WO2012106860A1

WO2012106860A1 - Method and system for configuring upstream forward error correction flowchart

Info

Publication number: WO2012106860A1
Application number: PCT/CN2011/075728
Authority: WO
Inventors: 黄健; 王康; 黄文杰
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-02-12
Filing date: 2011-06-14
Publication date: 2012-08-16
Also published as: CN102158308A; CN102158308B

Abstract

The invention discloses a method for configuring upstream Forward Error Correction (FEC) flowchart. The method includes following steps: an Optical Line Terminal (OLT) detects the Bit Error Rate (BER) of uplinks in real time, and configures an upstream FEC flowchart based on whether the BER reaches a preset condition. An OLT is also disclosed by the invention. The OLT includes a detection module, which is set to detect the BER of uplinks in real time, and a configuration module, which is set to configure an upstream FEC flowchart based on whether the BER reaches a preset condition. With the invention, dynamically configuring the upstream FEC function of an Optical Network Unit (ONU) in real-time is enabled, and the upstream bandwidth utilization rate can be improved maximally.

Description

Method and system for configuring uplink forward error correction process

TECHNICAL FIELD The present invention relates to a Passive Optical Network (PON), and more particularly to a method and system for configuring an upstream Forward Error Correction (FEC) process.

Background technique

The 10-Gigabit-capable Passive Optical Network (XG-PON) device includes: an Optical Line Terminal (OLT) and an Optical Network Unit (ONU). In the XG-PON operating network, the common networking system is shown in Figure 1. The system consists of an Element Management Server (EMS), an OLT, a splitter, and one or more ONUs (maximum 1024). The transmission direction from the OLT to the ONU is the downstream direction (downstream), and the transmission direction from the ONU to the OLT is the upstream direction (upstream), thereby implementing functions such as data service and configuration management.

As a "point-to-multipoint" topology, the XG-PON network needs to be transmitted through the Optical Distribution Network (ODN), and at the same time, the Service Network Interface (SNI) and the user network interface. (User Network Interface, UNI for short) has inevitable optical signal loss, so the entire data transmission process has a large impact on the Bit Error Rate (BER). Optical network systems By using forward error correction techniques, data can be transmitted at low bit error rates, thereby avoiding the use of retransmission mechanisms.

The ITU-T G987.3 protocol stipulates that the OLT and the ONU must support the FEC configuration in the uplink and downlink directions. The downlink FEC requirements are always enabled. The uplink FEC needs to be dynamically configured by the OLT. In the XG-PON system, the uplink FEC is based on the RS (248, 232) (Reed-Solomon, Reed-Solomon) method for encoding and decoding, by introducing uplink transmission data in the physical adaptation sublayer. Redundancy, ensuring detection and correction of transmission errors at the decoding location, RS (248, 232) as a type of multi-ary cyclic code with extremely strong error correction capability, not only for correcting random errors, but also for correcting sudden errors very effective. In the prior art, the operator initiates the uplink FEC configuration process on the OLT side through the client, and the uplink FEC function of the ONU cannot be dynamically configured in real time, and the dynamic FEC dynamic opening and closing cannot be implemented.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for configuring an uplink forward error correction process and an OLT to solve the problem of how to implement an uplink FEC function of an ONU in real time. In order to solve the above technical problem, the present invention provides a method for configuring an uplink forward error correction process, where the method includes: an optical line terminal detecting a bit error rate of an uplink in real time, according to whether the bit error rate is reached. Predetermine conditions to configure the upstream forward error correction process. In the method of the present invention, the step of detecting, by the optical line terminal, the bit error rate of the uplink in real time includes:

