KR20020041016A - Data Transmission Protocol Device through Phone Line - Google Patents

Abstract

PURPOSE: A data transmission protocol system using telephone lines is provided to develop a protocol to transmit computer network data using established telephone lines, to minimize data loss due to telephone signals and line interference, and to stably transmit and receive data even in a remote place. CONSTITUTION: A data transmission protocol system using telephone lines is composed of a router(10), a switching hub(16), a main distribution unit(11), and a subscriber unit(24). The router(10), connected to the Internet and an Ethernet line(1), routes IP datagrams. The switching hub(16), connected with the router(10) through the Ethernet line(1), switches Ethernet packets. The main distribution unit(11), connected with the switching hub(16), the telephone lines(2) incoming from an MDF(14) and subscriber lines(3), contains ATCM(Advanced Time Compression Multiplexing) modules to enable data to be transmitted and received through 2-wire telephone lines in an ATCM method. The subscriber unit(24), connected with a subscriber line(3), a telephone line(2) connected to a telephone(18) and an Ethernet line(1) connected to a PC(20), contains an ATCM module so that data can be transmitted and received through the 2-wire telephone line in the ATCM method.

Description

Data Transmission Protocol Device Using Phone Line {Data Transmission Protocol Device through Phone Line}

The present invention relates to a data transmission protocol apparatus using a telephone line, and more particularly, excessive installation and maintenance costs of ADSL or cable modem, which are mainly used for high-speed Internet service, which is increasing in demand, particularly in apartments, officetels, and hotels. In order to solve the problem of the present invention relates to a transport protocol apparatus that can configure a local area network at low intervals by using a two-wire telephone line already established in all homes and can provide high-speed Internet service.

Recently, due to the expansion of the Internet, the number of Internet users in general households as well as research institutes and corporations is increasing rapidly. However, Internet access by telephone modems used in homes cannot exceed the transmission speed of up to 56Kbps. The disadvantage is that it cannot afford the high transmission band required.

In this regard, Internet services using ADSL and cable modems are becoming more common under the name of high-speed Internet services.

The Asynchronous Digital Subscriber Line (ADSL) is a method of using an existing telephone network between a telephone company and a subscriber, and unlike a telephone modem, modulates and transmits digital data using digital technology without converting it to analog. It is necessary to install equipment to link the telephone network with the high-speed Internet network, and to provide a service area over a certain distance from the telephone station due to the distance limitations of the ADSL transmission technology itself.

In addition, the cable modem is connected to the Internet through a coaxial cable installed only for cable TV network subscribers.

In addition, the head-end connects to the Internet through a device called Cable Modem Termination System (CMTS), and subscribers connect to the Internet through a cable modem.

On the other hand, HomePNA technology is an industrial standard technology that transmits data using a two-wire telephone line.It uses a telephone line installed in apartments, officetels, and hotels to construct a local area network and installs a dedicated Internet line. The number of services is also increasing.

In this case, existing research institutes and businesses are the same as those using the Internet (remote network access devices and routers), but using a local area network composed of telephone lines instead of the commonly used Ethernet network. Because of this, it is possible to provide high-speed Internet service to homes at relatively low cost.

However, the ADSL has the advantage that high-speed data service is possible by using the existing telephone network installed between the telephone company and the subscriber.However, in order to service using this method, a new ADSL modem must be newly installed on both sides of the subscriber line. In addition, the price of the high-speed Internet interlocking equipment to be installed is also expensive, there is a problem in that the economic efficiency is low, installation cost and maintenance costs are high.

In addition, the cable TV network is difficult to be generalized in that the number of domestic cable TV subscribers is not high and the cable modem installed in each home is expensive.

Above all, the two services have a high transmission rate per line, but the actual speed experienced by the subscriber is inherently due to the practical problem that the Internet band interworked at the telephone company or cable head-end cannot accommodate this to the maximum in specification. It is far below specification speed.

