KR20010103952A - 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.

A communication method according to the present invention is a communication method applied to a communication system in which a plurality of subscriber units are branched and combined on at least one communication cable, wherein the first subscriber unit scans each of the reception channels in the reception channel group. First step; A second step of, if the call channel setting request is received from the user, the first subscriber unit checking whether there is an unused channel; A third step of setting a reception channel of the unused channel as its own transmission channel and a transmission channel of the unused channel as its own reception channel if an unused channel exists; A fourth step of sending, by the first subscriber unit, a call channel establishment request message including identifier information of the second subscriber unit and its own identifier information through the established communication channel; When the second subscriber unit scans each of the reception channels in the reception channel group and receives a message having a destination identifier, the second subscriber unit corresponds to the reception channel corresponding to the currently selected reception channel. A fifth step of setting a transmission channel as its own transmission channel; A sixth step of sending, by the second subscriber unit, a response through the established channel; And a seventh step of releasing the channel and scanning the channel when the call ends in the call state.

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. Such a wide area network basically has a service provider, and provides a communication service 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 receives a cable channel through the cable modem. 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: duplexer 2: first variable reference frequency generator

3: downconverter 4: intermediate frequency (IF) processing unit

5: control unit 6: interface

7: EEPROM 8: RAM

9 second variable reference frequency generator 10 upconverter

According to an aspect of the present invention, there is provided a communication system in which a plurality of subscriber units are branched and combined on at least one communication cable, the subscriber unit comprising: 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 for each subscriber unit, a reception channel group, and a transmission channel group corresponding to the reception channel one-to-one, wherein the control means scans each of the reception channels in the reception channel group. By identifying the unused communication channel through the communication channel, the unused receiving channel is set as its own transmission channel and the transmission channel corresponding to the unused receiving channel is set as its own receiving channel when a call channel setting request is made. And a call channel setting request message including an identifier and a unique identifier of a communication counterpart.

In addition, the communication method according to the present invention is a communication method applied to a communication system in which a plurality of subscriber units are branched and combined on at least one communication cable, the first subscriber unit for each of the reception channels in the reception channel group. Scanning a first step; A second step of, if the call channel setting request is received from the user, the first subscriber unit checking whether there is an unused channel; A third step of setting a reception channel of the unused channel as its own transmission channel and a transmission channel of the unused channel as its own reception channel if an unused channel exists; A fourth step of sending, by the first subscriber unit, a call channel establishment request message including identifier information of the second subscriber unit and its own identifier information through the established communication channel; When the second subscriber unit scans each of the reception channels in the reception channel group and receives a message having a destination identifier, the second subscriber unit corresponds to the reception channel corresponding to the currently selected reception channel. A fifth step of setting a transmission channel as its own transmission channel; A sixth step of sending, by the second subscriber unit, a response through the established channel; And a seventh step of releasing the channel and scanning the channel when the call is terminated in the call state.

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 are branched and coupled to one communication cable (preferably a coaxial cable). Each subscriber unit communicates with a communication counterpart subscriber unit through a different frequency. 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. Further, in order to increase the number of subscribers by reusing the frequency, it can be simply achieved by adding one or more communication cables. In addition, by providing a signal amplifier at regular intervals in accordance with 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 1 is a duplexer, 2 is a first variable reference frequency generator, 3 is a down converter, 4 is an intermediate frequency (IF) processor, 5 is a controller, and 6 A silver interface, 7 denotes an EEPROM, which is an electrically erasable and programmable read-only memory, 8 denotes a RAM, a read-write memory, 9 denotes a second variable reference frequency generator, and 10 denotes an upconverter.

The subscriber unit according to the invention employs a duplexer 1 at the end of the communication cable in order to transmit and receive data via one communication cable. In addition, in the present invention, the receiving channel of the subscriber unit is continuously changed, and the transmitting channel is set to a channel corresponding to the receiving channel. To this end, the down converter 3 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 2 operated by the control of the control unit 5. Here, the down converter 3 may be configured as a primary and a secondary down converter according to the frequency used. The down-converted signal by the down converter 3 is amplified and filtered by the intermediate frequency (IF) processor 4 and is provided to the controller 5.

