Bandwidth allocation method and apparatus, electronic device, storage medium, and program product

Abstract

The embodiments of the present disclosure provide a bandwidth allocation method and apparatus, an electronic device, a storage medium, and a program product. The method comprises: acquiring traffic buffer information of an optical network unit (ONU) and bandwidth allocation information of an optical link terminal (OLT); determining a single-frame multi-burst count of a transmission container (T-CONT) in the ONU based on the traffic buffer information and the bandwidth allocation information; allocating bandwidth for the ONU based on the determined single-frame multi-burst count; and sending the allocated bandwidth to the ONU.

Description

Bandwidth allocation method and device, electronic equipment, storage medium and program product

[0001] Cross-reference to Related Applications

[0002] This application claims priority to Chinese Patent Application No. 202410661293.1, filed May 24, 2024, with the Chinese Patent Office, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] Embodiments of the present disclosure relate to, but are not limited to, the field of communication. BACKGROUND

[0004] Since multiple optical network units (ONUs) share a bandwidth, if the bandwidth is not allocated reasonably, when the ONUs upload data to an optical link terminal (OLT), resource grabbing or data collision problems may occur, and the quality of network service decreases. Initially, to solve this problem, a static bandwidth allocation method is used, in which a fixed transmission gap is allocated to each ONU, and the ONU can only upload data within the allocated time slot. Since this method does not consider the overall network load, the ONU may have no data to upload within the transmission time, causing bandwidth waste, or the ONU has too much data to transmit within the allocated gap, causing delay. SUMMARY

[0005] Embodiments of the present disclosure provide a bandwidth allocation method, device, electronic equipment, storage medium and program product.

[0006] In a first aspect, embodiments of the present disclosure provide a bandwidth allocation method, which can include: obtaining traffic buffer information of an optical network unit (ONU) and bandwidth allocation information of an optical link terminal (OLT); determining a single-frame multi-burst number of a transmission container (TCONT) in the ONU based on the traffic buffer information and the bandwidth allocation information; allocating bandwidth to the ONU based on the determined single-frame multi-burst number; and sending the allocated bandwidth to the ONU.

[0007] In a second aspect, embodiments of the present disclosure provide a bandwidth allocation device, which includes: an obtaining module configured to obtain traffic buffer information of an optical network unit (ONU) and bandwidth allocation information of an optical link terminal (OLT); a determining module configured to determine a single-frame multi-burst number of a transmission container (TCONT) in the ONU based on the traffic buffer information and the bandwidth allocation information; an allocating module configured to allocate bandwidth to the ONU based on the determined single-frame multi-burst number; and a sending module configured to send the allocated bandwidth to the ONU.

[0008] In a third aspect, an electronic device is provided, which includes one or more processors, and a memory having one or more computer programs stored thereon, wherein the one or more computer programs, when executed by the one or more processors, cause the one or more processors to implement the bandwidth allocation method.

[0009] In a fourth aspect, a computer-readable storage medium is provided, which has a computer program stored thereon, wherein the computer program, when executed by a processor, implements the bandwidth allocation method.

[0010] In a fifth aspect, a computer program product is provided, which includes a computer program, wherein the computer program, when executed by a processor, implements the bandwidth allocation method. BRIEF DESCRIPTION OF DRAWINGS

[0011] In the drawings of the embodiments of the present disclosure:

[0012] FIG. 1 is a flowchart of a bandwidth allocation method according to an embodiment of the present disclosure;

[0013] FIG. 2 is a schematic diagram of a PON system in the related art;

[0014] FIG. 3 is a schematic diagram of an adaptive single-frame multi-burst number decision algorithm structure according to an embodiment of the present disclosure;

[0015] FIG. 4 is a schematic diagram of a single TCONT continuous period according to an embodiment of the present disclosure;

[0016] FIG. 5 is a schematic diagram of a bandwidth allocation method according to an embodiment of the present disclosure;

[0017] FIG. 6 is a block diagram of a bandwidth allocation apparatus according to an embodiment of the present disclosure;

[0018] FIG. 7 is a block diagram of an electronic device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the technical solutions of the present disclosure, the bandwidth allocation method, apparatus, electronic device, storage medium and program product provided by the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0020] The embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings, but the embodiments shown can be embodied in many different forms and should not be construed as 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 disclosure to those skilled in the art.

[0021] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and together with the detailed description serve to explain the present disclosure, but do not limit the present disclosure. The above and other features and advantages of the present disclosure will become more apparent from the detailed description in conjunction with the accompanying drawings, in which:

[0022] The present disclosure can be described with reference to plan views and / or cross-sectional views by idealized figures of the present disclosure. Thus, the example illustrations can be modified according to manufacturing techniques and / or tolerances.

[0023] The embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0024] The terms used in the present disclosure are only used to describe particular embodiments, and are not intended to limit the present disclosure. As used in the present disclosure, the term "and / or" includes any and all combinations of one or more of the associated listed items. As used in the present disclosure, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used in the present disclosure, the terms "comprises," "comprising," "consists of," and "consisting of" 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.

[0025] Unless otherwise defined, all terms used in the present disclosure, including technical and scientific terms, have the same meaning as those commonly understood by one of ordinary skill in the art. It will be further 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.

[0026] In order to improve the bandwidth allocation quality and provide more stable and reliable network services, DBA algorithms that can adapt to network load changes are adopted successively.

[0027] A passive optical network (PON) system generally includes an OLT, an optical splitter (OS), and a plurality of ONUs, and is a point-to-multipoint system. In the PON system, a broadcast mode is adopted for sending in the downlink direction from the OLT to the ONUs, each ONU receives the same service, and based on information such as a flow ID, the service belonging to the ONU is parsed, and invalid services are filtered; a time division mode is adopted for sending services in the uplink direction from the ONUs to the OLT, and the uplink traffic is converged at the OS and sent to the OLT.

