KR20010103953A - A communication system and method for communicating between subscribers via one cable - Google Patents

Abstract

The present invention relates to a communication system and a method in which a plurality of subscriber units are connected through one communication cable, and each subscriber unit communicates with a communication counterpart subscriber unit using a frequency division multiple access scheme.

The communication method according to the present invention is a communication method applied to a communication system including a control station for branching and combining a plurality of subscriber units on at least one communication cable and allocating a communication channel for communication between each subscriber unit. In response to the call channel setting request being received from the user while the subscriber unit sets the reception channel as the control channel for communication with the control station, the identifier and the identifier of the communication counterpart to the control station through the control channel. Transmitting a communication channel establishment request message including a first step; A second step of the control station selecting an unused communication channel when the subscriber unit of the communication counterpart is not busy; Transmitting, by the control station, the selected communication channel information to the subscriber unit requesting the call and the subscriber unit of the communication counterpart; A fourth step of establishing a communication channel using the communication channel information transmitted from the control station in the subscriber unit requesting the call and the subscriber unit of the communication counterpart; A fifth step of setting, by the subscriber unit, its communication channel as a control channel when the call is terminated in a call state, and sending a call termination to the control station; And a sixth step of updating, at the control station, status information of the communication channel and status information of the subscriber unit.

Description

Communication system and method for communication between subscribers through one cable {A COMMUNICATION SYSTEM AND METHOD FOR COMMUNICATING BETWEEN SUBSCRIBERS VIA ONE CABLE}

The present invention relates to a communication system and method for communicating between subscribers through one cable, and more particularly, a plurality of subscriber units are connected through one communication cable such as a coaxial cable, and each subscriber unit is frequency division multiplexed. A communication system and a method for communicating with a communication counterpart subscriber unit using a connection method.

The most commonly used communication networks are circuit switched networks such as public switched telephone networks (PSTN) and packet switched networks in asynchronous transfer mode (ATM). The circuit switching method enables communication by connecting actual circuits between units for communication, and the packet switching method uses a communication line (for example, a coaxial cable or an optical cable) capable of high-speed data transmission. Packetizes the information of many terminals and transmits them simultaneously through one communication line.

Currently, it is estimated that there are 19 million Internet users in Korea, and as so many people use the Internet, users are demanding higher speed communication systems. In order to satisfy the demands of the Internet users, communication networks that can provide significantly faster data transmission and various services than the existing telephone modems are limited. For example, a cable that realizes a transmission speed of up to 30Mbps using a cable TV network, a digital subscriber network (xDSL) or wireless data that can transmit MPEG level video signals in real time while using a telephone line as it is. And a wireless subscriber network (WLL) for implementing a telephone network. This wide area network is basically a service provider (Service Provider), a method of providing communication services to subscribers by cable, telephone line and wireless. For example, in the case of a cable modem using a cable TV network, a service provider transmits a communication signal to each subscriber's home by using a device that interworks a cable network with an internet network at a cable broadcasting station, and the subscriber uses a cable modem to connect 1-2 of them will be used for Internet communication.

However, these conventional communication networks require a lot of initial costs because expensive equipment has to be installed in order to provide communication services to subscribers, and there are problems such as additional circuits to expand the number of subscribers.

Accordingly, the present invention is to solve the problems of the prior art as described above, an object of the present invention is a communication system and a method that allows a plurality of subscribers to communicate over a single communication cable using frequency division multiple access technology To provide.

1 is a schematic network diagram for explaining a communication system according to the present invention;

2 is a detailed block diagram of a subscriber unit according to the present invention;

3 is a process flow diagram for communicating between subscribers in accordance with the present invention.

