WO2009155830A1

WO2009155830A1 - Exchanging method, equipment and system for the optical access system

Info

Publication number: WO2009155830A1
Application number: PCT/CN2009/072291
Authority: WO
Inventors: 钟文彪; 高海; 董英华; 周恩松
Original assignee: 华为技术有限公司
Priority date: 2008-06-25
Filing date: 2009-06-16
Publication date: 2009-12-30
Also published as: CN101615927A

Abstract

An exchanging method, equipment and system for the optical access system are provided. The station side of the optical access system includes the first interface and the second interface. The first interface is coupled to the working path, and the second interface is coupled to the standby path. The method includes that of: obtaining the time of two time points and/or the time difference between the two time points at which the downlink frame head is sent from the first interface and the uplink frame head is received from the second interface; obtaining the adjusting time between the first interface and the second interface according to the time of two time points and/or the time difference between the two time points; adjusting the time for transmitting the frame head at the second interface according to the adjusting time, and performing the exchanging from the first interface to the second interface. During the normal communication, by using the embodiment of the invention, the downlink frame head of the standby interface could be adjusted. It is avoided that the ONU should enter the state of re-registering and distance measuring. A great lot of exchanging time is saved, and the ONU would not be offline, therefore there is almost no impact on the service.

Description

Switching method, device and system for optical access system

[1] This application claims priority from Chinese Patent Application filed on June 25, 2008, to the Chinese Patent Office, Application No. CN200810126402.0, entitled "A Light Access System Switching Method, Apparatus and System" The entire contents of which are incorporated herein by reference.

[2] Technical field

[3] The present invention relates to the field of communications technologies, and in particular, to an optical access system switching method, device, and system

[4] Background of the invention

The Network, PON) system is a system that provides users with optical access solutions. The PON system includes optical line terminals (Central Line, CO) (Optical Line)

Termination, OLT) , through optical distribution network (Optical Distribution

Network, ODN) Connect to the customer premises network (Customer Premise Netwrok,

CPN) user premises equipment, such as optical network units (Optical Network

Unit, ONU) or optical network terminal (Optical Network

Termination, ONT), where passive means that the ODN mainly includes passive components such as optical splitters/splitters, which do not require or require only a small amount of expensive active electronic equipment. In the PON system, the main signal processing functions are performed at the central office equipment OLT and the customer premises equipment ONU/ONT. From the content of the bearer, the typical PON system now includes APON/BPON (ATM Based

PON), EPON (Ethernet Based PON) and GPON (Gigabit)

PON), etc.; divided into wavelength-multiplexed passive optical networks TDM-PON, wavelength division multiplexing passive optical network (Wave Division Multiple PON, WDM)

PON), Code Division Multiple Access PON,

CDMA-PON).

With the development and application of passive optical network technology, the requirements for system performance are getting higher and higher, and the demand for protection of PON system, including device level protection and/or line level protection, is proposed. Among them, line level The protection involves the protection of the active and standby optical fibers to ensure that one of the optical fibers fails and does not affect the service. The device-level protection involves the protection of the active and standby processing modules to ensure that one of the processing modules fails and does not affect the service.

[7] After implementing protection switching, you need to consider the impact of the primary and secondary transmission delays.

The existing adjustment methods are: opening up a ranging window, performing ranging for each user separately, and calculating the delay based on the ranging result, thereby performing adjustment using the calculated delay. For example, the PON port backup network diagram shown in Figure 1: The OLT system's central office OLT includes two PON modules PON LT1 and PON

LT2 is connected to the optical fibers F1 and F2 of the ODN through port 1 and port 2 (or channel 1 and channel 2) respectively. The PON LT1 is the main PON module, the port 1 is the working path interface, and the PON LT2 is the standby. The PON module, which is the interface of the standby path, describes the active/standby switchover process of the prior art. As shown in Figure 2, the following steps are included:

[8] Step s201: When the active and standby interfaces need to be switched, stop sending data from port 1 (the interface of the working path), and the ONUs go offline;

[9] Step s202: Register and measure each ONU through port 2 (the interface of the alternate path), so as to obtain the delay parameters related to port 2, such as equalization delay (Equalization)

Delay, EQD), EQD is a waiting delay in the ONU to ensure that the ONU does not have an uplink collision, so that all ONUs are at the same physical distance;

[10] Step s203: After all the online ONUs are back online, the network led by the interface of the original alternate path is established, and the active/standby switchover is completed.

In the process of implementing the present invention, the inventors have found that the prior art has at least the following disadvantages:

[12] In this way, each online ONU needs to be re-registered online after going offline, and the OLT can only perform one ONU registration operation at a time. To complete the measurement of all users, it can be expensive. In the meantime, the on-line time of the ONU is slow and the service interruption is too long during the active/standby switchover. Moreover, each ONU needs to re-range to determine the new EQD, so the entire switching process is very expensive. long. On the other hand, as the number of users increases, the range of ranging is further lengthened, which is unacceptable to operators and users. Therefore, this kind of protection structure can not meet the requirements of protection switching during the system failure.