[0028] To avoid the conflict of uplink traffic from different ONUs, a DBA (Dynamic Bandwidth Allocation) algorithm is used to allocate the uplink transmission bandwidth of the ONUs in the system, and the uplink time slot of each ONU is adjusted so that the time of service arriving at the OLT is staggered. However, each ONU can only send data in the time slot allocated by the DBA algorithm, and the uplink time slot window of each ONU is limited. The waiting window from the end of a time slot to the beginning of the next time slot belongs to the uplink time of other ONUs, and in this waiting window time, the ONU may have new data arriving and buffering, and needs to wait for the next allocated time slot to send the buffered data, so the waiting delay is close to the waiting window time. If the uplink is sent only once in a frame (125 microseconds), then in a stable case, the waiting window time is close to 125 microseconds, and each ONU needs to wait for a time close to 125 microseconds to send the newly arrived buffered data.

[0029] To solve this problem, the single-frame multi-burst idea has been proposed. Single-frame multi-burst refers to increasing the number of uplink times in a frame to reduce the waiting window time and thus improve the delay performance. However, this method mainly solves the problem by fixing the number of bursts, and does not fully utilize the redundant resources to improve the delay performance, and lacks flexibility in dealing with different traffic, different priority services and other scenarios.

[0030] The traffic buffering information of the ONUs and the bandwidth allocation information of the OLT are obtained, the number of single-frame multi-bursts of the TCONT in the ONU is determined based on the traffic buffering information and the bandwidth allocation information, the adaptive adjustment of the number of single-frame multi-bursts is realized, the redundant resources can be fully utilized based on the traffic buffering information and the bandwidth allocation information to speed up the response time of the service, different traffic, different priority services and other scenarios can be dealt with, the delay performance can be flexibly improved, and the bandwidth is allocated to the ONUs based on the determined number of single-frame multi-bursts, and the allocated bandwidth is sent to the ONUs, thereby improving the quality of bandwidth allocation and providing more stable and reliable network services.

[0031] The bandwidth allocation method of the embodiments of the present disclosure can be applied to, but is not limited to, the DBA algorithm in the PON system, and can be applied to devices that implement the DBA algorithm, such as the OLT.

[0032] The embodiments of the present disclosure will be described in detail below.

[0033] The embodiments of the present disclosure provide a bandwidth allocation method, as shown in FIG. 1, which can include steps S11-S14.

[0034] In step S11, the traffic buffering information of the optical network unit (ONU) and the bandwidth allocation information of the optical line terminal (OLT) are obtained.

[0035] The whole PON system mainly includes three basic units of OLT, ONU and OS. As shown in FIG. 2, the OLT is responsible for resource scheduling, bandwidth control and other tasks in the network; the ONU (such as ONU1, ONU2, …, ONUn, n is a positive integer) is the user end of the network, responsible for receiving and sending data; the optical splitter is the message forwarding station in the network, responsible for connecting the OLT and the ONU, distributing the optical signals from the OLT to each ONU, and converging the data in the ONU and sending to the OLT.

[0036] The DBA algorithm module is located at the OLT side, and predicts and allocates the bandwidth required by the ONU side through the traffic cache information or traffic detection information sent by the ONU side, and sends the authorization to the ONU through the OLT.

[0037] In step S12, the single-frame multi-burst number of the transmission container TCONT in the ONU is determined based on the traffic cache information and the bandwidth allocation information.

[0038] In the embodiment of the present disclosure, the single-frame multi-burst number of the transmission container TCONT in the ONU is determined based on the traffic cache information and the bandwidth allocation information, which can include: judging whether the actual use bandwidth of each TCONT in the ONU is less than the calculated allocation bandwidth of the single-frame multi-burst number to be added according to the bandwidth allocation information, and judging whether there is traffic cache in the TCONT according to the traffic cache information, and increasing the single-frame multi-burst number or keeping the single-frame multi-burst number unchanged according to the obtained first judgment result; and / or, judging whether there is cache traffic backlog in each TCONT in the ONU according to the bandwidth allocation information and the traffic cache information, and reducing the single-frame multi-burst number or keeping the single-frame multi-burst number unchanged according to the obtained second judgment result.

[0039] In the embodiment of the present disclosure, an adaptive single-frame multi-burst number decision algorithm is proposed, which can output an algorithm result of increasing or reducing or keeping the single-frame multi-burst number based on the above-mentioned traffic cache information on the ONU side and the bandwidth allocation information on the OLT side.

[0040] In the embodiments of the present disclosure, as shown in FIG. 3, the adaptive single-frame multi-burst number decision algorithm can be applied in the OLT, and can be applied in but not limited to the DBA algorithm. For each TCONT (such as TCONT1, TCONT2, …, TCONTm1 in ONU1, TCONT1, TCONT2, …, TCONTmn, mn and m1 are positive integers, in ONUn) in each ONU (such as ONU1, …, ONUn), the traffic buffer information and the bandwidth allocation information are judged (for example, which can include but is not limited to the remaining bandwidth and the buffer traffic backlog judgment), so as to determine whether to adjust the single-frame multi-burst number and how to adjust the single-frame multi-burst number according to the judgment result.

[0041] In the embodiments of the present disclosure, as shown in FIG. 3, the adaptive single-frame multi-burst number decision algorithm can be implemented by a preset burst number decision module 11. The burst number decision module 11 sends the algorithm result of the adaptive single-frame multi-burst number decision algorithm to a bandwidth allocation (BA) module 12 and a bandwidth map (BWMAP) entry generation module 13.

[0042] In the embodiments of the present disclosure, the bandwidth allocation module 12 can adjust the total allocatable bandwidth based on the burst number result output by the burst number decision module 11 (that is, the single-frame multi-burst number determined according to the embodiments of the present disclosure), and allocate bandwidth for all ONUs based on the adjusted total allocatable bandwidth. After the bandwidth allocation is completed, the bandwidth allocation result is sent to the bandwidth map entry generation module 13. The bandwidth map entry generation module 13 generates entries (that is, bandwidth allocation results determined based on the single-frame multi-burst number) based on the bandwidth allocation result and the authorization entry decision result (for example, the decision result of increasing or decreasing or keeping the single-frame multi-burst number), and sends the final bandwidth allocation result to each ONU.

