Time-frequency division multiplexing optical access method, and electronic device, readable medium and product

Abstract

Provided in the embodiments of the present disclosure are a time-frequency division multiplexing optical access method, and an electronic device, a readable medium and a product. The method is applied to an optical line terminal (OLT), and comprises: determining the start time and length of a burst signal of an ONU on each available frequency channel; and sending to the ONU the start time and length of the burst signal of the ONU on each available frequency channel, such that the ONU generates the burst signal on each available frequency channel on the basis of the start time and length of the burst signal. By means of the method, burst signals on different available frequency channels can be accurately recovered.

Description

Time-frequency division multiplexing optical access method, electronic device, readable medium and product TECHNICAL FIELD

[0001] The present disclosure relates to the field of optical access technology, in particular to a time-frequency division multiplexing optical access method, an electronic device, a readable medium and a product. BACKGROUND

[0002] The access network is the "last mile" of the information transmission channel. Although the backbone network has undergone tremendous changes in updating and iteration, the development of the access network has been slow and has been unable to meet the requirements of high speed and low delay. The passive optical network (PON) is a commonly used access network. Common PONs include a time-division multiplexing passive optical network (TDM-PON) and a frequency-division multiplexing passive optical network (FDM-PON). The TDM-PON uses non-overlapping time slots to transmit different signals. The TDM-PON controls different optical network units (ONUs) to transmit burst data packets of different lengths to an optical line terminal (OLT) in their respective time slots in the link. Therefore, the OLT uses a trans-impedance amplifier (TIA) receiver that supports burst mode to receive signals, so as to avoid overlapping of different burst signals when they reach the OLT. The FDM-PON is a technology that implements frequency division multiplexing on frequency spectrum resources. Each ONU can be allocated a different frequency channel to transmit signals.

[0003] In order to obtain higher bandwidth utilization of the PON and improve the flexibility of the PON system, the next generation PON uses a time-frequency division multiplexing passive optical network (TFDM-PON) technology. However, since the TIA receiver can only correctly receive burst signals of a single frequency channel, the signal gain of the signals of the remaining frequency channels will produce obvious jitter when the TIA automatic gain control establishes the single frequency channel, and all the signals of the frequency channels cannot be accurately recovered at the same time, which affects the normal reception of burst signals by the PON system. SUMMARY

[0004] The embodiment of the present disclosure provides a time-frequency division multiplexing optical access method, an electronic device, a readable medium and a product, which are used for realizing one-time accurate receiving of burst signals of different frequency channels.

[0005] In a first aspect, the embodiment of the present disclosure provides a time-frequency division multiplexing optical access method applied to an optical line terminal (OLT), and the method comprises the following steps:

[0006] determining start time and length of burst signals of an optical network unit (ONU) on each available frequency channel;

[0007] sending the start time and length of the burst signals of the ONU on each available frequency channel to the ONU, so that the ONU generates burst signals of each available frequency channel based on the start time and length of the burst signals.

[0008] In a second aspect, the embodiment of the present disclosure provides a time-frequency division multiplexing optical access method applied to an ONU, and the method comprises the following steps:

[0009] generating burst signals corresponding to each available frequency channel based on start time and length of burst signals of each available frequency channel; wherein the start time and length of the burst signals are determined by an OLT;

[0010] sending the burst signals to the OLT through the respective available frequency channels.

[0011] In a third aspect, the embodiment of the present disclosure provides an electronic device, which comprises a memory and a processor; the memory stores a computer program which can be executed by the processor; when the computer program is executed by the processor, the time-frequency division multiplexing optical access method provided by the embodiment of the present disclosure is realized.

[0012] In a fourth aspect, the embodiment of the present disclosure provides a computer readable medium, which stores a computer program; when the computer program is executed by a processor, the time-frequency division multiplexing optical access method provided by the embodiment of the present disclosure is realized.

[0013] In a fifth aspect, the embodiment of the present disclosure provides a computer program product, which comprises computer readable code or a non-volatile computer readable storage medium carrying computer readable code; when the computer readable code is executed in a processor of an electronic device, the processor in the electronic device executes the time-frequency division multiplexing optical access method provided by the embodiment of the present disclosure.

[0014] The time-frequency division multiplexing optical access method provided by the embodiments of the present disclosure determines the start time and length of the burst signal of the ONU on each available frequency channel, and sends the start time and length of the burst signal of the ONU on each available frequency channel to the ONU, so that the ONU generates the burst signal of each available frequency channel based on the start time and length of the burst signal. In this way, the burst signals of different available frequency channels can reach the OLT at the same time, thereby avoiding signal gain jitter, so that the OLT can accurately receive the burst signals of different available frequency channels, and then accurately recover the burst signals on different available frequency channels. BRIEF DESCRIPTION OF DRAWINGS

[0015] FIG. 1 is an application scenario diagram of the embodiments of the present disclosure;

[0016] FIG. 2 is a schematic diagram of the OLT receiving the burst signals of different ONUs;