The parity error is woven, and the bit error rate is estimated based on the bit interleaved parity error. In the method of the present invention, the step of configuring the uplink forward error correction process according to whether the bit error rate reaches a predetermined condition comprises: the optical line terminal determining that the bit error rate reaches a predetermined condition And the configuration information of the current uplink forward error correction process is inconsistent with the configuration information corresponding to the predetermined condition, and then configuring a unicast template message, where the unicast template message includes a corresponding forward error correction flag bit and a template index number, and then And transmitting the unicast template message continuously; if the predetermined uplink response message is continuously received, configuring the uplink forward error correction process according to the configuration information corresponding to the predetermined condition. In the method of the present invention, the template index number is different from the template index number of the broadcast template message used by the current system. In the method of the present invention, the predetermined uplink response message is three uplink response messages. In the method of the present invention, the step of configuring the uplink forward error correction process according to whether the bit error rate reaches a predetermined condition includes: the optical line terminal determining that the bit error rate is higher than a pre- If the upper limit is set, the uplink forward error correction process is configured. If the bit error rate is lower than the preset lower limit, the uplink forward error correction process is configured to be closed. In order to solve the above technical problem, the present invention further provides an optical line terminal, where the optical line terminal includes: a detecting module, configured to: detect a bit error rate of an uplink in real time; and a configuration module, where: The uplink forward error correction procedure is configured according to whether the bit error rate reaches a predetermined condition. In the optical line terminal of the present invention, the detecting module includes:

a bit interleaving parity error; and an estimating unit configured to estimate a bit error rate based on the bit interleaving parity error. In the optical line terminal of the present invention, the configuration module includes: a first determining unit, configured to: determine whether the bit error rate reaches a predetermined condition; and second determining unit, configured to: in the first determining When the unit determines that the bit error rate reaches a predetermined condition, it determines whether the configuration information of the current uplink forward error correction process is consistent with the configuration information corresponding to the predetermined condition; and the configuration unit is configured to: If the unit determines that the configuration information of the current uplink forward error correction process is inconsistent with the configuration information corresponding to the predetermined condition, the unicast template message is configured to be continuously sent; if the predetermined uplink response message is continuously received, according to the predetermined condition The uplink forward error correction process is configured by the corresponding configuration information, where the unicast template message includes a corresponding forward error correction flag bit and a template index number. In the optical line terminal of the present invention, the template index number is different from the broadcast template used by the current system. The template index number of the information is not the same. In the optical line terminal of the present invention, the predetermined uplink response message is three uplink response messages. In the optical line terminal of the present invention, the configuration module includes: a determining module, configured to: determine whether the bit error rate is higher than a preset upper limit value, or determine whether the bit error rate is lower than a preset a lower limit value; a configuration module, configured to: when the determining module determines that the bit error rate is higher than a preset upper limit value, configure to enable an uplink forward error correction process; When the module determines that the bit error rate is lower than a preset lower limit value, the module closes the uplink forward error correction process.

In summary, the present invention provides a method for configuring an uplink forward error correction process and an OLT, so as to implement real-time dynamic configuration of an uplink FEC function of an ONU, which can maximize uplink bandwidth utilization, and can be flexibly considered in consideration of actual needs of users. Choose to manually or automatically configure the uplink FEC, which is more in line with the user's daily use and maintenance needs.

1 is a block diagram of an XG-PON system networking system; FIG. 2 is a schematic diagram of an OLT according to an embodiment of the present invention; FIG. 3 is a flowchart of a method for configuring an uplink forward error correction process according to the present invention; A flowchart of a method for adjusting uplink forward error correction according to Embodiment 1 of the present invention; FIG. 5 is a flowchart of a method for adjusting uplink forward error correction according to Embodiment 2 of the present invention.

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other. The schematic diagram of the XG-PON system in the embodiment of the present invention is as shown in FIG. 1. The system in this embodiment includes: an EMS 100, an OLT 200, and an ONU 300, where

The EMS 100 is configured to: send the command and related parameters for manually configuring the uplink FEC to the OLT 200, and query the current FEC configuration information of the target ONU 300; the OLT 200 is configured to: detect the uplink BER in real time; implement the uplink FEC process; The profile message is sent to the target ONU 300 and the ONU 300 uplink FEC is configured; the response message sent by the ONU 300 is received and judged and processed; the ONU 300 response message timer is closed and the OLT side uplink FEC is configured; and the uplink FEC process is closed;

The ONU 300 is configured to: receive the OLT 200 to send a unicast Profile message, and enable or disable the uplink FEC according to the FEC flag in the message; and send a response message to the profile message to the OLT 200. As shown in FIG. 2, the OLT 200 of this embodiment may include the following module, a detecting module, configured to: detect a bit error rate of an uplink in real time; and a configuration module, configured to: according to the bit error Whether the rate reaches a predetermined condition to configure the uplink forward error correction process. The detecting module includes: a detecting unit and an estimating unit, where