[13] Summary of the invention

[14] Embodiments of the present invention provide a method, an apparatus, and a system for switching an optical access system, to simplify the active and standby The port switching process shortens the interruption of services during the active/standby switchover.

An embodiment of the present invention provides a method for switching an optical access system, where the central end of the optical access system includes a first interface and a second interface, and the first interface is coupled to the working path, where The second interface is coupled to the alternate path, including:

[16] obtaining the inter-turn difference between the inter-turn and/or the two inter-turn points of the two inter-points that are sent from the first interface and the two inter-frames that receive the uplink header from the second interface;

[17] obtaining an adjustment time between the first interface and the second interface according to the inter-turn difference between the two inter-turn points and/or between the two inter-turn points;

[18] adjusting the time of transmitting the frame header on the second interface according to the adjusting day adjustment, so that the frame transmitted on the alternate path after adjusting the time is transmitted to the receiving end frame position and transmitted on the working path The frame is consistent in the frame position of the receiving end, and the time of the transmitting frame header includes the time of transmitting the downlink frame header or the time of receiving the uplink frame header, and performs switching from the first interface to the second interface.

An embodiment of the present invention further provides an optical line terminal, where the optical line terminal includes a first interface function module, a second interface function module, and a control module.

[20] the first interface function module is configured to provide an interface processing function of the working path;

[21] the second interface function module is configured to provide an interface processing function of the alternate path;

[22] The control module is configured to acquire, by the first interface function module, a downlink frame header and a second interface function module, where the two interface points of the uplink frame header are received, and/or two inter-points Inter-turn difference, according to the inter-turn between the two inter-turn points and/or the inter-turn difference between the two inter-turn points, obtain the adjustment time of the second interface function module, according to the adjustment day adjustment Transmitting a downlink frame header or receiving an uplink frame header from the second interface function module, so that the frame transmitted on the alternate path reaches the frame header position of the receiving end and the frame transmitted on the working path reaches the frame header of the receiving end The positions are consistent, and then the switching of the first interface function module to the second interface function module is controlled.

An embodiment of the present invention further provides an optical access system, where the optical access system includes an optical line terminal and an optical network unit, and a connection path between the optical line terminal and the optical network unit includes a working path. And the alternate path, the optical line terminal includes a first interface and a second interface, the first interface is coupled to the working path, and the second interface is coupled to the standby path,

[24] the optical line terminal is configured to acquire a downlink frame header from the first interface and receive an uplink frame from the second interface. The inter-turn difference between the two inter-turn points of the head and/or between the two inter-turn points, based on the inter-turn difference between the two inter-turn points and/or between the two inter-turn points Obtaining an adjustment interval of the second interface; adjusting the time of transmitting the frame header on the second interface according to the adjusting the daytime adjustment, so that the frame transmitted on the alternate path after adjusting the daytime arrives at the receiving end frame header The position and the frame transmitted on the working path are consistent at the position of the receiving end frame, and the time of the transmitting frame header includes transmitting the time of the downlink frame header or receiving the time of the uplink frame header, and then executing from the working path to the standby. The path is switched.

[25] The embodiment of the invention further provides a switching control device,

The switching control device includes: an inter-turn acquisition unit, an adjustment unit, and a switching control unit; the switching control device further includes a first inter-turn acquisition unit and/or a second inter-turn acquisition unit;

[26] The first inter-time acquisition unit is configured to acquire a downlink frame header from the interface of the working path and a time interval between the two inter-frame points of the uplink frame header from the interface of the backup path;

[27] The second inter-time acquisition unit is configured to acquire, by the interface of the working path, the downlink frame header and the interface of the backup path to receive the inter-turn difference between the two inter-frame points of the uplink frame header;

[28] The adjustment inter-time acquisition unit is configured to calculate an interface and an alternate path of the working path according to the inter-turn obtained by the first inter-frame acquisition unit and/or the inter-turn obtained by the second inter-frame acquisition unit Adjustment between interfaces;

[29] The adjusting unit is configured to adjust, according to the adjustment, the adjustment time acquired by the inter-time acquisition unit, the frame transmission frame header of the alternate path, so that the frame transmitted on the alternate path after the adjustment is reached The receiving end frame header position and the frame transmitted on the working path are consistent at the receiving end frame header position, and the transmission frame header includes transmitting the downlink frame header or receiving the uplink frame header.

[30] The switching control unit is configured to control the switching of the interface of the working path to the interface of the standby path after the adjusting unit adjusts the time of the interface transmission frame header of the alternate path.

[31] Embodiments of the invention have the following advantages:

[32] In the normal pass, by acquiring the downlink header from the first interface and the two inter-points of the upstream header from the second interface, and/or between the two inter-points The difference between the downlink frame headers of the standby interface is adjusted to avoid the ONU entering the re-registration and ranging state, which saves a lot of switching time, and the ONU does not go offline, which has little impact on the service.

