CN114554322B

CN114554322B - Method and device for acquiring transmission delay

Info

Publication number: CN114554322B
Application number: CN202011359749.7A
Authority: CN
Inventors: 郑刚
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-11-27
Filing date: 2020-11-27
Publication date: 2023-06-27
Anticipated expiration: 2040-11-27
Also published as: CN114554322A

Abstract

The application discloses a method and a device for acquiring transmission delay, and belongs to the field of communication. The method comprises the following steps: the first ONU receives a first message sent by the OLT through a first PON channel and determines the receiving time for receiving the first message as T1; receiving a second message sent by a second ONU through a first network channel, and determining the receiving time for receiving the second message as T2; the second message is sent by the second ONU in response to the event that the third message is received, and the third message is sent by the OLT to the second ONU through the second PON channel; the first network channel is a transmission channel established by the first ONU and the second ONU through a first network protocol; acquiring a transmission delay delta t1 of a first network channel between a first ONU and a second ONU; a PON channel transmission delay difference between the OLT and the first ONU and the second ONU, respectively, is determined based at least on T1, T2, and Δt1. The method and the device can avoid suspending transmission service.

Description

Method and device for acquiring transmission delay

Technical Field

The present invention relates to the field of communications, and in particular, to a method and apparatus for obtaining transmission delay.

Background

The passive optical network (passive optical network, PON) comprises an optical line terminal (optical line terminal, OLT) and a plurality of optical network units (optical network unit, ONUs), the OLT being connected to each ONU. The OLT needs to acquire the transmission delay from itself to each ONU, and determines the time slot of each ONU based on the transmission delay of each ONU, so that each ONU sends uplink data to the OLT in the respective time slot.

Currently, when the OLT discovers that a new ONU is on-line in the PON, the OLT measures a transmission delay between itself and the ONU within a time window, and then determines a time slot for the ONU based on the transmission delay, so that the ONU transmits upstream data within the time slot. The start time stamp of the time window is located after the OLT discovers the ONU, and the time length of the time window is a designated length.

In carrying out the present application, the inventors have found that the prior art has at least the following problems:

the OLT and the ONU in the PON only do the operation of measuring the transmission delay in the time window, and suspend the transmission service, and the time length of the time window is longer, often several hundred microseconds, and the time of the service suspension is too long.

Disclosure of Invention

The application provides a method and a device for acquiring transmission delay so as to avoid suspending transmission service. The technical scheme is as follows:

in a first aspect, the present application provides a method for obtaining a transmission delay, where in the method, a first optical network unit ONU receives, through a first passive optical network PON channel, a first message sent by an optical line terminal OLT, and determines a receiving time for receiving the first message to be T1. The first ONU receives a second message sent by a second ONU through a first network channel, the receiving time for receiving the second message is determined to be T2, the second message is sent by the second ONU in response to an event of receiving a third message, and the third message is sent to the second ONU through a second PON channel by the OLT. The first network channel is a transmission channel established by the first ONU and the second ONU through a first network protocol, and the first network is a network different from the PON. The first ONU acquires the transmission delay delta t1 of a first network channel between the first ONU and the second ONU. The first ONU determines a PON channel transmission delay difference value between the OLT and the first ONU and the second ONU, respectively, based at least on T1, T2, and Δt1.

Because the second ONU sends the second message to the first ONU through the first network channel after receiving the third message of the OLT, the first ONU determines the receiving time T2 of the second message, and because the first ONU obtains the transmission delay delta T1 of the first network channel between the first ONU and the second ONU, the first ONU can determine the transmission delay difference value of the PON channel between the OLT and the first ONU and the second ONU respectively based on at least T1, T2 and delta T1. The first PON channel transmission delay between the OLT and the first ONU is known, so the second PON channel transmission delay between the OLT and the second ONU can be obtained based on the first PON channel transmission delay and the PON channel transmission delay difference. Therefore, when the transmission time delay of the second PON channel is acquired, the OLT only needs to send the first message and the third message, and a time window is not required to be started independently to measure the transmission time delay of the second PON channel, so that the phenomenon that transmission service is suspended is avoided.

In one possible implementation, the first message and the third message are sent simultaneously by the OLT. Thus, the first ONU can determine the PON channel transmission delay difference value between the OLT and the first ONU and between the OLT and the second ONU respectively based on T1, T2 and delta T1, and the complexity of the implementation scheme is simplified.

In another possible implementation, the first message and the third message are sent by the OLT at different times. The first ONU obtains a time difference Δt2 between a transmission time T3 when the OLT transmits the first message and a transmission time T4 when the OLT transmits the third message, Δt2=t4-T3. Thus, the first ONU determines the PON channel transmission delay difference value between the OLT and the first ONU and between the OLT and the second ONU respectively based on T2, T1, delta T1 and delta T2, and the PON channel transmission delay difference value can be accurately obtained.

In another possible implementation, the first message includes T3, the third message includes T4, and the second message includes T4; alternatively, the third message comprises Δt2 and the second message comprises Δt2; alternatively, the first message includes Δt2.

In another possible implementation, the first network is a wireless fidelity wifi network or a cellular communication network.

In a second aspect, the present application provides an apparatus for obtaining a transmission delay, configured to perform the method performed by the first ONU in the first aspect or any one of possible implementations of the first aspect. In particular, the apparatus comprises means for performing the method performed by the first ONU in the first aspect or in any of the possible implementations of the first aspect.

In a third aspect, the present application provides an apparatus for acquiring a transmission delay, the apparatus comprising a transceiver, a processor, and a memory. Wherein the transceiver, the processor and the memory may be connected by an internal connection. The memory is configured to store a program, and the processor is configured to execute the program in the memory and cooperate with the transceiver to cause the apparatus to perform the method performed by the first ONU in the first aspect or any of the possible implementations of the first aspect.

