KR0183275B1 - Channel assignment method for subnetwork of satellite communication system - Google Patents

Abstract

In the present invention, in allocating and managing available radio resources for a user network subscriber, each user management network subscriber can be allocated a call channel within the number of licensed channels regardless of frequency band. The present invention relates to a channel allocation method and apparatus for managing a user operation network of a satellite communication system, and the subscriber of a user network can freely allocate a communication channel within a range of licensed channels regardless of frequency bands. Of course, the channel usage can be adjusted according to the call volume, and for the satellite network manager, it is easy to establish or terminate a new user network and easily expand or reduce the available channel range for each user network. More efficient network management can be achieved. Shall be.

Description

Channel Allocation Method and User Equipment for User Management Network Management of 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 memory map illustrating a data storage state of a user network available channel storage unit 70 shown in FIG.

7 is a flowchart illustrating a channel allocation process for user management network management of a 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 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, 60: 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 70: user management network available channel storage

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system using satellites. In particular, in allocating and managing available radio resources for a subnetwork subscriber, the number of channels licensed by each user operating network subscriber regardless of frequency band The present invention relates to a channel allocation method and apparatus for managing a user operating network of a satellite communication system that is capable of allocating a call channel within a range.

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 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 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 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 transmits a control message through a service channel in a normal state and then communicates the state of each base station 3 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. 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 is applied to both base stations. 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, which separates and transmits and receives 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 an applied frequency signal 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 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: 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 polling for checking the 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 a call is requested from a specific base station, the base station determines whether the other base station can communicate with each other based on the information obtained during the polling process. It is a network control unit that performs system control such as assigning T) to both base stations so that both base stations can 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 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 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 44, 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; 46 is a channel information storage unit for storing the use state of the communication channel allowed by the 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 quadrature 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 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. 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, if 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 packet data is input from the service channel controller 42 of the network controller 40, the processor 41 first reads the state 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. The communication channel is allocated by sending messages 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. The communication end process is executed by setting the area to 0 again.

However, in the above-described satellite communication system, there is a user network (subnetwork) that receives a license for a certain area of radio resources and operates its own network therein, so that limited communication resources are operated more efficiently. To do this, they need to be optimized, assigned and managed more systematically.

Conventionally, there has been proposed a method for distributing available radio resources to each user network (subnetwork) in frequency bands, but in this case, when call demands are concentrated, there is a problem in that channel allocation is performed by being biased in a predetermined frequency band. As a result, when a new user management network is newly established or terminated, or when the size of an existing operation network needs to be expanded or reduced, it is inconvenient to re-adjust overall frequency allocation.

The present invention has been made in view of the above circumstances, and the available radio resources are allocated to the user network (subnetwork) which is assigned and operated by a plurality of channels from the satellite management station within the range of channel numbers, regardless of frequency band. The purpose of the present invention is to provide a channel allocation method and apparatus for a user operation network of a satellite communication system that can freely allocate a channel and manage it.

The channel allocation method for user management network management 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 In the satellite communication system that can be executed, the user operation network allocation information storage step of storing the channel assignment information allocated to each user network (subnetwork), and the call request subscriber to the user request network for the call request of any base station And a valid channel searching step of checking whether or not the user management network is assigned to the subscriber, and an effective channel searching step of searching for an effective channel according to the result of the checking in the determining whether the subscriber is assigned to the network.

In addition, a channel assignment apparatus for a user 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 coupled to a plurality of subscribers, and a call 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 stores channel assignment information assigned to each user network. The user management network available channel storage means, the channel information storage means for storing the available communication channel usage status, and the channel information storage means and the user management network available channel storage means when a call request is received from an arbitrary base station subscriber. Based on the stored data, it searches for the effective channel for each channel and allocates and manages channels according to the search results. Characterized in that configured to include a control means for control.

That is, according to the present invention having the above-described configuration, the subscriber of the Slub network can be freely assigned a channel within the range of authorized channels irrespective of the frequency band as well as variably adjust the channel usage according to the call volume. As a satellite communication network manager, it is easy to establish or terminate a new user network, and more efficiently manage the network such that the available channel range of each user network can be easily expanded or reduced. It becomes possible.