Interleaving parity error; the estimating unit is set to: estimate the bit error rate based on the bit interleaving parity error. In a preferred embodiment, the configuration module may include: a first determining unit, configured to: determine whether the bit error rate reaches a predetermined condition; and second determining unit, configured to: in the first determining When the unit determines that the bit error rate reaches a predetermined condition, it determines whether the configuration information of the current uplink forward error correction process is consistent with the configuration information corresponding to the predetermined condition; and the configuration unit is configured to: When the determining unit determines that the configuration information of the current uplink forward error correction process is inconsistent with the configuration information corresponding to the predetermined condition, configuring the unicast template And then continuously transmitting; if the predetermined number of uplink response messages are continuously received, configuring the uplink forward error correction process according to the configuration information corresponding to the predetermined condition, where the unicast template message includes a corresponding forward direction The error correction flag bit and the template index number are different from the template index number of the broadcast template message used by the current system, and the predetermined uplink response message is three uplink response messages. In another preferred embodiment, the configuration module may include: a determining module, configured to: determine whether the bit error rate is higher than a preset upper limit value, or determine whether the bit error rate is lower than a preset lower limit value; and a configuration module, configured to: when the determining module determines that the bit error rate is higher than a preset upper limit value, configure to enable an uplink forward error correction process; When the determining module determines that the bit error rate is lower than a preset lower limit value, the uplink prior error correction process is configured to be closed. FIG. 3 is a flowchart of a method for configuring an uplink forward error correction process according to the present invention. As shown in FIG. 3, the method mainly includes:

S10. The OLT detects the bit error rate of the uplink in real time, and configures an uplink forward error correction process according to whether the bit error rate reaches a predetermined condition. A method for adjusting uplink forward error correction according to an embodiment of the present invention implements adaptive configuration of an uplink FEC function by cyclically detecting an BER of an uplink. You can configure the manual configuration mode and the automatic configuration mode on the OLT. You can configure the uplink FEC function for a specific ONU or the uplink FEC function for all ONUs to which the OLT belongs. The process of adjusting the uplink forward error correction of the manual configuration mode is as shown in the first embodiment. The process of adjusting the uplink forward error correction of the automatic configuration mode is as shown in the second embodiment. 4 is a flowchart of a method for adjusting uplink forward error correction according to Embodiment 1 of the present invention. The embodiment mainly relates to manually configuring an uplink FEC to implement an uplink data error correction function, including the following steps: S201: OLT receiving After the FEC configuration information of the NE management server is started, the configuration of the uplink FEC process is started. First, the OLT queries the local database for the FEC configuration information of the target ONU. If the FEC configuration information is compared, if it is consistent, the process proceeds directly to S208; if not, the process proceeds to S202;

S202: The OLT queries the configuration information of the broadcast profile message used by the current system, and ensures that the unicast profile message and the broadcast profile message use different template index numbers (Profile Index;), wherein the range of the template index number of the unicast and broadcast profile messages is (0 ~ 3); 0LT queries the configuration information of the broadcast profile message used by the current system. In the case that the profile index is the same in the downlink profile message, the OLT sends the previously sent unicast profile message because the broadcast profile message will overwrite the previously sent unicast profile message. The order of the broadcast and unicast profile messages is maintained, and the profile index used by the ONUs is maintained on the OLT side.

S203: The OLT side configures the unicast profile message content, including configuring the FEC flag bit and the used Profile Index, and updating the OLT side database at the same time;

S204: Wait for the downlink unicast profile message period sending timer to expire;

S205: The OLT sends three unicast profile messages to the target ONU, and starts the OLT to receive the ONU response message timer. The ONU enables or disables the uplink FEC according to the FEC flag in the message. The OLT sends at least two unicast profile messages to the target. The ONU, in this embodiment, selects to send three unicast profile messages.

S206: The OLT counts the number of received ONU uplink response messages, if it is greater than or equal to 3, step S209 is performed; if less than 3, step S207 is performed;

S207: The OLT determines whether the timer for receiving the ONU response message expires. If the timeout occurs, the process directly executes S208; if not, executes S206; S208: The OLT directly returns the prompt information, and reports the configuration state, and the configuration process ends; for example, in the local database. If the FEC configuration information of the target ONU is set to "ON" and the received FEC configuration information is "ON", the prompt information is returned directly, and the current FEC configuration status is reported as "enabled".