[33] BRIEF DESCRIPTION OF THE DRAWINGS [34] FIG. 1 is a network diagram of a common port backup of a passive optical network in the prior art;

[35] FIG. 2 is a flow chart of the active/standby switchover of the port of the PON of the prior art passive optical network;

[36] FIG. 3 is a schematic structural diagram of a switching device of an active/standby interface of an OLT device according to an embodiment of the present invention;

4 is a schematic structural diagram of a network device according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a network device according to another embodiment of the present invention; FIG.

FIG. 6 is a flowchart of a method for switching an active/standby interface of an OLT device according to an embodiment of the present invention.

[40] Mode for carrying out the invention

[41] The embodiments of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[42] An embodiment of the present invention provides a switching control apparatus, as shown in FIG. 3, including:

[43] The first inter-time acquisition unit 11 is configured to acquire a downlink frame header from the interface of the working path and a time interval between the two inter-frame points of the uplink frame header received from the interface of the alternate path;

[44] The second inter-time obtaining unit 12 is configured to obtain, by sending, between the downlink frame header from the interface of the working path and the two inter-points of the uplink frame header from the interface of the alternate path (inter-segment)吋 ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; The interface of the path receives the inter-turn difference between the upstream frame headers;

[45] The inter-time acquisition unit 13 is configured to calculate an adjustment between the interface of the working path and the interface of the alternate path, such as sending the downlink frame header according to the interface from the working path acquired by the first inter-frame acquisition unit. And receiving an adjustment between the interface of the working path of the uplink frame header and the interface of the standby path, and transmitting the downlink from the interface of the working path acquired by the second inter-frame obtaining unit 12 The frame header is received from the interface of the alternate path to receive the adjustment between the interface of the working path and the interface of the alternate path.

[46] The storage unit 15 is configured to store at least one inter-turn information acquired by the first inter-turn acquisition unit 11, the second inter-time acquisition unit 12, and the inter-time acquisition unit 13;

[47] The adjusting unit 17 is configured to adjust, according to the interface of the working path stored by the storage unit 15 and the inter-interface information of the alternate path, the interface of the alternate path to send the downlink frame header. Specifically, if the interface of the alternate path receives the uplink frame header of the ONU and the interface of the working path is received by the interface of the ONU, the adjustment frame is T1, and the downlink frame sent from the interface of the alternate path Head than working path interface The transmitted downlink frame header is advanced by T1; if the uplink frame header from the ONU is received from the interface of the alternate path earlier than the interface of the ONU uplink frame header from the interface of the working path, the adjustment time is T2, and the backup is performed. The interface of the path uses the clock frame header of the lag T2 engraved than the interface of the working path as the downlink frame header. The time interval for transmitting the downlink frame header may be the amount of time between the positions of the downlink frame headers. The adjusting unit 17 can also adjust the time interval at which the alternate path interface receives the uplink frame header or adjust the position of the upstream frame header. That is to say, the adjusting unit 17 adjusts the transmission of the frame header on the interface of the alternate path according to the adjustment of the adjustment time stored by the storage unit 15, so that the frame transmitted on the alternate path after the adjustment is reached at the receiving end frame position and The frames transmitted on the working path are consistent in the frame header position of the receiving end, and the time of the transmitting frame header includes the time interval of transmitting the downlink frame header or the time interval of receiving the uplink frame header, that is, the following two cases are included: Adjusting the time interval for transmitting the downlink frame header so that the downlink frame transmitted on the alternate path after the adjustment is reached to the receiving end. The U-frame header position and the downlink frame of the working path are the same as the frame header position of the receiving end ONU吋; b Adjusting the time interval of receiving the uplink frame header so that the frame header position of the uplink frame transmitted on the alternate path after the adjustment period reaches the receiving end OLT吋 and the uplink frame transmitted on the primary path reach the receiving end OLT frame header position.

[48] The switching control unit 19 is configured to control the switching of the interface of the working path to the interface of the standby path after the interface of the adjusting path of the adjusting unit 17 transmits the downlink frame header or receives the uplink frame header.

[49] The first inter-turn acquisition unit 11 and the second inter-turn acquisition unit 12 in the active/standby switching device may need only one of them, or two of them.

[50] In addition, the first inter-frame acquisition unit 11 may transmit an interface function module of the working path by transmitting an interface function module of the working path, and may send a downlink frame header, and/or may detect the synchronization signal according to the detected The synchronization signal acquisition sends the downlink frame header from the interface of the working path. The first inter-time acquisition unit 11 records the inter-frame of the interface function module of the uplink frame header to the alternate path by monitoring the interface function module of the alternate path, thereby obtaining the time interval of receiving the uplink frame header from the interface of the alternate path. The second inter-time obtaining unit 12 can monitor the interface function module of the working path and the interface function module of the standby path, and the interface function module that detects the working path sends the downlink frame header to start counting, and detects the interface function of the alternate path. The module receives the uplink frame header and ends the calculation, thereby obtaining the inter-turn difference between the downlink frame header sent from the interface of the working path and the uplink frame header received from the interface of the alternate path.

[51] As shown in FIG. 4, a specific example based on FIG. Embodiments of the present invention provide a passive optical network The network equipment in the network is responsible for business processing and distribution, ONU management, and synchronous clock processing. In the embodiment of the present invention, as shown in FIG. 4, the network device 300 includes:

[52] One or more network side service interface function modules PON

The NT380 is responsible for sending and receiving service data packets and/or management packets to the upper layer network device.