In a fourth aspect, the present application provides a computer program product comprising a computer program stored in a computer readable storage medium and loaded by a device to implement the instructions of the method of the first aspect or any possible implementation of the first aspect.

In a fifth aspect, the present application provides a computer readable storage medium storing a computer program loaded by a device to execute instructions of the method of the first aspect or any possible implementation manner of the first aspect.

In a sixth aspect, the present application provides a system for obtaining a transmission delay, where the system includes a first ONU and a first device, where the first ONU is configured to receive, through a first PON channel, a first message sent by an optical line terminal OLT, and determine a receiving time for receiving the first message is T1. And receiving a second message sent by the second ONU through the first network channel, and determining the receiving time for receiving the second message to be T2, wherein the second message is sent by the second ONU in response to the event of receiving a third message, and the third message is sent by the OLT to the second ONU through the second PON channel. The first network channel is a transmission channel established by the first ONU and the second ONU through a first network protocol, and the first network is a network different from the PON. Time information is sent to the first device, the time information including T1 and T2.

The first device is configured to receive the time information, obtain a transmission delay Δt1 of a first network channel between the first ONU and the second ONU, and determine a PON channel transmission delay difference value between the OLT and the first ONU and between the OLT and the second ONU, respectively, based on at least T1, T2, and Δt1.

Since the second ONU transmits the second message to the first ONU through the first network channel after receiving the third message of the OLT, the first ONU determines the receiving time T2 of the second message, and transmits T1 and T2 to the first device. And because the first device acquires the transmission delay delta T1 of the first network channel between the first ONU and the second ONU, the first device can determine the difference value of the transmission delay of the PON channel between the OLT and the first ONU and between the OLT and the second ONU respectively based on at least T1, T2 and delta T1. The first PON channel transmission delay between the OLT and the first ONU is known, so the second PON channel transmission delay between the OLT and the second ONU can be obtained based on the first PON channel transmission delay and the PON channel transmission delay difference. Therefore, when the transmission time delay of the second PON channel is acquired, the OLT only needs to send the first message and the third message, and a time window is not required to be started independently to measure the transmission time delay of the second PON channel, so that the phenomenon that transmission service is suspended is avoided.

In one possible implementation, the first device is a second ONU.

In another possible implementation, the first device is an OLT, and the first device receives Δt1 sent by the first ONU or receives Δt1 sent by the second ONU, where Δt1 is acquired by the first ONU or the second ONU.

Drawings

Fig. 1 is a schematic diagram of a PON architecture according to an embodiment of the present application;

FIG. 2 is a schematic diagram of an architecture of an industrial control network according to an embodiment of the present application;

fig. 3 is a flowchart of a method for obtaining a transmission delay according to an embodiment of the present application;

fig. 4 is a flowchart of another method for obtaining a transmission delay according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of an apparatus for acquiring transmission delay according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of another apparatus for acquiring transmission delay according to an embodiment of the present application;

fig. 7 is a schematic diagram of a system structure for acquiring transmission delay according to an embodiment of the present application.

Detailed Description

Embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

The following is a brief introduction to the concepts involved in this application.

The first ONU: is an ONU in the PON that has registered in the OLT on-line.

The second ONU: is an ONU in the new access PON and is not registered on-line in the OLT.

A first message: is a message sent by the OLT to a first ONU (second ONU) in the PON.

A second message: is a message sent by the second ONU to the first ONU in the first network, the first network and the PON being two different networks. And the second ONU sends the second message to the first ONU after receiving the message sent by the OLT.

Third message: is a message sent by the OLT to the second ONU in the PON.

T1 or Tr1: is the time at which the first ONU receives the first message.

T2: is the time at which the first ONU receives the second message.

T3: is the time when the OLT sends the first message.

T4: is the time when the OLT sends the third message.

Tr2: is the time at which the first message was received by the second ONU.

Δt1: a transmission delay of a first network channel between the first ONU and the second ONU, the first network channel being a channel between the first ONU and the second ONU in the first network.

Δt2: is the time difference between the transmission time T3 at which the OLT transmits the first message and the transmission time T4 at which the OLT transmits the third message.

Deltat 3: is the time difference between the time the second ONU receives the third message and the time the second message is sent, is a known constant.

It should be noted that any time mentioned above should be regarded as a time corresponding to the same reference; in the concrete implementation, the local time is read, and if the local time and the absolute time of the network are at fixed intervals, compensation is carried out; if no gap exists, no compensation is required.

Referring to fig. 1, an embodiment of the present application provides a PON, including:

the system comprises an OLT and a plurality of ONUs, wherein each ONU in the plurality of ONUs is connected with the OLT through an optical fiber.

In the PON, a PON channel exists between each ONU and the OLT, so that for each ONU, the ONU can transmit data to the OLT or receive data transmitted by the OLT through the PON channel between the ONU and the OLT.

Referring to fig. 1, the plurality of ONUs may also access the first network such that for any two ONUs of the plurality of ONUs, the two ONUs may establish a first network channel in the first network using a first network protocol, and data may be transmitted between the two ONUs through the first network channel.

The first network and PON are two different networks. The first network protocol is a protocol employed by the first network. For example, the first network may be a wireless fidelity (wifi) network, a cellular communication network, or a wired network, among others. The first network protocol may include a wifi protocol employed by a wifi network, a microwave protocol employed by a cellular communication network, a 5G network protocol or a 4G network protocol, and/or an ethernet protocol employed by a wired network, etc.

The following description is needed: the PON can be applied to an industrial control scenario or other scenario in which control devices and controlled devices are connected to the PON. The control device manages or controls different controlled devices through the PON, and the controlled devices may be industrial robots, sensors, servo transmission devices, or input/output (I/O) devices, etc. The controller may be a terminal integrated management system (integrated terminal management system, ITMS) or a home network management platform, etc.

