KR100594046B1 - Method and appratus for transmitting data in giga bit ethernet passive optical network - Google Patents

Abstract

The present invention relates to a method for transmitting data in an optical line termination (OLT) based on a time division multiple access (TDMA) method in an optical network unit (ONU) in a Gigabit Ethernet passive fluorescence subscriber network. Measuring a data transmission time, comparing the measured data transmission time with a predetermined normal transmission time, and if the measured data transmission time is less than the normal transmission time, maintaining transmission of the data and transmitting the measured data transmission If the time is greater than the normal transmission time, the transmission of the data is stopped.

Transmission control unit, normal transmission time, data transmission time

Description

METHOD AND APPRATUS FOR TRANSMITTING DATA IN GIGA BIT ETHERNET PASSIVE OPTICAL NETWORK}             

1 is a configuration diagram of a Gigabit Ethernet passive fluorescence subscriber network to which the present invention is applied;

2 is a view showing the configuration of an ONU (Optical Network Unit) according to an embodiment of the present invention,

3 is a diagram showing the configuration of an ONU including a transmission control function block according to the present invention;

4 to 6 illustrate embodiments in which a transmission control function block is located in a physical layer;

7 is a diagram showing the configuration of a transmission control function block according to an embodiment of the present invention;

8 is an operation flowchart of an ONU according to the present invention;

9 is a diagram showing the effect on Gigabit Ethernet PON when an error of ONU occurs;

10 is a block diagram illustrating ONU error occurrence according to the present invention;

11 to 13 are views showing the configuration of an optical network unit (ONU) according to another embodiment of the present invention,

14 is a view showing the configuration of a laser control block according to the present invention;

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Gigabit Ethernet Passive Optical Network (Gigabit Ethernet Passive Optical Network), and more particularly to a method for transmitting data to an optical line termination (OLT) by an optical network unit (ONU).

 In the Gigabit Ethernet passive optical subscriber network structure currently being standardized in IEEE802.3ah EFM, as shown in FIG. 1, communication between a plurality of ONUs 110-1, 110-2, 110-3 and one OLT 100 is not possible. Occurs. 1 is a block diagram of a Gigabit Ethernet passive fluorescence subscriber network to which the present invention is applied. In the case of downlink transmission transmitted from the OLT 100 toward the ONUs 110-1, 110-2, and 110-3, the OLT 100 broadcasts to all ONUs 110-1, 110-2, and 110-3. In casting, the corresponding ONUs 110-1, 110-2, and 110-3 use a mechanism to receive only their data. However, in the case of uplink transmission from the ONUs 110-1, 110-2, and 110-3 toward the OLT 100, a plurality of ONUs 110-1, 110-2, and 110-3 use the transmission medium. You are configuring a shared topology. This is similar to a conventional bus topology. Accordingly, each ONU 110-1, 110-2, and 110-3 transmits a frame to the OLT 100 based on a time division multiple access (TDMA) scheme. Therefore, each ONU (110-1, 110-2, 110-3) is assigned the time to transmit from the OLT (100), the corresponding ONU (110-1, 110-2, 110-3) is only that time The frame can be transmitted. However, if a failure occurs in any ONU during uplink transmission, abnormal data is transmitted over a predetermined time. This affects the time allotted to other ONUs. Other ONUs recognize that the failed ONU continues to occupy the transmission path, resulting in serious errors in upstream data. This is illustrated in FIG. 9. 9 is a diagram illustrating the effect on the Gigabit Ethernet PON when an ONU error occurs. According to FIG. 9, the ONU1 110-1 successfully transmits the ONU1 data frame for a predetermined time, that is, during the first period, whereas the ONU2 110-2 fails to generate the ONU2 within the second period due to an error in the ONU. The data cannot be transmitted and occupies the transmission path until then. That is, the ONU 110-2 continues to transmit the ONU2 data in which an error occurs over a predetermined time, and accordingly, a data collision occurs in the third section where the ONU3 110-3 should transmit the ONU3 data. As a result of this collision, the entire transmission of Gigabit Ethernet passive fluorescence subscriber network is impossible.

Accordingly, an object of the present invention is to provide a method and apparatus for stably transmitting data from an ONU to an OLT.

In order to achieve the above object, the present invention provides a method for transmitting data in an optical line termination (OLT) based on a time division multiple access (TDMA) method in the optical network unit (ONU) in a Gigabit Ethernet passive fluorescence subscriber network, Measuring a data transmission time during data transmission with the OLT; comparing the measured data transmission time with a predetermined normal transmission time; and as a result of the comparison, the measured data transmission time is smaller than the normal transmission time. And if the measured data transmission time is greater than the normal transmission time, stopping the transmission of the data.

