KR0183272B1 - Channel management method and apparatus thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system using satellites. Particularly, an available channel is allocated to a subscriber operating network (subnetwork) that is assigned and operated by a plurality of channels, and the available channel is divided into a predetermined frequency bandwidth and managed. The present invention relates to a channel management method and apparatus for operating a subscriber management network of a satellite communication system. The system includes a separate memory for managing subscribers operating a subscriber management network, thereby dividing and managing the subscriber operating network into frequency bands. It is characterized by being able to more efficiently manage the radio resources.

Description

Channel Management Method and Apparatus for Operation of Subscriber Management Network in Satellite Communication System

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

FIG. 2 is a block diagram showing the configuration of the central control station 2 shown in FIG.

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

4 is a memory map diagram of the channel information storage unit 46 shown in FIG.

5 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.

FIG. 6 is a diagram for explaining an example of subnetwork allocation of a satellite system. FIG.

7 is a flowchart illustrating a channel management operation for subscriber management network operation of the satellite communication system 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 changer 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 44: Program Storage

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

50: network management system 60: processor

70: subscriber management network allocation information storage unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system using satellites. Particularly, a satellite configured to divide and allocate available channels into a predetermined frequency bandwidth for a subnetwork double speed subscriber that is assigned and operated with multiple channels. A channel management method and apparatus for communication system subscriber management network operation.

Recently, with the rapid development of communication technology, satellite communication, which enables subscribers who are located at remote sites to make calls through satellites, is becoming 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 or as a communication method in a mountainous country such as Korea.

In the above-mentioned satellite communication, there are two types of PAMA (Pre Assignment Multiple Access) method for allocating communication channels for each subscriber according to the channel allocation method and Demand Assignment Multiful Access (DAMA) method for allocating communication channels according to the subscriber's request. In general, in the satellite communication system for communication between subscribers, many DAMA methods are adopted in consideration of the cost and the effectiveness of the communication channel.

1 is a block diagram showing the overall system configuration of a general satellite communication system according to the DAMA method.

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 terminals such as a computer, data terminals 13A and 13B, and facsimile 14A and 14B, and data transmission / reception with the central control station 2 The base station that provides.

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 configuration, the central control station 2 transmits a control message through a service channel in a normal state, and thus, the state of each base station 3, that is, communication based on a response message transmitted from the base station 3. It performs a polling function to check the available capacity or the utilization status of 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.

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.

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

In FIG. 2, 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 frequency. Orthogonal Mode Transducer (OMT) 23 for separating and transmitting and receiving signals transmitted and received through the antenna 22 by 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) for converting a frequency signal applied through the low noise amplifier 23 into an intermediate frequency signal IF of 70 MHz, for example. )to be.

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 Carreir (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: Up Converter) for converting into microwaves of 14.0 to 14.5 GHz to generate an uplink frequency signal, and a high output amplifier (HPA) for amplifying an uplink frequency signal output from the frequency up-converter 32. : High Power Amplifier.

Reference numeral 40 denotes a polling function for checking the status 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 that both base stations directly communicate with each other by allocating the "

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 3 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 The packet information is extracted from the message authorized by the unit 26 to generate a slotted ALOHA (S-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

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 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 40. Is a channel information storage unit that stores a state of use of a communication channel allowed by a satellite.

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

In the normal state, the network controller 40 of FIG. 2 performs a polling operation to check the state of each base station.

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, a message of the TDM stream is generated and outputted 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 orthogonal mode converter 22 and the low noise amplifier 23 to the frequency down converter. The signal is applied to (24) and converted into an intermediate frequency signal of 70 MHz, and then applied to the SCPC channel unit 26 through the IF combination / distributor 25, demodulated and decoded, and then applied to the network controller 40.

In addition, the network controller 40 extracts packet information from the message applied by the service channel controller 42 to generate an S-ALOHA packet, and then writes the packet information into the dual port RAM 43. The packet data is read from the port RAM 43, and the base station information storage unit 45 is updated and registered based on the packet data, thereby retaining state information for each base station.

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

On the other hand, 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 via the antenna 21 of FIG. When the packet data is input from the service channel controller 42 of the network controller 40, the processor 41 first reads the status information of the base station called from the base station information storage unit 45, and the base station currently communicates. In this case, it is determined whether or not the communication state is possible, and if it is determined that the communication is possible, the communication channel currently available from the channel information storage unit 46 is examined.

4 is a diagram illustrating memory mapping of the channel information storage unit 46. The channel information storage unit 46 has a storage area corresponding to the number of communication channels allowable by satellites, and stores each of them. In the area, binary data of 0 or 1 is stored depending on whether a corresponding communication channel is used. The binary data is changed and set by the processor 41 according to the use state of the communication channel.

That is, when there is a call request from any base station, when the busy state of the communication channel is 1, the processor 41 checks the communication channel written with 0 in the channel information storage unit 46 and calls it with the calling base station. By assigning the allocated base stations, both base stations can perform communication directly through the assigned communication channel. This communication channel is allocated by sending a message to both base stations, and at this time, the corresponding area of the channel information storage unit 46 corresponding to the allocated communication channel is set to 1 so that the communication channel can be assigned later. Will be referenced.

When the communication end message is transmitted from the calling base station after allocating the communication channel, the processor 41 transmits a message indicating that the communication is terminated to both base stations where the communication has been performed, and the channel information storage unit 46 transmits a message. By setting the area back to '0', the communication termination process is executed.

However, in the above-described satellite communication system, there is a subscriber network (subnetwork) which allocates radio resources of a certain area and operates and manages its own network in its own interior. In order to manage limited resources more efficiently, they are optimized and allocated. And more systematic management.