Referring to fig. 2, in case of applying the PON to an industrial control scenario, the PON may serve as an industrial control network, the OLT may communicate with control devices, and each ONU may communicate with one or more controlled devices. In this way, the control device can send control data to the controlled device through the PON, and the controlled device can send response data in response to the control data to the control device through the PON, so that the control device controls or manages the controlled device.

Optionally, the control device is connected to the OLT, or the control device is connected to the OLT through one or more network devices, including a broadband access server (broadband remote access server, BRAS) or the like.

Alternatively, the control data sent by the control device to the controlled device may be a control command. The response data transmitted by the controlled device to the control device may be data in response to the control command. For example, assuming that the controlled device is a temperature sensor, the control data transmitted by the control device may be a temperature measurement command, the controlled device receives the temperature measurement command, measures the temperature, and the response data transmitted to the control device is a measured temperature value.

In PON, a broadcast system may be used for downstream transmission, and the downstream transmission direction is a direction in which an OLT transmits data to ONUs, and the OLT simultaneously transmits data to each ONU in the PON by using the broadcast system. The uplink transmission may use a time division multiplexing mode, and the direction of the uplink transmission is the direction in which the ONU sends data to the OLT.

The uplink transmission process in the time division multiplexing mode may be: the OLT allocates corresponding time slots for transmitting uplink data for each ONU in the PON, each ONU transmits data to the OLT when the corresponding time slot is reached, and the data transmitted by each ONU simultaneously reaches the OLT, namely, the OLT simultaneously receives the data transmitted by each ONU.

Wherein the time slot corresponding to each ONU is determined based on the distance between the OLT and each ONU. The distance between the OLT and each ONU may be different in the PON, so that the determined time slots corresponding to each ONU may also be different.

For example, in an industrial control scenario, the downlink transmission procedure may be: the OLT receives control data to be sent to at least one controlled device by the control device, and allocates time slots for the ONUs based on the distance between the OLT and the ONUs in the PON. And encapsulating the control data to be sent to at least one controlled device and the time slot identifiers corresponding to the ONUs into an Ethernet frame, and broadcasting and sending the Ethernet frame to the ONUs in the PON. I.e. the OLT simultaneously sends the ethernet frame to each ONU in the PON. For each ONU in the PON, the ONU receives the Ethernet frame, reads control data to be sent to a controlled device in communication with the ONU and a time slot identifier corresponding to the ONU from the Ethernet frame, and sends the read control data to the controlled device in communication with the ONU.

The uplink transmission process may be: for the controlled device in communication with the ONU, the controlled device receives the control data and responds to the control data, i.e. the controlled device sends response data to the ONU. The ONU receives the response data, packages the response data into an Ethernet frame, and sends the Ethernet frame to the OLT when the time slot corresponding to the ONU arrives. The other ONUs in the PON send ethernet frames to the OLT as the ONUs do, and the ethernet frames sent by the ONUs in the PON arrive at the OLT at the same time. The OLT receives the Ethernet frames sent by each ONU, acquires the response data of the controlled device from each Ethernet frame, and sends the response data of the controlled device to the control device.

As can be seen from the above examples, the OLT needs to obtain the distance between the OLT and each ONU first, so that the time slots can be allocated to each ONU. The distance between the OLT and each ONU is obtained based on the PON channel transmission delay between the OLT and each ONU in the PON. Therefore, for any ONU accessing the PON, the OLT needs to first acquire a PON channel transmission delay between the OLT and the ONU in the PON, and then can obtain a distance between the OLT and the ONU based on the PON channel transmission delay.

Referring to fig. 3, an embodiment of the present application provides a method for acquiring transmission delay, which is applied to the network architecture shown in fig. 1 or fig. 2, in the method, PON channel transmission delay differences between an OLT and two different ONUs are acquired, and PON channel transmission delay between the OLT and the ONUs is acquired based on the PON channel transmission delay differences. The method comprises the following steps:

Step 301: the OLT sends a first message to the first ONU and a third message to the second ONU.

The first ONU is an ONU in the PON that has registered on-line in the OLT. Registering an ONU on-line at an OLT means: the OLT acquires the first PON channel transmission time delay between the first ONU and the OLT in advance, and/or the first ONU acquires the first PON channel transmission time delay between the first ONU and the OLT in advance.

The second ONU is an ONU newly accessing the PON, the second ONU also accessing the first network. For any one ONU that has registered online in the OLT, the ONU may discover the newly accessed second ONU in the first network, send a discovery notification message to the OLT, and may establish a first network channel with the second ONU in the first network.

The discovery notification message is used to notify the OLT that there is a new ONU accessing the PON.

Optionally, the discovery notification message includes a device identification of the second ONU.

Optionally, the device identifier of the second ONU is a Sequence Number (SN) of the second ONU, and so on.

In the PON, there is a first PON channel between the OLT and a first ONU, and a second PON channel between the OLT and a second ONU. The OLT receives the discovery notification message, transmits a first message to the first ONU over the first PON channel, and transmits a third message to the second ONU over the second PON channel based on a trigger of the discovery notification message.

In step 301, the OLT may send the first message and the third message in a broadcast transmission manner, that is, the OLT sends the first message to the first ONU and sends the third message to the second ONU at the same time, where the first message and the third message are the same message. When the OLT adopts the broadcast transmission method, the OLT may send a first message (a third message) to each ONU (including at least the first ONU and the second ONU) in the access PON.

Optionally, after receiving the discovery notification message, the OLT may further select an ONU from the ONUs that have registered online in the OLT as the first ONU, where the first message (third message) includes a device identifier of the first ONU.

In step 301, the OLT may also send the first message and the third message in a unicast transmission manner, that is, the OLT may send the first message to the first ONU and the third message to the second ONU at different times.

In the case of unicast transmission, the discovery notification message received by the OLT includes the device identifier of the second ONU. The OLT selects one ONU from the ONUs registered on-line in the OLT as a first ONU, sends a first message to the first ONU, and sends a third message to the second ONU based on the device identification of the second ONU, wherein the third message comprises the device identification of the first ONU.