[53] At least two interfaces, at least one of which has an alternate path. When the interface of the working path corresponding to the interface of the alternate path needs to be switched, the interface can be switched from the interface of the working path to the interface of the alternate path.

[54] At least two logically independent line interface function modules PON LT

340, corresponding to one interface, complete the line interface termination, and interwork with the network side service interface function module 38 0.

[55] Among them, each line interface function module PON

The LT 340 includes at least one optoelectronic conversion module 342 and at least one message processing module 344, as shown in Figure 4, PON

The LT340-1 includes two photoelectric conversion modules 342-11, 342-12, and a message processing module 344-1. The message processing module ₃₄₄ is responsible for functions such as service processing, synchronization clock processing, and frame header processing. The photoelectric conversion module 34 2 realizes photoelectric conversion and/or electro-optical conversion, and may be a module that is integrated and received, or a module that is separated and transmitted. There are two photoelectric conversion modules on the packet processing modules 344-1 and 344-M in the device described in FIG. 4, which are only one example. The photoelectric conversion module connected to each packet processing module is not limited and may be one. Two, three, or four, and so on. In the context, two photoelectric conversion modules are taken as an example, and are not mentioned unless otherwise specified.

In the embodiment of the present invention, in order to implement the protection switching function, the network device 300 includes a control module 360, which can perform a control function of protection switching. The structure of the control module 360 is consistent with the structure of the switching device shown in FIG. The first inter-turn acquisition unit 11 and/or the second inter-time acquisition unit 12, the adjustment inter-time acquisition unit 13, the storage unit 15, the adjustment unit 17, and the switching control unit 19 are included. The functions of these units of the control module 360 are shown in the specific structure and description of the switching device in Fig. 3, and will not be repeatedly described herein. The optical receiving module 342-11 and the optical transmitting module 342-12 may also be an integrated optical transceiver module (not shown). Interface function module with PON LT340-1 as working path, PON

Taking the LT340-M as an interface function module of the alternate path, the message processing module 344-1 will lower the frame hair. The control module 360 sends the received uplink frame hair to the control module 360. Therefore, the first inter-frame acquisition unit and/or the second inter-frame acquisition unit of the control module 360 can be configured according to the message. The header sent by the processing module 340-1 and the message processing module 340-M obtains the time between transmitting the downlink frame header from the interface of the working path to receiving the uplink frame header from the interface of the alternate path. The frame header synchronization module 390 can also provide the downlink synchronization chirp signal to the control module 360, so that the control module 360 can obtain the downlink frame header from the primary port according to the downlink synchronization chirp signal or send the downlink frame from the primary port. Head reference.

FIG. 5 is a schematic diagram of another network device according to an embodiment of the present invention. The network device 400 in Figure 5 includes at least two PON LTs 420 (e.g., PON LT

420-1, ..., 420-M), network side service interface module 380 and frame header synchronization module 390. Similar to PO N LT340 in Figure 4, each PON

The LT includes at least one message processing module 344, and each of the message processing modules 344 is coupled to at least one of the photoelectric conversion modules 342, such as the PON in FIG.

The LT420-1 includes a message processing module 344-1, photoelectric conversion modules 342-11, 342-12. Unlike the PO N LT340 in Figure 4, each PON

The LT420 includes a control module 360, and its own PON LT and other PONs.

The message processing module on the LT is coupled to receive a frame header sent by the message processing module. Specifically, to PO

N LT420-M is the interface function module of the alternate path, PON

The LT420-1 is an interface function module of the working path. The control module 360-M performs the switching control function as an example. The control module 360-M receives the downlink frame header sent by the message processing module 344-1, and receives the packet processing module _344. - The uplink header sent by the M, so that the two frames of the downlink header are transmitted from the interface of the working path and the uplink header is received from the interface of the alternate path, and/or the downlink is sent from the interface of the working path. The inter-turn difference between the header of the frame header and the interface of the alternate path is received. The PON LT420-M can also obtain the reference for transmitting the downlink header by the primary port or the reference for transmitting the downstream header from the primary port by using the chirp signal provided by the frame header synchronization module 390. By using the switching device provided by the foregoing embodiment of the present invention, adjusting the time frame of transmitting the downlink frame header or receiving the uplink frame header from the interface of the alternate path, so that the frame header position of the frame transmitted on the alternate path arrives at the receiving end The frame transmitted on the working path arrives at the receiving end and the frame header position is the same.釆In this way, the active/standby switchover of the port is performed, avoiding 0. The NU enters the re-registration and ranging state, which saves a lot of switching time. The same ONU does not need to go offline, and has almost no impact on the business.

[58] In an embodiment of the present invention, it can be implemented

"1: Γ protection, can also achieve "1: N" protection. Among them, "1 : Γ protection means that each working path interface has an alternate path for backup; "1 : N" protection means N work The interface of the path shares the interface of an alternate path. The implementation of the "1: N" protection is similar to the above "1: 1" protection method and will not be repeated here.