* Explanation of symbols for main parts of the drawings

1 communication channel control station 2 subscriber unit

11: duplexer 12: first variable reference frequency generator

13 down converter 14 intermediate frequency (IF) processing unit

15 control unit 16 interface

17: EEPROM 18: RAM

19: second variable reference frequency generator 20: up converter

The present invention for achieving the above object is a communication system comprising a control station for branching and coupling a plurality of subscriber units on at least one communication cable, and assigns a communication channel for communication between each subscriber unit, The control station, including a database for managing the information and communication channel information for each subscriber unit, and establishes an unused communication channel according to the communication channel setting request of each subscriber unit, the subscriber unit, Way; At least one reference frequency generating means for generating the reference frequency differently according to the control of the control means; Means for downconverting the received signal according to a reference frequency provided from said reference frequency generating means; Means for upconverting a signal to be transmitted according to a reference frequency provided from said reference frequency generating means; And memory means for storing the unique identifier information of each subscriber unit and control channel information for communication with the control station, wherein the control means, upon request of setting up a call channel, through the control channel. Transmits a communication channel setting request message including its identifier and an identifier of a call counterpart, establishes its own communication channel according to the communication channel information transmitted from the control station, and communicates with the communication counterpart subscriber unit; It is done.

In addition, the communication method according to the present invention is a communication system applied to a communication system including a control station for branching and combining a plurality of subscriber units on at least one communication cable and allocating a communication channel for communication between each subscriber unit. The method according to claim 1, wherein when a call channel setting request is received from a user with the subscriber unit setting a reception channel as a control channel for communication with the control station, a communication counterpart with its identifier and communication counterpart via the control channel. Transmitting a communication channel establishment request message including an identifier of the first message; A second step of the control station selecting an unused communication channel when the subscriber unit of the communication counterpart is not busy; Transmitting, by the control station, the selected communication channel information to the subscriber unit requesting the call and the subscriber unit of the communication counterpart; A fourth step of establishing a communication channel using the communication channel information transmitted from the control station in the subscriber unit requesting the call and the subscriber unit of the communication counterpart; A fifth step of setting, by the subscriber unit, its communication channel as a control channel when the call is terminated in a call state, and sending a call termination to the control station; And updating the status information of the communication channel and the status information of the subscriber unit by the control station.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram illustrating a communication system according to the present invention.

The inventor of the present invention solves this problem by combining a technology commonly used in wireless communication with a wired communication technology in order to support voice and / or non-voice communication at high speed while minimizing the expansion of communication lines. That is, since wireless communication uses public media that are all identical communication media, various multiple access technologies have been developed and used. Accordingly, the inventors of the present invention have made the present invention with the idea that the multiple access technology used in the wireless communication can be applied to the wired communication line to increase the subscriber problem and the data processing speed.

As shown in FIG. 1, in the communication system according to the present invention, a plurality of subscriber units 2 are branched and coupled to one communication cable (preferably a coaxial cable), and one communication channel is controlled to the one communication cable. The station 1 is connected. In addition, each subscriber unit communicates with the communication counterpart subscriber unit through different frequencies, and the communication channel control station 1 performs a function of allocating a communication channel required for each subscriber unit to communicate. That is, the communication channel control station 1 is provided with a database storing each subscriber's unique identifier information and communication channel information, and the database includes status information indicating whether each subscriber unit is currently in a call and the information of each communication channel. Status information indicating whether or not to use is stored. In addition, between each subscriber unit 2 and the communication channel control station 1, a call request, channel setting and channel return are performed through a control channel that is already fixedly allocated, where at least one control channel exists. That is, the subscriber unit can communicate with the communication channel control station 1 through a control channel already fixedly allocated, and can communicate with the communication channel control station 1 through another control channel when one control channel is in use. .

In this way, a plurality of subscriber units can communicate without frequency interference through one communication cable. Here, the frequency using method may be applied to all the methods used in the conventional wireless communication as it is. In addition, by providing a signal amplifier at regular intervals according to the transmission distance, it is possible to increase the transmission distance of the signal.

2, a detailed configuration of a subscriber unit according to the present invention will be described.