In addition, in case of local area network method using HomePNA technology, it is easy to install because there is already installed telephone line and there is not much necessary equipment, so it can provide high speed internet service to general homes at relatively low cost, but the limitation of distance is within 300m. There is a problem that the data loss rate is high and the safety is limited due to the interference between the voice signal and the line.

The present invention has been made in order to achieve the above object, by developing a protocol for transmitting the network data of a computer through a pre-provisioned telephone line and implementing it as a circuit, the loss of data due to the interference of the telephone signal and the adjacent line It is an object of the present invention to provide a data transmission protocol device using a telephone line capable of transmitting and receiving stable data over a long distance while minimizing the number of points.

It is another object of the present invention to provide an easy device for constructing a local area network in a multi-family house or a building and providing high-speed Internet service.

1 is a conceptual diagram of a service using a main distribution device and a subscriber device according to an embodiment of the present invention.

FIG. 2 is a block diagram of the main distribution device of FIG. 1.

3 is a conceptual diagram of a service using a hub-based main distribution device and a card type subscriber device according to another embodiment of the present invention.

4 is a block diagram of the hub combined main distribution device of FIG.

FIG. 5 is a block diagram of an ATCM module embedded in the main distribution device and the subscriber device of FIG. 1.

FIG. 6 is a block diagram of an ATCM module embedded in the hub-based main distribution device and the card type subscriber device of FIG. 3.

7 is a structural diagram of an ATCM frame according to the present invention.

8 is a structural diagram of an ATCM sub-frame according to the present invention.

9 is a structural diagram of an ATCM link frame according to the present invention.

10 is a structural diagram of an ATCM link frame header according to the present invention.

<Description of the symbols for the main parts of the drawings>

10 router 11: main distribution device

11a, 12a: Ethernet PHY11b, 12b: ATCM Module

11ba, 12ba: Ethernet PHY Interface

11bb, 12bb: ATCM Link

11bc, 12bc: ATCM PHY11bd, 12bd: Memory Controller

11be, 12be: Packet buffer 11bf, 12bf: PCI interface

11c, 12c: AFE12: main distribution device for hub

12d: CPU12l: system ROM

12f: system RAM 12g: switch controller

12h: Packet buffer 14: MDF

16: switching hub 18: telephone

20: PC22: card type subscriber device

24: subscriber device 30: ATCM frame

32: ATCM subframe 34: ATCM link frame

36: ATCM Link Frame Header

Hereinafter, the present invention will be described with reference to FIGS. 1 to 10.

In order to achieve the above object, the present invention provides a device for enabling the transmission and reception of data using the telephone line (2):

One side is connected to the Internet and the other side is connected to the Ethernet line (1) for a router 10 for routing IP datagrams,

A switching hub 16 connected to the router 10 and the Ethernet line 1 to switch Ethernet packets;

A link / connected to the switching hub 16 and to a telephone line 2 and a subscriber line 3 coming out of the MDF 14 of the common house, and functioning to transmit / receive data via a two-wire telephone line in a time compression multiplexing manner. A main distribution device 11 having an ATCM module 11b which is a protocol of a physical layer,

A link which is connected to the subscriber line 3, the telephone line 2 connected to the telephone 18 and the Ethernet line 1 connected to the PC 20, and functions to transmit and receive data through a two-wire telephone line in a time compression multiplexing manner. Subscriber device 24 with built-in ATCM module 11b, which is a protocol of the physical layer,

Characterized in that configured.

Advanced Time Compression Multiplexing (ATCM), the core technology of the present invention, is a link / physical layer protocol that allows data transmission and reception via a two-wire telephone line (2).

As a type of time division multiplexing (TDM) technology, a time slot is divided into a transmission section and a reception section, as in the conventional TCM technology, to implement bidirectional transmission, and the transmission section and the reception section are assigned the same size. Rather, it can be arbitrarily allocated according to the technical and commercial needs of the network configuration, or dynamically allocated according to the situation of data traffic on both sides of the circuit.