The present invention also provides an optical network unit (ONU) for transmitting data in an optical line termination (OLT) based on a time division multiple access (TDMA) scheme in a Gigabit Ethernet passive fluorescence subscriber network. A switch unit for outputting the input OLT transmission data to a transmission line connected to the OLT, and measuring transmission time of the OLT transmission data when the transmission of the OLT transmission data is started, and controlling the switch unit when the transmission time is smaller than a predetermined normal transmission time. Maintains the output of the data, and if the transmission time of the OLT transmission data is greater than the normal transmission time, the transmission control function block configured to control the switch unit to stop the output of the OLT transmission data is a physical layer of ONU. It is provided in one of PCS, PMA, and PMD layers.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. And a detailed description of known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

First, a configuration of a Gigabit Ethernet Passive Optical Network (GEPON) to which the present invention is applied will be described with reference to FIG. 1. 1 is a block diagram of a Gigabit Ethernet passive fluorescence subscriber network to which the present invention is applied. As shown in FIG. 1, the passive fluorescence subscriber network is composed of one OLT 100 and a plurality of ONUs 110-1 to 110-3 connected to the OLT 100. 1 illustrates an example in which three ONUs 110-1 to 110-3 are connected to one OLT 100. A plurality of end users 120-1 through 120-3 may be connected to the ONUs 110-1 through 110-3.

Data 131 to 133 transmitted by the end users 120-1 to 120-3 are transmitted to the OLT 100 via ONUs 110-1 to 110-3, and the OLT 100 is transmitted to the OLT 100. Data to be transmitted is transmitted to the end users 120-1 through 120-n via the ONUs 110-1 through 110-3. In GEPON, transmission of such data, that is, an Ethernet frame, is performed at a transmission speed of 1 Gbps or more, and in the uplink transmission, the OLT 100 multiplexes each of the ONUs 110-1 to 110-3 in a time division multiplexing (TDM) manner. Access the data. In the downlink transmission, the ONUs 110-1 to 110-3 select and receive only data to be received by the OLT 100 from among data broadcast by the OLT 100.

In the uplink transmission of data of the GEPON, the plurality of ONUs 110-1 to 110-3 must be transmitted on the uplink channel by combining data without collision of TDM time slots and must be able to efficiently access the channel.

Accordingly, the present invention measures the time taken to transmit data when the ONU 110 starts to transmit the data to the OLT 100 and, if the measured time exceeds the preset normal transmission time, transmit the data. Stop. The normal transmission time is a time taken to transmit all of the maximum transmittable data at a time when the transmission line connected to the OLT 100 of the ONU 110 is occupied.

The configuration of the ONU 110 operating as described above is shown in FIG. 2 is a diagram illustrating a configuration of an optical network unit (ONU) according to an embodiment of the present invention. The ONU 110 includes a media access control (MAC) layer and a physical layer. Referring to FIG. 2, the physical layer includes a physical coding sub-layer (PCS) 160, a physical medium attachment (PMA) 150, and a physical medium dependent (PMD) 190. The PCS layer 160 operates 8B / 10B coding at transmission and 10B / 8B decoding at reception. The PMA layer 150 performs serialization / deserialization of data, and the PMD layer 190 performs modulation and pulse shaping for sending data to a transmission line. . The configuration of the ONU 110 shown in FIG. 2 follows the standard of IEEE802.3.

Since the present invention relates to the transmission of data by the ONU 110 or the OLT 100, FIG. 2 shows only components related to data transmission in each layer. In terms of data transmission, the PCS layer 160 includes an encoder 10 for encoding data from higher layers, and the PMA layer 150 includes a multiplexer 20 for multiplexing data from encoder 10. The PMD layer 190 includes a modulator 30 for modulating the multiplexed data and a waveform shaper 30 for waveform shaping the signal of the modulated data.

Meanwhile, according to the present invention, the physical layer including the PCS layer 160, the PMA layer 150, and the PMD layer 190 has a case where data having an error from the upper layer is transmitted as shown in FIG. The transmission control function block 310 to detect and block. That is, the transmission control function block 310 may be located at any position of the physical layer 400 when transmitting and receiving data in the physical layer including the PCS, PMA, and PMD layers.