In the case of the unicast transmission mode, the first message may further include a transmission time T3 when the OLT transmits the first message, and the third message includes a transmission time T4 when the OLT transmits the third message. Alternatively, the first message comprises Δt2, Δt2=t4-T3, and/or the third message comprises Δt2.

Δt2 is the time difference between the transmission time T3 at which the OLT transmits the first message and the transmission time T4 at which the OLT transmits the third message.

Optionally, the first message and the third message include indication information, where the indication information is used to instruct the ONU to perform a procedure of acquiring a PON channel transmission delay, and the PON channel transmission delay is a transmission delay between the OLT and the ONU in the PON.

Step 302: the first ONU receives the first message through the first PON channel and determines the receiving time for receiving the first message to be T1.

In step 302, the first ONU receives a first message through the first PON channel, where the first message includes indication information, and determines, based on a trigger of the indication information, that a procedure for acquiring a transmission delay needs to be performed. Since the first ONU has successfully registered with the OLT, the first ONU performs the initial operation of the flow as: the current timing time T1 of the first ONU is acquired, and the T1 is determined as the receiving time of the first message.

Step 303: the second ONU receives the third message over the second PON channel and transmits the second message to the first ONU over the first network channel in response to an event of receiving the third message.

In step 303, the second ONU receives a third message through the second PON channel, where the third message includes indication information, and determines, based on the triggering of the indication information, that a procedure for acquiring a transmission delay needs to be performed. Since the second ONU is not registered in the OLT yet and the transmission delay of the second PON channel between the second ONU and the OLT is unknown, the second ONU performs the initial operation of the flow as follows: the second message is sent to the first ONU over the first network channel.

Optionally, the OLT sends a third message in a broadcast sending manner, where the third message may or may not include the device identifier of the first ONU. The third message comprises the equipment identifier of the first ONU, and the second ONU sends the second message to the first ONU through a first network channel between the second ONU and the first ONU based on the equipment identifier of the first ONU. And if the third message does not include the device identifier of the first ONU, the second ONU selects one ONU from ONUs having the first network channel with the second ONU as the first ONU, and transmits the second message to the first ONU based on the first network channel with the first ONU.

Optionally, the OLT sends a third message in a unicast sending manner, where the third message includes a device identifier of the first ONU, and the second ONU sends the second message through a first network channel between the second ONU and the first ONU based on the device identifier of the first ONU.

Alternatively, in case the third message comprises T4, the second message may also comprise T3. Alternatively, where the third message includes Δt2, the second message may also include Δt2.

Step 304: the first ONU receives the second message and determines the receiving time for receiving the second message to be T2.

In step 304, the first ONU receives the second message through the first network channel, acquires the time T2 currently counted by the first ONU, and determines T2 as the receiving time of receiving the second message.

When the OLT transmits the first message by adopting the broadcast transmission mode, for other ONUs in the PON that do not receive the second message, the other ONUs discard the received first message.

Step 305: the first ONU acquires the transmission delay delta t1 of a first network channel between the first ONU and the second ONU.

In step 305, the first ONU sends a measurement message to the second ONU through the first network channel, and obtains a first sending time Ta, which is the time of sending the measurement message. The second ONU receives the measurement message, acquires the first receiving time Tb, and the first receiving time Tb is the time for receiving the measurement message. And the second ONU acquires the second transmission time as Tc when determining to transmit a measurement response, and transmits the measurement response to the first ONU through the first network channel, wherein the measurement response comprises a first receiving time Tb and the second transmission time Tc. The first ONU receives the measurement response, acquires a second receiving time Td, and the second receiving time Td is the time for receiving the measurement response. The first ONU obtains a transmission delay Δt1= (Td-Ta) - (Tc-Tb) of a first network channel between the first ONU and the second ONU.

Optionally, after the first ONU establishes a first network channel between the first ONU and the second ONU in the first network, the first ONU obtains a transmission delay Δt1 of the first network channel.

Step 305 is not performed in sequence with the processes of steps 301 to 304, and step 305 may be performed before step 301, or step 305 may be performed after step 304, or step 305 may be performed simultaneously with the process.

Step 306: the first ONU determines a PON channel transmission delay difference value between the OLT and the first ONU and the second ONU, respectively, based at least on T1, T2, and Δt1.

Under the condition that the OLT transmits the first message and the third message in a broadcast transmission mode, the first ONU determines a PON channel transmission delay difference value between the OLT and the first ONU and between the ONU and the second ONU respectively based on T1, T2 and delta T1. The PON channel transmission delay difference may be T2-T1- Δt1- Δt3.Δt3 is the time difference between the time the second ONU receives the third message and the time the second message is sent, and is a known constant.

When the OLT transmits the first message and the third message in a unicast transmission manner, the first ONU obtains a time difference Δt2 between a transmission time T3 when the OLT transmits the first message and a transmission time T4 when the OLT transmits the third message, where Δt2=t4-T3. And determining PON channel transmission delay difference values between the OLT and the first ONU and the second ONU respectively based on T2, T1, delta T1 and delta T2. The PON channel transmission delay difference may be T2-T1- Δt1- Δt2- Δt3.

Optionally, the operation of the first ONU to acquire Δt2 may be:

in case the first message comprises T3 and the second message comprises T4, the first ONU obtains T3 from the first message and T4 from the second message, calculating Δt2=t4-T3.

In case the first message comprises Δt2, or the second message comprises Δt2, the first ONU reads Δt2 from the first message, or reads Δt2 from the second message.

