KR20030084453A - Ethernet frame transmission apparatus using 2 wire lines - Google Patents

Abstract

PURPOSE: An apparatus for transferring Ethernet frame through 2 lines is provided to have an effect that the Ethernet frame is transferred by using only 2 lines such as a telephone line by utilizing the device used at a conventional 4 lines type Ethernet. CONSTITUTION: An apparatus for transferring Ethernet frame through 2 lines includes a communication media access control processor(11), an impact control processor(21), an analog signal processor(22), a physical-layer processor(12) and a transformer(13). The communication media access control processor(11) implements Ethernet frame transmission and reception and the impact control processor(21) implements the transmission and reception by using two lines without collision. The physical layer process block(12) transmits the frame data by encoding the frame data arrived from the communication media access control processing block(11), reconstructs the original frame by decoding the received signal and performs the transmission and reception of the link pulse. And, the transformer(13) maintains the electrical insulation between the physical layer process blocks(12) and performs the function to the line impedance matching.

Description

Ethernet frame transmission apparatus using 2 wire lines}

The present invention relates to a method and apparatus for transmitting a conventional 10 Mbps Ethernet frame transmission method (10Base-T) that transmits and receives on separate lines by two lines.

The present invention uses the characteristic that the frame transmission and reception of the half-duplex method is performed at different times, so that the existing method using the four-wire line can be transferred to the two-wire line. In addition, the transmission distance can be extended by adding an amplifier to amplify the received signal on the receiving side, and when using a filter to separate the signal band, it is possible to transmit Ethernet frame and telephone signal at the same time by using two-wire telephone line. Can be utilized as

Conventional 10Base-T Ethernet supports both a full duplex method for transmitting and receiving at the same time and a half-differential method for transmitting different transmission and receiving times. Accordingly, as shown in FIG. 1, a line for transmitting a frame and a line for receiving a frame are separately allocated and used. In case of operating in the metastasis mode, frame transmission is simultaneously performed on each line. Frames are sent only to either the transmit or receive line. To this end, Carrier Sense Multiple Access / Collision Detection (CSMA / CD) is used. This method uses a method that stops transmission by recognizing a collision if a signal is simultaneously loaded on the transmission line and the reception line.

The present invention aims to enable Ethernet communication using two lines of wire while using the existing medium access control unit 11, physical layer processing unit 12, and a transformer as it is. Prior arts of the Home PNA (Phoneline Networking Alliance) and Gigalink Time Division Multiplexing Subscriber Loop (TDSL) technologies are also delivering Ethernet packets on two wires. A separate physical layer processor must be used for this purpose. Therefore, a dedicated device for home PNA and time division multiplexing has to be used, which has a disadvantage in that development cost and device price are higher than that of a general physical layer processor for Ethernet.

Since the collision control processing unit 21 of the present invention provides the same transmission right at both ends by using a token, it has the advantage of higher efficiency of using the line at a higher load than the carrier sensing multiple access / collision detection (CSMA / CD) method. In addition, it is possible to transmit and receive Ethernet frame with two lines, but it is easy to extend the transmission distance by the amplifier, so it can be used for low-cost Internet access devices using the internal lines in hotels and apartments.

In order to transmit Ethernet frames in both directions using two lines, it is necessary to transmit the frames at different times at both ends, and to maintain high line utilization efficiency even when the traffic generated at both ends is different or changes dynamically. do. In addition, in order to detect whether the connection is normal in the existing Ethernet, the link pulse periodically transmitted by the transmitting side of the physical layer processing unit 12 should be transmitted only to the other side and it should not be transmitted to the receiving side.

In the present invention, a method in which both nodes alternately have a right to transmit a frame is applied so that both nodes transfer the frame fairly by using two lines of wires so that a collision does not occur. High line utilization is maintained even under high loads. In other words, the node receiving the frame has the right to transmit the frame, and the collision avoidance method is applied that transmits the token frame of short length to the other party only when there is no frame to transmit. Token frame is composed of only the preamble portion of the normal Ethernet frame before the start of the data area is characterized in that it is not recognized as a data frame even if it is transmitted to the media access control processor (11).

In the 10Base-T Ethernet, the physical layer processor 12 operates normally only when a normal link pulse is received from the other side. When the frame is not transmitted, the transmitting side of the physical layer processor 12 periodically transmits a link pulse to detect that the receiving side is normally connected to the transmitting side. Therefore, in case of transmitting / receiving with 2 wires, in order to prevent the link pulse transmitted by itself from being received by itself, the analog switch 22 is detected so that the transmitted link pulse is not transmitted to the receiving side of the physical layer processing unit 12. To control. In this method, since only two wires can transmit link pulses generated from each node to the other side, both nodes have a characteristic of determining whether the link connection between nodes is normally performed.