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

FIG. 5 is a block diagram showing a channel allocation apparatus for a user network of a satellite communication system according to an embodiment of the present invention. The same reference numerals are used, and detailed description thereof is omitted.

In FIG. 5, reference numeral 70 denotes a user management network available channel storage unit which stores, as data, the number of channels allocated to each user network according to a control command of the processor 60, which will be described later. Whenever channel allocation is performed for a user management network subscriber, the processor 60 down-counts the number of available channels of the corresponding user management network stored in the user management network available channel storage unit 70 by '1' at the present time. The remaining number of allocated channels will be saved as data.

On the other hand, Figure 6 shows a memory map for showing the data storage state of the user operating network available channel storage unit 70.

In addition, reference numeral 60 denotes a processor that executes a monitoring function of a communication channel. When a call request is received from an arbitrary base station, the subscriber network which requests the call setup by searching the base station information storage unit 45 is separately registered. If the subscriber is assigned to the user network, if the remaining channel of the user management network is not '0', the channel information storage unit 46 is available. One channel among the valid channels is allocated.

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

When the number of radio license channels to be allocated to each user network is determined, the satellite network manager inputs the number of available channels allocated to each user network through the network management system 50 of FIG. 60 records this data in the user management network available channel storage unit 70 as shown in FIG. 6 for future channel assignment.

On the other hand, if the call request message from any base station in Figure 5 is input to the processor 60 through the service channel controller 42 (step ST1), the processor 60 first starts from the base station information storage unit 45; It reads the status information of the base station of the call request target, that is, the called base station (step ST2), and checks whether the called base station subscriber is in a call state.

On the other hand, if the base station subscriber called in 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 channel information of the calling party subscriber is read from the user operating network available channel storage unit 70 (step ST5) to check whether there is a remaining channel currently available. (Step ST6) When there is no remaining channel, that is, when it is determined that the number of remaining channels = 0 (ST7 step), a call failure message such as busy is sent to the call base station (ST8 step). If there are remaining channels available, the channel information storage unit 46 is searched to index valid channels.

If the channel to be used as the effective channel indexing result is determined, the processor 60 sends a message to both base stations and allocates a communication channel (step ST10). Then, the corresponding address data of the channel information storage unit 46 is' Changing to 1 'indicates that the channel is currently in use. (ST11 step)

Then, when the communication end message is transmitted from the calling base station after the above-mentioned allocation of the communication channel (step ST12), the processor 60 sends a message indicating that the communication is terminated for both base stations where communication has been performed, and the channel information. The communication termination process is executed by setting the corresponding area of the storage unit 46 back to '0'. (ST13 step)

That is, according to the above embodiment, the user network subscriber can freely allocate the call channel within the authorized channel number range regardless of the frequency band, and also adjust the channel use according to the call volume. As a satellite communication network manager, new user operation network (subnetwork) can be easily established or terminated, and the available channel range of each user network (sub network) can be easily expanded or reduced.

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 the satellite communication system, a plurality of base stations, each of which is combined with a plurality of subscribers, can be connected through a satellite to perform communication between arbitrary base stations, and the user management network storing channel assignment information allocated to each user network. Validation according to the allocation information storage step, the user operation network allocation check step of confirming whether the call requesting subscriber is the subscriber assigned to the user management network for the call request of any base station, and the result of the confirmation at this allocation check step A channel assignment method for user management network management of a satellite communication system, characterized in that it comprises a valid channel search step for searching for a channel. 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 may include user operating network available channel storage means for storing channel assignment information allocated to each user network, channel information storage means for storing a used state of a used communication channel, and an arbitrary base station subscriber. And a control means for searching the effective channel for each channel based on the data stored in the channel information storing means and the user operating network available channel storing means, and allocating and managing channels according to a search result when a call request is made. Channel allocation for user management network management of the satellite communication system, characterized in that configured .