[0043] In the embodiments of the present disclosure, to implement the adaptive single-frame multi-burst number decision algorithm, the main ideas adopted include: increasing the single-frame multi-burst number when there is redundancy in resources (such as allocated bandwidth), and decreasing the single-frame multi-burst number when the resources are insufficient. The ideas of increasing the single-frame multi-burst number and decreasing the single-frame multi-burst number are as follows.

[0044] The idea of increasing the single-frame multi-burst number: when there is remaining bandwidth and periodic authorization entry redundancy, the single-frame multi-burst number of the TCONT (Transmission Container) with high priority is preferentially increased. The periodic authorization entry redundancy can mean that the current single-frame multi-burst number is less than the preset maximum number threshold.

[0045] Single frame multi-burst number reduction idea: reduce the single frame multi-burst number of the TCONT with low priority when there is no residual bandwidth and no acceleration processing of the traffic cache.

[0046] In the embodiments of the present disclosure, the adaptive increase idea and the reduction idea can solve the problem of long waiting time delay when there is residual bandwidth and redundant grant entries, and the problem of long time delay caused by insufficient total available bandwidth when there is no residual bandwidth redundancy, and can realize adaptive adjustment of the single frame multi-burst number when the traffic changes.

[0047] In the embodiments of the present disclosure, the strategy of the adaptive single frame multi-burst number decision algorithm can include an increase strategy, a reduction strategy and a maintenance strategy.

[0048] Increase strategy: when the actual use bandwidth of all TCONTs in the current ONU is less than the calculated bandwidth after the next increase, and there is no backlog of cached traffic in all TCONTs, it indicates that there is bandwidth redundancy, and the single frame multi-burst number can be increased.

[0049] Reduction strategy: when the backlog of cached traffic of any one TCONT in the current ONU increases, and there is no residual bandwidth to accelerate the processing of the backlog, the single frame multi-burst number can be reduced.

[0050] Maintenance strategy: when the conditions required to meet the increase strategy and the reduction strategy are not met, the single frame multi-burst number can be maintained unchanged.

[0051] In the embodiments of the present disclosure, the adaptive single frame multi-burst number decision algorithm in the embodiments of the present disclosure will be described in detail below.

[0052] In the embodiments of the present disclosure, first, the detailed scheme for determining whether the single frame multi-burst number can be increased is introduced.

[0053] In the embodiments of the present disclosure, determining the single frame multi-burst number of the transmission container TCONT in the ONU based on the traffic cache information and the bandwidth allocation information can include: judging whether the actual use bandwidth Bx of each TCONT in the ONU is less than the calculated allocation bandwidth By of the single frame multi-burst number to be increased according to the bandwidth allocation information, and judging whether there is cached traffic in the TCONT according to the traffic cache information, and increasing the single frame multi-burst number or maintaining the single frame multi-burst number unchanged according to the obtained first judgment result.

[0054] In the embodiments of the present disclosure, the increasing the number of single-frame multi-bursts or keeping the number of single-frame multi-bursts unchanged according to the obtained first judgment result can include: in the case that the judgment results of all TCONTs in the ONU meet the first preset condition, increasing the number of single-frame multi-bursts of one or more TCONTs in all TCONTs of the ONU or keeping the number of single-frame multi-bursts of all TCONTs of the ONU unchanged under the constraint of a preset maximum number threshold.

[0055] In the embodiments of the present disclosure, the first preset condition can include: the actual used bandwidth of the TCONT is less than the allocated bandwidth calculated for increasing the number of single-frame multi-bursts; and there is no traffic cache in the TCONT.

[0056] In the embodiments of the present disclosure, the above information can be directly determined according to the obtained traffic cache information of the ONU and the bandwidth allocation information of the OLT.

[0057] In the embodiments of the present disclosure, only in the case that all TCONTs in the ONU meet the first preset condition, the following number increasing strategy is performed on the TCONTs (any one or more, possibly part of the TCONTs, possibly all the TCONTs, defined by demand) contained in the ONU: increasing the number of single-frame multi-bursts or keeping the number of single-frame multi-bursts unchanged under the constraint of a preset maximum number threshold of single-frame multi-bursts. If any one or more TCONTs do not meet the first preset condition, the above number increasing strategy will not be performed.

[0058] In the embodiments of the present disclosure, increasing the number of single-frame multi-bursts of one or more TCONTs in all TCONTs of the ONU or keeping the number of single-frame multi-bursts of all TCONTs of the ONU unchanged under the constraint of a preset maximum number threshold can include: judging whether the total number of currently set single-frame multi-bursts in the ONU reaches the preset maximum number threshold; in the case that the total number of currently set single-frame multi-bursts does not reach the preset maximum number threshold, increasing the number of single-frame multi-bursts of one or more TCONTs in the ONU; in the case that the total number of currently set single-frame multi-bursts has reached the preset maximum number threshold, keeping the currently set number of single-frame multi-bursts of all TCONTs unchanged.

[0059] In the embodiments of the present disclosure, the maximum number threshold De2 can be defined by demand, and the detailed value of the maximum number threshold De2 is not limited.

[0060] In the embodiments of the present disclosure, increasing the number of single-frame multi-bursts of one or more TCONTs in the ONU can include: increasing the number of single-frame multi-bursts of each TCONT in turn according to the order of decreasing priority of the one or more TCONTs.

[0061] In the embodiments of the present disclosure, when the number of single-frame multi-bursts for the TCONT in the ONU is increased, the number of single-frame multi-bursts for the TCONT with high priority can be increased preferentially, and the number of single-frame multi-bursts for one or more TCONTs to be increased is increased in order of gradually decreasing priority of the TCONTs. When the total number of single-frame multi-bursts has reached the maximum threshold, the current number of single-frame multi-bursts is kept unchanged.

[0062] In the embodiments of the present disclosure, the increased number of single-frame multi-bursts can be configured, for example, to increase by a second preset value, or to be doubled, etc.

[0063] In the embodiments of the present disclosure, the detailed scheme for determining whether the number of single-frame multi-bursts can be reduced is introduced below, which can include two schemes: in the first scheme, whether there is a backlog of buffered traffic and whether there is excess bandwidth to handle the backlog of buffered traffic are determined; in the second scheme, whether there is a backlog of buffered traffic and whether there is excess bandwidth to handle the backlog of buffered traffic are determined, and whether the backlog of buffered traffic has been accelerated is determined.