In the present invention, the reception signal amplifier 61 is added to the reception side to extend the transmission distance while maintaining the advantages of the two-wire type, and the external noise is added by adding a band pass filter 71 to receive only the band of the Ethernet signal region. Can reduce the effect of

Figure 1 10Base-T Delivery Method for Delivering Traditional Ethernet Frames

2 is a structure of the present invention for performing frame transmission and reception using the 2-strand line

Fig. 3 Structure of Transceiver of Existing Ethernet Using Reduced Media Independent Interface

4 Transceiver Structure of Existing Ethernet Using Media Independent Interface

5 is a configuration of an analog signal processor of the present invention

6 is a configuration of an analog signal processor that can extend the transmission distance of the present invention

7 is a configuration of an analog signal processing unit that can reduce the influence of external noise of the present invention

8 is a structure of a collision control processor of the present invention using a reduced media independent interface

9 is a structure of a collision control processor of the present invention using a media independent interface

10 operation procedure of the state controller of the present invention

11 is a block diagram of the Internet service network using a telephone line to which the present invention is applied

The present invention aims to enable Ethernet communication using two wires while using the medium access control processor 11, the physical layer processor 12, and the transformer 13, which were used in the conventional Ethernet of FIG. do.

The conventional media access control processor 11 transmits the physical layer processing unit 12 to the physical layer processing unit 12 through the standard interface according to the operation mode when the frame to be transmitted arrives, and receives the received frame from the physical layer processing unit 12. . In case of full duplex mode, it transmits regardless of the line condition. When the received frame is overfilled and the receiving buffer is over the specified value, the flow control frame is transmitted. In the half-duplex mode, transmission is attempted only when no signal is detected on the receiving side.If a signal is detected on the receiving side after the transmission starts, the other side transmits the frame at the same time and stops the transmission because it considers a collision. Wait for the specified time and try sending again. The physical layer processor 12 encodes and transmits frame data arriving from the media access control processor 11, decodes the received signal, and restores the original frame. In addition, the transmitting side generates a periodic link pulse and transmits it to the other side, and when the receiving side periodically receives a link pulse or frame, the transmitting side plays a role of generating a link signal that the link connection with the other side is normally performed. Also, when operating in the half-duplex mode, it detects whether a frame transmission is simultaneously performed at both ends (collision signal), and delivers it to the media access control processor 11. The transformer maintains electrical insulation between the line and the physical layer processing unit and performs line impedance matching.

2 shows a configuration of the present invention. Instead of the conventional media access control processing unit 11 and the physical layer processing unit 12, the carrier sensing multiple access / collision detection (CSMA / CD) scheme used in Ethernet has the right of frame transmission alternately at both ends. The collision control processor 21 for transmitting and receiving the two lines without collision and the link pulse transmitted between the physical layer processor 12 and the transformer 13 to prevent the link pulse from being received by the self. An analog signal processing unit 22 performing a role is added, and the line side transmission / reception terminal of the transformer is characterized in that it has a configuration. The analog signal processor 22 additionally includes an amplifier for extending the transmission distance or a band limiting filter for minimizing the influence of external noise. In the present invention, since the transmission and reception is performed by two lines, the medium access control processor 11 should always operate in a half-duplex manner.

3 shows the structure of the prior art having a reduced medium independent interface between the medium access control processing unit 11 and the physical layer processing unit 12. As shown in FIG. This interface includes a reception data 32 in which transmission frame data is carried out, a transmission possible 31 representing a time when transmission frame data is valid, a reception data 34 in which reception frame data is carried out, and a reception time indicating a valid time of reception frame data. Valid 33, and a reference clock 35 for synchronizing all signals. In this interface, if there is no explicit signal indicating a collision, and both the transmittable 31 and the reception valid 33 appear at the same time, the medium access control processing unit 11 recognizes the collision.

4 shows the structure of the prior art having a media independent interface between the medium access control processing unit 11 and the physical layer processing unit 12. As shown in FIG. This interface includes a transmission data 43 carrying transmission frame data, a transmission possible 42 indicating when the transmission frame data is valid, a transmission clock 41 for synchronizing transmission data, and reception data carrying reception frame data. (48), the reception validity 47 indicating the time when the reception frame data is valid, the reception clock 44 for synchronizing the reception data, the signal detection 45 indicating that a signal is being received on the line, and both ends simultaneously It consists of a signal conflict 46 that indicates that a collision has occurred by transmission.

