KR100205640B1 - Channel allocation method and apparatus thereof in satellite communication system - Google Patents

Abstract

The present invention combines all channels provided by a satellite into a link and stores the channel data for the unused channel and the channel data to be assigned first in a separate memory when the user requests the channel allocation. The present invention relates to a channel assignment method and apparatus for a satellite communication system configured to allocate a channel based on data, wherein the satellite communication system is capable of performing communication by combining a plurality of subscribers through a satellite. Channel storage means for link-combining and storing channel information; first unused channel information storage means for storing information of a channel that is allocated first and then released from channel data of the channel memory; and is allocated among channel data of the channel memory. To store information about the channel that was released last If the last dummy channels, and information storage means, the channel allocation request characterized in that configured to include a channel allocation means for allocating a channel based on the channel data of the first non-used channel information storing means.

Description

Channel allocation method and apparatus thereof in satellite communication system

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

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

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

4 is a memory map diagram of the channel information storage section 45 in FIG.

5 is a functional block diagram showing a schematic configuration of an apparatus for allocating a channel of a satellite communication system according to an embodiment of the present invention.

FIG. 6 is an operation flowchart for explaining the operation of the apparatus of FIG.

* Explanation of symbols for main parts of the drawings

1: satellite 2: central control station

3A, 3B: base station 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 upconverter

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: First unused channel memory 80: Last unused channel memory

90: Unused channel memory 90 _{1 to} 90 _N : Channel memory

The present invention relates to the allocation of communication channels in a communication system using satellites. In particular, all channels provided from a satellite are combined by a link, and then channel data for first unused channels and channel data to be allocated first are stored in a separate memory. The present invention relates to a channel assignment method and apparatus for a satellite communication system configured to allocate a channel based on the priority assignment channel data when a user requests an assignment of a channel by storing.

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 DAMA (Demand Assignment Multiple Access) method for allocating communication channels according to 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-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 a terminal having jurisdiction over the base station 3B, it is determined whether the 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 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 satellite 1, an uplink signal, and a downlink signal, and 22 denotes an antenna 21 using a polarization property of frequency. Orthogonal Mode Transducer (OMT) for separating and transmitting and receiving signals transmitted and received through 23, 23 is a low-noise amplifier for low-noise amplifying downlink frequency signals of 12.25 ~ 12.75 GHz input through the orthogonal mode converter (22) Low Noise Amplifier (LNA), 24 is a frequency down converter (DC) for converting a frequency signal applied through the low noise amplifier 23 into an intermediate frequency signal IF of 70 MHz, for example.

In addition, 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 IF signal of 70 MHz applied from the IF combination / distributor 25. For example, a frequency upconverter (UC) for converting the microwave into a microwave of 14.0 to 14.5 GHz to generate an uplink frequency signal, 33 is a high output amplifier for amplifying the uplink frequency signal output from the frequency upconverter 32 ( HPA: 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. When there is a call request from a specific base station, it is determined whether the other base station can communicate with each other based on the information obtained in 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 Packet information is extracted from the message authorized by the unit 26 to generate a S-ALOHA (Slotted ALOHA) packet, and a TDM (Time Division Multiplex) stream is generated for the SCPC channel unit 31. 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 01 dual port RAM 43. After reading the written packet data, the TDM stream generates a message and outputs it to the SCPC channel unit 31.

Then, the SCPC channel unit 31 converts the message into an intermediate frequency signal of 70 MHz by encoding and modulating the message, and outputs the intermediate frequency signal. The intermediate frequency signal is combined for each frequency in the IF combination / distributor 25, The frequency increasing converter 32 converts the uplink frequency signal of, for example, 14.5 GHz. The uplink frequency signal is output through the high power amplifier 33, the quadrature mode converter 22, and the antenna 21, and then transmitted to each base station 3 through the satellite 1 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 through the frequency down converter. It is applied to (24) is converted into an intermediate frequency signal of 70 MHz, 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. The packet data is read from the port RAM 43, and the base station information storage unit 45 is renewed 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. In addition, the channel information storage unit 46 has a storage area corresponding to the number of communication channels to which satellites are allowed. Each storage area stores binary data of "0" or "1" 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, the processor 41 examines the communication channel written as "0" in the channel information storage unit 46 when the busy state of the communication channel is "1". By allocating for the calling base station and the called base station, it is possible for both base stations to perform communication directly through this assigned communication channel. The communication channel is allocated by sending messages to both base stations, and the corresponding area of the channel information storage unit 46 corresponding to the allocated communication channel is set to " 1 " Reference is made during allocation.

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 to "0" again, the communication termination process is executed.

Meanwhile, as described above, when the user requests the allocation of the traffic channel, the processor 41 of the network controller 40 searches for a channel that is not currently used and a channel that is currently in use from the channel information storage unit 46. In this case, the memory search operation of the processor 41 may be performed such that any memory of the channel information storage unit 46 is “0” until there is a channel that is not currently used from the first address to the last address of the channel information storage unit 46. Until it finds the area set as, it continues to search, and it starts searching again from the first address in the same way whenever there is a new request.