After the first ONU obtains the PON channel transmission delay difference, the first ONU may further send the PON channel transmission delay difference and a device identifier of the second ONU to the OLT. The OLT receives the PON channel transmission delay difference value and the equipment identifier of the second ONU, accumulates the first PON channel transmission delay between the OLT and the first ONU and the PON channel transmission delay difference value, and takes the accumulated value as the second PON channel transmission delay between the OLT and the second ONU corresponding to the equipment identifier. Or the first ONU accumulates the first PON channel transmission time delay between the OLT and the first ONU and the PON channel transmission time delay difference value, and sends the accumulated value and the equipment identification of the second ONU to the OLT. The OLT receives the device identification of the second ONU and the accumulated value, and takes the accumulated value as the transmission delay of a second PON channel between the OLT and the second ONU corresponding to the device identification.

And when the OLT acquires the transmission delay of the second PON channel, the second ONU is registered in the OLT to be on line. The OLT may also determine a distance between the OLT and the second ONU based on a second PON channel transmission delay between the OLT and the second ONU.

In the embodiment of the application, the OLT sends a first message to the first ONU through a first PON channel between the OLT and the first ONU, and sends a third message to the second ONU through a second PON channel between the OLT and the second ONU. And the second ONU sends the second message to the first ONU through a first network channel between the second ONU and the first ONU after receiving the third message. The first ONU receives the first message and acquires a receiving time T1 for receiving the first message, and receives the second message and acquires a receiving time T2 for receiving the second message. Because the first ONU further obtains the transmission delay Δt1 of the first network channel between the first ONU and the second ONU, the first ONU determines the PON channel transmission delay difference between the OLT and the first ONU and between the OLT and the second ONU, respectively, based on at least T1, T2, and Δt1. The first PON channel transmission delay between the OLT and the first ONU is known, so the second PON channel transmission delay between the OLT and the second ONU can be obtained based on the first PON channel transmission delay and the PON channel transmission delay difference. In the process of acquiring the transmission delay of the second PON channel, the OLT only needs to send the first message and the third message, and does not need to independently start a time window to measure the transmission delay of the second PON channel, so that the phenomenon of suspending transmission service is avoided.

Referring to fig. 4, an embodiment of the present application provides a method for acquiring a transmission delay, which is applied to the network architecture shown in fig. 1 or fig. 2, and in the method, a PON channel transmission delay between an OLT and an ONU is directly acquired. The method comprises the following steps:

step 401: the OLT transmits the first message to the second ONU over a second PON channel between the OLT and the second ONU.

The discovery notification message is used to notify the OLT that there is a new ONU accessing the PON. Optionally, the discovery notification message includes a device identification of the second ONU.

The OLT receives the discovery notification message, and based on the trigger of the discovery notification message, transmits a first message to ONUs (including a second ONU and ONUs that have been registered on-line with the OLT) in the access PON by using a broadcast transmission method. Or, the OLT receives the discovery notification message, where the discovery notification message includes a device identifier of the second ONU, and sends the first message to the second ONU based on the device identifier of the second ONU.

Optionally, before sending the first message, the OLT selects an ONU from the ONUs that have been registered in the OLT for online as the first ONU, and the first message includes a device identifier of the first ONU.

Optionally, the first message includes a transmission time T at which the OLT transmits the first message _send 。

Since the first ONU is an ONU that has been registered online in the OLT, the first ONU comprises a time relationship between the first ONU and the OLT, and/or the OLT comprises a time relationship between the first ONU and the OLT.

The OLT may be time synchronized with the first ONU in advance, so that the OLT and/or the first ONU obtains a time relationship between the first ONU and the OLT in advance. The time relationship may be a time difference Δt2 between the first ONU and the OLT, and the time difference Δt2 may be 0 or greater than 0.

Wherein, for the first ONU and the second ONU which are accessed into the PON, a first PON channel exists between the OLT and the first ONU, and a second PON channel exists between the OLT and the second ONU in the PON. The OLT thus transmits the first message to the first ONU over the first PON channel and/or transmits the first message to the second ONU over the second PON channel.

Optionally, the first message includes indication information, where the indication information is used to instruct the ONU to execute a procedure of acquiring a PON channel transmission delay.

Step 402: the second ONU receives the first message over the second PON channel and transmits the second message to the first ONU over the first network channel in response to an event of receiving the first message.

In step 402, the second ONU receives a first message through the second PON channel, where the first message includes indication information, and determines, based on a trigger of the indication information, that a procedure for acquiring a PON channel transmission delay needs to be performed. Since the second ONU is not registered in the OLT and is on-line, the transmission delay of the second PON channel between the second ONU and the OLT is unknown, so the second ONU performs the initial operation of the flow as follows: the second message is sent to the first ONU over a first network channel, the first network channel being a channel between the second ONU and the first ONU in the first network.

Optionally, when the first message includes a transmission time T _send In the case of (2), the second message may also include a transmission time T _send 。

Alternatively, the second message may include the indication information.

Optionally, in the case that the first message includes a device identifier of the first ONU, the second ONU sends the first message to the first ONU through the first network channel based on the device identifier of the first ONU. In case that the first message does not include the device identification of the first ONU, the second ONU selects one ONU from the ONUs that have been registered on-line with the OLT as the first ONU, and transmits the first message to the first ONU through the first network channel.

Step 403: the first ONU receives the second message through the first network channel, and determines the first receiving time as Tr1, wherein the first receiving time Tr1 is the time when the first ONU receives the second message.

In step 403, the first ONU receives a second message through the first network channel, where the second message includes indication information, and determines that a procedure for acquiring a transmission delay needs to be performed based on triggering of the indication information. Since the first ONU is already registered on-line with the OLT, the initial operation of the first ONU to perform the flow is: the current timing time Tr1 of the first ONU is acquired, and Tr1 is determined as the first receiving time for receiving the second message.

Step 404: the first ONU acquires the transmission delay delta t1 of a first network channel between the first ONU and the second ONU.

Optionally, the detailed implementation process of the first ONU to obtain the transmission delay Δt1 may refer to the relevant content in step 305 in the embodiment shown in fig. 3, which is not described in detail herein.