According to an embodiment of the present invention, an optical access system includes an optical line terminal and an optical network unit, and a connection path between the optical line terminal and the optical network unit includes a working path and an alternate path, where the optical line terminal includes The first interface and the second interface, the first interface is coupled to the working path, and the second interface is coupled to the standby path, where the optical line terminal is configured to acquire a downlink frame header and a second interface from the first interface. Receiving the inter-turn difference between the two inter-turn points of the upstream frame header and/or between the two inter-turn points, according to the inter-turn between the two inter-turn points and/or between the two inter-turn points Inter-time difference, obtaining an adjustment period for transmitting a frame header on the second interface; performing, according to the adjusting the inter-turn adjustment, a switching from a working path to an alternate path during a transmission of the frame header of the second interface, where The transmitting the frame header on the second interface includes transmitting a downlink frame header on the second interface or receiving an uplink frame header on the second interface.

[60] The following describes the switching control method of the corresponding control function module in Figures 2, 3 and 4. Line interface function module PON LT420-M as PON

The backup of the LT420-1 is taken as an example. The photoelectric conversion module 342-11 is a light emitting module, the photoelectric conversion module 342-12 is a light receiving module, the photoelectric conversion module 342-M1 is a light emitting module, and the photoelectric conversion module 342-M2 is a light receiving module. The module, that is, the downstream optical signal transmitted by the photoelectric conversion module 342-11, is sent to the optical network unit through a working path (or referred to as a primary path), and the photoelectric conversion module 342-M2 receives the upstream optical signal from the alternate path.

[61] In the normal communication process, the downlink header is sent from the interface of the working path and the two headers of the uplink header are received from the interface of the alternate path, and/or the downlink is obtained from the interface of the working path. The frame header and the inter-turn difference between the two inter-turn points of the uplink frame header are received from the interface of the alternate path, and the interface that needs to be switched from the interface of the working path to the alternate path, according to the above-mentioned inter-day and/or 吋The interface of the inter-differential adjustment alternate path sends the downlink frame header and the downstream frame header and slave sent from the interface of the alternate path. The downlink frame header sent by the interface of the working path is consistent with the ONU. After the time adjustment, the interface from the working path to the backup path is switched, so that the active/standby switchover of the OLT device port is implemented.

[62] Specifically, as shown in FIG. 6, the OLT device switching method in the embodiment of the present invention includes the following steps: [63] Step s601: Acquire a downlink frame header from an interface of the working path and receive an uplink from an interface of the alternate path. The inter-turn between the two inter-points of the frame header, and/or the inter-turn difference between the two inter-points that receive the downlink header from the primary interface and the upstream header from the interface of the alternate path;

[64] Step s602: Send a downlink frame header from the interface of the alternate path according to the inter-turn difference between the two inter-turn points and/or between the two inter-turn points, so as to make it and the slave working path The downlink frame header sent by the interface reaches the ONU's time.

[65] Step s603: Perform the switching of the interface of the working path to the interface of the alternate path.

[66] Specifically, in an embodiment of the present invention, the interface function module of the working path and the interface function module of the standby path may be configured to obtain a downlink frame header from the interface of the working path and an uplink frame from the interface of the standby path. The inter-turn difference between the two inter-turn points of the head and/or between the two inter-turn points; this method is to use the method of mutually transmitting the frame header, and the interface function module of the working path sends the downlink frame to the ONU. Header, the peer sends the downlink frame hair to the control module. For example, the downlink frame header is driven into two paths, one is sent to the ONU, and the other is sent to the control module. After receiving the downlink frame header sent by the interface function module of the working path, the control module can obtain the downlink frame header position of the interface of the working path, and the time point of the downlink frame header position can be recorded by the internal high frequency chirp, the interface The switch that adjusts the alternate path sends the downlink header, so that the frame transmitted on the alternate path arrives at the receiving end and the frame transmitted on the working path arrives at the receiving end. Or not adjusting the alternate path interface to send the time of the downlink frame header, and adjusting the alternate path interface to receive the time of the uplink frame header, or adjusting the amount of time of the downlink frame header, or adjusting the amount of the position of the uplink frame header. .

In another embodiment of the present invention, the interface function module of the frame header synchronization module and the alternate path may also be monitored, and the downlink frame header is sent from the interface of the working path and the uplink frame header is received from the interface of the alternate path. The inter-turn difference between the inter-turn points and/or the two inter-turn points, wherein the frame header synchronization module provides an interface of the working path and a sync frame header of the interface of the alternate path. Two methods are provided for obtaining the inter-frame of the downstream frame header from the interface of the working path. In this method, the synchronization frame header is used, and the interface function module of the working path and the interface function module of the alternate path are sent by the frame header synchronization module to send the downlink frame. Head synchronization, that is, the control module directly detects the unified downlink synchronization frame header to obtain the downlink frame header position of the interface of the working path from the primary interface, and the downlink header position of the interface of the working path can pass through the internal The high frequency chime is recorded, the interface is switched, and the interface of the alternate path is adjusted to transmit the frame header, so that the frame transmitted on the alternate path reaches the frame header position of the receiving end and the frame transmitted on the working path reaches the frame of the receiving end frame. The head position is the same, or the alternate path interface is not adjusted to transmit the time of the downlink frame header, and the amount of time of the position of the downlink frame header is adjusted, or the amount of time of the position of the uplink frame header is adjusted.