[0017] FIG. 3 is a flowchart of a time-frequency division multiplexing optical access method provided by the embodiments of the present disclosure;

[0018] FIG. 4 is a schematic diagram of the loop delay of different ONUs in different available frequency channels in the embodiments of the present disclosure;

[0019] FIG. 5 is a schematic diagram of the loop delay of different ONUs in different available frequency channels in the embodiments of the present disclosure;

[0020] FIG. 6 is a schematic diagram of balancing the waiting delay, the start time and length of the burst signal in the embodiments of the present disclosure;

[0021] FIG. 7 is a structural schematic diagram of a PLOAM message provided by the embodiments of the present disclosure;

[0022] FIG. 8 is a schematic diagram of the OLT receiving the burst signals with the same time length T_A but different frequencies at the same time in the embodiments of the present disclosure;

[0023] FIG. 9 is a schematic diagram of balancing the waiting delay, the start time and length of the burst signal in another embodiment of the present disclosure;

[0024] FIG. 10 is a schematic diagram of balancing the waiting delay, the start time and length of the burst signal in another embodiment of the present disclosure;

[0025] FIG. 11 is a flowchart of a time-frequency division multiplexing optical access method provided by the embodiments of the present disclosure;

[0026] FIG. 12 is a flowchart of a time-frequency division multiplexing optical access method provided by the embodiments of the present disclosure;

[0027] FIG. 13 is a structural schematic diagram of a time-frequency division multiplexing optical access device provided by the embodiments of the present disclosure;

[0028] FIG. 14 is a structural schematic diagram of a time-frequency division multiplexing optical access device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] In order for those skilled in the art to better understand the technical solutions of the present disclosure, the time-frequency division multiplexing optical access method, electronic device, readable medium and product provided by the present disclosure are described in detail below with reference to the drawings.

[0030] In the following, example embodiments will be described more fully with reference to the accompanying drawings, in which example embodiments can be embodied in different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0031] In the case of no conflict, each embodiment of the present disclosure and each feature in the embodiments can be combined with each other.

[0032] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0033] The terms used herein are only used to describe specific embodiments and are not intended to limit the present disclosure. As used herein, the singular forms "a" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the terms "comprise" and / or "consist of", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0034] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0035] FIG. 1 is an application scenario diagram of an embodiment of the present disclosure. As shown in FIG. 1, the PON system includes an OLT 1, a splitter 2 and a plurality of ONUs 3, the OLT 1 is connected to the splitter 2 through an optical transmission medium 4, and the splitter 2 is connected to the ONUs 3 through the optical transmission medium 4. When sending a burst signal, the ONU 3 sends a burst signal to the OLT 1 through an optical transmission line and the splitter 2, and when the OLT 1 receives the burst signal, the TIA in the OLT 1 quickly adjusts the output swing to ensure that the information of different ONUs is normally received and demodulated.

[0036] Fig. 2 is a diagram showing OLT receiving burst signals of different ONUs, wherein the horizontal axis represents time T and the vertical axis represents frequency channel. As shown in Fig. 2, the first frequency channel transmits the burst signal sent by ONU1, the second frequency channel and the third frequency channel transmit the burst signals sent by ONU2 and ONU3. If a TIA receiver of a TDM-PON system is used, the PON system can normally receive the burst signal sent by ONU1, but since the burst signals sent by ONU2 and ONU3 are transmitted through the second frequency channel and the third frequency channel, the gain of the burst signals sent by ONU2 and ONU3 will fluctuate when the TIA receiver establishes the burst signal sent by ONU1 in the automatic gain control, which results in that the burst signals sent by ONU2 and ONU3 cannot be accurately recovered at one time, and the normal reception of the burst signals of the PON system is affected.

[0037] The embodiment of the present disclosure provides a time-frequency division multiplexing optical access method, in which the OLT can receive the burst signals of different frequency channels at the same time when transmitting the burst signals, the fluctuation of the burst signals of different frequency channels is avoided, and thus the burst signals of different frequency channels can be accurately received at one time.

[0038] Fig. 3 is a flowchart of a time-frequency division multiplexing optical access method provided by the embodiment of the present disclosure. As shown in Fig. 3, the time-frequency division multiplexing optical access method provided by the embodiment of the present disclosure comprises the following steps.

[0039] In step S301, the start time and length of the burst signal of the ONU on each available frequency channel are determined.

[0040] The available frequency channel refers to the available frequency channel of the time-frequency division multiplexing optical access system, and the available frequency channel is known in advance.

[0041] The start time and length of the burst signal can be determined in different ways. In the embodiment of the present disclosure, the start time and length of the burst signal of the ONU on each available frequency channel are determined based on the equalization waiting delay of the optical network unit ONU on the available frequency channel. The start time and length of the burst signal are determined by using the equalization waiting delay, and the information interaction mechanism of the existing OLT and ONU does not need to be modified.

[0042] In the embodiment of the present disclosure, the equalization waiting delay is a parameter related to the available frequency channel, and the equalization waiting delays of different available frequency channels can be the same or different. In the embodiment, the OLT can obtain the equalization waiting delays of different available frequency channels by using test signals.