The present invention has been made in view of the above circumstances, and allocates and manages the available channels by dividing the available channels into a predetermined frequency bandwidth for a subscriber network (subnetwork) that is assigned and operated by a plurality of channels from the satellite management station. An object of the present invention is to provide a channel management method and apparatus for operating a subscriber management network of a satellite communication system.

The channel management method for the subscriber management network operation of the satellite communication system according to the first aspect of the present invention for realizing the above object is to combine a plurality of base stations, each of which is combined with a plurality of subscribers via satellite to communicate between any base station A satellite communication system, which is operable, comprising: a subscriber management network allocation information storing step of storing frequency band allocation information allocated to each subscriber network; and a call requesting subscriber for the call request of an arbitrary base station. And a valid channel searching step of checking whether the subscriber management network is assigned to the network, and a valid channel searching step of searching for an effective channel according to the result of the checking in the speed checking step.

In addition, a channel management apparatus for a subscriber management network of a satellite communication system according to a second aspect of the present invention for realizing the above object is to provide a plurality of base stations, each of which is combined with a plurality of subscribers, and a communication channel between each base station In a satellite communication system having a satellite and a central control station which allocates and controls a usable call channel for a base station with a call request, the central control station receives frequency band allocation information allocated to each subscriber network. A subscriber management network allocation information storage unit for storing, a channel information storage means for storing the available communication channel usage state, and the channel information storage means and the subscriber management network allocation information storage unit when a call request is received from an arbitrary base station subscriber. And control means for controlling whether to search for an effective channel for each channel based on the data stored in the channel. It is characterized by.

That is, according to the present invention having the above-described configuration, the available channel is allocated to the satellite network to divide the available channels into a predetermined frequency bandwidth and manage them. Based on the frequency band, it is possible to more efficiently and simply manage radio resources.

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

FIG. 5 is a block diagram illustrating a channel management apparatus for operating a subnetwork of a satellite communication system according to an embodiment of the present invention. FIG. 5 shows the same reference numerals in FIG. Number it and omit its detailed description.

In FIG. 5, reference numeral 70 denotes a subscriber management network allocation information storing unit for storing frequency band allocation information allocated to each subnetwork according to a control command of the processor 60 which will be described later. As shown in FIG. 6, the network allocation information storage unit 70 performs a subscriber management network among remaining available channels except for a time division multiplex (TDM) and a slotted aloha (S / A) channel for transmitting and receiving control data with a base station. address information (add) for the frequency band allocated to the subnetwork is stored.

On the other hand, reference numeral 60 denotes a processor that executes a monitoring function of a communication channel, which identifies whether a subscriber requesting a call setup is a subscriber assigned to a separately registered subnetwork when there is a call request from an arbitrary base station. In the case of a subscriber assigned to the subscriber management network, the frequency allocation address (add) information of the subscriber is read from the subscriber management network and the allocation information storage unit 70, and channel allocation is performed based on this, and thus the frequency band allocated in advance. It manages to be able to allocate available channels within the scope of.

Next, the operation of the system having the above-described configuration will be described in more detail using the flowchart shown in FIG.

In FIG. 5, when a call request message from an arbitrary base station is input to the processor 60 through the service channel controller 42 (step ST1), the processor 60 first calls from the base station information storage unit 45. The status information of the requested base station, that is, the called base station, is read (step ST2) to check whether the called base station subscriber is in a callable state (step ST3).

On the other hand, when the base station subscriber called in the step ST3 is currently busy or for some other reason, the call is terminated after the processor 60 transmits a call impossible message to the call base station (ST4). Step) If it is determined that the call is available, the address data previously allocated from the subscriber management network allocation information storage unit 70 is read (step ST5), and the channel information storage unit 46 is searched based on this. (ST6), it is checked whether the channel of the corresponding address is in use (ST7). If the channel of the corresponding address is found to be in use ('1'), this means that there is no available channel. In increments of '1', the above checking operation is repeated until the valid channel is confirmed. (ST8 step)

When a channel having a channel state of '0' is identified, the processor 60 transmits a message to both base stations and allocates a call channel (step ST9). Then, the corresponding address data of the channel information storage unit 46 is '1'. After the change is set to (step ST10), a message indicating that the call is terminated is transmitted from the call base station. Then, it is checked (step ST11), and the corresponding address data of the channel information storage unit 46 is '0'. By changing the setting, the channel assignment and all channel management operations for the call request are terminated. (ST12 step)

That is, according to the above embodiment, the available channels are divided into predetermined frequency bandwidths for the subnetwork, which is allocated and operated by the satellite management station, based on the assigned frequency bands. By doing so, it becomes possible to manage radio resources more efficiently and simply.

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)

A satellite communication system in which a plurality of base stations, each of which is combined with a plurality of subscribers, is coupled to each other to perform communication between arbitrary base stations. The satellite communication system stores frequency band allocation information allocated to each subnetwork. The subscriber management network allocation information storing step, the available channel information checking step of reading the address data of the available channel assigned to the called subscriber for the call request of any base station, and the address data confirmed in the available channel information checking step. A channel management method for operating a subscriber management network of a satellite communication system, characterized in that it comprises a valid channel search step for searching for an effective channel on the basis. In a satellite communication system having 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. The central control station includes a subscriber management network allocation information storage unit for storing frequency band allocation information allocated to each subscriber network, channel information storage means for storing the available state of available communication channels, and an arbitrary base station. And a control means for controlling whether to search for an effective channel for each channel based on data stored in the channel information storage means and the subscriber management network allocation information storage unit when a call request is received from a subscriber. Channel management device for subscriber management network operation of system.