[68] further provides a frame header synchronization module that records a downlink frame header of a working path in a frame header synchronization module of a working path by using a synchronous inter-chamber system, and transmits the frame header synchronization module to the alternate path through the interworking information channel, thereby The alternate path gets the downstream frame header position of the working path.

[69] The above control can be completed on an independent control function entity, that is, the control module can be set on an independent control function entity, centralized control of interface function modules and protection line interface function modules of multiple working paths, This method can realize centralized control of multiple line interface function modules, which is more convenient for system scheduling, configuration maintenance and management, especially 1: N or x: N (X represents a natural number greater than 1, and N represents a natural number greater than 1) Protection systems can reduce control complexity.

[70] The above control can also be done on the interface function module with the alternate path of the control module, that is, the control module can be set on the interface function module of the alternate path, which is more obvious for the protection advantage of 1:1, protection The exchange is faster.

[71] In order to adjust the interface function module of the alternate path to send the downlink frame header, the adjustment time needs to be obtained, including:

[72] The control module detects the position of the downlink frame header of the interface function module of the working path, such as the downlink frame header sent by the interface function module that receives the working path or the downlink frame header reference signal sent by the frame header synchronization module, The inter-turn T1 of the inter-turn point is recorded. Specifically, the inter-turn point can be determined by an internal high-frequency chime. The interface function module of the alternate path receives the uplink frame, detects the uplink frame header, records the time Τ2 of the time point, and then uses T1 and Τ2 to calculate the adjustment time, and takes an uplink and downlink round trip cycle as an example to adjust the daytime interval. Τ can be obtained by:

[73] T=T2-Tl-2*Tf-Tr (1)

[74] In the above formula (1), T2 indicates that the interface function module of the alternate path receives the time of the uplink frame header, T1 indicates that the interface function module of the working path transmits the time of the downlink frame header, and Tf indicates the frame length of one frame. Cycle (eg The frame length of one frame in GPON is 125μ _§ ), and Tr is the response time of the ONU. The Tf may be determined according to a frame length period specified by the system protocol, and the Tr may include at least one of the following: an ONU's own response time, a system requiring the ONU to wait for delay, and an equalization delay EQD. In order to simplify the processing, the value of Tr can be replaced by a mean value; but considering the particularity of the ONU and the line, an information table can be maintained, and information such as the inter-turn Tr of each ONU and the T2 and T1 of each ONU can be recorded. The inter-turn T of each ONU is calculated according to the information table.

[75] According to the above description, the adjustment time can be obtained by:

[76] Τ=ΔΤ -2*Tf-Tr (2)

[77] In the above formula (2), ΔΤ

=T2-T1 can be obtained by the meter. This method does not need to know the specific time between each point, only need to know the time between the two points; Tf and Tr and The same in equation (1), no longer praise.

[78] It is worth noting that the above equations (1) and (2) are not limited to the application of one uplink and downlink cycle, but can be extended to multiple uplink and downlink cycles. In addition, simple changes in the formula, such as error adjustment. The daytime and the like are all within the scope of the present invention.

[79] Since the ONU has the following states: 01 : The ONU is just powered on, in the initial state;

02: ONU waits to receive network parameter status; 03: 0NU waits to receive serial number request status; 04: Ranging status; 05: Running status (normal status); 06: POPUP

State (waiting state); 07: Emergency stop state. If 0NU does not receive the service, it will enter 06 (waiting state) from 05 (normal state), or in certain situations such as data conflict, it will enter 07: emergency stop state from 05 (normal state). In order to solve the above problem, the frame header of the downlink frame may be sent by adjusting the interface function module of the alternate path, so that the downlink frame header sent from the interface of the alternate path and the downlink frame sent from the primary interface reach the time of the ONU are not consistent. Impact on the reception of the 0NU service. The following describes the interface function module that adjusts the alternate path to send the downlink header:

[80] In order to adjust the inter-turn, it is also necessary to determine an adjustment direction, such as comparing the time between receiving the uplink header from the second interface and transmitting the downlink header from the first interface; when receiving from the second interface The time between the uplink frame header and the downlink frame header sent from the first interface is greater than a predetermined value, and the determination needs to be advanced; when the uplink frame header is received from the second interface, and the downlink frame is sent from the first interface. The head of the head is less than the predetermined value Hey, make sure you need to delay. This predetermined value can be set according to the specific conditions, such as equations (1) and (2), and the predetermined value can be set to 0; wherein, if ΔΤ is directly compared, the predetermined value is 2*Tf+Tr.

[81] When interface switching is required, if the switching time of the working line interface is TO, then the alternate line interface sends the downlink frame header to the TO-T, that is, if the time 1>0 is adjusted, it will be used. The interface function module of the path sends the inter-time transmission of the downlink frame header. If the inter-turn time is <0, the interface function module of the alternate path sends the inter-turn delay of the downlink frame header. Of course, it is also possible to not know the switching time Τ0 of the working line interface, for example, using the reference time point of each frame transmission period, and adjusting the time based on the reference point.