2 is a detailed block diagram of a subscriber unit according to the present invention, in which 11 is a duplexer, 12 is a first variable reference frequency generator, 13 is a down converter, 14 is an intermediate frequency (IF) processor, 15 is a control unit, and 16 A silver interface, 17 denotes an EEPROM which is an electrically erasable and programmable read-only memory, 18 denotes a RAM which is a read-write memory, 19 denotes a second variable reference frequency generator, and 20 denotes an upconverter.

The subscriber unit according to the invention employs a duplexer 11 at the end of the communication cable to transmit and receive data via one communication cable. In addition, in the present invention, the communication channel of the subscriber unit is set to the communication channel allocated by the communication channel control station 1, respectively. To this end, the down converter 13 of the subscriber unit of the present invention down-converts a signal received in a predetermined band with a frequency supplied from the first variable reference frequency generator 12 operated by the control of the controller 15. Here, the down converter 13 may be configured as a primary and a secondary down converter according to the frequency used. The down-converted signal by the down converter 13 is amplified and filtered by the intermediate frequency (IF) processor 14 and is provided to the controller 15.

On the other hand, the signal transmitted to the communication counterpart subscriber unit is up-converted by the up-converter 20 and transmitted through the duplexer 11, the up-converter 20 is operated by the control of the control unit 15, the second The reference signal supplied from the variable reference frequency generator 19 is used to upconvert the transmission signal. Meanwhile, in the present invention, the reference frequency generator is described as being provided on the receiving and transmitting sides, respectively, which may generate different reference frequencies using one reference frequency generator, and this modification will be very obvious to those skilled in the art.

The control unit 15 includes an interface 16 for connecting to an external non-voice or voice communication device, a program for performing overall operations, information for each subscriber unit, and control for communication with the communication channel control station 1. EEPROM 17, which is an electrically erasable and programmable read-only memory that stores channel information, and RAM 18, which temporarily stores data, are connected respectively.

The control unit 15 is a device such as a central processing unit (CPU) operated according to a program, and the control unit 15 has a function for communicating with a communication channel control station through a control channel, a communication channel setting function, data modulation and Perform demodulation control functions. That is, the controller 5 sets its communication channel as the control channel by using the control channel information already stored in its memory. The call request signal including the identifier of the communication counterpart and its own identifier is transmitted through the control channel.

When the communication channel setting function receives communication channel information for communication with a communication counterpart through a control channel in a state where a call request is made to the communication channel control station through the above process, the communication channel is set as the received information. Set. Then, the communication possible state with the counterpart subscriber unit is confirmed, whereby the communication channel setting is completed. Here, the checking of the communication status with the counterpart subscriber unit may be performed by checking whether a signal is received from the counterpart subscriber unit through the reception channel. Recognizes that there is, switches its channel to the control channel, and then notifies the communication channel control station. When the channel for communication is established through this process, the controller 15 controls the modulation and demodulation of the transmission and reception signals. The modulation / demodulation control function in the control unit 15 is performed by software by a conventional algorithm, and a detailed description thereof will be omitted.

3 is an overall flowchart of a communication method according to the present invention.

First, each subscriber unit usually sets its own communication channel as a control channel for communication with a communication channel control station. When the communication channel setting request is received, it is checked whether the currently set control channel is in use. If it is in use, it sets its communication channel as a new control channel, and if not, transmits a call request message including its identifier and the other party's identifier to the communication channel control station (101).

The communication channel control station extracts the identifier of the other party included in the call request message received through the control channel and confirms from the subscriber status table whether the requested party subscriber unit is currently busy or not (102). As a result of the check, if the call is in progress, the subscriber unit requesting the call is notified (103, 104). If not, the control channel informs the subscriber of the communication counterpart of the call through the control channel. The communication channel is checked for existence and an unused communication channel is selected (105). Here, if there is no unused communication channel, it is notified to the subscriber unit requesting the call. If there is an unused communication channel, the selected communication channel information is simultaneously transmitted to the subscriber unit requesting the call and the subscriber unit of the requested counterpart. At the same time, the status information of the currently selected channel is changed to busy, and the subscriber information in the subscriber information table is changed to busy (106). The subscriber unit requesting the call and the communication counterpart subscriber unit receive the communication channel information transmitted from the communication channel control station through the control channel, and set its own communication channel to the received communication channel (107).