[0064] The first scheme is introduced first below.

[0065] In the embodiments of the present disclosure, whether there is a backlog of buffered traffic in each TCONT in the ONU is determined according to bandwidth allocation information and traffic buffer information, including: in each preset continuous period of each TCONT, the following operations are performed: comparing how much the traffic buffer information is between different periods in the continuous period, and comparing how much the bandwidth allocation information is between multiple periods after the different periods in the continuous period, and determining whether there is a backlog of buffered traffic in the TCONT according to the obtained first comparison result; wherein the bandwidth allocation information of the multiple periods after the different periods is used to represent the bandwidth allocated based on the traffic buffer information of the different periods, and the continuous period can refer to a dynamic bandwidth allocation (DBA) period, and the continuous period can include the current period and multiple periods before the current period which are continuous with the current period.

[0066] In the embodiments of the present disclosure, when the allocated bandwidth and the buffered traffic are determined, the bandwidth allocation information and the traffic buffer information in the continuous period composed of the current period (i.e., the current DBA period) of each TCONT and multiple periods before the current period can be used for determination.

[0067] In the embodiments of the present disclosure, the bandwidth allocation information of each period is determined based on the traffic information of the previous one or several periods, and therefore, when whether there is excess bandwidth or the backlog of buffered traffic is accelerated is determined, the bandwidth information of the next one or several periods of the period can be referred to.

[0068] In the embodiments of the present disclosure, the number of detailed periods in the continuous period described above is not limited, and can be defined by demand, for example, four continuous periods can be selected, for example, if the current period is period T4, the continuous period can include periods T1, T2, T3 and T4.

[0069] In the embodiments of the present disclosure, the number of detailed periods in the previous one or several periods (or the next one or several periods) described above is not limited, and can be defined by demand, or the number of periods can be determined according to actual communication settings, for example, the previous two periods can be selected, for example, the bandwidth allocation information of each period is determined based on the traffic information of the previous two periods.

[0070] In the embodiments of the present disclosure, the following will be described by taking an example that the continuous period of a single TCONT includes four periods, and the bandwidth allocation information of each period is determined based on the traffic information of the previous two periods.

[0071] In the embodiments of the present disclosure, as shown in FIG. 4, the four periods include a first period T1, a second period T2, a third period T3 and a fourth period T4, wherein the fourth period T4 is the current period, and T1, T2 and T3 are a plurality of continuous periods before T4.

[0072] In the embodiments of the present disclosure, the different periods described above can include a first period T1 and a second period T2, and the second period T2 is located after the first period T1; the plurality of periods after the different periods described above can include a third period T3 and a fourth period T4, and the fourth period T4 is located after the third period T3; the traffic buffer information can include a first buffer traffic B1 of the first period T1 and a second buffer traffic B2 of the second period T2; and the bandwidth allocation information includes a third bandwidth R3 allocated by the third period T3 and a fourth bandwidth R4 allocated by the fourth period T4.

[0073] In the embodiments of the present disclosure, as shown in FIG. 4, the bandwidths corresponding to the first period T1, the second period T2, the third period T3 and the fourth period T4 are R1, R2, R3 and R4 respectively, and the corresponding buffers (i.e. buffer traffic) are B1, B2, B3 and B4 respectively.

[0074] In the embodiment of the present disclosure, as shown in FIG. 5, the amount of flow buffer information in different periods in consecutive periods is compared, and the amount of bandwidth allocation information in multiple periods after different periods in consecutive periods is compared, and whether there is a buffer flow backlog in the TCONT is determined according to the obtained first comparison result, including: comparing the size of the first buffer flow B1 and the second buffer flow B2 and the size of the third bandwidth R3 and the fourth bandwidth R4; in the case that the first buffer flow B1 is greater than 0, the second buffer flow B2 is greater than or equal to the first buffer flow B1, and the fourth bandwidth R4 is less than or equal to the third bandwidth R3, it is determined that there is a buffer flow backlog in the TCONT, and there is no excess bandwidth in the allocated bandwidth of the TCONT to handle the buffer flow backlog; in the case that the first buffer flow B1 is greater than 0, the second buffer flow B2 is greater than or equal to the first buffer flow B1, and the fourth bandwidth R4 is greater than the third bandwidth R3, it is determined that there is a buffer flow backlog in the TCONT, and there is excess bandwidth in the allocated bandwidth of the TCONT to handle the buffer flow backlog; in the case that the second buffer flow B2 is less than the first buffer flow B1 or the first buffer flow B1 and the second buffer flow B2 are both equal to zero, and the fourth bandwidth R4 is less than or equal to the third bandwidth R3, it is determined that there is no buffer flow backlog in the TCONT, and the allocated bandwidth of the TCONT is reduced; in the case that the second buffer flow B2 is less than the first buffer flow B1 or the first buffer flow B1 and the second buffer flow B2 are both equal to zero, and the fourth bandwidth R4 is greater than the third bandwidth R3, it is determined that there is no buffer flow backlog in the TCONT, and the allocated bandwidth of the TCONT is increased.

[0075] In the embodiment of the present disclosure, for example, when the buffer flow of a certain TCONT in the ONU gradually increases, that is, B2≥B1>0, if the allocated bandwidth R4<=R3 (R3 is the bandwidth allocated based on B2, and R4 is the bandwidth allocated based on B3), it indicates that there is no excess bandwidth in the allocated bandwidth of the TCONT to allocate more bandwidth to the TCONT to accelerate the processing of the backlog.

[0076] In the embodiment of the present disclosure, for example, when the buffer flow of a certain TCONT in the ONU gradually increases, that is, B2≥B1>0, if the allocated bandwidth R4>R3, it indicates that there is a buffer flow backlog, and there is excess bandwidth to allocate more to the TCONT to accelerate the processing of the backlog.