[82] If the adjustment time is >0, that is, the case where the time is advanced, the backup service will be backed up through the upper layer network or the upper layer service channel before the switchover, and the interface function module of the backup work path is managed as ON U. Information such as equalization delay EQD. After the master/slave switchover, the interface function module of the control module controls the working path stops transmitting, and the interface function module of the alternate path is designated as the interface function module of the working path, starts to open the downlink transmission, and uses the adjusted transmission time frame of the time frame. The header is used as the downlink transmission frame header.

[83] If the adjustment time T<0, that is, the case where the transmission point is delayed, the downlink frame header sent from the interface of the alternate path is delayed later than the downlink frame header originally sent from the interface of the working path. Therefore, the downlink frame header sent from the interface of the alternate path arrives at the ONU and the downlink frame header sent from the interface of the working path arrives at the ONU. The downlink frame header of the OLT does not change for the ONU.

The ONU enters the re-registration and ranging state, which saves a lot of switching time. The same ONU does not go offline, and has almost no impact on the business.

[84] In addition, in order to make the ONU uplink header reach the standard requirement of the interface of the switched working path, the EQD on the ONU needs to be updated, and there are many methods for re-updating the EQD, for example, according to G.9 84. Standard, the command to update the EQD is issued in the downlink, and the EQD is adjusted to the time of the EQD-2T, so that the uplink frame header of the ONU reaches the standard requirement of the interface of the working path after the switching.

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented by hardware, or can be realized by means of software plus necessary general hardware platform, the present invention. The technical solution can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) A number of instructions are included to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform the methods described in various embodiments of the present invention.

The above disclosure is only a few specific embodiments of the present invention, but the present invention is not limited thereto, and any changes that can be considered by those skilled in the art should fall within the protection scope of the present invention.

Claims

Claim

[1] A method for switching an optical access system, where the central end of the optical access system includes a first interface and a second interface, the first interface is coupled to the working path, and the second interface is coupled to the second interface An alternate path, which is characterized by:

Acquiring the inter-turn difference between the two inter-turn points or the two inter-turn points of the two inter-points that are sent from the first interface and the second frame from the second interface;

Obtaining an adjustment time between the first interface and the second interface according to the inter-turn difference between the two inter-turn points or between the two inter-turn points;

Adjusting, according to the adjusting the inter-turn, adjusting the time of the frame header on the second interface, so that the frame transmitted on the alternate path after adjusting the inter-turn is at the position of the receiving end, and the frame transmitted on the working path is The position of the frame header is the same as that of the receiving end, and the time of the transmission frame header includes the time of transmitting the downlink frame header or the time of receiving the uplink frame header, and performs switching from the first interface to the second interface.

[2] The method according to claim 1, wherein the acquiring the downlink header from the first interface and the inter-turn or two inter-points of the two inter-frames receiving the uplink header from the second interface The difference between the turns includes:

The interface function module of the first interface and the interface function module of the second interface are monitored, and the downlink headers sent from the first interface and the two inter-points of the uplink headers received from the second interface are obtained. Interdipual difference; or

Monitoring the frame header synchronization module and the interface function module of the second interface, and obtaining between the two frames of the downlink header and the two headers of the uplink header from the second interface a frame header synchronization module, wherein the frame header synchronization module provides a synchronization frame header of the first interface and the second interface; and records a time point of the downlink frame header of the working path in the frame header synchronization module of the working path, and sends the information through the interworking information channel Giving the frame header synchronization module of the alternate path, so that the alternate path obtains the downlink frame header position of the working path, thereby obtaining the inter-day or two of the two inter-points that send the downlink frame header from the first interface and the uplink frame header from the second interface. The inter-turn difference between the points.

[3] The method according to claim 1, wherein the method further comprises:

Comparing the time interval between receiving the uplink frame header from the second interface and transmitting the downlink frame header from the first interface; When the timeout period of receiving the uplink frame header from the second interface is greater than the predetermined value 发送 between the times of transmitting the downlink frame header from the first interface, the time interval for transmitting the downlink frame header from the second interface is adjusted to be sent from the first interface. Adjusting the time between the time of the downlink frame header;

When the time period of receiving the uplink frame header from the second interface is less than a predetermined value 发送 between the times when the downlink frame header is sent from the first interface, the time interval for transmitting the downlink frame header from the second interface is adjusted to be from the first The interface sends the delay of the downlink frame header to the adjustment interval.

[4] The method of claim 1, wherein the method further comprises:

Sending a control frame to the optical network unit, and updating the equalization delay EQD on the optical network unit.

[5] The method according to any one of claims 1 to 4, wherein the method further comprises: transmitting, by the adjusting, the downlink frame header from the first interface and receiving the uplink from the second interface The inter-turn of the two inter-points of the frame header, the period of the frame length, and the response of the optical network unit are determined; or the adjustment period is that the downlink frame header is sent from the first interface and the uplink frame is received from the second interface. The inter-turn difference between the two inter-turn points of the head, the frame length period, and the response of the optical network unit are determined.