4 to 6 illustrate embodiments in which the transmission control function block 310 is located in the physical layer 400. The transmission control function block 310 is located in the PCS layer 160 as shown in FIG. 4 and detects and blocks when an error occurs from the MAC, or blocks the PMA layer 150 as shown in FIG. It can be located to block the error data from the PCS layer. In addition, the transmission control function block 310 may be located in the PMD layer 190, as shown in FIG. As such, the function of the transmission control function block 310 is not repeated for each layer but is located in any one of the physical layers.

7 is a diagram showing the configuration of a transmission control function block according to an embodiment of the present invention. As shown in FIG. 7, the transmission control function block 310 includes a switch unit 153 and a transmission control unit 155. As described above, the transmission control function block 310 may be located in any one of layers of PCS, PMA, and PMD, which are physical layers, and will be described in detail below.

The switch unit 153 outputs data input by turning on / off under the control of the transmission control unit 155 to the transmission line or stops output. The transmission line is a line connecting the OLT 100 and the ONU 110. When the transmission control unit 155 outputs data to the switch unit 153 at the upper layer, the transmission control unit 155 drives a timer to measure the time taken for data transmission to determine whether the data is normal data or abnormal data. Specifically, if the measured data transmission time is less than the preset normal transmission time, the transmission control unit 155 determines that the data is normal and maintains the switch unit 153 in the on state. However, if the measured data transmission time is greater than the preset normal transmission time, the transmission control unit 155 turns off the switch unit 153 by determining that it is abnormal data and stops outputting the transmission line of data.

That is, the transmission control unit 155 determines whether an error has occurred in the upper layer by determining whether the data is normal or abnormal based on the time consumed during data transmission, and stops outputting the abnormal data to the transmission line. For example, a Jabber controller may be used as the transmission controller 155.

An operation process of the ONU 110 configured as described above will be described with reference to FIG. 8. 8 is a flowchart of operation of the ONU 110 in accordance with the present invention. The ONU 110 checks whether there is data transmission to the OLT 100 in step 201, and proceeds to step 203 if there is data transmission. In step 203, the ONU 110 measures the time that data transmission is in progress from the moment when data transmission starts and proceeds to step 205. In step 205, the ONU 110 compares the data transmission time measured in step 203 with a preset normal transmission time. As a result of comparison, the ONU 110 proceeds to step 207 if the measured data transmission time is less than the normal transmission time, and proceeds to step 209 if the measured data transmission time is larger than the normal transmission time. In this case, when the measured data transmission time is less than the normal transmission time, it means that the data is normal, which means that the data is also transmitted normally. If the measured data transmission time is larger than the normal transmission time, it means that the data is abnormal and that an error may occur in the data transmission. Accordingly, the ONU 110 successfully completes the data transmission and ends the data transmission in step 207. In step 209, the ONU 110 stops data transmission and ends data transmission.

As described above, the ONU 110 according to the present invention detects the occurrence of error data during uplink transmission of data and blocks data transmission, thereby enabling smooth data transmission of the entire GEPON. This is shown in FIG.

FIG. 10 is a view illustrating blocking of occurrence of an ONU error in accordance with the present invention. FIG. As shown in FIG. 10, data is successfully transmitted during a first section in which ONU1 data of ONU1 110-1 is transmitted. Then, during the second period in which the ONU2 data of the ONU2 110-2 is transmitted, the ONU2 110-2 detects ONU2 data having an error in accordance with the determination of the transmission controller 115 provided according to the present invention, and switches The unit 153 is driven to stop the data transmission at the start of the third section in which the ONU3 data of the ONU3 110-3 is transmitted. Accordingly, in the third section, the ONU3 110-3 may normally transmit ONU3 data, and smooth data transmission may be performed in the entire GEPON.

As described above, the transmission control function block 310, which may include and use a Jabber controller, may be located regardless of the specific position of the physical layer when transmitting and receiving data in the PCS, PMA, and PMD layers of the physical layer. Can be. The transmission control function block 310 detects and blocks the data when an error occurs from a higher level.

On the other hand, the EPON MAC layer, or more precisely, the multi-point MAC control layer above the MAC layer generates a laser control signal and generates a laser control signal. The laser of the PMD layer below the PMA is ON / OFF controlled.

In the ONU / ONT, when data is not transmitted, it is desirable to turn off the laser that can act as a noise source when transmitting data of another ONU so as not to interfere with data transmission of other ONU / ONTs.

Therefore, when the transmission control unit is applied to the EPON, it is preferable to turn off the laser when data transmission is not performed by the transmission control function block 310 for the above reason.