[0043] In some embodiments, the equalization waiting delay of the optical network unit (ONU) on any one of the available frequency channels is obtained by the following steps: obtaining the loop delay of the ONU on the available frequency channels; determining the equalization waiting delay of the ONU on the available frequency channels based on the preset burst signal preset time length and the loop delay of the ONU on the available frequency channels.

[0044] In the formula, the burst signal preset time length is a preset time length used for calculating the equalization waiting delay.

[0045] In some embodiments, the burst signal preset time length is greater than the maximum link delay time length of the time-frequency division multiplexing (TFDM) optical access system. The maximum link delay time length of the TFDM optical access system is known to the system, and can also be obtained by a test signal. The obtaining manner of the maximum link delay time length is not limited in the embodiments of the present disclosure.

[0046] In some embodiments, the loop delay of the ONU on each available frequency channel is obtained by the following steps: sending a test signal to the ONU through each available frequency channel during the registration process of the ONU to the OLT or the idle stage of the ONU; and determining the loop delay of the ONU on each available frequency channel based on a response signal returned by the ONU.

[0047] For the loop delay of any one of the available frequency channels, the OLT can send a test signal to the ONU, and then determine the loop delay of the ONU on each available frequency channel based on a response signal returned by the ONU.

[0048] In some embodiments, the test signal includes a ranging signal.

[0049] For example, it is assumed that the TFDM-PON system includes M groups of available frequency channels (frequency carriers), denoted as F1, F2, …, and FM. During the idle stage of the ONU, the OLT sends a ranging signal to the ONU through all the available frequency channels, accurately measures, records, and maintains the loop delay of each ONU on different frequency channels to the OLT, and the loop delay is denoted as T_FM_i, where FM represents the Mth available frequency channel, i represents the ith ONU, and T_FM_i represents the loop delay of the ith ONU on the Mth available frequency channel.

[0050] In the embodiments of the present disclosure, the OLT can also send a test signal to the ONU through all the available frequency channels during the registration stage of the ONU, accurately measure, record, and maintain the loop delay of each ONU on different frequency channels to the OLT.

[0051] Figure 4 is a schematic diagram of loop delays of different ONUs in different available frequency channels in an embodiment of the present disclosure. As shown in Figure 4, the time-frequency division multiplexing optical access system includes three ONUs, and includes M available frequency channels F1,..., FM. For ONU1, the loop delays corresponding to the available frequency channels F1,..., FM are T_F1_1,..., T_FM_1, respectively; for ONU2, the loop delays corresponding to the available frequency channels F1,..., FM are T_F1_2,..., T_FM_2, respectively; for ONU3, the loop delays corresponding to the available frequency channels F1,..., FM are T_F1_3,..., T_FM_3, respectively.

[0052] However, the TFDM-PON system provided by the embodiments of the present disclosure can obtain the loop delays of all available frequency channels. After obtaining the loop delays of each available frequency channel, the loop delays of different available frequency channels can be recorded and maintained (updated in time if there is a change).

[0053] After obtaining the loop delays of different available frequency channels, the equalization waiting delay of the ONU on the available frequency channel is determined based on the preset burst signal preset time length and the loop delay of the ONU on the available frequency channel.

[0054] In some embodiments, the equalization waiting delay is determined by the difference between the burst signal preset time length and the loop delay, i.e., for any available frequency channel, the equalization waiting delay of the available frequency channel can be determined by subtracting the loop delay of the available frequency channel from the burst signal preset time length. The equalization waiting delay is denoted as TW_FM_i, where FM represents the Mth available frequency channel, i represents the ith ONU, and TW_FM_i represents the equalization waiting delay of the ith ONU on the Mth available frequency channel.

[0055] For example, assuming that the burst signal preset time length is 10 ms and the loop delay is 5 ms, the equalization waiting delay is 10-5 = 5 ms. For another example, assuming that the burst signal preset time length is 10 ms and the loop delay is 1 ms, the equalization waiting delay is 10-1 = 9 ms.

[0056] Figure 5 is a schematic diagram of loop delays of different ONUs in different available frequency channels in an embodiment of the present disclosure. As shown in Figure 5, for the 1st frequency channel of ONU1, the equalization waiting delay TW_F1_1 is equal to the preset time length of the burst signal T_B minus the loop delay of the 1st frequency channel T_F1_1, and for the Mth frequency channel of ONU1, the equalization waiting delay TW_FM_1 is equal to the preset time length of the burst signal T_B minus the loop delay of the Mth frequency channel T_FM_1. For the 1st frequency channel of ONU2, the equalization waiting delay TW_F1_2 is equal to the preset time length of the burst signal T_B minus the loop delay of the 1st frequency channel T_F1_2, and for the Mth frequency channel of ONU2, the equalization waiting delay TW_FM_2 is equal to the preset time length of the burst signal T_B minus the loop delay of the Mth frequency channel T_FM_2. For the 1st frequency channel of ONU3, the equalization waiting delay TW_F1_3 is equal to the preset time length of the burst signal T_B minus the loop delay of the 1st frequency channel T_F1_3, and for the Mth frequency channel of ONU3, the equalization waiting delay TW_FM_3 is equal to the preset time length of the burst signal T_B minus the loop delay of the Mth frequency channel T_FM_3.