On the other hand, the signal transmitted to the communication counterpart subscriber unit is up-converted by the up-converter 10 and transmitted through the duplexer 1, the up-converter 10 is a second variable operated by the control of the controller 5 The transmission signal is up-converted using the reference frequency supplied from the reference frequency generator 9. 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 5 includes an interface 6 for connecting to an external non-voice or voice communication device, a program for performing an overall operation, information on each subscriber unit, a reception channel group, and a transmission channel corresponding to the reception channel group. EEPROM 7, which is an electrically erasable and programmable read-only memory storing a group, and RAM 8, which temporarily stores data and temporarily stores usage state information of respective channels, are connected.

The control unit 5 is a device such as a central processing unit (CPU) that operates according to a program, and the control unit 5 largely monitors the state of use of the reception channel and whether or not a destination signal is received. It performs reception channel setting function, data modulation and demodulation control function. That is, the control unit 5 sequentially scans a reception channel belonging to a reception channel group to determine a state of use of the channel, and receives a signal having the same destination identifier as its own unique identifier (ID) through the scanned reception channel. Keep an eye on it. Here, the usage status of the channel may be determined by sequentially scanning each reception channel, checking whether there is a signal received through the reception channel, and setting a usage flag if there is a signal received. . This information is temporarily stored in RAM.

The transmit / receive channel setting function is classified according to whether it is a transmitting side or a receiving side. First, referring to the case where the user is the transmitting side, when the telephone number or the unique number of the other party for the call is input from the external communication device through the interface 6, the controller 5 inputs the interface 6 through the interface 6. Temporarily save the information. And, by using the information already scanned and temporarily stored to check whether there is a communication channel that is not currently in use, and if there is a communication channel that is not in use, the reception channel of the communication channel that is not in use as its own transmission channel, It acquires transmission channel information corresponding to the unused reception channel from and sets its own reception channel to the obtained channel. Thereafter, a call channel setting request signal including a unique identifier of the counterpart and its unique identifier information is transmitted through the transmission channel on the communication cable.

On the other hand, the case of the receiving side is as follows.

While performing a sequential scan for each channel for a receiving channel group and receiving a signal having a destination identifier (ID) identical to its own unique identifier (ID), the scan current receiving channel is set as its own receiving channel. The channel corresponding to the set reception channel is set as its own transmission channel. Then, the channel setting response including the counterpart subscriber unit identifier is sent out on the communication cable through the set transmission channel.

When a transmission / reception channel for communication is established through this process, the controller 5 controls demodulation of a signal received through a reception channel and modulation of a signal to be transmitted. The modulation / demodulation control function in the control unit 5 is performed in software by a conventional algorithm, and a detailed description thereof will be omitted.

3 is a flowchart illustrating the operation of the control unit as described above in more detail.

First, the controller sequentially scans channels belonging to a reception channel group stored in a memory. In operation 101, the usage state information of the channel determined in the scanning process is stored in the memory. When the channel setting request is received from the user in this state (102), the unique identifier information of the subscriber unit is determined using the telephone number or the unique number of the communication counterpart input by the user, and the unique identifier information of the counterpart is stored (103). ). Then, it is checked whether the reception channel of the unused call channel identified during the scanning process is still in the unused state (104). In identifying unused communication channels, there may be a method of confirming by sequentially rescanning all receiving channels as one method, and preferentially checking the unused communication channels identified through the present scanning process by another method. There may be a way to check whether it is used by scanning. More preferably, the latter method is used, and when the latter method is used, an unused communication channel can be identified within a shorter time.

As a result of checking all communication channels, if there is no unused communication channel, the communication is notified (105). If there is an unused communication channel, the reception channel of the currently selected unused communication channel is set as its own transmission channel. At the same time, the transmission channel of the selected unused channel is set as its own reception channel. That is, one communication channel is composed of one fixed reception channel and one fixed transmission channel pair, and the corresponding transmission channel can be identified by checking the reception channel that is not in use. The checked transmission and reception channels are alternately set to their own reception channel or transmission channel according to the situation.