In the above-described embodiment of the present invention, since the transmission control function block 310 operates irrespective of laser control, when the transmission control function block 310 is operated in a state where the laser control is turned on, The transmission of abnormal data can be prevented, but since the laser is still on, it can act as a noise source when transmitting data from another ONU.

In this way, when a malfunction occurs in the device above the PMA and sends down data larger than the maximum packet size defined in Ethernet, the transmission control unit is activated to prevent further data from being transmitted to the lower side. ON / OFF cannot be controlled.

Therefore, another embodiment of the present invention has the same control state as the conventional laser control when transmitting data by the transmission control function block 310, and laser control when not transmitting data by the transmission control unit. Always turn off the laser regardless of the control status. Hereinafter, the functional block including the laser controller and the laser is called a laser control block. Hereinafter, a configuration according to another embodiment of the present invention will be described in detail.

11 to 13 are views illustrating a configuration of an optical network unit (ONU) according to another embodiment of the present invention. These figures show that the transmission control function block 310 is included in any one of each physical layer of the PCS, PMA, and PMD and the laser control block 320 is included in the PMD layer 190 according to another embodiment of the present invention. do.

Specifically, referring to FIGS. 3 and 11 to 13, the ONU 110 includes a media access control (MAC) layer 170 and a physical layer 400, and the physical layer 400 is a physical layer (PCS). Coding Sub-layer (160) layer, PMA layer 150 and Physical Medium Dependent (PMD) layer 190, which follows the hierarchical structure of IEEE802.3. The ONU 110 transmits the above-described transmission control function block to any one of the Physical Coding Sub-layer (PCS) layer 160, the PMA layer 150, and the Physical Medium Dependent (PMD) layer of the physical layer 400. The PMD layer 190 includes a laser control block 320 that includes a 310 and operates in conjunction with the transmission control function block 310.

The laser control block 320 has the same control state as the conventional laser control when data is transmitted from the transmission control function block 310, and from the upper level when data is not transmitted from the transmission control function block 310. Regardless of which Laser Control command is issued, the state of the laser is always turned off or false.

14 is a view showing the configuration of a laser control block according to an embodiment of the present invention. 14 shows a relationship between the laser control block 320 and the transmission control function block 310.

According to another embodiment of the present invention, the laser control block 320 of the PMD layer 190 includes a laser controller 193 and a laser controller for controlling the laser 193 to output data from the upper layer to the transmission line. 195). The laser 193 is controlled on by the laser controller 195 to transmit data from the upper level to the transmission line.

 The laser controller 195 receives a laser control signal from a multi-point MAC control layer, which is an upper layer of the MAC layer 170. Also, the laser controller 195 receives a transmission control signal from the transmission control function block 310 according to another embodiment of the present invention.

As described above, the transmission control signal from the transmission control function block 310 is a control signal that determines whether the data is normal or abnormal based on the time consumed during the data transmission and outputs the data accordingly. . This control signal is output to the switch section 153 to control the switch section 153 on / off.

On-control of the switch section 153 causes the transmission line output of the data to continue, and off-control of the switch section 153 stops the transmission line output of the data.

According to another embodiment of the present invention, the control unit 195 of the laser control block 320 controls the switch unit 153 when the upper level devices operate normally. Since it is output to the on control, the laser 193 is controlled according to the laser control signal which is the output of the multipoint MAC control layer.

That is, when the laser controller 195 of the laser control block 320 determines that the upper devices operate normally according to the control signal from the transmission control function block 310, the multipoint MAC control layer is applied. By outputting the same value as the laser control signal which is the output of the to have the same control state as the conventional laser control.

According to the present invention, when the laser control unit 195 of the PMD layer 190 transmits an abnormal data frame from the upper layer, the control signal provided from the transmission control function block 310 controls the switch unit 154. Since the output is controlled to be off, the laser 193 is controlled to be turned off or false irrespective of the laser control signal from the multipoint MAC control layer.

That is, when the laser controller 195 determines that the upper devices are abnormally operated according to the control signal from the transmission control function block 310, the laser controller 195 and the laser control signal from the multipoint MAC control layer are used. Irrespective of the control, the laser 193 is turned off or false.

As described above, according to another embodiment of the present invention, in the Gigabit Ethernet passive fluorescence subscriber network, the laser controller is installed in the PMD layer, so that an error occurs due to a malfunction of the device in the upper layer (PCS or MAC) of the PMD layer. When data is continuously transmitted, the laser can be controlled irrespective of the laser control signal from the Multipoint MAC Control layer so that the laser can act as a noise source when transmitting data from another ONU. Turn it off so that other ONU / ONTs do not interfere with data transmission.