[0057] It should be noted that if no new ONU is registered in the time-frequency multiplexed optical access system, the maximum and minimum loop delays will not change, and thus the equalization waiting delays of the available frequency channels will not change, and thus the OLT does not need to frequently update the equalization waiting delays of the available frequency channels, and the complexity of the time-frequency multiplexed optical access method is reduced.

[0058] In step S302, the OLT sends the start time and length of the burst signal of the ONU in each available frequency channel to the ONU, so that the ONU generates the burst signal of each available frequency channel based on the start time and length of the burst signal.

[0059] The OLT maintains a global clock, and assigns different available frequency channels to corresponding ONUs to send burst signals (burst data), and sets the start time and length allowed for each ONU to send the burst signal in the corresponding available frequency channel.

[0060] Figure 6 is a diagram showing the equalization waiting time, the start time and the length of the burst signal in the embodiment of the present disclosure, wherein the horizontal axis represents time and the vertical axis represents frequency. As shown in Figure 6, for the first available frequency channel, the start time of the burst signal is at time t1, and the equalization waiting time for the ONU 3 to send the burst signal is TW_F1_3; for the second available frequency channel, the start time of the burst signal is at time t1, and the equalization waiting time for the ONU 1 to send the burst signal is TW_F2_1; for the third available frequency channel, the start time of the burst signal is at time t1, and the equalization waiting time for the ONU 2 to send the burst signal is TW_F3_2.

[0061] At the start time of the burst signal at time t2, for the first available frequency channel, the equalization waiting time for the ONU 3 to send the burst signal is TW_F1_3, and the length is T_A; for the second available frequency channel, the equalization waiting time for the ONU 2 to send the burst signal is TW_F2_2, and the length is T_A; for the third available frequency channel, the equalization waiting time for the ONU 1 to send the burst signal is TW_F3_1, and the length is T_A.

[0062] In some embodiments, the length T_A can be the same or different. Figure 6 shows the length T_A as the length of the burst signal.

[0063] When the OLT determines the start time and the length of the burst signal of each ONU on the different available frequency channels, the start time and the length of the burst signal of each ONU on the different available frequency channels are sent to the ONU, and the ONU generates the burst signal of each available frequency channel based on the start time and the length of the burst signal, and sends the burst signal to the OLT through the corresponding available frequency channel.

[0064] In some embodiments, the start time and the length of the burst signal of each ONU on the different available frequency channels are sent to the ONU, including: configuring the start time and the length of the burst signal of each ONU on the different available frequency channels, and the correspondence between the available frequency channel and the start time of the burst signal and the length of the burst signal in a physical layer operation, management and maintenance (PLOAM) message; and sending the PLOAM message to the ONU.

[0065] FIG. 7 is a structure diagram of a PLOAM message according to an embodiment of the present disclosure. As shown in FIG. 7, the PLOAM message includes a bandwidth map (BWmap), and the BWmap includes N*8 bytes. The bandwidth map includes N allocation structure fields, and each allocation structure field is set with 8 bytes. Each allocation structure field includes an allocation ID (Alloc-ID) field, a flags field, a start time (Start Time) field, a grant size (Grant Size) field, a forced wake-up indication (FWI) field, a burst profile field, and a header error check (HEC) field. The Alloc-ID field occupies 14 bits, the flags field occupies 2 bits, the Start Time field occupies 16 bits, the Grant Size field occupies 16 bits, the FWI field occupies 1 bit, the burst profile field occupies 2 bits, and the HEC field occupies 13 bits. Each flag includes a dynamic bandwidth report (DBRu) field and a physical layer operations, administration and maintenance report (PLOAMu) field, and each field occupies 1 bit.

[0066] In some embodiments, the start time of the burst signal, the length of the burst signal, and the available frequency channel of the burst signal are configured in different fields in the PLOAM message. In the registration activation process, the corresponding information can be directly obtained from the PLOAM message, and no large changes need to be made to the existing PLOAM message.

[0067] For example, as shown in FIG. 7, the start time of the burst signal can be set in the Start Time field, the length of the burst signal can be set in the Grant Size field, and the available frequency channel of the burst signal can be set in any field in the allocation structure, such as any one of the Alloc-ID field, the flags field, the Start Time field, the Grant Size field, the FWI field, the burst profile field, or the HEC field.

[0068] The OLT maintains the available frequency channel, the start time, and the length of the burst signal corresponding to each ONU, and sends the available frequency channel, the start time, and the length of the burst signal to the ONU through the PLOAM message. It should be noted that the OLT sends the burst signal parameters of the ONU to each ONU in advance through the PLOAM message.

[0069] In some embodiments, the method further comprises: receiving the burst signals transmitted by the ONUs through different available frequency channels; and performing demultiplexing and demodulation processing on the burst signals to obtain frequency signals on the different available frequency channels.