[0077] In the embodiment of the present disclosure, for example, when the buffer flow of a certain TCONT in the ONU gradually decreases or is 0, that is, B1>B2 or B1=B2=0, if the allocated bandwidth R4<=R3, it indicates that there is no buffer flow backlog, and the allocated bandwidth of the TCONT is reduced. Since there is no buffer flow backlog, the reduction of the allocated bandwidth of the TCONT will not affect the normal processing of the flow.

[0078] In the embodiments of the present disclosure, for example, when the buffer traffic of a certain TCONT in the ONU gradually decreases or is 0, that is, B1>B2 or B1=B2=0, if the allocated bandwidth R4>R3, it indicates that there is no buffer traffic backlog, and the bandwidth allocated to the TCONT increases, which indicates that there is idle bandwidth in the allocated bandwidth.

[0079] In the embodiments of the present disclosure, by the above scheme, it can be determined whether there is buffer traffic backlog in each TCONT in an ONU, and whether the single-frame multi-burst times of the TCONT need to be reduced can be determined according to the determination result of each TCONT.

[0080] In the embodiments of the present disclosure, reducing the single-frame multi-burst times or keeping the single-frame multi-burst times unchanged according to the obtained second determination result includes: in a case where the determination result of any one or more TCONTs in the ONU meets a second preset condition, reducing the single-frame multi-burst times of one or more TCONTs in all TCONTs or keeping the single-frame multi-burst times of all TCONTs unchanged under the constraint of a preset minimum number threshold.

[0081] In the embodiments of the present disclosure, the second preset condition can include: there is buffer traffic backlog in the TCONT, and there is no excess bandwidth in the allocated bandwidth of the TCONT to process the buffer traffic backlog.

[0082] In the embodiments of the present disclosure, as long as at least one TCONT in all TCONTs contained in one ONU meets the second preset condition that there is buffer traffic backlog in the TCONT, and there is no excess bandwidth in the allocated bandwidth of the TCONT to process the buffer traffic backlog, the following strategy can be directly executed on the TCONTs (any one or more, which can be part of the TCONTs or all the TCONTs, and is defined by the user according to the demand) contained in the ONU: reducing the single-frame multi-burst times of one or more TCONTs in all TCONTs or keeping the single-frame multi-burst times of all TCONTs unchanged under the constraint of a preset minimum number threshold.

[0083] The second scheme is introduced below.

[0084] In the embodiments of the present disclosure, in a case where it is determined by the foregoing embodiment scheme that any one or more TCONTs meet the second preset condition, it can be further detected whether the buffer traffic backlog of the any one or more TCONTs has been accelerated, and a strategy of adjusting the single-frame multi-burst times or keeping the single-frame multi-burst times unchanged is determined according to the detection result. The other embodiments are described in detail below.

[0085] In the embodiments of the present disclosure, in the case that the determination result of any one or more TCONTs in the ONU satisfies the condition that there is a backlog of buffered traffic in the TCONT and there is no excess bandwidth in the allocated bandwidth of the TCONT to handle the backlog of buffered traffic, the method can further include: detecting whether the backlog of buffered traffic in each TCONT that satisfies the condition that there is a backlog of buffered traffic in the TCONT and there is no excess bandwidth in the allocated bandwidth of the TCONT to handle the backlog of buffered traffic has been accelerated.

[0086] In the embodiments of the present disclosure, the buffered traffic information can further include: third buffered traffic in a third period and fourth buffered traffic in a fourth period; and the detecting whether the backlog of buffered traffic in each TCONT that satisfies the condition that there is a backlog of buffered traffic in the TCONT and there is no excess bandwidth in the allocated bandwidth of the TCONT to handle the backlog of buffered traffic has been accelerated can include: for each TCONT that satisfies the condition, performing the following operations: comparing the size of the third buffered traffic and the fourth buffered traffic in the TCONT; in the case that the third buffered traffic is greater than 0 and the fourth buffered traffic is greater than the third buffered traffic, determining that the backlog of buffered traffic in the TCONT has not been accelerated; and in the case that the fourth buffered traffic is less than or equal to the third buffered traffic, determining that the backlog of buffered traffic in the TCONT has been accelerated.

[0087] In the embodiments of the present disclosure, based on the above detection result, a second determination scheme for determining whether the number of single-frame multi-bursts can be reduced can be determined.

[0088] In the embodiments of the present disclosure, according to the obtained second determination result, the number of single-frame multi-bursts can be reduced or kept unchanged, which can include: in the case that the determination result of any one or more TCONTs in the ONU satisfies a third preset condition, reducing the number of single-frame multi-bursts of one or more TCONTs in all TCONTs of the ONU or keeping the number of single-frame multi-bursts of all TCONTs of the ONU unchanged under the constraint of a preset minimum number threshold.

[0089] In the embodiments of the present disclosure, the third preset condition can include: there is a backlog of buffered traffic in the TCONT, there is no excess bandwidth in the allocated bandwidth of the TCONT to handle the backlog of buffered traffic, and the backlog of buffered traffic in the TCONT has not been accelerated. In the embodiments of the present disclosure, through the above detection scheme, if it is detected that the backlog of buffered traffic in each TCONT that satisfies the second preset condition has been accelerated, it can be determined that there is no TCONT in all TCONTs of the ONU that satisfies the second preset condition, and the third preset condition is no longer satisfied, at this time, the number of single-frame multi-bursts of all TCONTs of the ONU can be kept unchanged.

[0090] In the embodiments of the present disclosure, if it is detected that all TCONTs satisfying the second preset condition still have at least one TCONT with backlog of cache traffic that is not processed at a high speed, it can be determined that all TCONTs contained in the ONU still have at least one TCONT satisfying the third preset condition, and at this time, the single-frame multi-burst frequency reduction strategy can be implemented, that is, under the constraint of the preset minimum single-frame multi-burst frequency threshold, the single-frame multi-burst frequency of one or more TCONTs of all TCONTs of the ONU is reduced or the single-frame multi-burst frequency of all TCONTs of the ONU is kept unchanged.