S209: The OLT closes the receiving ONU response message timer, and the OLT side configuration starts the uplink FEC, and the configuration process is completed.

FIG. 5 is a flowchart of a method for adjusting uplink forward error correction according to Embodiment 2 of the present invention, where the embodiment is After being set to the automatic configuration mode, the OLT real-time loop detects the uplink and 10 Gigabit passive optical network transmission aggregation.

(XG-PON Transmission Convergence, XGTC) The bit-interleaved even parity (BIP) error of the frame and the estimated BER. When the uplink BER exceeds the reasonable threshold range set by the user, the uplink FEC is immediately started. The energy flow process; when the uplink BER is lower than the reasonable threshold value set by the user, the uplink FEC shutdown process is immediately started. This embodiment includes the following steps:

S301: The OLT real-time loop detects the BIP error of the uplink XGTC frame and estimates the BER;

S302: The OLT determines whether the uplink BER exceeds the upper limit of the reasonable threshold range set by the user, and if yes, immediately executes S303; if not, continues to execute S301; S303: The OLT immediately starts to enable the uplink FEC process;

S304: The OLT queries the FEC configuration information of the target ONU in the local database, and compares with the configuration information that needs to be executed. If the configuration is the same, that is, the FEC configuration information of the target ONU stored in the local database is enabled, the current configuration needs to be performed. If the information is to enable the uplink FEC process, the process continues to S301; if the information is inconsistent, the FEC configuration information of the target ONU stored in the local database is the uplink FEC is closed, and the current configuration information to be executed is to enable the uplink FEC process, then the process proceeds to S305;

S305: The OLT queries the configuration information of the broadcast profile message used by the current system, and ensures that the unicast Profile message and the broadcast profile message use different profile indexes.

The OLT queries the configuration information of the broadcast profile message used by the current system. In the case that the profile index is the same in the downlink profile message, the OLT properly sets the unicast profile message sent by the broadcast profile message, and the OLT sets the broadcast and unicast profile message reasonably. In the order, the OLT side maintains the Profile Index used by the ONU.

S306: The OLT side configures the unicast profile message content, including configuring the FEC flag bit and the used Profile Index, and updating the OLT side database at the same time; S307: Waiting for the downlink profile message period sending timer to expire;

S308: The OLT sends a unicast profile message to the target ONU, and starts the OLT to receive the ONU response message timer, and the ONU enables or disables the uplink FEC according to the FEC flag bit in the message; S309: The OLT counts the number of received ONU uplink response messages, if it is greater than or equal to 3, then immediately executes S311; if the number is less than 3, immediately executes S310;

S310: The OLT determines whether the timer for receiving the ONU response message expires. If the timeout occurs, S301 is directly executed; if not, the process continues to S309; S311: The OLT closes the receiving ONU response message timer, and the OLT side configures to enable the uplink FEC process;

S312: OLT real-time loop detection uplink BER;

S313: The OLT determines whether the uplink BER is lower than a lower limit of a reasonable threshold value set by the user, and if yes, immediately executes S314; if not, proceeds to S312; S314: The OLT immediately starts to close the uplink FEC process. The process of closing the uplink FEC is basically the same as the process of enabling the uplink FEC. For details, see steps S304 to S311. By using the method in the embodiment of the present invention, the uplink information and the BER are detected in real time on the OLT side to implement dynamic adjustment of the uplink FEC, which can ensure low error rate transmission data, and simultaneously pass uplink and downlink PLOAM messages between the OLT and the ONU. The dynamic interaction effectively improves the quality and efficiency of uplink data transmission. The method and system for adjusting uplink forward error correction according to the embodiment of the present invention, when the uplink BER exceeds or falls below a reasonable threshold range set by the user, the OLT adaptively turns on or off the uplink FEC, maximizing the maximum Upstream bandwidth utilization, and taking into account the actual needs of users, can be flexibly selected to manually or automatically configure uplink FEC, which is more in line with the daily use and maintenance needs of users. During the configuration of the uplink FEC, the OLT sends configuration information to the specified ONU through the downlink profile physical layer operation management and maintenance (PLOAM). The content of the message includes the FEC flag bit and the PROFILE used. INDEX, ONU enables or disables the upstream FEC function based on the FEC flag in the message.