Step 404 is not performed in sequence with the processes of steps 401 to 403, and step 404 may be performed before step 401, or step 404 may be performed after step 403, or step 404 may be performed simultaneously with the process.

Step 405: the first ONU transmits time information, which is acquired by the first ONU based on the first receiving time Tr1, the transmission delay Δt1, and the time relationship, and the time information is used to acquire the second PON channel transmission delay between the OLT and the second ONU.

Optionally, the time information includes a first receiving time Tr1, a first transmission delay Δt1, and the time relation, or the time information is a second receiving time Tr2, or the time information is a second PON channel transmission delay, and the second receiving time Tr2 is a time counted by the OLT when the second ONU receives the second message. The time relation may be a time difference Δt2 between the first ONU and the OLT.

Optionally, in the case that the time information is a transmission delay of the second PON channel, the first ONU obtains a transmission time T of the OLT for transmitting the second message _send Based on T1, Δt1, Δt2 and T _send And acquiring the transmission delay of a second PON channel between the OLT and the second ONU. Wherein the transmission delay of the second PON channel is T1-delta T2-T _send- Deltat 3. Deltat 3 is the time difference between the time when the second ONU receives the first message and the time when the second message is sent, which is a known constant

The first message includes a transmission time T _send And/or the second message comprises a transmission time T _send The first ONU can acquire the transmission time T from the second message or the first message _send 。

Alternatively, in the case where the time information includes the second reception time Tr2, the second PON channel transmission delay may be obtained in two manners, which are respectively:

the first way is: the first ONU obtains a second reception time Tr2 based on Tr1, Δt1, and Δt2, and transmits the second reception time Tr2 to the OLT. The second receiving time Tr2 may be Tr1- Δt1- Δt2- Δt3. The OLT receives the second receiving time Tr2, and the OLT packetsIncluding a second reception time Tr2 and a transmission time T for transmitting the first message _send So the transmission delay of the second PON channel between the OLT and the second ONU is obtained to be T2-T _send 。

The second way is: the first ONU obtains a second reception time based on Tr1, Δt1, and Δt2, and transmits the second reception time Tr2 to the second ONU. The second receiving time Tr2 may be Tr1- Δt1- Δt2- Δt3. The first message sent by the OLT comprises a sending time T _send The second ONU receives the second receiving time Tr2, and the second ONU comprises the second receiving time Tr2 and the transmitting time T _send So the transmission delay of the second PON channel between the OLT and the second ONU is obtained to be T2-T _send And sending the second PON channel transmission delay to the OLT.

Alternatively, in the case where the time information includes the first reception time Tr1, the first transmission delay Δt1, and the time relationship Δt2, there may be a first mode or a second mode for acquiring the transmission delay of the second PON channel, where the first mode and the second mode are respectively:

in one mode, the first ONU transmits the time information to the OLT, and the OLT receives the time information. At this time, the OLT includes a first receiving time Tr1, a first transmission delay Δt1, a time relation Δt2, and a transmission time T for transmitting the first message _send The OLT is based on Tr1, Δt1, Δt2 and T _send And acquiring the transmission delay of a second PON channel between the OLT and the second ONU. Wherein the transmission delay of the second PON channel can be Tr 1-deltat 2-T _send -Δt3。

In a second mode, the first ONU transmits the time information to the second ONU, and the second ONU receives the time information. At this time, the second ONU includes the first receiving time Tr1, the first transmission delay Δt1, and the time relationship Δt2, obtains the second receiving time Tr2 based on Tr1, Δt1, and Δt2, and sends the second receiving time Tr2 to the OLT. The second receiving time Tr2 may be Tr1- Δt1- Δt2- Δt3. The OLT acquires the transmission delay of a second PON channel between the OLT and the second ONU as T2-T _send 。

Optionally, when the first message includes a transmission time T _send In the case of (a), i.e. the second ONU further comprises a transmission time T _send The implementation process of the second mode can also beThe method comprises the following steps: the second ONU is directly based on T1, delta T2 and T _send And acquiring the transmission delay of a second PON channel between the OLT and the second ONU, and transmitting the transmission delay of the second PON channel to the OLT. Wherein, the transmission delay of the second PON channel can be T1-delta T2-T _send -Δt3。

And the OLT obtains the transmission delay of the second PON channel, which indicates that the second ONU is registered in the OLT to be on line. The OLT may also acquire a distance between the OLT and the second PON based on the second PON channel transmission delay.

In the embodiment of the application, the OLT sends the first message to the second ONU through a second PON channel between the OLT and the second ONU. The second ONU sends the second message to the first ONU over a first network channel with the first ONU immediately after receiving the first message. The first ONU receives the second message and acquires a first reception time Tr1 for receiving the second message. Because the first ONU further acquires the transmission delay Δt1 of the first network channel between the first ONU and the second ONU, the first ONU acquires time information based on the first reception time Tr1, the transmission delay Δt1, and the time relationship Δt2 between the first ONU and the OLT, and transmits the time information. The OLT may thus acquire the second PON channel transmission delay between the OLT and the second ONU based on the time information. In this way, in the process of acquiring the transmission delay of the second PON channel, the OLT only needs to send the first message, and does not need to independently start a time window to measure the transmission delay of the second PON channel, thereby avoiding the suspension of transmission service.

Referring to fig. 5, an embodiment of the present application provides an apparatus 500 for obtaining a transmission delay, where the apparatus 500 is disposed in the first ONU provided in any foregoing embodiment, and includes:

a receiving unit 501, configured to receive, through a first passive optical network PON channel, a first message sent by an optical line terminal OLT;

a processing unit 502, configured to determine a receiving time for receiving the first message to be T1;

the receiving unit 501 is further configured to receive, through the first network channel, a second message sent by the second ONU;

the processing unit 502 is further configured to determine that a receiving time for receiving the second message is T2; the second message is sent by the second ONU in response to the event that the third message is received, and the third message is sent by the OLT to the second ONU through the second PON channel; wherein the first network channel is a transmission channel established by the apparatus 500 and the second ONU through a first network protocol, and the first network is a network different from the PON;

the processing unit 502 is further configured to obtain a transmission delay Δt1 of a first network channel between the apparatus 500 and the second ONU;

the processing unit 502 is further configured to determine PON channel transmission delay differences between the OLT and the device 500 and the second ONU, respectively, based on at least T1, T2 and Δt1.