In the above description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the equivalent of claims and claims.

As described above, according to the present invention, when data is transmitted in a Gigabit Ethernet passive fluorescence subscriber network, abnormal data generation can be sensed so that the data can be smoothly transmitted.                     

In addition, the present invention in the gigabit Ethernet passive fluorescence subscriber network is turned off the laser that can act as a noise source when it is determined that the upper devices are operating abnormally in accordance with the control signal from the transmission control unit of the other devices Do not interfere with data transmission.

In addition, the transmission control function block of the present invention may be implemented by being included in any one of the physical layer PCS, PMA, PMD, and in this case, the control signal from the transmission control function block is the same as in the above-mentioned other embodiments. It can also be used in conjunction with laser control.

Claims (10)

In the Gigabit Ethernet passive fluorescence subscriber network, the ONU (Optical Network Unit) transmits data to the optical line termination (OLT) based on the Time Division Multiple Access (TDMA) method, Measuring a data transmission time when transmitting data to the OLT; Comparing the measured data transmission time with a predetermined normal transmission time; And maintaining the transmission of the data if the measured data transmission time is less than the normal transmission time, and stopping the transmission of the data if the measured data transmission time is greater than the normal transmission time. How to feature. In an optical network unit (ONU) transmission apparatus for transmitting data in an optical line termination (OLT) based on a time division multiple access (TDMA) scheme in a gigabit Ethernet passive fluorescence subscriber network, A switch unit for outputting the OLT transmission data input from the transceiver unit to a transmission line connected to the OLT under control; When the transmission of the OLT transmission data is started, the transmission time of the OLT transmission data is measured. If the transmission time of the OLT transmission data is smaller than a predetermined normal transmission time, the switch unit controls the output of data, and the transmission time of the OLT transmission data is greater than the normal transmission time. And a transmission control function block comprising a transmission control unit for controlling the switch unit to stop the output of the OLT transmission data when the larger value. The ONU transmission device according to claim 2, wherein the transmission control function block is located in one of the PCS, PMA, and PMD layers which are the physical layers of the ONU. In an optical network unit (ONU) transmission apparatus for transmitting data in an optical line termination (OLT) based on a time division multiple access (TDMA) scheme in a gigabit Ethernet passive fluorescence subscriber network, When the transmission of data to the OLT is started, the transmission time of the OLT transmission data is measured. If the transmission time of the OLT transmission data is greater than the normal transmission time, the transmission of the OLT transmission is maintained. And a transmission control function block for stopping data transmission. In a method of transmitting data to an OLT / ONU based on a time division multiple access (TDMA) scheme in an optical network unit (ONU) / optical line termination (OLT) in a Gigabit Ethernet passive fluorescence subscriber network, Interrupting data transmission due to an error in the upper layer, If the transmission of the data is interrupted, turning off the laser of the Physical Medium Dependent (PMD) layer regardless of the laser control signal provided from the multipoint MAC control layer, which is a higher layer of the PMA. Way. The method of claim 5, wherein the stopping of the data transmission comprises: Measuring a data transmission time during the data transmission; Comparing the measured data transmission time with a predetermined normal transmission time; And maintaining the transmission of the data if the measured data transmission time is less than the normal transmission time, and stopping the transmission of the data if the measured data transmission time is greater than the normal transmission time. A data transmission method characterized by the above-mentioned. In the transmission device for transmitting data to the OLT / ONU based on the Time Division Multiple Access (TDMA) method in a Gigabit Ethernet passive fluorescence subscriber network, A switch unit for outputting transmission data to a lower layer, When the transmission of the transmission data is started, the transmission time of the transmission data is measured, and when the transmission time is smaller than the predetermined normal transmission time, the control unit maintains the output of the data, and when the transmission time is larger than the normal transmission time, the control unit controls the transmission data. A transmission control function block including a transmission control unit for stopping the output of the; And a PMD layer including a signal controlling the switch from the transmission control function block and a laser control signal provided from a multipoint MAC control layer, and a laser control unit controlling a laser according to these signals. Transmission device. 8. The multipoint MAC control layer output of claim 7, wherein the laser controller of the PMD layer determines that the devices before the laser controller operate normally according to a switch control signal from the transmission control function block. And transmitting the laser according to the laser control signal. The laser controller of claim 7, wherein the laser controller of the PMD layer determines that the devices before the laser controller operate abnormally according to a switch control signal from the transmission controller. A transmission device for controlling the laser to be off or false irrespective of the control signal. 8. The transmission apparatus of claim 7, wherein the transmission control unit is a jabber controller.

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