5 shows an example of the configuration of the analog signal processor 22 of the present invention. The simplest configuration includes a link pulse detector 52 for detecting a link pulse signal from a line on the transmitting side, and an analog switch 53 for preventing transmission of a received signal according to the link pulse sensor signal. The analog signal processor having such a configuration enables the analog signal position 53 on the receiving side not to transmit the link signal to the receiving side only at the time when the transmitting side transmits the link pulse, thereby enabling the transmission and reception of the same link signal as that of the 4-wire type.

6 shows another configuration example of the analog signal processor 22 of the present invention. Link pulse detector 52 for detecting a link pulse signal from the line on the transmitting side, an analog switch 53 for preventing the transmission of the received signal according to the link pulse detector signal, and a received signal amplifier for amplifying the received signal. 61 is additionally connected to the receiving side. This configuration has a feature that can increase the transmission distance by amplifying the size of the received signal. The reception signal amplifier 61 may additionally have a function of automatically changing the amplification degree according to the magnitude of the reception signal.

7 shows another configuration example of the analog signal processor 22 of the present invention. Link pulse detector 52 for detecting a link pulse signal from the line on the transmitting side, an analog switch 53 for preventing the transmission of the received signal according to the link pulse detector signal, and a received signal amplifier for amplifying the received signal. A band pass filter 71 for passing only a signal of a band in which an actual data signal is distributed to 61 is additionally connected. This configuration has the advantage of reducing the influence of noise signals in other bands because only the band through which the actual data signal is distributed passes.

8 shows the configuration of the collision control processing unit 21 that can be applied to the case where the reduced type medium independent interface is provided. Busy state generator 82 for controlling the transmittable time of the medium access controller, token generator 81 for generating a token frame consisting of only a short preamble signal if there is no transmitted frame, if there is a transmission right, transmittable and received It consists of a state controller 83 for controlling the token generator 81 and the busy state generator 82 by grasping the transmission and reception state from the valid signal. The token generator generates a signal that causes the physical layer processor 12 to transmit a token frame having a short length consisting of only a preamble signal when the frame is not transmitted by the media access control processor 11 during the transmission right. Do this. The busy state generator 82 serves to forcibly generate the reception valid 33 signal so that the medium access control processor cannot transmit when the user does not have a transmission right. The state controller 83 grasps the frame transmission of the medium access control processing unit 11 and the frame state received from the other party to determine the point of time having the transmission right, and accordingly, the token generator 81 and the busy state generator 82 Serves to control.

9 shows the configuration of the collision control processing unit 21 that can be applied to the case having a media independent interface. Busy state generator 92 for controlling the timing of transmission of the medium access controller 41, token generator 91 for generating a token frame consisting of only a short preamble signal when there is no transmitted frame, if it has a transmission right; It is composed of a state controller 93 for controlling the token generator 91 and the busy state generator 92 by grasping the transmission and reception state from the possible 41 and the signal detection 45 signal. Each component is the same as using the reduced-independent media interface, but the busy state generator 92 uses the signal detection 45 signal representing the entire frame region including the preamble signal instead of the reception valid signal representing the data frame region. A busy state that restricts transmission of the embedded access control processor 11 is generated. The token generator 91 and the busy state generator 92 operate in synchronization with the transmission clock and the reception clock, respectively, instead of the reference clock.

10 is a state operation diagram showing the operation of the state controller. Since the media access control processor alternately performs frame transmission and frame reception, it should transmit the frame or token if it has the right to transmit, and wait for the frame or token to be received if it does not have the right to transmit. The transmission state controller has seven states according to the transmission and reception states of the frame. The transmission state controller indicates the busy state generation limiting the transmission and the token frame generation passing the transmission right according to each state. That is, state 1 (101) indicates a state having a transmission right and is a state in which a medium access control processor can transmit a frame. When the medium access control processor starts transmitting the frame within the prescribed time, it transitions to state 6 106 in the frame transmission state, and transitions to state 2 102 in which the token is transmitted when the transmission time has elapsed. State 2 transitions to state 3 (103), which is a reception standby state after transmitting a short packet consisting of only preambles, by transmitting the transmission right to the other side. When the reception of the frame or token is started in the waiting state of the state 3, the state transitions to the state 4 104 of the receiving state. If no frame or token is received within the time specified in state 3, the state transitions to the state 1 (101) in the transmission state. When frame reception ends in state 4 (104), the state transitions to state 5 (105) waiting for a defined time delay between frames. In state 5, the terminal waits for the minimum specified time between frames to transmit after the defined time. When the transmission is completed in the state 6 (106) of transmitting the data frame, the state transitions to the state (7) 107 which waits for the prescribed time delay between frames. In state 7 (107), the state transitions to state 3 (103), which is a reception standby state after a prescribed time delay.

