KR980013014A - Two-channel allocation method and apparatus using dual reference point adopting method of satellite communication system - Google Patents

Abstract

The present invention sets a starting point of an available frequency band and a center frequency divided into two as a reference point at the time of channel allocation in assigning a transmission channel (TX channel) and a reception channel (RX) required for bidirectional voice communication, The present invention relates to a two-channel allocation method and apparatus using a dual reference point adopting method of a satellite communication system in which two channels having a predetermined frequency interval are simultaneously allocated to a pair of channels, The channel assignment is set as a reference point, and based on this, two channel pairs having a constant frequency interval are paired to form a channel pair, and an available channel pair available for a call request of an arbitrary subscriber is searched to find each channel The channel information is read out from the memory so that the channel information allocated based on the color information is transmitted to both base stations, / RTI > < RTI ID = 0.0 >

Description

Two-channel allocation method and apparatus using dual reference point adopting method of satellite communication system

The present invention relates to a satellite communication system and, more particularly, to a satellite communication system, in which a starting point of an available frequency band and a center frequency divided into two are allocated to a satellite communication system in order to allocate transmission (T?) Tangential and reception (R?) Channels required for bidirectional voice communication Channel allocation method using a dual reference point adopting method of a satellite communication system in which two channels having a constant frequency interval are simultaneously allocated as a pair is set as a reference point at the time of channel establishment.

Generally speaking, a voice communication using a satellite refers to providing a two-way communication service so that a voice communication can be executed between two subscribers of the mobile station via a geostationary satellite located at an altitude of 36077krn. FIG. 2 is a block diagram showing an overall system configuration of a DAMA (Demand Assignment) satellite communication system in which a communication channel is required according to a request.

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 numeral 3A and 3B denote exchangers 11A and 11B and telephones 12A and 12B ), A data terminal (13A, 13B) and a facsimile (14A, 14B) such as a computer, and also has an interface function with the central control station (2) And provides a call function.

In FIG. 1, reference symbol S denotes a service channel (Servi'co Channel) for transmitting and receiving control data, and T denotes a trunk channel for transmitting and receiving data and voice.

In the above configuration, the central control station 2 periodically transmits a control message through a TDM (Time Division Multiplex) field service channel, and then transmits the control message from the corresponding base station 3 in a Slotted Aloha And analyzes the response message and performs a polling function for checking the state of each base station 3, that is, the use state of the communication capacity 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 or not the base station 3B can communicate with the base station 3B based on the information obtained in the polling process , And in the case of the communication enabled state, the available traffic channels T of the satellites are allocated to the base stations 3A and 3B so that the base stations 3A and 3B can directly perform mutual communication.

Thereafter, when communication is completed between the base stations 3A and 3B and the communication end signal is applied from the base station 3A having the communication request to the central control station 2, The communication end processing is executed to release the traffic channel T that was provided to both the base stations 3A and 3B.

On the other hand, the radio resources that can be provided by the satellite system, that is, the number of communication channels, are related to the specifications of a satellite transponder mounted on the satellite 1, Which illustrates a channel division state of a satellite transponder having a bandwidth of 36 MHz in order to explain the present invention.

The channel allocation illustrated in FIG. 2 is a case in which a TD ter- an channel and an S / A channel are respectively assigned to the two end portions of the available frequency band. The control data to be transmitted from the central control station 2 to the base station 3 side is transmitted in a TDM manner with a frequency band of 83.2 KHz while the control data transmitted from the base station 3 side to the central control station 2 The data is transmitted in the S / A scheme having a frequency band of 41.6 KHz. Accordingly, as shown in FIG. 2, three channels (90 KHz) among 1200 communication taps divided in units of 30 KHz are TDM service channels S, and at least two channels (60 KHz) are S / A-type service channel 5, and the remainder is used as a traffic channel T

For bidirectional voice communication, two channels of a transmission channel (TX) and a reception channel (RX) are required. When a call request is made from an arbitrary subscriber, the central control station 2 It is necessary to efficiently select two channels and allocate them as a transmission channel (TX) and a reception channel (RX) necessary for communication between the two subscribers.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method and apparatus for allocating a transmission channel (TX channel) and a credit (RX) channel required for bidirectional voice communication, The present invention provides a two-channel allocation method and apparatus using a dual reference point adopting method of a satellite communication system in which two channels having a constant frequency interval are simultaneously allocated as a pair at a time when a channel is allocated.