Optionally, the processing unit 502 obtains the transmission delay Δt1, which is referred to in step 305 of the embodiment shown in fig. 3 and will not be described in detail herein.

Optionally, the processing unit 502 determines the PON channel transmission delay difference according to the related content in step 306 of the embodiment shown in fig. 3, which is not described in detail herein.

Optionally, the first message and the third message are sent simultaneously by the OLT.

Optionally, the first message and the third message are sent by the OLT at different times, and the processing unit 502 is further configured to:

acquiring a time difference delta T2 between a transmission time T3 of the first message transmitted by the OLT and a transmission time T4 of the third message transmitted by the OLT, wherein delta T2 = T4-T3;

a PON channel transmission delay difference between the OLT and the device 500 and the second ONU, respectively, is determined based on T2, T1, Δt1 and Δt2.

Optionally, the first message includes T3, the third message includes T4, and the second message includes T4; alternatively, the third message comprises Δt2 and the second message comprises Δt2; alternatively, the first message includes Δt2.

Optionally, the first network is a wireless fidelity wifi network or a cellular communication network.

In the embodiment of the application, since the processing unit obtains the transmission delay Δt1 of the first network channel between the first ONU and the second ONU, the processing unit determines the PON channel transmission delay difference between the OLT and the first ONU and between the OLT and the second ONU, respectively, at least based on T1, T2, and Δt1. The first PON channel transmission delay between the OLT and the device is known, so that the second PON channel transmission delay between the OLT and the second ONU can be obtained based on the first PON channel transmission delay and the PON channel transmission delay difference. Therefore, when the transmission time delay of the second PON channel is acquired, the OLT only needs to send the first message and the third message, and a time window is not required to be started independently to measure the transmission time delay of the second PON channel, so that the phenomenon that transmission service is suspended is avoided.

Referring to fig. 6, an apparatus 600 for acquiring transmission delay is provided in an embodiment of the present application. The apparatus 600 may be the first ONU in any of the embodiments described above. The device 600 comprises at least one processor 601, an internal connection 602, a memory 603 and at least two transceivers 604.

The apparatus 600 is a hardware-structured apparatus that can be used to implement the functional modules in the apparatus 500 described in fig. 5. For example, it will be appreciated by those skilled in the art that the processing unit 502 in the apparatus 500 shown in fig. 5 may be implemented by the at least one processor 601 invoking code in the memory 603, and the receiving unit 501 in the apparatus 500 shown in fig. 5 may be implemented by the at least two transceivers 604.

Optionally, the apparatus 600 may be further configured to implement the function of the first ONU in any of the foregoing embodiments.

Optionally, a portion of the at least two transceivers 604 may be in communication with the PON for receiving data transmitted by the OLT or for transmitting data to the OLT. There is another portion of the transceivers 604, the other portion of the transceivers 604 being in communication with the first network for transmitting data to other ONUs in the first network or for receiving data transmitted by other ONUs.

Alternatively, the processor 601 may be a general purpose central processing unit (central processing unit, CPU), network processor (network processor, NP), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the programs of the present application.

The internal connection 602 may include a pathway to transfer information between the components. Alternatively, the internal connection 602 is a board or bus, etc.

The at least two transceivers 604 are used to communicate with other devices or communication networks.

The memory 603 may be, but is not limited to, a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (random access memory, RAM) or other type of dynamic storage device that can store information and instructions, or an electrically erasable programmable read-only memory (electrically erasable programmable read-only memory, EEPROM), a compact disc read-only memory (compact disc read-only memory) or other optical disc storage, optical disc storage (including compact disc, laser disc, optical disc, digital versatile disc, blu-ray disc, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. The memory may be stand alone and coupled to the processor via a bus. The memory may also be integrated with the processor.

The memory 603 is used for storing application program codes for executing the embodiments of the present application, and the processor 601 controls the execution. The processor 601 is configured to execute application code stored in the memory 603 and cooperate with at least two transceivers 604 to cause the apparatus 600 to perform the functions of the methods of the present patent.

In a particular implementation, the processor 601 may include one or more CPUs, such as CPU0 and CPU1 of FIG. 6, as an embodiment.

In a specific implementation, the apparatus 600 may include multiple processors, such as the processor 601 and the processor 607 in fig. 6, as an embodiment. Each of these processors may be a single-core (single-CPU) processor or may be a multi-core (multi-CPU) processor. A processor herein may refer to one or more devices, circuits, and/or processing cores for processing data (e.g., computer program instructions).

Referring to fig. 7, an embodiment of the present application provides a system 700 for acquiring a transmission delay, where the system 700 includes a first ONU701 and a first device 702.

The first ONU701 is configured to receive, through a first passive optical network PON channel, a first message sent by the optical line terminal OLT, and determine a receiving time for receiving the first message is T1. And receiving a second message sent by the second ONU through the first network channel, and determining the receiving time for receiving the second message to be T2, wherein the second message is sent by the second ONU in response to the event of receiving a third message, and the third message is sent by the OLT to the second ONU through the second PON channel. The first network channel is a transmission channel established by the first ONU and the second ONU through a first network protocol, and the first network is a network different from the PON. Time information is sent to the first device 702, including T1 and T2.

The first device 702 is configured to receive the time information, obtain a transmission delay Δt1 of a first network channel between the first ONU and the second ONU, and determine a PON channel transmission delay difference value between the OLT and the first ONU and between the OLT and the second ONU, respectively, based on at least T1, T2, and Δt1.