[0070] For example, the burst signals of different frequencies are demultiplexed by processing in the electrical domain or the digital domain, and then subsequent signal processing is performed to demodulate the burst signals of the corresponding frequency channels, thereby completing the reception of the burst signals.

[0071] When the ONUs transmit the burst signals to the OLT, each ONU transmits a burst signal of the same time length T_A but different frequencies in the same time window controlled by the global clock, and the burst signals arrive at the OLT at the same physical time, thereby achieving alignment of the burst signals at the OLT. In other words, the OLT receives the burst signals of all available frequencies at the same time.

[0072] FIG. 8 is a schematic diagram of the OLT receiving burst signals of the same time length T_A but different frequencies at the same time according to an embodiment of the present disclosure. As shown in FIG. 8, the OLT receives the burst signals of the same time length T_A transmitted by three ONUs on three available frequency channels at the same time.

[0073] The TIA amplifier in the OLT operates in the linear amplification range, and can correctly receive all available burst signals at one time, i.e., the OLT receives all burst signals of different frequencies at one time in the conventional TDM-PON manner, and then performs demodulation processing on the burst signals to complete the reception of the burst signals.

[0074] In the embodiment of the present disclosure, the lengths of the burst signals can be the same, as shown in FIG. 8, but the embodiment is not limited thereto, and the lengths of the burst signals can also be different.

[0075] The OLT maintains a global clock according to the busy degree of the network, and assigns different available frequency channels to the corresponding ONUs to transmit the burst signals. When transmitting the burst signals, each ONU can transmit a burst signal of different length at different starting time.

[0076] Figure 9 is a diagram of balancing the equalization waiting time, the start time and the length of the burst signal in another embodiment of the present disclosure. As shown in Figure 9, in the first available frequency channel, the burst signal sent by ONU3 at time t1 has an equalization waiting time of TW_F1_3 and a length of T_A1, and the burst signal sent at time t2 has an equalization waiting time of TW_F1_3 and a length of T_A2, where T_A1 and T_A2 have different lengths but the same equalization waiting time. In the second available frequency channel, the burst signal sent by ONU1 at time t1 has an equalization waiting time of TW_F2_1 and a length of T_A1, and the burst signal sent by ONU2 at time t2 has an equalization waiting time of TW_F2_2 and a length of T_A2, where T_A1 and T_A2 have different lengths and different equalization waiting times. In the third available frequency channel, the burst signal sent by ONU2 at time t1 has an equalization waiting time of TW_F3_2 and a length of T_A1, and the burst signal sent by ONU1 at time t2 has an equalization waiting time of TW_F3_1 and a length of T_A2, where T_A1 and T_A2 have different lengths and different equalization waiting times.

[0077] The time-frequency division multiplexing optical access method provided in the embodiments of the present disclosure can enable each ONU to send burst signals of different lengths at different times under the control of a global clock, and can also enable the alignment of the burst signals at the OLT, thereby increasing the flexibility of the TFDM-PON system and avoiding the gain jitter of the burst signals, so that the OLT can accurately recover the burst signals on different available frequency channels.

[0078] When the ONUs send burst signals of different lengths at different times, the OLT needs to modify the Grant Size field in the PLOAM message in advance, and configure the length and the start time of the burst signal to the ONUs in advance.

[0079] In the embodiments of the present disclosure, if the traffic of the ONU is small (not busy), the channels of different frequencies are allowed not to send burst signals. Even if there is no burst signal sent by the ONU, the transmission of the burst signal will not fail.

[0080] Figure 10 is a diagram of balancing the equalization waiting time, the start time and the length of the burst signal in another embodiment of the present disclosure. As shown in Figure 10, in the third available frequency channel, ONU1 does not send a burst signal at time t2, which does not affect the sending of the burst signal by ONU2 using the second available frequency channel, nor does it affect the sending of the burst signal by ONU3 using the first available frequency channel, and the OLT can normally receive the burst signals sent by ONU2 and ONU3.

[0081] The time-frequency division multiplexing optical access method provided by the embodiments of the present disclosure determines the start time and length of the burst signal of the ONU on each available frequency channel, and sends the start time and length of the burst signal of the ONU on each available frequency channel to the ONU, so that the ONU generates the burst signal of each available frequency channel based on the start time and length of the burst signal. This can ensure that the burst signals of different available frequency channels reach the OLT at the same time, thereby avoiding signal gain jitter, so that the OLT can accurately receive the burst signals of different available frequency channels, and further accurately recover the burst signals on different available frequency channels.

[0082] In a second aspect, the embodiments of the present disclosure also provide a time-frequency division multiplexing optical access method, which is applied to an ONU.

[0083] FIG. 11 is a flowchart of a time-frequency division multiplexing optical access method provided by an embodiment of the present disclosure. As shown in FIG. 11, the time-frequency division multiplexing optical access method provided by the embodiments of the present disclosure includes:

[0084] Step S1101, generating the burst signal corresponding to each available frequency channel based on the start time and length of the burst signal of each available frequency channel.