That is, whenever multiple users require call setup. Finding a channel that is not currently used vaguely from the first address of the memory storing the channel information is a very inefficient operation.

Accordingly, the present invention was created in view of the above circumstances, and combines all channels provided by a given satellite into a link, and then stores the channel data for the unused channel and the channel data to be assigned first in a separate memory. It is an object of the present invention to provide a channel assignment method and apparatus for a satellite communication system in which a channel is allocated based on the priority assignment channel data when a channel is allocated.

The channel allocation method of the satellite communication system according to the first aspect of the present invention for realizing the above object is a satellite communication system capable of performing communication by combining a plurality of subscribers through satellites, all of which satellites provide. A link combining storage step of combining and storing channels by link, a first unused channel information storing step of storing channel information of the first unused channel from the link-coupled channel data in a separate memory, and a channel allocation request from a user And a channel assignment step of assigning a channel based on the channel data stored from the first unused channel information storage step when the link is combined.

In addition, the channel allocation device of the satellite communication system according to the second aspect of the present invention is a satellite communication system that can perform communication by combining a plurality of subscribers via satellite, link link storage of all channels provided by the satellite Channel storage means for storing the first unused channel information storage means for storing the information of the channel allocated and released first among the channel data of the channel memory Last unused channel information storing means for storing channel information, and channel allocating means for allocating a channel based on the channel data of the first unused channel information storing means when a channel allocation request is made. .

According to the present invention having the above-described configuration, when the user requests the channel allocation, the channel is allocated from the unused channels based on the channel information first, thereby saving channel allocation time and greatly reducing unnecessary searching operations of the processor. Can be reduced.

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 allocation method and apparatus for a satellite communication system according to an embodiment of the present invention. In FIG. 5, parts having substantially the same functions as those of FIG. The detailed description is omitted.

In the drawing, reference numeral 60 denotes a processor that executes a monitoring function of a communication channel, which is not used in the channel information storage unit 46 when there is a call request from any base station. In addition to performing call control functions such as checking the communication channel in the state and assigning it to the calling base station and the called base station, both base stations can perform communication directly through the assigned communication channel. It stores the channel information and the information about the first released channel among the unused channels separately, and if the subscriber requests channel allocation based on this, the processor controls channel allocation based on the channel information. .

In addition, reference numeral 70 denotes a predetermined channel for assigning a channel that is allocated first and then released first when a call allocation request of a user occurs among a plurality of channel data of the unused channel memory 90 to be described later. The first unused channel memory for storing channel information, reference numeral 80 denotes the last unused channel in which predetermined channel information for the most recently released channel is stored among the plurality of channel memories of the current unused channel memory 90. Channel memory.

In addition, reference numeral 90 denotes an unused channel memory for storing channel data for a channel which is currently not in use. The unused channel memory 90 is, for example, a channel which is released just before an arbitrary channel is allocated and released. The channel information for the channel is stored in the previous channel information area, and the channel information of the channel released immediately after the random channel is allocated and released in the next channel information area.

In particular, a memory area for a channel that is allocated first among the unused channels of the unused channel memory 90 and released first, that is, a channel to be presumed to be allocated first among the unused channels, may be predetermined. The unused start information and the next channel information are divided and stored, and are allocated among the unused channels of the unused channel memory 90 and released later, that is, the memory for the channel to be allocated last among the unused channels. The area is divided into a predetermined unused end information area for displaying the previous channel information area and the end of the unused channel.

On the other hand, when the system is initialized, all the channels provided by any satellite are unused channels, and thus all channels are combined into a link and stored in the in-use channel memory 90, where the channel for the channel of the lowest frequency is used. The memory stores the unused start information area and the next channel information area, that is, channel information of the next frequency band. In addition, the channel memory for the channel of the highest frequency band among the channels provided by the satellite is divided into the previous channel information area, that is, the channel information area of the previous frequency band and the unused end information area.

Next, the apparatus of FIG. 5 is demonstrated with reference to the operation flowchart of FIG.

First, when the system is initialized (step ST1), all channels provided to the satellite become unused channels, so that the processor 60 resets all the memories of the unused channel memory 90 and combines them into a link ( ST2 step).

Subsequently, the processor 60 stores the information on the channel of the lowest frequency band among the provided channels in the first unused channel memory 70 (step ST3).

In addition, the processor 60 stores the information on the channel of the highest frequency band in the last unused channel memory 80 (step ST4).

Subsequently, the processor 60 displays an unused start information area and a next frequency for displaying the first channel, that is, the channel of the lowest frequency band, among the unused channels in the first channel memory area 90 ₁ of the unused channel memory 90. Each channel is divided into regions for storing the channel information of the band and stored respectively (step ST5).

In addition, the processor 60 may store the channel information of the previous frequency band in the last channel memory area 90 _N of the unused channel memory 90 and the last channel of the unused channel, that is, the channel of the highest frequency band. The data is divided equally into the unused end information area for displaying (step ST6).