[6] An optical line terminal, wherein the optical line terminal comprises a first interface function module, a second interface function module, and a control module,

The first interface function module is configured to provide an interface processing function of the working path; the second interface function module is configured to provide an interface processing function of the standby path; and the control module is configured to acquire the function of the first interface The module sends the downlink frame header and the second interface function module to receive the inter-turn difference between the two inter-turn points of the uplink frame header or between the two inter-turn points, according to the inter-turn or two吋 of the two inter-turn points Obtaining the inter-turn difference between the points, obtaining the adjustment time of the second interface function module, and transmitting the downlink frame header or receiving the uplink frame header from the second interface function module according to the adjustment time adjustment The frame header position of the frame transmitted on the path reaches the receiving end and the frame transmitted on the working path reaches the frame header position of the receiving end, and then the switching of the first interface function module to the second interface function module is controlled.

[7] The optical line terminal according to claim 6, wherein the control module acquires the downlink of the first interface function module by monitoring the first interface function module and the second interface function module The frame header and the second interface function module receive the inter-turn or two of the two inter-points of the uplink frame header The inter-turn difference between the points.

[8] The optical line terminal according to claim 6, wherein the optical line terminal further includes a frame header synchronization module, configured to provide synchronization between the first interface function module and the second interface function module Frame header,

The control module acquires, by using the frame header synchronization module and the second interface function module, the first interface function module to send a downlink frame header and the second interface function module to receive two uplink points of the uplink frame header. The inter-turn difference between the two or two inter-turn points.

[9] The optical line terminal according to claim 6, wherein the optical line terminal further includes a frame header synchronization module, configured to provide synchronization between the first interface function module and the second interface function module Frame header,

The control module monitors the first interface function module, records the time point of the downlink frame header of the working path, and sends the frame header synchronization module to the alternate path through the interworking information channel, so that the alternate path obtains the downlink frame header position of the working path. Thereby, the inter-turn difference between the two inter-turn points or the two inter-turn points of the two inter-frame points that transmit the downlink frame header from the first interface and the uplink frame header from the second interface is obtained.

[10] The optical line terminal according to claim 6, wherein the optical line terminal further includes an update module, configured to update an equalization delay EQD on the optical network unit, where the balanced delay EQD needs to be updated. The downlink network frame is sent to the optical network unit.

[11] An optical access system, wherein the optical access system includes an optical line terminal and an optical network unit, and a connection path between the optical line terminal and the optical network unit includes a working path and an alternate path. The optical line terminal includes a first interface and a second interface, where the first interface is coupled to the working path, and the second interface is coupled to the standby path.

The optical line terminal is configured to acquire a inter-turn difference between two inter-turn points or two inter-turn points of the two downlink points that are sent from the first interface and the second frame from the second interface, according to the Obtaining the inter-turn difference between the two inter-turn points or between the two inter-turn points, obtaining an adjustment interval of the second interface; adjusting the inter-turn of the line header on the second interface according to the adjustment Therefore, the frame transmitted on the alternate path after the adjustment of the inter-frame arrives at the receiving end, the frame header position and the frame transmitted on the working path are consistent at the receiving end, the frame header position, and the transmission frame header includes the transmission downlink. The turn of the frame header or the time of receiving the upstream frame header, and then the switching from the working path to the alternate path is performed.

[12] A switching control device, characterized in that

The switching control device includes: an inter-turn acquisition unit, an adjustment unit, and a switching control unit; the switching control device further includes a first inter-turn acquisition unit and/or a second inter-time acquisition unit; wherein the first inter-turn acquisition a unit, configured to acquire a downlink frame header from an interface of the working path and a time interval of receiving two downlink points of the uplink frame header from an interface of the alternate path;

The second inter-time acquisition unit is configured to acquire, by the interface of the working path, the downlink frame header and the interface of the standby path to receive the inter-turn difference between the two inter-frame points of the uplink frame header;

The adjustment inter-time acquisition unit is configured to calculate an adjustment between an interface of the working path and an interface of the standby path according to the inter-turn obtained by the first inter-frame acquisition unit or the inter-turn obtained by the second inter-frame acquisition unit Daytime

The adjusting unit is configured to adjust, according to the adjustment of the inter-time adjustment unit, the transmission of the frame header on the interface of the alternate path, so that the frame transmitted on the alternate path after the adjustment of the inter-turn arrives at the receiving end吋 The frame header position and the frame transmitted on the working path are consistent at the receiving end 吋 frame header position, and the time of the transmission frame header includes transmitting the downlink frame header or receiving the uplink frame header;

The switching control unit is configured to control switching of the interface of the working path to the interface of the standby path after the adjusting unit adjusts the time of the interface transmission frame header of the alternate path.

[13] The switching control device according to claim 12, further comprising:

And a storage unit, configured to store at least one inter-turn information acquired by the first inter-turn acquisition unit, the second inter-time acquisition unit, and the inter-time acquisition unit.