After the transmission and reception channels are set as described above, the transmission channel setting request signal including the unique identifier information and the unique identifier information of the call counterpart is transmitted through the established transmission channel (107). If the response message is not received from the subscriber unit of the communication counterpart in the response waiting state 108 for a predetermined time (109), the call is notified and if the response message is received within the predetermined time (109), the call channel is set. Notify that the call is switched to the call state (113).

Meanwhile, if a message having the same destination identifier as its own identifier is received while sequentially scanning the reception channel (110), the reception channel selected while scanning is set as its own reception channel and corresponding to the selected reception channel. The transmission channel information to be obtained is obtained from the memory, and its transmission channel is set as the obtained channel (111). In addition, the information of the other subscriber unit included in the received message is temporarily stored in the memory. Then, a response is transmitted 112 to the counterpart subscriber unit through the set transmission channel. When the communication channel is established through the above process, the communication channel is informed that the communication channel is established and the communication state is switched (113). When the call is terminated in the call state (114), the current channel is initialized to release the communication channel (115), and the process of continuously scanning the receiving channel is performed.

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 (6)

A communication system in which a plurality of subscriber units are branched and combined on at least one communication cable, 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 for each subscriber unit, a reception channel group, and a transmission channel group corresponding to the reception channel one-to-one, The control means, By identifying each communication channel in the reception channel group, the unused communication channel is identified, and when the call channel setting request is made, the unused reception channel is used as its own transmission channel, and the transmission channel corresponding to the unused reception channel is owned. And a call channel setting request message including a unique identifier of the communication counterpart and a unique identifier of the communication counterpart. The method of claim 1, The control means, Channel scanning means for sequentially scanning each of the receiving channels in the receiving channel group and checking whether a message having a destination identifier equal to its own unique identifier is received; When the call channel setting request is received from the user, the unused receiving channel is set as its own transmission channel, and the transmission channel corresponding to the unused receiving channel is set as its own receiving channel, and the destination identifier is set by the channel scanning means. A message for setting a currently selected reception channel as its own reception channel and a transmission channel corresponding to the selected reception channel as its own transmission channel when a message is detected; And Means for controlling modulation / demodulation of transmitted and received signals Communication system comprising a. The method of claim 2, The memory means, Save the usage status information of the channel currently being scanned, And the channel scanning means checks whether or not the channel is used preferentially for the channel marked as not in use, using the use state information of the channel stored in the memory means. A communication method applied to a communication system in which a plurality of subscriber units are branched and combined on at least one communication cable, A first step of the first subscriber unit scanning for each of the receiving channels in the receiving channel group; A second step of, if the call channel setting request is received from the user, the first subscriber unit checking whether there is an unused channel; A third step of setting a reception channel of the unused channel as its own transmission channel and a transmission channel of the unused channel as its own reception channel if an unused channel exists; A fourth step of sending, by the first subscriber unit, a call channel establishment request message including identifier information of the second subscriber unit and its own identifier information through the established communication channel; When the second subscriber unit scans each of the reception channels in the reception channel group and receives a message having a destination identifier, the second subscriber unit corresponds to the reception channel corresponding to the currently selected reception channel. A fifth step of setting a transmission channel as its own transmission channel; A sixth step of sending, by the second subscriber unit, a response through the established channel; and Step 7 of releasing the channel and scanning the channel when the call ends in the call state Communication method comprising a. The method of claim 4, wherein The first step, Sequentially selecting, by the first subscriber unit, each of the receiving channels in the receiving channel group; Checking whether there is a signal received through the selected reception channel; And Marking the selected receiving channel as in use when a signal is detected and marking as not in use if a signal is not detected Communication method comprising a. The method of claim 5, Confirmation of the unused receiving channel of the second step, And selecting first receiving channels marked as unused among the scanned receiving channels and checking whether a signal is detected.