Thereafter, when a channel allocation request is made from a user (step ST7), the processor 60 reads channel information from the first unused channel memory 70 and allocates a corresponding channel to the user (step ST8).

Also, the processor 60 is coupled to the next link from the next channel information area stored in the corresponding memory 90 ₁ of the unused channel memory 90 based on the channel information of the first unused channel memory 70. The read channel information is read, and then the previous channel information area of the memory area 90 ₂ of the unused channel memory 90 corresponding to the read channel information is set as unused start information. .

Subsequently, the processor 60 stores the channel information of the channel where the unused start information is set in the operation of the ST9 in the first unused channel memory 70 (step ST10).

Subsequently, when the above operation has elapsed, the processor 60 sets a predetermined flag to indicate that the processor 60 is in use in the designated memory area of the allocated channel (step ST11).

As mentioned above, the channel allocation to the channel request of the user is made (ST12 step).

Thereafter, when the allocated channel is released (step ST13), the processor 60 reads the last unused channel information from the last unused channel memory 80 and the unused channel memory corresponding to the channel information ( The released channel information is stored in the unused end information area in the predetermined memory area 90 _N of step 90 (step ST14).

In addition, the processor 60 stores the channel information read from the last unused channel memory 80 in the previous channel information area of the released channel memory of the unused channel memory 90 (step ST15).

In addition, the processor 60 stores the unused end information in the next channel information area among the channel memory areas 90 ₁ released from the unused channel memory 90 (step ST16).

That is, the channel is allocated and released by priority, for example, when channel 1 is allocated, it is assumed that channel 1 disappears in link combining of the unused channel memory 90, and channel 1 is released. In link coupling of the unused channel memory 90, the first channel after the current last channel memory region 90 _N may be considered to be link coupled.

On the other hand, if it is initialized as described above, the link is sequentially linked as the unused channel from the lowest channel to the highest channel (90 _{1 to} 90 _N ), but the time that the number of channels are allocated and one channel is reallocated elapses. In this case, the order of the channel memories coupled to the unused channel memories 90 may vary greatly.

This is because the users requesting the channel assignment will be different, and the time to use the assigned channel will also be different.

However, even if the order of the channel memories coupled to the unused channel memory 90 is changed as described above, the operation of the processor 60 is the same. The processor 60 may later allocate channel 2, which is the next channel, when a channel allocation request is received from the user.

According to the above embodiment, when the user stores the information of the unused channel and the user requests the channel allocation, the channel is allocated from the unused channel based on the priority channel information, thereby saving channel allocation time. In addition, unnecessary search operations of the processor can be greatly 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.

As described above, according to the present invention, a user requests channel allocation by combining all channels provided by a satellite into links and then storing channel data for unused channels and channel data to be allocated first in a separate memory. In this case, a channel assignment method and apparatus for a satellite communication system configured to allocate a channel based on the priority assignment channel data can be realized.

Claims (10)

A satellite communication system in which a plurality of subscribers can be combined to perform communication by using a satellite, comprising: a link combining storage step of combining and storing all channels provided by an arbitrary satellite as a link; and first from the link combined channel data. The first unused channel information storage step of storing the channel information of the unused channel in a separate memory, and when a channel allocation request is received from the user, the link is combined to allocate a channel based on the stored channel data from the first unused channel information storage step. And a channel assignment step comprising: a channel assignment method of a satellite communication system. The method of claim 1, further comprising storing the last unused channel information from the link-coupled channel data in a separate memory. The satellite communication method according to claim 1, wherein the channel assignment step stores, when an arbitrary channel is allocated, channel information of a channel coupled to a next link of the corresponding channel is stored in a memory of the first unused channel information storage step. How the system allocates channels. 2. The method of claim 1, wherein the channel allocation step is set to a predetermined flag indicating that the channel is in use in the link-coupled memory region of the channel when an arbitrary channel is allocated. The channel allocation of the satellite communication system according to claim 1, further comprising storing channel information of the released channel in the memory of the last unused channel information storing step when the allocated channel is released. Way. 2. The method of claim 1, further comprising coupling the released channel to the last link when the allocated channel is released. A satellite communication system in which a plurality of subscribers can be combined to perform communication by using a satellite, comprising: channel storage means for link-combining and storing all channels provided by the satellites; First unused channel information storage means for storing information of the first released channel, the last unused channel information storage means for storing information of the channel allocated most recently from the channel data of the channel memory, and channel assignment And channel allocating means for allocating a channel based on the channel data of said first unused channel information storing means when requested. The satellite communication system according to claim 6, wherein the channel allocating means updates and stores the first unused channel information storing means as channel information of a channel coupled to a next link of the channel when an arbitrary channel is allocated. Channel assignment method of. The channel assignment apparatus of claim 6, wherein the channel assignment means updates and stores the last unused channel information storage means as channel information of the corresponding channel when the allocated channel is released. 7. The method of claim 6, wherein the channel assignment means controls to join the channel to the last link of the channel storage means when any channel is released.