When the communication channel is established through this process, it is checked whether a signal is received within a predetermined time between the subscriber units, and when the signal is received, the communication channel is completed and is in a call state (108). If the call is terminated in the call state (109), the subscriber unit changes its communication channel to the control channel and then notifies the end of the call to the communication channel control station via the control channel (110). When receiving the call termination message including the identifier of the subscriber unit through the control channel, the communication channel control station changes the usage state information of the terminated communication channel to unused and changes the state information of the subscriber unit (111).

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

According to the present invention as described above, multiple subscribers can communicate using a frequency division multiple access scheme through one communication cable, thereby providing high-speed communication while reducing initial installation and maintenance costs, and expansion of subscribers It has an easy effect.

Claims (4)

A communication system comprising a control station for branching and coupling a plurality of subscriber units on at least one communication cable, and allocating a communication channel for communication between each subscriber unit. The control station, Including a database for managing the information and communication channel information for each subscriber unit, and establishes an unused communication channel according to the communication channel setting request of each subscriber unit, The subscriber unit, Control means; At least one reference frequency generating means for generating the reference frequency differently according to the control of the control means; Means for downconverting the received signal according to a reference frequency provided from said reference frequency generating means; Means for upconverting a signal to be transmitted according to a reference frequency provided from said reference frequency generating means; And Memory means for storing unique identifier information of each subscriber unit and control channel information for communication with the control station, The control means, Upon request of setting up a communication channel, transmits a communication channel setting request message including its identifier and an identifier of a call counterpart to the control station through a control channel, and transmits its own communication according to the communication channel information transmitted from the control station. And establish a channel to communicate with the communication counterpart subscriber unit. The method of claim 1, The control means, Channel monitoring means for checking whether a message having a destination identifier equal to its own unique identifier is received through the control channel while setting its initial communication channel as a control channel; Call channel setting request means for generating and transmitting a communication channel setting request message including an identifier of a communication counterpart and an identifier of a communication counterpart through the set control channel when a call channel setting request is received from a user; Communication channel setting means for setting its own communication channel using the communication channel information received from the control station; Modulation / demodulation control means for controlling modulation / demodulation of a signal transmitted / received through the set communication channel; And And a call completion notification means for changing a communication channel of the communication channel to a control channel after the completion of the call and transmitting a call completion message including an identifier of the call counterpart and an identifier of the call counterpart through the control channel. . A communication method applied to a communication system including a control station for branching and combining a plurality of subscriber units on at least one communication cable, and allocating a communication channel for communication between each subscriber unit. When the subscriber unit receives a call channel setting request from the user while setting the receiving channel as a control channel for communication with the control station, the subscriber unit includes its identifier and an identifier of a communication counterpart through the control channel. A first step of transmitting a communication channel establishment request message; A second step of the control station selecting an unused communication channel when the subscriber unit of the communication counterpart is not busy; Transmitting, by the control station, the selected communication channel information to the subscriber unit requesting the call and the subscriber unit of the communication counterpart; A fourth step of establishing a communication channel using the communication channel information transmitted from the control station in the subscriber unit requesting the call and the subscriber unit of the communication counterpart; A fifth step of setting, by the subscriber unit, its communication channel as a control channel when the call is terminated in a call state, and sending a call termination to the control station; And A sixth step of updating, by the control station, status information of the communication channel and status information of the subscriber unit; Communication method comprising a. The method of claim 3, wherein The second step, Confirming a state of the communication counterpart subscriber using an identifier of the communication counterpart included in the communication channel establishment request message as an index key; If the state of the communication counterpart subscriber is busy, transmitting the call to the subscriber unit requesting the call, and notifying the subscriber unit of the communication counterpart via the control channel if there is no call; And Selecting an unused communication channel from the channel status table Communication method comprising a.