[0085] The start time and length of the burst signal are determined by the OLT. In some embodiments, the start time and length of the burst signal are determined by the OLT based on the equalization waiting delay of the ONU on the available frequency channel.

[0086] Since the start time and length of the burst signal are related to the available frequency channel, the OLT determines the start time and length of the burst signal for each ONU according to the equalization waiting delay of the available frequency channel, and the ONU generates the burst signal according to the start time and length of the burst signal sent by the OLT.

[0087] The OLT maintains a global clock, assigns different available frequency channels to the corresponding ONU to send the burst signal, and sets the start time and length allowed for each ONU to send the burst signal on the available frequency channel. The ONU sends the burst signal with a length of T_A in the same time window under the control of the global clock.

[0088] In some embodiments, the lengths of the burst signals of different available frequency channels are the same, different, or zero.

[0089] As shown in FIG. 8, the OLT receives the burst signals of the same length T_A from the ONUs in the same time window under the control of the global clock at the same time. As shown in FIG. 9, the OLT can make the ONUs send burst signals of different lengths at different times according to the busy degree of network traffic. As shown in FIG. 10, if the ONUs are not busy, the OLT runs the ONUs to not send burst signals, i.e., the length of the burst signal is zero, as shown in FIG. 10, the ONU1 in the third available frequency channel does not send a burst signal at t2.

[0090] In the embodiments of the present disclosure, the ONUs send data of the same time length T_A but different frequencies in the same time window under the control of the global clock, and the burst signals arrive at the OLT at the same physical time, thereby realizing the alignment of the burst signals of the OLT. Even if the lengths are different or zero, the burst signals can arrive at the OLT at the same physical time.

[0091] In step S1102, the burst signals are sent to the OLT through the respective available frequency channels.

[0092] In some embodiments, sending the burst signals to the OLT through the respective available frequency channels comprises: sending the burst signals to the OLT through the available frequency channels in the same time window under the control of the global clock.

[0093] In some embodiments, before generating the burst signals corresponding to the respective available frequency channels based on the start time and the length of the burst signals of the respective available frequency channels, the method further comprises: receiving test signals sent by the OLT through the respective available frequency channels; and returning response signals of the respective available frequency channels to the OLT, so that the OLT determines the loop delay based on the response signals.

[0094] In the registration process of the ONU to the OLT or the idle stage of the ONU, the OLT sends test signals to the ONU through the respective available frequency channels; and determines the loop delay of the ONU on the respective available frequency channels based on the response signals returned by the ONU.

[0095] For the loop delay of any available frequency channel, the OLT can send a ranging signal to the ONU, and then determine the loop delay of the ONU on the respective available frequency channels based on the response signal returned by the ONU. The specific determination manner of the loop delay is the same as that provided in the first aspect, which is not described herein again.

[0096] In some embodiments, the time-frequency division multiplexing optical access method further comprises: receiving a PLOAM message sent by the OLT, and different fields of the PLOAM message are configured with the start time of the burst signal, the length of the burst signal, and the available frequency channel of the burst signal.

[0097] The OLT transmits the start time and length of the burst signal and the correspondence between the available frequency channel and the start time of the burst signal and the length of the burst signal by using the PLOAM message, which is the same as the first aspect, and details are not repeated here.

[0098] The time-frequency multiplexing optical access method provided by the embodiments of the present disclosure can ensure that the burst signals of different available frequency channels reach the OLT at the same time, thereby avoiding signal gain jitter, enabling the OLT to accurately receive the burst signals of different available frequency channels, and further accurately recovering the burst signals on different available frequency channels.

[0099] In order for those skilled in the art to more clearly understand the technical solutions provided by the embodiments of the present disclosure, the technical solutions provided by the embodiments of the present disclosure are described in detail below with specific embodiments.

[0100] FIG. 12 is a flowchart of a time-frequency multiplexing optical access method provided by an embodiment of the present disclosure. As shown in FIG. 12, the time-frequency multiplexing optical access method provided by the embodiments of the present disclosure includes:

[0101] Step S1201, the OLT sends ranging signals of all available frequency channels to the ONU in the ONU registration stage.

[0102] Step S1202, the ONU returns response signals of each available frequency channel to the OLT.

[0103] Step S1203, the OLT determines the loop delay of each ONU on each available frequency channel based on the response signals.

[0104] Step S1204, the OLT determines the equalization waiting delay of the ONU on the available frequency channel based on the preset length of the burst signal and the loop delay of the ONU on the available frequency channel.

[0105] Step S1205, the OLT determines the start time and length of the burst signal of the ONU on each available frequency channel based on the equalization waiting delay of the optical network unit (ONU) on the available frequency channel.

[0106] Step S1206, the OLT maintains a global clock, allocates different frequency channels to each ONU, and sends the start time and length of the burst signal of the ONU on each available frequency channel to the ONU.

[0107] Step S1207, the ONU generates the burst signal corresponding to each available frequency channel based on the start time and length of the burst signal of each available frequency channel.