One of ordinary skill in the art will appreciate that all or part of the steps in the above methods may be passed through the program. The instructions are related to hardware completion, and the program can be stored in a computer readable storage medium such as a read only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the foregoing embodiment may be implemented in the form of hardware, or may be implemented in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software.

The above is only a preferred embodiment of the present invention, and of course, the present invention may be embodied in various other embodiments without departing from the spirit and scope of the invention. Corresponding changes and modifications are intended to be included within the scope of the appended claims.

INDUSTRIAL APPLICABILITY The present invention realizes real-time dynamic configuration of the uplink FEC function of the ONU, which can maximize the uplink bandwidth utilization, and can flexibly select the manual or automatic configuration of the uplink FEC in consideration of the actual needs of the user, which is more in line with the daily use of the user. Maintenance needs.

Claims

Claim

A method for configuring an uplink forward error correction process, the method comprising: the optical line terminal detecting a bit error rate of an uplink in real time, and configuring uplink forward correction according to whether the bit error rate reaches a predetermined condition Wrong process.

The method of claim 1, wherein the step of detecting, by the optical line terminal, the bit error rate of the uplink in real time comprises:

The parity error is woven, and the bit error rate is estimated based on the bit interleaved parity error.

The method of claim 1, wherein the step of configuring the uplink forward error correction process according to whether the bit error rate reaches a predetermined condition comprises: the optical line terminal determining If the bit error rate reaches a predetermined condition, and the configuration information of the current uplink forward error correction process is inconsistent with the configuration information corresponding to the predetermined condition, the unicast template message is configured, and the unicast template message includes a corresponding forward error correction flag. And the template index number, and then continuously sending the unicast template message; if the predetermined uplink response message is continuously received, configuring the uplink forward error correction process according to the configuration information corresponding to the predetermined condition.

The method according to claim 3, wherein the template index number is different from the template index number of the broadcast template message used by the current system.

The method of claim 3, wherein the predetermined uplink response message is three uplink response messages.

The method of claim 1, wherein the step of configuring the uplink forward error correction procedure according to whether the bit error rate reaches a predetermined condition comprises: the optical line terminal determining If the bit error rate is higher than the preset upper limit, the uplink forward error correction process is configured. If the bit error rate is lower than the preset lower limit, the configuration is disabled. Uplink forward error correction process.

An optical line terminal, the optical line terminal comprising: a detecting module, configured to: detect a bit error rate of an uplink in real time; and a configuration module, configured to: according to whether the bit error rate reaches Predetermine conditions to configure the upstream forward error correction process.

The optical line terminal according to claim 7, wherein the detecting module comprises:

a bit interleaving parity error; and an estimating unit configured to estimate a bit error rate based on the bit interleaving parity error.

The optical line terminal according to claim 7, wherein the configuration module comprises: a first determining unit, configured to: determine whether the bit error rate reaches a predetermined condition; and second determining unit, configured to And determining, by the first determining unit, that the bit error rate reaches a predetermined condition, determining whether the configuration information of the current uplink forward error correction process is consistent with the configuration information corresponding to the predetermined condition; and configuring a unit, setting If the second determining unit determines that the configuration information of the current uplink forward error correction process is inconsistent with the configuration information corresponding to the predetermined condition, the unicast template message is configured to be continuously sent; if the predetermined uplink response is continuously received And the message, the uplink forward error correction process is configured according to the configuration information corresponding to the predetermined condition, where the unicast template message includes a corresponding forward error correction flag bit and a template index number.

The optical line terminal according to claim 9, wherein the template index number is different from a template index number of a broadcast template message used by the current system.

The optical line terminal according to claim 9, wherein the predetermined uplink response message is three uplink response messages.

The optical line terminal according to claim 7, wherein the configuration module comprises: a determining module, configured to: determine whether the bit error rate is higher than a preset upper limit value, or determine the bit Whether the error rate is lower than the preset lower limit value; and the configuration module is configured to: when the determining module determines that the bit error rate is higher than a preset upper limit value, configure to enable the uplink forward direction The error correction process is performed. When the determining module determines that the bit error rate is lower than a preset lower limit value, the uplink forward error correction process is configured to be closed.