The first device is a second ONU or OLT.

And under the condition that the first equipment is a second ONU, the second ONU receives the time information and acquires the transmission delay delta T1 of a first network channel between the first ONU and the second ONU, so that the second ONU comprises T1, T2 and delta T1, and the difference value of the transmission delay of the PON channel can be determined. The second ONU also transmits the PON channel transmission delay difference value to the OLT. Because the OLT includes the first PON channel transmission delay between the OLT and the first ONU, the OLT accumulates the first PON channel transmission delay and the PON channel transmission delay difference to obtain the second PON channel transmission delay between the OLT and the second ONU.

In the case that the first device is the OLT, the OLT further receives Δt1 sent by the first ONU or receives Δt1 sent by the second ONU, where Δt1 is acquired by the first ONU or the second ONU. Thus, the second ONU includes T1, T2, and Δt1, so that the PON channel transmission delay difference can be determined. Because the OLT includes the first PON channel transmission delay between the OLT and the first ONU, the OLT accumulates the first PON channel transmission delay and the PON channel transmission delay difference to obtain the second PON channel transmission delay between the OLT and the second ONU.

In this embodiment of the present application, since the second ONU sends the second message to the first ONU through the first network channel after receiving the third message of the OLT, the first ONU determines the receiving time T2 of the second message, and sends T1 and T2 to the first device. And because the first device acquires the transmission delay delta T1 of the first network channel between the first ONU and the second ONU, the first device can determine the difference value of the transmission delay of the PON channel between the OLT and the first ONU and between the OLT and the second ONU respectively based on at least T1, T2 and delta T1. The first PON channel transmission delay between the OLT and the first ONU is known, so the second PON channel transmission delay between the OLT and the second ONU can be obtained based on the first PON channel transmission delay and the PON channel transmission delay difference. Therefore, when the transmission time delay of the second PON channel is acquired, the OLT only needs to send the first message and the third message, and a time window is not required to be started independently to measure the transmission time delay of the second PON channel, so that the phenomenon that transmission service is suspended is avoided.

It will be understood by those skilled in the art that all or part of the steps for implementing the above embodiments may be implemented by hardware, or may be implemented by a program for instructing relevant hardware, where the program may be stored in a computer readable storage medium, and the storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.

The foregoing description of the preferred embodiments is merely illustrative of the principles of the present application, and not in limitation thereof, and any modifications, equivalents, improvements and/or the like may be made without departing from the spirit and scope of the present application.

Claims

1. A method for acquiring transmission delay, the method comprising:

the method comprises the steps that a first optical network unit ONU receives a first message sent by an optical line terminal OLT through a first passive optical network PON channel, and the receiving time for receiving the first message is determined to be T1;

the first ONU receives a second message sent by a second ONU through a first network channel, and determines the receiving time for receiving the second message as T2; the second message is sent by the second ONU in response to an event that receives a third message, where the third message is sent by the OLT to the second ONU through a second PON channel; wherein the first network channel is a transmission channel established by the first ONU and the second ONU through a first network protocol, and the first network is a network different from a PON;

the first ONU acquires the transmission delay delta t1 of the first network channel between the first ONU and the second ONU;

The first ONU determines a PON channel transmission delay difference value between the OLT and the first ONU and the second ONU respectively at least based on T1, T2 and delta T1, and the first message and the third message are sent by the OLT at the same time; or alternatively, the process may be performed,

the first ONU acquires a time difference delta T2 between a transmission time T3 of the first message transmitted by the OLT and a transmission time T4 of the third message transmitted by the OLT, wherein delta T2 = T4-T3; and determining PON channel transmission delay differences between the OLT and the first ONU and the second ONU respectively based on T2, T1, Δt1 and Δt2, wherein the first message and the third message are transmitted by the OLT at different times.

2. The method of claim 1, wherein the first message comprises T3, the third message comprises T4, and the second message comprises T4; alternatively, the third message comprises Δt2, and the second message comprises Δt2; alternatively, the first message includes Δt2.

3. The method of claim 1 or 2, wherein the first network is a wireless fidelity wifi network or a cellular communication network.

4. An apparatus for acquiring a transmission delay, the apparatus comprising:

A receiving unit, configured to receive a first message sent by an optical line terminal OLT through a PON channel of a first passive optical network;

a processing unit, configured to determine a receiving time for receiving the first message to be T1;

the receiving unit is further configured to receive a second message sent by a second ONU through a first network channel;

the processing unit is further configured to determine that a receiving time for receiving the second message is T2; the second message is sent by the second ONU in response to an event that receives a third message, where the third message is sent by the OLT to the second ONU through a second PON channel; wherein the first network channel is a transmission channel established by the device and the second ONU through a first network protocol, and the first network is a network different from a PON;

the processing unit is further configured to obtain a transmission delay Δt1 of the first network channel between the device and the second ONU;

the processing unit is further configured to determine PON channel transmission delay differences between the OLT and the device and the second ONU, respectively, based on at least T1, T2, and Δt1, where the first message and the third message are sent by the OLT at the same time; or alternatively, the process may be performed,

The processing unit is further configured to obtain a time difference Δt2 between a transmission time T3 when the OLT transmits the first message and a transmission time T4 when the OLT transmits the third message, where Δt2=t4-T3; and determining PON channel transmission delay differences between the OLT and the device and the second ONU, respectively, based on T2, T1, Δt1, and Δt2, the first message and the third message being transmitted by the OLT at different times.

5. The apparatus of claim 4, wherein the first message comprises T3, the third message comprises T4, and the second message comprises T4; alternatively, the third message comprises Δt2, and the second message comprises Δt2; alternatively, the first message includes Δt2.

6. The apparatus of claim 4 or 5, wherein the first network is a wireless fidelity wifi network or a cellular communication network.

7. A computer storage medium having stored thereon a computer program which, when executed by a processor, implements the method according to any of claims 1-3.