In order to achieve the above object, a two-channel allocation method using a dual reference point adopting method of a satellite communication system according to a first aspect of the present invention comprises combining a plurality of base stations combined with a plurality of subscribers through an artificial satellite, The base station sets a starting point of an available frequency band and a center frequency divided into two as reference points for channel allocation and forms a channel pair by pairing two channels having a constant frequency interval based on the center frequency. A valid channel pair search step of searching for a valid channel pair usable for a call request of an arbitrary subscriber, a step of searching for a valid channel pair which is usable from the memory, the channel frequency information for each channel of the valid channel pair indexed in the effective channel search step, The shipment includes a channel frequency information reading step, channel information allocated based on the read channel frequency information, And transmitting the station is characterized in that is configured to include a channel allocation step of allocating the transmit / receive channel.

A two-channel allocation apparatus using a dual point-of-reference channel scheme in a satellite communication system according to a second aspect of the present invention includes a plurality of base stations respectively associated with a plurality of subscribers, a satellite for providing a communication channel between each base station, A satellite communication system comprising a central control station for assigning and controlling a usable communication channel to a requesting base station, the central control station comprising: control means for controlling call processing between the base stations, And the state information of each base station obtained by the polling operation of the control means is stored. Channel information storing means for storing a use state of the channel pair by forming a channel pair by pairing two channels having a constant frequency interval on the basis of a set reference point, And channel frequency information storage means for storing frequency information for each channel as data. When a call request is made from an arbitrary base station subscriber, the data stored in the base station information storing means and the channel information storing means And the channel assignment is controlled according to the channel information of the detected effective channel.

That is, according to the present invention, in allocating the TX channel and the RX channel required for bidirectional voice communication, the starting point of the available frequency band and the center frequency divided into two, It is possible to simultaneously allocate two channels having a certain frequency interval by simultaneously setting them as a pair of reference points, thereby eliminating the necessity of individually allocating the transmission / reception channels twice and performing the channel allocation faster.

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

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

In FIG. 3, reference numeral 21 denotes an antenna for transmitting and receiving a downlink signal transmitted from a satellite side, as opposed to an uplink signal obtained on the side of the satellite 1, and reference numeral 22 denotes a polarization characteristic of a frequency An OMT Orthogonal Mode Transducer 23 for separating and inputting signals transmitted and received through the antenna 22 by using the orthogonal mode converter 22 and an orthogonal mode transducer 23 for outputting a downlink frequency signal of 12.25-12.75 GHz, A low noise amplifier (LNA) 24 for low noise amplifying the signal; a frequency down converter 24 for converting an applied frequency signal through the low noise amplifier 23 to an intermediate frequency signal IF of, for example, 70 MHz; : Down Converter).

In addition, reference numeral 25 denotes a frequency division multiplexer for separating the intermediate frequency signal IF applied from the frequency down converter 24 into a plurality of intermediate frequency signals, (IF C / D: IF Combiner / Distributor) that combines and outputs intermediate frequency signals applied from the intermediate frequency combining / distributing unit (SCU) 31, And an intermediate frequency combining / demultiplexing unit 25 for demodulating, decoding, and outputting an intermediate frequency signal, wherein the intermediate frequency combining / distributing unit 25 is employed for system scalability when a plurality of SCPC channel units are used.

Reference numeral 31 denotes an SCPC channel unit for encoding and modulating a message output from the network control unit 40 to be described later and outputting the message. Reference numeral 32 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 14.0 to 14.5 GHz to generate an uplink frequency signal, And is a high power amplifier (HPA) that amplifies the uplink frequency signal output from the up converter 32.

Reference numeral 40 denotes a polling function for sending a control message to each base station 3 through the SCPC channel unit 26 and then checking the status of each base station 3 based on a response message transmitted from the corresponding base station If there is a call request from a specific base station, it is determined whether or not the other base station is in a communication-enabled state based on the information obtained in the polling process. If the communication base station is in a communication-enabled state, ) To both base stations so that both base stations can directly perform mutual communication, and the like

Reference numeral 70 denotes a network management system for managing the overall network of the satellite communication system by managing the network control unit 47 by a time management system.

