of each base station obtained by the polling operation of the control means, and channel information for storing the use state of paired channel pairs by pairing adjacent communication channels by two adjacent channels. Storage means and frequency information for two channels corresponding to each address of the channel information storage means as data Is configured to include a channel frequency information storage unit, and the control means searches for an effective channel pair based on data stored in the base station information storage means and the channel information storage means when a call request is received from an arbitrary base station subscriber. The channel assignment is controlled according to the channel information.

That is, according to the present invention having the above-described configuration, in allocating a transmission (TX) channel and a reception (RX) channel required for two-way voice communication, one adjacent channel is selected from the remaining available channels except for the service channel. Simultaneous allocation in pairs eliminates the hassle of assigning separate transmit / receive channels twice, resulting in faster channel assignments.

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

3 is a configuration diagram showing the configuration of the central control station 2 that executes the above-described transmission / reception channel allocation function.

In FIG. 3, reference numeral 21 denotes an antenna for transmitting and receiving a downlink signal transmitted from the satellite side as opposed to an uplink signal transmitted to the satellite 1 side, and 22 denotes a polarization characteristic of the frequency. Orthogonal Mode Transducer (OMT) 23 for separating and transmitting and receiving signals transmitted and received through the antenna 22 using the downlink frequency of 12.25 to 12.75 GHz, for example, inputted through the Orthogonal Mode Transducer 22 Low Noise Amplifier (LNA) for low noise amplification, 24 is a frequency down converter (DC: Down) for converting an applied frequency signal through the low noise amplifier 23 into an intermediate frequency signal IF of 70 MHz, for example. Converter).

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

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

And, reference numeral 40 is a polling function that checks the state of each base station 3 based on a response message transmitted from the base station 3 after transmitting a control message to each base station 3 through the SCPC channel unit 26. If there is a call request from a specific base station, the other base station determines whether the other base station can communicate with each other based on the information obtained during the polling process. ) Is a network control unit that performs system control, such as assigning the two base stations to both base stations to directly communicate with each other.

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.

On the other hand, Figure 4 is a schematic diagram showing the configuration of the above-described network control unit 40, reference numeral 41 in the drawing is a processor that controls the entire system, in particular, call processing between the base station, 42 is the SCPC channel A packet information is extracted from a message authorized by the unit 26 to generate a slotted packet (S-ALOHA), 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

Reference numeral 43 is also 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 41, 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. Is a channel information storage unit that stores a state of use of a communication channel allowed by a satellite.

5 is a diagram showing memory mapping of the channel information storage unit 46. The channel information storage unit 46 is an acceptable communication channel that is determined by the specifications of a transponder mounted on a satellite. Of the number of traffic channels In addition to having as many storage areas, binary data of "0" or "1" is stored in each storage area depending on whether two communication channels TX and RX corresponding to the corresponding address are used. The binary data is changed and set by the processor 41 according to the use state of the communication channel.

Meanwhile, as shown in FIG. 5, the channel information storage unit 46 allocates a transmit / receive channel as a pair, and thus, 5 service channels among 3,200 channels (3 channels for TDM and S / Since 1195 channels (except two channels for A) are paired by two adjacent channels, a storage area of 0 to 596 addresses is provided.

In FIG. 4, reference numeral 48 denotes a channel frequency information storage unit for storing channel frequency information corresponding to each address of the channel information storage unit 46 as data. The channel information storage unit 46 is searched by an effective channel search. If any one of the addresses is designated as an allocation channel, the channel frequency information is provided for each pair of 2-channels.

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

Normally, the network controller 40 of FIG. 3 periodically checks the state of each base station by performing a polling operation.

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

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

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

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

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

Hereinafter, the transmission / reception channel allocation operation proceeds in more detail with reference to the flowchart of FIG. 6.

When there is a call request from any base station to any other base station during the above-described polling operation, that is, a message indicating the call request from the satellite 1 is received through the antenna 21 of FIG. When the corresponding packet data is input from the service channel controller 42 of 40, the processor 41 first checks this (ST1), and then reads the status information of the called base station from the base station information storage unit 45 (ST2). The base station determines whether the current communication is possible (ST3), in this case, if the called base station is in a communication impossible state for reasons such as busy, the processor 41 sends a call impossible message to the call base station. At step ST4, the channel assignment operation is terminated, and when it is determined that the communication is possible, the channel information storage unit 46 is searched to find a currently available communication channel.

At this time, the processor 41 checks whether the channel pair of the corresponding address is in use from the start address of the channel information storage unit 46 (ST6), in which the channel pair of the corresponding address is in use ('1'). If it is found to be, this means that there is no available channel, and the above-mentioned checking operation is repeated until the valid channel pair is confirmed by increasing the address '1' (ST7).

When a channel pair having a channel state of '0' is identified, the processor 41 determines two channels of the channel pair from the channel frequency information storage unit 48 based on the address data of the channel pair identified as the effective channel. The frequency information is read out (ST8) and transmitted to both base stations to allocate a transmission / reception channel for a two-way voice call (ST9).

As a result, as shown in FIG. 7, two channels are paired and paired, and a transmission and reception channel for bidirectional communication is allocated.

Subsequently, the processor 41 changes and sets the corresponding address data of the channel information storage unit 46 to '1' (ST10), and then checks this when a message indicating that the call is terminated from the call base station is transmitted ( ST11), by changing and setting the corresponding address data of the channel information storage unit 46 to '0', the channel allocation for the call request and the overall channel management operation are terminated. (ST12)

That is, according to the above embodiment, in allocating a transmission (TX) channel and a reception (RX) channel required for two-way voice communication, two adjacent channels are simultaneously allocated as a pair from the remaining available channels except for the service channel. This eliminates the hassle of assigning separate transmit / receive channels twice, resulting in faster channel assignments.

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

Claims (2)

In a satellite communication system in which a plurality of base stations, each of which is combined with a plurality of subscribers, are combined through satellites to perform communication between arbitrary base stations, a pair of channels are paired by pairing available channels except adjacent service channels by two adjacent channels. A channel pair forming step for forming a channel, an effective channel pair searching step for searching an effective channel pair usable for a call request of an arbitrary subscriber, and channel frequency information for each channel of the effective channel pair indexed in the effective channel search step; And a channel allocating step of allocating the channel information based on the read channel frequency information to the terminal station and allocating a transmission / reception channel. 2-channel adjacent allocation method for two-way voice communication. A satellite communication system comprising a plurality of base stations, each of which is combined with a plurality of subscribers, a satellite for providing a communication channel between each base station, and a central control station which allocates and controls a usable communication channel for a base station with a call request. In addition, the central control station controls the entire system, and in particular, control means for controlling call processing between base stations, base station information storage means for storing state information of each base station obtained by the polling operation of the control means, and satellites. Channel information storage means for storing the usage status of paired channel pairs by pairing the allowable communication channels by two adjacent channels, and storing frequency information for two channels corresponding to each address of the channel information storage means as data. And a channel frequency information storage unit, wherein the control unit calls from any base station subscriber. If there is a phrase, the two-way voice of the satellite communication system characterized in that to search the effective channel pairs based on the data stored in the base station information storage means and the channel information storage means to control the channel assignment according to the channel information of the retrieved effective channel. 2-channel adjacent allocation device for communication.