[0108] Step S1208, the ONU sends burst signals to the OLT through different available frequency channels in the same time window under the control of the global clock.

[0109] Step S1209, the OLT receives the burst signals sent by different ONUs through different available frequency channels at the same physical time, and performs demultiplexing and demodulation processing on the burst signals to obtain frequency signals on each available frequency channel.

[0110] In a third aspect, an embodiment of the present disclosure provides a time-frequency division multiplexing optical access device, applied to an optical line terminal OLT.

[0111] FIG. 13 is a structural schematic diagram of a time-frequency division multiplexing optical access device according to an embodiment of the present disclosure. As shown in FIG. 13, the time-frequency division multiplexing optical access device according to an embodiment of the present disclosure comprises:

[0112] A determination module 1301 is configured to determine the start time and length of the burst signal of the ONU on each available frequency channel.

[0113] In some embodiments, the determination module 1301 determines the start time and length of the burst signal of the ONU on each available frequency channel based on the equalization waiting delay of the optical network unit ONU on the available frequency channel.

[0114] A first sending module 1302 is configured to send the start time and length of the burst signal of the ONU on each available frequency channel to the ONU, so that the ONU generates the burst signal of each available frequency channel based on the start time and length of the burst signal.

[0115] The time-frequency division multiplexing optical access device according to an embodiment of the present disclosure is used to execute the time-frequency division multiplexing optical access method according to the first aspect of the present disclosure. All the steps introduced in the first aspect can be implemented by using the time-frequency division multiplexing optical access device. In order to save space, they will not be described here.

[0116] The time-frequency division multiplexing optical access device according to an embodiment of the present disclosure, the determination module 1301 determines the start time and length of the burst signal of the ONU on each available frequency channel; the first sending module 1302 sends the start time and length of the burst signal of the ONU on each available frequency channel to the ONU, so that the ONU generates the burst signal of each available frequency channel based on the start time and length of the burst signal. This can ensure that the burst signals of different available frequency channels reach the OLT at the same time, thereby avoiding signal gain jitter, so that the OLT can accurately receive the burst signals of different available frequency channels, and further accurately recover the burst signals on different available frequency channels.

[0117] In a fourth aspect, the present disclosure provides a time-frequency division multiplexing optical access device, which is applied to an ONU.

[0118] FIG. 14 is a structural schematic diagram of a time-frequency division multiplexing optical access device according to an embodiment of the present disclosure. As shown in FIG. 14, the time-frequency division multiplexing optical access device according to an embodiment of the present disclosure comprises:

[0119] The generating module 1401 generates the burst signal corresponding to each available frequency channel based on the start time and length of the burst signal of each available frequency channel; wherein the start time and length of the burst signal are determined by the OLT.

[0120] The second sending module 1402 sends the burst signal to the OLT through the respective corresponding available frequency channel.

[0121] The time-frequency division multiplexing optical access device according to an embodiment of the present disclosure is used to execute the time-frequency division multiplexing optical access method according to the second aspect of the present disclosure. All the steps introduced in the second aspect can be implemented by using the time-frequency division multiplexing optical access device. In order to save space, they will not be described here.

[0122] The time-frequency division multiplexing optical access device according to an embodiment of the present disclosure generates the burst signal of each available frequency channel based on the start time and length of the burst signal, and the second sending module sends the burst signal to the OLT through the respective corresponding available frequency channel, which can ensure that the burst signals of different available frequency channels reach the OLT at the same time, thereby avoiding signal gain jitter, so that the OLT can accurately receive the burst signals of different available frequency channels, and further accurately recover the burst signals on different available frequency channels.

[0123] In a fifth aspect, the present disclosure provides an electronic device, which comprises a memory and a processor. The memory stores a computer program which can be executed by the processor. When the computer program is executed by the processor, any time-frequency division multiplexing optical access method according to an embodiment of the present disclosure is implemented.

[0124] The processor can be used to execute the determination of the start time and length of the burst signal of the ONU on each available frequency channel; and the sending of the start time and length of the burst signal of the ONU on each available frequency channel to the ONU, so that the ONU generates the burst signal of each available frequency channel based on the start time and length of the burst signal.

[0125] The processor can be further used to execute the generation of the burst signal corresponding to each available frequency channel based on the start time and length of the burst signal of each available frequency channel; wherein the start time and length of the burst signal are determined by the OLT; and the sending of the burst signal to the OLT through the respective corresponding available frequency channel.

[0126] In a sixth aspect, the embodiments of the present disclosure provide a computer readable medium, which stores a computer program. The computer program is executed by a processor to implement the method of any one of the time-frequency division multiplexing optical access methods.

[0127] In a seventh aspect, the embodiments of the present disclosure provide a computer program product, which includes computer readable code or a non-volatile computer readable storage medium carrying computer readable code. When the computer readable code is run in a processor of an electronic device, the processor in the electronic device implements the method of any one of the time-frequency division multiplexing optical access methods.