Line coding is optimized to be robust against noise and interference of adjacent lines, and ARQ (Automatic Repeat Request) method is implemented to recover lost data in one or more sections without loss.

7 is a structural diagram of an ATCM frame 30 according to the present invention.

In FIG. 7, the frame of the ATCM protocol is a master / slave structure, 'downstream' an operation transmitted by the master and received by the slave, and an 'upstream' operation performed by the slave and received by the slave. upstream).

Based on the start of the downstream, a time period in which one upstream is performed is defined as 'frame time' and this time is denoted as T _F.

Downstream data is called DS (Downstream Sub-frame) and this time period is denoted by T _DS , upstream data is called US (Upstream Sub-frame) and this time interval is denoted by T _US ,

The delay occurs due to the RC component of the line until the data transmitted from one side is received on the other side. This delay time is denoted as T _D.

The time from the master side to the end of the DS and the US becomes T _R , and the time from the slave side to the end of the DS and the US starts as T _S.

8 is a structural diagram of an ATCM subframe 32 according to the present invention.

One ATCM subframe 32 is composed of one framing bit and n channels, and 16-bit binary data forms one channel.

This channel is called a B-channel.

One symbol may be one binary data, and a time occupied by one binary data is referred to as BT (Bit Time).

With 1 BT set at 244.140625ns, 4.096 × 10 ⁶ symbols can be transmitted per second.

Framing bits are placed at the beginning of each DS / US subframe 32 for frame synchronization.

9 is a structural diagram of an ATCM link frame 34 according to the present invention.

The bit stream accommodated by one ATCM subframe 32 becomes the minimum unit of data that can be transmitted, which is one link layer frame.

The B1 channel is used as a link header, and is composed of header data of upper 8 bits and header checksum of lower 8 bits.

In addition, in the case of a specific subframe, additional header information may be required. In this case, the upper 8 bits of the B2 channel are used as an extended header.

The Bn channel is used as a checksum of the entire subframe data and uses CCITT-CRC16.

The B2 to Bn-1 channels are used as payloads for accommodating higher layer data to be actually transmitted.

10 is a structural diagram of an ATCM link frame header 36 according to the present invention.

In FIG. 10, the link frame header 36 includes the following fields.

BA-Bandwidth Allocation Mode (3bit)

001: Symmetric mode (T _DS = T _VS = nB)

010: DS mode (T _DS = (n-2) B, T _US = 2B)

100: US mode (T _US = 2B, T _DS = (n-2) B)

Miscellaneous: make no sense

USD-Upstream Data Exist (1 bit)

0: No US data, 1: US data

ACK-Acknowledgment for sub-frame received (1 bit)

1: CRC OK, 0: CRC Error

EHDR_ON-Extended Header ON (1 bit)

0: no extension header, 1: extension header

ND-No Data (1bit)

0: There is data, 1: No data

SFAB-Sub-frame Alternating Bit (1 bit)

Control bit for ARQ-Alternating Bit Protocol (ABP)

In addition, the extended header includes the following fields.

EHDR_ID-Extended Header ID (1 bit)

0: Roundtrip Delay

1: Sub-frame Size

EHDR-Extended Header (7bit)

Round trip delay (in order of 1-bit time, T _B )

Sub frame data size (in order of 1-8 channel)

The BA mode indicates the size (time period length of each subframe) of DS / US data of the next frame.

Determined by the master, reflected in the BA field of the DS header and passed to the slave. The initial value is 001 (symmetric mode-DS and US are the same size).

When there is data to be transmitted in its packet buffer, the slave transmits the USD value of the US header as 1.

The master determines the BA mode of the next frame based on the presence or absence of data to be transmitted stored in its packet buffer and the USD value of the US head.

The ACK reflects a checksum value of subframe data received by both master and slave.

In other words, if there is no error in the received US data, the master transmits with ACK = 1 in the next DS header, and if there is an error, transmits with ACK = 0.