4 is a block diagram schematically showing the configuration of the network control unit 40. In FIG. 4, reference numeral 41 denotes a processor that controls the entire system and further controls the communication between the base stations. The SCPC channel unit 26 extracts the packet information from the message applied by the SCPC channel unit 26 to generate a 5-ALOHA (So-called ALOHA) is a service channel controller (SCC) that generates a message of ultiple 7 stream.

Reference numeral 43 is a dual port RA link, which is provided for data transmission / reception between the processor 41 and the service channel controller 42.

Reference numeral 44 denotes a program storage unit for storing an operation program of the processor 41. Reference numeral 45 denotes a base station information storage unit for storing the status information of each base station obtained by the fling operation of the network control unit 40, Reference numeral 46 denotes a channel information storage unit in which a usage state of a communication channel allowed by the satellite is stored.

5 shows a memory mapping (broad emotional appending) of the channel information storage unit 46. The channel information storage 46 stores the channel information stored in the permissible (transponder) determined by the specifications of the transponder de- 0 "or " 1 ", depending on whether two communication channels (T & cir & RX) are available in each storage area, The original data is stored. And. This 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, considering that the channel information storage unit 46 allocates a pair of transmission / reception channels, 1707 channels are eventually mated with two channels, so that 1200 channels It is equipped with a storage area of half of 600 addresses. For the channel assigned to the service channel among these, the processor 41 controls the data to be allocated to the traffic channel T by setting the data of the corresponding address to "1" at all times.

7, 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 frequency information storage unit 46 stores the channel frequency information, The channel frequency information for each channel is provided for two channels of a pair of subwoofers based on the double reference point method. In other words. When an address for a pair of available channels is designated by searching for an effective channel pair, two channels having the same predetermined frequency interval between the channels are automatically and calculated.

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

The network control unit 40 of the third degree in the normal stage periodically performs the fling operation to check the status of each base station.

That is, the processor 41 and the network controller 40 write the packet data for checking the status of each base station into the dual port RAM 43. The service channel port router 42 is connected to the dual port RAM 43, And generates a message of the TD stream stream and outputs it to the SCPC channel unit.

Then, the SCPC channel unit 31 converts the IF signal into an intermediate frequency signal of, for example, 77 rH7 by encoding and modulating the message rate, and outputs the intermediate frequency signal to the IF combination / distribution unit 25, after. And is converted into an uplink frequency signal of, for example, 14.SGH7 by the frequency-to-frequency converter 32. [ The uplink frequency signal is amplified by the lobe output amplifier 33, the orthogonal mode converter 22 and the antenna 21 and then transmitted through the satellite 1 in FIG. 1 to the base station 3 .

On the other hand, the downlink frequency signal of 12.25 GH2 received from each base station 3 via the phosphorescent satellite 1 in the antenna 21 is transmitted through the orthogonal mode converter 22 and the low noise amplifier 23 Frequency downconverter 24 and converted to an intermediate frequency signal of 70 Sun H7. And then applied to the SCPC channel unit 26 through the combination / distribution (25) to be cooperated and decoded and then applied to the network control expansion unit 40.

And. The network controller 40 extracts the packet information from the service channel gat router 42 to generate a 5-ALOHA packet and writes the 5-ALOHA packet into the dual port RAM 3, The packet data is read out to the dual port network 43 and the state information of each base station is retained by renewing and registering the base station information storage unit 45 based on the packet data.

Also. The above-described polling operation is continuously executed for each base station.

Hereinafter, the transmission / reception channel allocation operation will be described in detail with reference to a flowchart of FIG.