[0128] Those skilled in the art can understand that all or some of the steps in the method disclosed above, the functions of the modules / units in the system and the device can be implemented as software, firmware, hardware and appropriate combinations thereof. In the hardware implementation, the division between the function modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component can have multiple functions, or one function or step can be performed by several physical components in cooperation. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor or a microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software can be distributed on a computer readable medium, which can include computer storage media (or non-transitory media) and communication media (or transitory media). As known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. In addition, as known to those skilled in the art, communication media generally includes computer readable instructions, data structures, program modules or other data in modulated data signals such as carrier waves or other transport mechanisms, and can include any information delivery medium.

[0129] Example embodiments have been disclosed herein and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation. In some instances, it will be apparent to those skilled in the art that features, characteristics or / and elements described in connection with a particular embodiment can be used in conjunction with other embodiments unless otherwise explicitly stated. Accordingly, it will be understood that various changes in form and details can be made without departing from the scope of the disclosure as set forth in the appended claims.

Claims

1. A time-frequency division multiplexing (T-FDM) optical access method applied to an optical line terminal (OLT), the method comprising: determining a start time and a length of a burst signal of an optical network unit (ONU) on each available frequency channel; and sending the start time and the length of the burst signal of the ONU on each available frequency channel to the ONU, so that the ONU generates a burst signal of each available frequency channel based on the start time and the length of the burst signal. The determination of the start time and the length of the burst signal of the ONU on each available frequency channel comprises: determining the start time and the length of the burst signal of the ONU on each available frequency channel based on an equalization waiting time of the ONU on the available frequency channel. The equalization waiting time of the ONU on any one of the available frequency channels is obtained by: obtaining a loop delay of the ONU on the available frequency channel; and determining the equalization waiting time of the ONU on the available frequency channel based on a preset burst signal preset time and the loop delay of the ONU on the available frequency channel.

2. The method of claim 1, wherein, The obtaining of the loop delay of the ONU on each available frequency channel comprises: sending a test signal to the ONU through each available frequency channel during a registration process of the ONU to the ONU or an idle stage of the ONU; and determining the loop delay of the ONU on each available frequency channel based on a response signal returned by the ONU. The test signal comprises a ranging signal.

3. The method of claim 2, wherein, The burst signal preset time is greater than a maximum link delay time of a T-FDM optical access system. The sending of the start time and the length of the burst signal of the ONU on each available frequency channel to the ONU comprises: configuring the start time and the length of the burst signal of the ONU on each available frequency channel and the available frequency channel configuration in a physical layer operation, administration and maintenance (PLOAM) message; and sending the PLOAM message to the ONU. The start time of the burst signal, the length of the burst signal and the available frequency channel configuration of the burst signal are configured in different fields in the PLOAM message.

4. The method of claim 3, wherein, The method further comprises: receiving the burst signal transmitted by the ONU through different available frequency channels; and performing demultiplexing and demodulation processing on the burst signal to obtain a frequency signal on each available frequency channel. 10.A T-FDM optical access method applied to an ONU, the method comprising: generating a burst signal corresponding to each available frequency channel based on a start time and a length of the burst signal of each available frequency channel, wherein the start time and the length of the burst signal are determined by an OLT; and sending the burst signal to the OLT through a corresponding available frequency channel. The sending of the burst signal to the OLT through a corresponding available frequency channel comprises: sending the burst signal to the OLT through the available frequency channels in a same time window under control of a global clock.

5. The method of claim 4, wherein, ​ 6. The method of claim 3, wherein, ​ 7. The method of claim 1, wherein, ​ ​ ​ 8. The method of claim 7, wherein, ​ 9. The method of claim 1, wherein, ​ ​ ​ ​ ​ ​ 11. The method of claim 10, wherein, ​ ​ 12. The method of claim 10, wherein, The burst signals of the different available frequency channels are of the same length, different lengths, or zero length.

13. The method of claim 10, wherein, Before generating the burst signal corresponding to each of the available frequency channels based on the start time and length of the burst signal of each of the available frequency channels, the method further comprises: receiving a test signal sent by the OLT through each of the available frequency channels; sending a response signal of each of the available frequency channels back to the OLT, so that the OLT determines the loop delay based on the response signal.

14. The method of claim 10, wherein, The method further comprises: receiving a PLOAM message sent by the OLT, different fields of the PLOAM message being configured with the start time of the burst signal, the length of the burst signal, and the available frequency channel of the burst signal.

15. An electronic device comprising a memory and a processor, wherein the memory stores a computer program executable by the processor, and the computer program is executed by the processor to implement the time-frequency division multiplexing optical access method according to any one of claims 1-9 or 10-14.

16. A computer readable medium having stored thereon a computer program, wherein the program is executed by a processor to implement the time-frequency division multiplexing optical access method according to any one of claims 1-9 or 10-14.

17. A computer program product comprising computer readable code, or a non-transitory computer readable storage medium carrying computer readable code, wherein the computer readable code, when run in a processor of an electronic device, causes the processor in the electronic device to perform the time-frequency division multiplexing optical access method according to any one of claims 1-9 or 10-14.

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