In case of slave, if ACK = 1 of received DS header, previous US data is successfully transmitted. If ACK = 0, previous US data was not transmitted correctly. do.

SFAB completes the ARQ protocol with the ACK field, and toggles and reflects the value every time new data is transmitted.

Even if the subframe currently received is CRC OK, the receiving side drops the data if the same value as the SFAB value of the previously stored subframe header is received.

ND indicates that there is no data in the current frame.

At this time, OxFFFF is filled in the channel of the payload part and transmitted.

The transmitting side fragments and transmits the upper layer data (Ethernet frame, etc.) to the payload size accommodated in the ATCM subframe 32, and the receiving side assembles it and delivers it to the upper layer. The last data fragmented fills only a portion of the subframe payload region.

In this case, an extension header is used to indicate the actual data size in the payload region.

As described above, the ATCM module 11b implements an ATCM link / physical layer protocol as a logic circuit.

1 is a conceptual diagram of a service using a main distribution device and a subscriber device according to an embodiment of the present invention.

5 is a block diagram of the ATCM module of FIG.

In FIG. 5, the ATCM module 11b includes an ATCM link 11bb, an ATCM PHY 11bc, an Ethernet PHY interface 11ba, a memory controller 11bd, a PCI interface 11bf, a packet buffer 11be, and the like. Has a function block.

Meanwhile, the subscriber unit 24 includes one ATCM module 11b, one analog front-end 11c, and one Ethernet PHY 11a.

The AFE 11c is an apparatus that is connected to the ATCM module 11b and is in charge of necessary analog signal processing.

It is connected to a telephone line (2, voice signal) and subscriber line (3, voice signal + data) and consists of filtering, reception gain control, signal shaping block, and the like.

It is connected to the subscriber line (3), telephone line (2), Ethernet line (1), the subscriber line (3) refers to the line connecting the MDF (14) carrying the telephone signal and data signal together with the subscriber premises, The telephone line 2 is a line connecting the subscriber device 24 and the telephone set 18 in the home.

Subscriber device 24 and PC 20 are connected one-to-one via Ethernet line 1.

Referring to FIGS. 1 and 5, the operation of the ATCM module 11b will be described with reference to the subscriber device 24 as an example.

First, a process in which transmission data of the PC 20 is carried to the subscriber line 3 via the subscriber device 24 is described.

The subscriber device 24 receives the network data received from the PC 20 through the Ethernet PHY interface 11ba and stores it in the packet buffer 11be.

When one Ethernet frame is completely stored in the packet buffer 11be, the ATCM link 11bb reads data from the packet buffer 11be and fragments into a payload size that can be accommodated in one ATCM subframe 32. fragment) and determine the values of the header field.

When the header and payload data are delivered to the ATCM PHY 11bc in a timely manner, the ATCM PHY 11bc starts line coding and transmits.

During transmission, the CRC generation block in the ATCM PHY 11bc calculates a checksum and appends the calculated value to the last B channel of the ATCM subframe 32 behind the payload.

The AFE 11c loads the coded signal output from the ATCM PHY 11c on the subscriber line 3.

Next, the process of receiving data from the subscriber line 3 via the subscriber device 24 to the PC 20 will be described.

In order to extract the data carried with the telephone signal through the subscriber line (3), the AFE 11c uses a high-pass filter to separate the signal of the entire data band and adjust the signal gain to adjust the ATCM PHY. Transfer to the receiving block of (11bc).

The receiver of the ATCM PHY 11bc decodes a signal input from the AFE 11c and restores data through a digital filter.

A digital phase-locked loop (PLL) is used for accurate decoding of the received data.

The recovered data is stored in the packet buffer 11be by the ATCM link 11bb, and this process is repeated. When all of the Ethernet frames are received and stored, the restored data is read back from the packet buffer 11be and the Ethernet PHY interface 11ba. Send data to the switching hub or PC via.

3 is a conceptual diagram of a service using a hub-based main distribution device and a card type subscriber device according to another embodiment of the present invention.