[0091] In the embodiments of the present disclosure, for example, when the cache traffic of a certain TCONT in the ONU gradually increases, that is, B2>B1>0, if the allocated bandwidth R4<=R3, it indicates that there is no remaining bandwidth to accelerate the processing of the backlog of the TCONT. At this time, if B4

[0092] In the embodiments of the present disclosure, for example, when the cache traffic of a certain TCONT in the ONU gradually increases, that is, B2>B1>0, if the allocated bandwidth R4<=R3, it indicates that there is no remaining bandwidth to accelerate the processing of the backlog of the TCONT. At this time, if 0

[0093] In the embodiments of the present disclosure, under the constraint of the preset minimum frequency threshold, reducing the single-frame multi-burst frequency of one or more TCONTs of the ONU or keeping the single-frame multi-burst frequency of all TCONTs of the ONU unchanged can include: determining whether the total number of currently set single-frame multi-burst frequencies of the ONU reaches the preset minimum frequency threshold; in the case where the total number of currently set single-frame multi-burst frequencies of the ONU does not reach the preset minimum frequency threshold, reducing the single-frame multi-burst frequency of one or more TCONTs of the ONU; in the case where the total number of currently set single-frame multi-burst frequencies of the ONU has reached the preset minimum frequency threshold, keeping the currently set single-frame multi-burst frequency of all TCONTs unchanged.

[0094] In the embodiments of the present disclosure, the minimum frequency threshold De1 can be defined according to requirements, and the detailed value of the minimum frequency threshold De1 is not limited.

[0095] In the embodiments of the present disclosure, the number of single-frame multi-bursts of one or more TCONTs in the ONU is reduced, including: in order of gradually increasing priority of the one or more TCONTs, the number of single-frame multi-bursts of each TCONT is reduced in turn.

[0096] In the embodiments of the present disclosure, when the number of single-frame multi-bursts of the TCONT in the ONU is reduced, the number of single-frame multi-bursts D of the TCONT with low priority can be reduced first, and in order of gradually increasing priority of the TCONT, the number of single-frame multi-bursts D of one or more TCONTs to be reduced is reduced in turn. In the case where the total number of single-frame multi-bursts has reached the minimum number threshold, the current number of single-frame multi-bursts D is kept unchanged.

[0097] In the embodiments of the present disclosure, the reduced number of single-frame multi-bursts D can be configured, for example, to reduce a first preset value, or to be halved, etc.

[0098] In the embodiments of the present disclosure, the method can further include: in the case where the first determination result of any one or more TCONTs in the ONU does not satisfy the first preset condition, and the second determination result of all TCONTs in the ONU does not satisfy the second preset condition or the third preset condition, the number of single-frame multi-bursts of all TCONTs in the ONU is kept unchanged.

[0099] In the embodiments of the present disclosure, for example, in the case where there is a backlog of buffered traffic in the TCONT, and there is excess bandwidth in the allocated bandwidth of the TCONT to handle the backlog of buffered traffic, the current number of single-frame multi-bursts can be kept unchanged, for example: when the buffered traffic of a certain TCONT in the ONU gradually increases, i.e. B2>B1>0, if the allocated bandwidth R4>R3, it means that there is a backlog of buffered traffic, and there is excess bandwidth to allocate to the TCONT to speed up the handling of the backlog. At this time, there is little difference between reducing and not reducing the number of single-frame multi-bursts, so the number of single-frame multi-bursts does not need to be reduced, and the current number of single-frame multi-bursts can be kept unchanged.

[0100] In step S13, the bandwidth is allocated to the ONU based on the determined number of single-frame multi-bursts.

[0101] In the embodiments of the present disclosure, the bandwidth can be allocated to the ONU based on the number of single-frame multi-bursts, which can be implemented by using the existing technology, and the detailed implementation scheme is not limited herein. For example, the bandwidth allocation module 12 can adjust the total allocatable bandwidth based on the burst number result output by the burst number decision module 11 (i.e. the finally determined number of single-frame multi-bursts according to the embodiments of the present disclosure), and allocate bandwidth to all ONUs based on the adjusted total allocatable bandwidth.

[0102] In step S14, the allocated bandwidth is sent to the ONU.

[0103] In the embodiments of the present disclosure, the bandwidth allocation module 12 can send the bandwidth mapping entry generation module 13 after the bandwidth allocation is completed, and the bandwidth mapping entry generation module 13 generates entries based on the bandwidth allocation result and the authorization entry decision result (i.e., the bandwidth allocation result based on the single-frame multi-burst number) and sends the final bandwidth allocation result to each ONU.

[0104] In the embodiments of the present disclosure, the present disclosure at least has the following advantages:

[0105] 1. The embodiments of the present disclosure adaptively determine the single-frame multi-burst number of the TCONT in the ONU by using the traffic buffer information of the ONU, the bandwidth allocation information of the OLT, the authorization entry (i.e., the maximum single-frame multi-burst number threshold and the minimum single-frame multi-burst number threshold), and the redundant resources such as the remaining bandwidth, which speeds up the response time of the service and thus improves the delay performance flexibly.

[0106] 2. The embodiments of the present disclosure can adaptively reduce the delay of different priority services in the PON system by fully utilizing the redundant resources, and the higher the priority of the service, the more the delay is reduced. Compared with the prior art, the embodiments of the present disclosure can realize the flexibility of the single-frame multi-burst number and further improve the delay performance.

[0107] The embodiments of the present disclosure also provide a bandwidth allocation device 100, as shown in FIG. 6, which can include: an acquisition module 101 configured to acquire traffic buffer information of an optical network unit (ONU) and bandwidth allocation information of an optical line terminal (OLT); a determination module 102 configured to determine a single-frame multi-burst number of a transmission container (TCONT) in the ONU based on the traffic buffer information and the bandwidth allocation information; an allocation module 103 configured to allocate bandwidth to the ONU based on the determined single-frame multi-burst number; and a sending module 104 configured to send the allocated bandwidth to the ONU.

[0108] In the embodiments of the present disclosure, any of the foregoing bandwidth allocation methods is applicable to the bandwidth allocation device, and thus will not be described again.

[0109] The embodiments of the present disclosure also provide an electronic device 200, as shown in FIG. 7, which can include: one or more processors 201; and a memory 202 having one or more computer programs stored thereon, wherein when the one or more computer programs are executed by the one or more processors 201, the one or more processors 201 implement the bandwidth allocation method.