The state controller instructs the token generator in the state 2 (102) in which the token should be transmitted, and instructs the busy state generator in the busy state generator in states 2, 3, and 4 in which the media access controller should prohibit frame transmission. It plays a role.

11 shows an application example of the present invention using the telephone line of the premises of an apartment or a hotel. Ethernet frame transmission and reception is possible with two phone lines, and the band used for Ethernet frame signal transmission is different from the telephone signal band, so when the high pass filter 113 and the low pass filter 112 are combined, Ethernet communication can be performed simultaneously with the telephone. Do.

The present invention has the effect of enabling the transmission and reception of Ethernet frames using a two-wire line such as a telephone line by using a device used in the conventional four-wire Ethernet to transmit and receive Ethernet frames only two wires. Since the existing Ethernet device is utilized, there is an advantage that a low-cost configuration is possible compared to the conventional technology using a separate dedicated device. In addition, it is possible to extend the transmission distance from 100m to 500 ~ 700m by adding an amplifier to amplify the received signal.

The present invention can be applied to the case of transmitting an Ethernet frame using a telephone line in the premises, such as an apartment or a hotel as shown in FIG. The two-line telephone line not only allows Ethernet frame transmission and reception, but also has the advantage of being used simultaneously with the telephone.

Claims (7)

Communication medium access control processing unit 11 for performing Ethernet frame transmission and reception in a half-duplex method, collision control processing unit 21 for transmitting and receiving on two lines without collision by having the right of frame transmission alternately at both ends, The analog signal processor 22, which prevents the link pulse transmitted by itself from being received from itself, encodes and transmits the frame data received from the media access control processor, decodes the received signal, and restores the original frame. And an Ethernet frame comprising a physical layer processing unit 12 for transmitting and receiving link pulses, and a transformer 13 for maintaining electrical insulation between the physical layer processing units and performing line impedance matching. Transmission device The collision control processor 21 of claim 1 makes the token generators 81 and 91 generating a token frame, which is a short control frame, and makes the line busy state so that the media access control processor cannot transmit the frame according to the control of the state controller. Busy state generators 82 and 92, and state controllers 83 and 93 for determining time of transmission right and time of no transmission right according to frame transmission and reception state of a data frame or token frame. Ethernet frame forwarding device The token generators 81 and 91 of claim 2 may use a frame consisting of only preambles as a token frame. The state controllers (83, 93) of paragraph 2, when the medium access control processor transmits a frame with the right to transmit, transition to the receive standby state after the interframe time delay after the frame transmission, and control if the frame is not transmitted within the prescribed time. Transmit signal to token generator, which is a frame, to token generator and transition to reception standby state.If a frame is received within the specified time in reception standby state, it is transitioned to transmission standby state after completion of reception. Ethernet frame transfer device characterized in that the transition to the transmission standby state if the frame is not received The analog signal processor 22 of claim 1 is connected between the link pulse detector 52 which detects when the transmitting side of the physical layer processor transmits the link pulse, and the transformer and the receiving side of the physical layer processing unit to switch the transmission of the received signal. Ethernet frame transmission device, characterized in that composed of an analog switch 53 so that the transmitted link pulse is not transmitted to the receiving side The analog signal processor of claim 1 has a link pulse detector 52 which detects when the transmitting side of the physical layer processor transmits the link pulse, an analog switch 53 capable of switching the transmission of the received signal to the receiving side of the physical layer processing unit, Ethernet frame transmission device, characterized in that it consists of a receiving signal amplifier 61 that can amplify the received signal to a predetermined size or more, so that the transmitted link pulse is not transmitted to the receiving side and additionally extends the transmission distance. The analog signal processor 22 of claim 1 includes a link pulse detector 52 for detecting a link pulse when the transmitting side of the physical layer processor transmits the link pulse, and an analog switch capable of switching the transmission of the received signal to the receiving side of the physical layer processing unit. 53), a reception signal amplifier 61 capable of amplifying the reception signal to a predetermined size or more, and a band pass filter 71 for passing only a signal band used by the reception signal, and additionally affected by external noise. Ethernet frame transfer device, characterized in that for reducing