FIG. 6 is a block diagram of an ATCM module embedded in the hub-based main distribution device and the card type subscriber device of FIG. 3.

The card type subscriber unit (SU-NIC) 22 is a card type and is inserted into a PCI slot inside the PC 20.

No Ethernet PHY is required and consists of one ATCM module 12b and one AFE 12c.

It is installed in the PC 20 through the PCI interface 12bf of the ATCM module 12b, and the data between the PC 20 and the card type subscriber device 22 is on the PCI bus and the PC 20, not Ethernet. The operation is the same as that of the subscriber device 24 except that it is delivered by the operating ATCM driver S / W.

FIG. 2 is a block diagram of the main distribution device of FIG. 1.

The main distribution unit 11 is composed of n ATCM modules 11b, n AFEs 11c, and n Ethernet PHYs 11a.

Referring to FIG. 2, n subscriber devices 24 are aggregated in one case, and the operation and principle of data transmission and reception are the same as those of the subscriber device 24.

In FIG. 1, the Ethernet interfaces of the main distribution device 11 are connected to each port of the switching hub 16 and connected to the Internet through the router 10.

4 is a block diagram of the hub combined main distribution device of FIG.

The Main Distribution Unit-Manageable Switch 12 combines the functions of the main distribution unit 11 and the switching hub 16, and includes n ATCM modules 12b, n AFEs 12c, and a switch controller. 12g, the CPU 12d, the system ROM 12l, the system RAM 12f, the packet buffer 12h, and the Ethernet PHY 12a.

Unlike the main distribution device 11, each ATCM module 12b is connected to each port of the switch controller 12g through an Ethernet interface, and the other ATCM module 12b and the AFE 12c interface are the main distribution device. Same as that of (11).

In the case of the subscriber device 24 or the main distribution device 11, the Ethernet interface of the ATCM module 11b operates as a MAC corresponding to the Ethernet PHY 11a, whereas in this case, the Ethernet PHY corresponding to the Ethernet MAC ( 12a).

The CPU (12d) is mounted to control the switch controller 12g and to port the network management protocol agent so that the network administrator can monitor and control the status of each port.

According to the present invention, it is possible to provide a high-speed Internet service at a low price by establishing a local area network without a separate wiring by using a two-wire telephone line already installed in all homes of the apartment.

In addition, according to the present invention, although the transmission speed is 2 to 4 times faster than the conventional one, it is robust to noise and interference, and lost data can be recovered even if data is lost due to strong noise at one moment.

In addition, according to the present invention, the ATCM protocol allows the transmission band and the reception band to be arbitrarily allocated as described above, or is dynamically allocated according to the situation of data traffic on both sides of the circuit, thereby optimizing the data transmission band. In addition, it is possible to provide a differentiated service for each subscriber according to the needs of service providers.

Claims (14)