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 a call request from the satellite 1 via the antenna 21 in the third stage is received, When the corresponding packet data is inputted from the service channel controller 42 of the control unit 40, the processor 41 first confirms this (571) and then reads the state information of the called base station from the base station information storage unit 45 (572), the base station determines whether the current communication is available (573). At this time, if the calling base station is unable to communicate due to medium reason, the processor 41 sends a call unavailable message to the calling base station (574) and terminates the channel busy operation. The channel information storage unit 46 is searched to find a currently available communication channel. (575)

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. At this time, the channel pair of the corresponding address is in use state ('1' It is determined that there is no usable channel, so that the confirmation operation is repeated until the valid channel pair is confirmed while incrementing by '1'. (577)

The channel pair having the channel state of '0' is confirmed. Based on the address data of the channel pair confirmed to the valid panel, the processor 41 extracts the channel pair of the two channels constituting the corresponding channel pair from the channel frequency information storage unit 48 (570), and transmits the information to both base stations, thereby allocating a transmission / reception channel for bidirectional voice communication. (579) As a result, as shown in FIG. 7, transmission and reception channels for bidirectional communication are allocated in the form of a pair of two channels paired.

Then, the processor 41 changes the corresponding address data of the channel information storage unit 46 to '1' (5710). If a message indicating that the call is ended is transmitted from the calling base station, the processor 41 confirms 5711). The corresponding address data of the tag information storage unit 46 is changed to '0', thereby ending the channel allocation for the call request and the allotted channel operation. (5712)

That is, according to the embodiment, in allocating the transmission (Tx) channel and the reception (nx) channel required for bidirectional voice communication, the starting point of the available frequency band and the center frequency divided into two are set as reference points It is possible to simultaneously allocate the two channels having a certain frequency interval based on the same, thereby eliminating the need to separately allocate the jumped transmission / reception channel twice and performing the channel allocation faster.

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

FIG. 1 is an overall system configuration diagram for explaining an outline of a general satellite communication system,

FIG. 2 is a view illustrating a channel division state of a satellite transponder mounted on the inside of the artificial satellite 1 in FIG. 1,

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 a configuration of a network control unit 40 in a satellite communication system according to an embodiment of the present invention;

5 shows a memory map of the channel information storage unit 46 shown in FIG. 4,

FIG. 6 is a flowchart for explaining a channel allocation process of a device having a configuration of FIG. 4;

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

DESCRIPTION OF THE REFERENCE NUMERALS

1: satellite, 2: central control station,

3A, 3B: r1717, cIA, lIB: 77i7,

12A, 12B: telephone, 13A. 13B: Data terminal.

14A, 14B: facsimile, 21: antenna,

22: orthogonal mode converter. 23: 'Low noise amplifier.

Frequency down converter '75: Intermediate frequency combination / divider,

26, 31: SCP jig channel unit, 32: frequency up converter.

33: high output heavy aerator, 40: network control unit,

41: processor, 42: service channel,

43: Dual port RAAK. 44: program storage unit,

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

48: Channel frequency information storage unit, 50: Network management system

Claims (2)

A satellite communication system that enables communication between arbitrary base stations by combining a plurality of base stations, each of which is associated with a plurality of subscribers, via an artificial satellite, wherein a start point of the available frequency band and a center frequency of two- A channel pair forming step of forming a channel pair by pairing two channels having a predetermined frequency interval based on the channel pair forming step, an effective channel pair searching step of searching a usable channel pair usable for a call request of an arbitrary subscriber, A channel frequency information reading step of reading channel frequency information for each channel of the effective channel pair indexed in the effective channel searching step from the memory, a step of transmitting the allocated channel information to both base stations based on the read channel frequency information, / RTI > of the satellite communication system, characterized in that the system comprises a channel assignment system 2-channel assignment method using the reference point approach adopted. 1. A satellite communication system having a plurality of base stations each associated with a plurality of subscribers, a satellite for providing a communication channel between each base station, and a central control station for assigning and controlling a usable communication channel to a base station having a call request , The central control station has control means for controlling the entire system as well as call processing between the base stations and base station information storing means for storing the state information of each base station obtained by the polling operation of the control means, A channel information storing means for storing a usage state of the tag pair by forming a channel pair by pairing two channel seams having a constant frequency interval based on a set reference point, And channel frequency information storage means for storing frequency information for the frequency band information as data, When a call request is made from an arbitrary base station subscriber, searches for an effective channel pair based on the data stored in the base station information storing means and the channel information storing means, and controls channel allocation according to the channel information of the detected effective channel. Two-channel allocation device using dual reference points adopted in satellite communication system ※ Note: It is disclosed by the contents of the first application.