[0110] In the embodiments of the present disclosure, the electronic device can include an OLT.

[0111] The embodiment of the present disclosure further provides a computer readable storage medium, wherein the computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the bandwidth allocation method.

[0112] The embodiment of the present disclosure further provides a computer program product, which comprises a computer program, and the computer program is executed by a processor to implement the bandwidth allocation method.

[0113] Those skilled in the art can understand that all or some of the function modules / units disclosed above can be implemented as software, firmware, hardware and their appropriate combinations.

[0114] 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 executed by several physical components in cooperation.

[0115] Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit (CPU), 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 is well 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, random access memory (RAM, more specifically SDRAM, DDR, etc.), read only memory (ROM), electrically erasable programmable read only memory (EEPROM), FLASH memory or other magnetic disk storage; compact disc read only memory (CD-ROM), digital versatile disc (DVD) or other optical disk storage; magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices; any other medium that can be used to store the desired information and that can be accessed by a computer. In addition, it is well known to those skilled in the art that communication media typically includes computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and can include any information delivery medium. The foregoing description of the exemplary embodiments of the present disclosure is provided for the purpose of illustration only and not for the purpose of limitation, and that various modifications within the scope of the present disclosure are possible from this detailed description. Accordingly, the exemplary embodiments of the present disclosure are defined only by the claims.

[0116] The present disclosure has disclosed example embodiments, and while specific terminology has been employed, it is merely in the service of a general descriptive purpose and should not be construed as limiting. In some instances, it will be apparent to those skilled in the art that features, characteristics, and / or elements described in connection with a particular embodiment can be used in conjunction with other embodiments unless otherwise explicitly stated. As such, those skilled in the art will appreciate that various changes can be made in form and detail without departing from the scope of the disclosure as set forth in the appended claims.

Claims

1. A bandwidth allocation method, comprising: obtaining traffic buffer information of an optical network unit (ONU) and bandwidth allocation information of an optical line terminal (OLT) ; determining a single frame multi-burst number of a transmission container (TCONT) in the ONU based on the traffic buffer information and the bandwidth allocation information; allocating bandwidth to the ONU based on the determined single frame multi-burst number; sending the allocated bandwidth to the ONU.

2. The bandwidth allocation method of claim 1, wherein, The determining a single frame multi-burst number of a TCONT in the ONU based on the traffic buffer information and the bandwidth allocation information comprises: determining, according to the bandwidth allocation information, whether an actual used bandwidth of each TCONT in the ONU is less than an allocated bandwidth calculated by adding a single frame multi-burst number, and determining, according to the traffic buffer information, whether there is traffic buffer in the TCONT, and increasing the single frame multi-burst number or keeping the single frame multi-burst number unchanged according to a first determination result; and / or determining, according to the bandwidth allocation information and the traffic buffer information, whether there is a traffic backlog in each TCONT in the ONU, and decreasing the single frame multi-burst number or keeping the single frame multi-burst number unchanged according to a second determination result.

3. The bandwidth allocation method of claim 2, wherein, The increasing the single frame multi-burst number or keeping the single frame multi-burst number unchanged according to the first determination result comprises: in a case where determination results of all the TCONTs in the ONU satisfy a first preset condition, increasing the single frame multi-burst number of one or more TCONTs of all the TCONTs in the ONU or keeping the single frame multi-burst number of all the TCONTs in the ONU unchanged under constraint of a preset maximum number threshold.

4. The bandwidth allocation method of claim 3, wherein, The first preset condition comprises: the actual used bandwidth of the TCONT is less than the allocated bandwidth calculated by adding the single frame multi-burst number; and there is no traffic buffer in the TCONT.

5. The bandwidth allocation method of claim 3, wherein, The increasing the single frame multi-burst number of one or more TCONTs of all the TCONTs in the ONU or keeping the single frame multi-burst number of all the TCONTs in the ONU unchanged under constraint of a preset maximum number threshold comprises: determining whether a total number of currently set single frame multi-burst numbers in the ONU reaches a preset maximum number threshold; in a case where the total number of the currently set single frame multi-burst numbers does not reach the preset maximum number threshold, increasing the single frame multi-burst number of one or more TCONTs in the ONU; in a case where the total number of the currently set single frame multi-burst numbers has reached the preset maximum number threshold, keeping the currently set single frame multi-burst number of all the TCONTs unchanged.

6. The bandwidth allocation method of claim 5, wherein, The increasing the single frame multi-burst number of one or more TCONTs in the ONU comprises: increasing the single frame multi-burst number of each TCONT in turn in an order of priority of the one or more TCONTs gradually decreasing.

7. The bandwidth allocation method of claim 2, wherein, The judging whether there is a backlog of buffered traffic in each TCONT in the ONU according to the bandwidth allocation information and the traffic buffer information comprises: in each preset continuous period of each TCONT, performing the following operations: comparing how much the traffic buffer information is between different periods in the continuous period, and comparing how much the bandwidth allocation information is between multiple periods after the different periods, and determining whether there is a backlog of buffered traffic in the TCONT according to the obtained first comparison result; wherein, the bandwidth allocation information of the multiple periods after the different periods is used to represent the bandwidth allocated based on the traffic buffer information of the different periods, the continuous period refers to a dynamic bandwidth allocation (DBA) period, and the continuous period includes a current period and multiple periods before the current period and continuous with the current period.

8. The bandwidth allocation method of claim 7, wherein, the different periods include a first period and a second period, and the second period is after the first period; the multiple periods after the different periods include a third period and a fourth period, and the fourth period is after the third period; the traffic buffer information includes first buffered traffic of the first period and second buffered traffic of the second period; the bandwidth allocation information includes third bandwidth allocated in the third period and fourth bandwidth allocated in the fourth period.