A device for enabling the transmission and reception of data using a telephone line: A router that connects one side to the Internet and the other side to an Ethernet line to route IP datagrams, A switching hub connected to the router and an Ethernet line to switch Ethernet packets; Main distribution that is connected to the switching hub and connected to the telephone line and subscriber line from the MDF of the common house, and the ATCM module which is a link / physical layer protocol for data transmission and reception through a two-wire telephone line by time compression multiplexing. Device, It is connected to the subscriber line, the telephone line connected to the telephone, and the Ethernet line connected to the PC, and is a subscriber device incorporating ATCM module, which is a link / physical layer protocol for transmitting and receiving data through a two-wire telephone line in a time compression multiplexing manner. , Data transmission protocol device using a telephone line, characterized in that configured. The method according to claim 1, wherein the ATCM module divides a time slot into a transmission section and a reception section, and arbitrarily determines the size of each section or dynamically allocates the size of the section according to data traffic occurrence in both directions. A data transmission protocol device using a telephone line. The method of claim 1, wherein the frame of the ATCM module is a master / slave structure when the operation transmitted by the master and received by the slave is downstream, and the operation transmitted by the slave and received by the master is called upstream. The time period T _{F at} which one upstream is made based on the start of the downstream, The delay time caused by the RC component of the line until the time interval T _DS of the downstream data _DS , the time interval T _US of the upstream data, and the data transmitted from one side are received on the opposite side ( T _D ), the time from the master side to the end of the DS to US (T _R ), and the slave side from the end of the DS to start the US (T _S ) of the data using the telephone line Transmission protocol device. The method of claim 1, wherein the subframe of the ATCM module, A data transmission protocol device using a telephone line comprising one framing bit and n channels located at the front for frame synchronization, and 16-bit binary data forming one channel. The method according to claim 1, wherein the link frame of the ATCM module, Used as a link header, a B1 channel consisting of the header data of the upper 8 bits and the header checksum of the lower 8 bits, If necessary, if additional header information is required in a specific subframe, the B2 channel in which the upper 8 bits are used as an extension header, Bn channel used as a checksum of the entire subframe data and using CCITT-CRC16, A data transmission protocol device using a telephone line, comprising a B2 to Bn-1 channel used as a payload for receiving data of an upper layer to be actually transmitted. 6. The apparatus of claim 5, wherein the link frame header of the ATCM module is composed of the following fields. BA-Bandwidth Allocation Mode (3bit) 001: Symmetric mode (T _DS = T _VS = nB) 010: DS mode (T _DS = (n-2) B, T _US = 2B) 100: US mode (T _US = 2B, T _DS = (n-2) B) Miscellaneous: make no sense USD-Upstream Data Exist (1 bit) 0: No US data, 1: US data ACK-Acknowledgment for sub-frame received (1 bit) 1: CRC OK, 0: CRC Error EHDR_ON-Extended Header ON (1 bit) 0: no extension header, 1: extension header ND-No Data (1bit) 0: There is data, 1: No data SFAB-Sub-frame Alternating Bit (1 bit) Control bit for ARQ-Alternating Bit Protocol (ABP) 7. The apparatus of claim 6, wherein the extended header comprises the following fields. EHDR_ID-Extended Header ID (1 bit) 0: Roundtrip Delay 1: Sub-frame Size EHDR-Extended Header (7bit) Round trip delay (in order of 1-bit time, T _B ) Sub frame data size (in order of 1-8 channel) The apparatus of claim 6, wherein the transmitting side fragments and transmits the upper layer data in a payload size accommodated in the ATCM subframe, and the receiving side reassembles the data and transmits the same to the upper layer. . The apparatus of claim 1, wherein the main distribution device comprises a plurality of ATCM modules, a plurality of AFEs connected to the ATCM modules, and a plurality of AFEs for handling necessary analog signals, and a plurality of Ethernet PHYs. . The apparatus of claim 1, wherein the subscriber device comprises one ATCM module, one AFE connected to the ATCM module, and one Ethernet AFE for processing necessary analog signals. The method according to claim 10 or 11, wherein the ATCM module, A data transmission protocol device using a telephone line, comprising an ATCM link, an ATCM PHY, an Ethernet PHY interface, a memory controller, a PCI interface, and a function block of a packet buffer. The method of claim 1, wherein the subscriber device is a card-type subscriber device that is inserted into a PCI slot inside the computer consisting of one ATCM module, one AFE is installed in the PC via an interface that the ATCM module has a telephone line Data transmission protocol device used. The method of claim 1, wherein the main distribution device combined with the functions of the main distribution device and the switching hub is composed of a plurality of ATCM modules, a plurality of AFEs, switch controllers, CPU, system ROM, system RAM, packet buffer, Ethernet PHY The ATCM module is a data transmission protocol device using a telephone line, characterized in that connected to each port of the switch controller via an Ethernet interface. The apparatus of claim 1, wherein the ATCM module implements an Automatic Repeat Request (ARQ) scheme for restoring lost data in one or more sections without loss.