9. The bandwidth allocation method of claim 8, wherein, The comparing how much the traffic buffer information is between different periods in the continuous period, and comparing how much the bandwidth allocation information is between multiple periods after the different periods, and determining whether there is a backlog of buffered traffic in the TCONT according to the obtained first comparison result comprises: comparing the size of the first buffered traffic and the second buffered traffic and the size of the third bandwidth and the fourth bandwidth; in the case that the first buffered traffic is greater than 0, the second buffered traffic is greater than or equal to the first buffered traffic, and the fourth bandwidth is less than or equal to the third bandwidth, it is determined that there is a backlog of buffered traffic in the TCONT, and there is no excess bandwidth in the allocated bandwidth of the TCONT to handle the backlog of buffered traffic; in the case that the first buffered traffic is greater than 0, the second buffered traffic is greater than or equal to the first buffered traffic, and the fourth bandwidth is greater than the third bandwidth, it is determined that there is a backlog of buffered traffic in the TCONT, and there is excess bandwidth in the allocated bandwidth of the TCONT to handle the backlog of buffered traffic; in the case that the second buffered traffic is less than the first buffered traffic or both the first buffered traffic and the second buffered traffic are equal to zero, and the fourth bandwidth is less than or equal to the third bandwidth, it is determined that there is no backlog of buffered traffic in the TCONT, and the allocated bandwidth of the TCONT is reduced; In a case that the second buffered traffic is less than the first buffered traffic or the first buffered traffic and the second buffered traffic are both equal to zero, and the fourth bandwidth is greater than the third bandwidth, it is determined that there is no buffered traffic backlog in the TCONT, and the bandwidth allocated to the TCONT is increased.

10. The bandwidth allocation method of claim 9, wherein, The method further comprises: In a case that the judgment result of any one or more of the TCONTs in the ONU meets a second preset condition, the single-frame multi-burst number of one or more of all the TCONTs of the ONU is reduced or the single-frame multi-burst number of all the TCONTs of the ONU is kept unchanged under the constraint of a preset minimum number threshold.

11. The bandwidth allocation method of claim 10, wherein, The second preset condition comprises: There is buffered traffic backlog in the TCONT, and there is no excess bandwidth in the allocated bandwidth of the TCONT to process the buffered traffic backlog.

12. The bandwidth allocation method of claim 9, wherein, In a case that the judgment result of any one or more of the TCONTs in the ONU meets the condition that there is buffered traffic backlog in the TCONT, and there is no excess bandwidth in the allocated bandwidth of the TCONT to process the buffered traffic backlog, the method further comprises: detecting whether the buffered traffic backlog in each of the TCONTs meeting the condition that there is buffered traffic backlog in the TCONT, and there is no excess bandwidth in the allocated bandwidth of the TCONT to process the buffered traffic backlog has been processed at a high speed.

13. The bandwidth allocation method of claim 12, wherein, The traffic buffered information further comprises: third buffered traffic of a third period and fourth buffered traffic of a fourth period; The detection of whether the buffered traffic backlog in each of the TCONTs meeting the condition that there is buffered traffic backlog in the TCONT, and there is no excess bandwidth in the allocated bandwidth of the TCONT to process the buffered traffic backlog has been processed at a high speed comprises: for each of the TCONTs meeting the condition, the following operations are performed: Comparing the third buffered traffic and the fourth buffered traffic in the TCONT; In a case that the third buffered traffic is greater than 0, and the fourth buffered traffic is greater than the third buffered traffic, it is determined that the buffered traffic backlog in the TCONT has not been processed at a high speed; In a case that the fourth buffered traffic is less than or equal to the third buffered traffic, it is determined that the buffered traffic backlog in the TCONT has been processed at a high speed.

14. The bandwidth allocation method of claim 12, wherein, The method further comprises: In a case that the judgment result of any one or more of the TCONTs in the ONU meets a third preset condition, the single-frame multi-burst number of one or more of all the TCONTs of the ONU is reduced or the single-frame multi-burst number of all the TCONTs of the ONU is kept unchanged under the constraint of a preset minimum number threshold.

15. The bandwidth allocation method of claim 14, wherein, The third preset condition comprises: The TCONT has a backlog of buffered traffic, the TCONT has no excess bandwidth allocated to handle the backlog of buffered traffic, and the backlog of buffered traffic in the TCONT is not being expedited.

16. The bandwidth allocation method of claim 10 or 14, wherein, The method of reducing or keeping the single-frame multi-burst number of one or more TCONTs of the ONU unchanged under the constraint of a preset minimum number threshold, comprises: determining whether the total number of currently set single-frame multi-burst numbers of the ONU reaches a preset minimum number threshold; in the case that the total number of currently set single-frame multi-burst numbers of the ONU does not reach the preset minimum number threshold, reducing the single-frame multi-burst number of one or more TCONTs of the ONU; in the case that the total number of currently set single-frame multi-burst numbers of the ONU has reached the preset minimum number threshold, keeping the currently set single-frame multi-burst number of all the TCONTs unchanged.

17. The bandwidth allocation method of claim 16, wherein, The method of reducing the single-frame multi-burst number of one or more TCONTs of the ONU, comprises: reducing the single-frame multi-burst number of each TCONT in turn according to the order of increasing priority of one or more TCONTs.

18. The bandwidth allocation method of claim 2, wherein, The method further comprises: in the case that the first determination result of any one or more TCONTs of the ONU does not meet the first preset condition, and the second determination result of all the TCONTs of the ONU does not meet the second preset condition or the third preset condition, keeping the single-frame multi-burst number of all the TCONTs of the ONU unchanged. 19.A bandwidth allocation apparatus, comprising: an acquisition module configured to acquire traffic buffer information of an optical network unit (ONU) and bandwidth allocation information of an optical line terminal (OLT) ; a determination module configured to determine a single-frame multi-burst number of a transmission container (TCONT) of the ONU based on the traffic buffer information and the bandwidth allocation information; an allocation module configured to allocate bandwidth to the ONU based on the determined single-frame multi-burst number; a sending module configured to send the allocated bandwidth to the ONU. 20.An electronic device, comprising: one or more processors; a memory having one or more computer programs stored thereon, wherein the one or more computer programs, when executed by the one or more processors, cause the one or more processors to implement the bandwidth allocation method of any one of claims 1-18. 21.A computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the bandwidth allocation method of any one of claims 1-18. 22.A computer program product comprising a computer program, wherein the computer program, when executed by a processor, implements the bandwidth allocation method of any one of claims 1-18.

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