Dynamic subcarrier bandwidth resource allocation method and device and readable storage medium

Abstract

The invention relates to the technical field of passive optical networks, and discloses a dynamic subcarrier bandwidth resource allocation method and device and a readable storage medium, and the method comprises the steps: obtaining actual bandwidth requests in REPORT messages of all optical network units in a time-frequency division multiplexing coherent passive optical network where an optical line terminal is located; selecting a corresponding transmission container type for each service type corresponding to each actual bandwidth request; the method comprises the following steps: allocating fixed subcarrier bandwidths to fixed bandwidth transmission containers on all optical network units, and according to a sequence of a guaranteed bandwidth type, a non-guaranteed bandwidth type and a best effort bandwidth type, according to a preset bandwidth upper limit corresponding to each type of transmission container based on an earliest idle time principle; subcarrier bandwidths are distributed to all the transmission containers in all the types in sequence, and subcarrier bandwidth distribution is completed; according to the invention, under the condition that the resource utilization rate is not sacrificed, the time delay performance of the time delay sensitive service is obviously improved.

Description

Technical Field

[0001] The present invention relates to the technical field of passive optical networks, and in particular to a method, a device and a readable storage medium for dynamic subcarrier bandwidth resource allocation. Background Art

[0002] The International Telecommunication Union's telecommunications standardization group ITU-T has completed the standardization of the next-generation PON (i.e., higher-rate passive optical network) that provides a single-wavelength 50Gbps line rate. Since then, ITU-T has launched a new standard for the next-generation ultra-high-speed PON (VHSP), namely G.supp l.VHSP, which aims to provide a line rate of up to 100 / 200Gbps on a single wavelength. To achieve this goal, coherent passive optical network (CPON) is considered a promising solution due to its coherent detection technology with high sensitivity, advanced modulation format, and powerful digital signal processing (DSP) capabilities.

[0003] Time-frequency division multiplexing (TFDM) is a key access technology in CPON, which can be used to share upstream bandwidth between multiple optical network units (ONUs) in two dimensions: time slot and subcarrier. Time-frequency division multiplexing coherent passive optical network (TFDM-CPON) can achieve flexible switching between subcarriers through lasers based on digital subcarrier multiplexing technology, and 4×25G TFDM-CPON architecture has also been proposed. In addition, TFDM-CPON uses the existing REPORT / GRANT mechanism in ITU-T TDM-PON to dynamically allocate bandwidth to the transmission containers (T-CONTs) of optical network units (ONUs), and defines four types of T-CONTs for each ONU to carry services of different priorities, namely T-CONT 1, T-CONT 2, T-CONT 3 and T-CONT 4, among which T-CONT1 is assigned to the highest priority service, while T-CONT 4 has the lowest priority. For data frames belonging to the same T-CONT, they have the same priority and are scheduled by the first-in first-out (FIFO) strategy. In the existing mechanism, all delay-sensitive (TS) services are given equal priority.

[0004] To support delay-sensitive services, a simple approach in TFDM-CPON is to allocate a dedicated subcarrier to them to avoid scheduling delays. However, the traffic of delay-sensitive services may show high burst characteristics, so this solution of using dedicated subcarriers for each service will lead to resource waste, especially when the granularity of the subcarrier is coarse (such as the transmission rate of each subcarrier is 25Gb / s). Therefore, how to effectively allocate two-dimensional resources (i.e., time slots and subcarriers) to meet the delay requirements of TS services without sacrificing bandwidth utilization requires further research. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the problem in the prior art that it is impossible to meet the TS service delay requirement while ensuring bandwidth utilization.

[0006] In order to solve the above technical problems, the present invention provides a method for dynamic subcarrier bandwidth resource allocation, comprising:

[0007] Obtaining the actual bandwidth request in the REPORT message of all optical network units in the time-frequency division multiplexing coherent passive optical network where the optical line terminal is located;

[0008] Selecting a transmission container type corresponding to each service type in a REPORT message corresponding to each actual bandwidth request; the transmission container types include a fixed bandwidth type, a guaranteed bandwidth type, a non-guaranteed bandwidth type, and a best-effort bandwidth type;

[0009] A fixed subcarrier bandwidth is allocated to fixed bandwidth transmission containers on all optical network units, and then subcarrier bandwidth is allocated to each transmission container of each type in turn in the order of guaranteed bandwidth type, non-guaranteed bandwidth type and best effort bandwidth type, based on the earliest idle time principle and the preset bandwidth upper limit corresponding to each type of transmission container, to complete the subcarrier bandwidth resource allocation for all bandwidth requests in the time-frequency division multiplexing coherent passive optical network.

[0010] Preferably, the preset bandwidth upper limit corresponding to each type of transmission container is expressed as:

[0011]

[0012] Among them, AB j represents the preset bandwidth upper limit of the j-th type of transmission container, M represents the total number of subcarriers in the time-frequency division multiplexing coherent passive optical network, T c Indicates the preset polling period, T r Indicates the length of the REPORT message, S j represents the total number of optical network units that require the jth type of transmission container, w j Represents the weight of the j-th transmission container.

[0013] Preferably, the allocating subcarrier bandwidth to each transmission container of each type in sequence according to the order of guaranteed bandwidth type, non-guaranteed bandwidth type and best effort bandwidth type, based on the earliest idle time principle and the preset bandwidth upper limit corresponding to each type of transmission container, includes:

[0014] In the order of guaranteed bandwidth type, non-guaranteed bandwidth type, and best-effort bandwidth type, in each type:

[0015] Initialize the remaining total bandwidth to the total available bandwidth of the transport container of this type;

[0016] Based on the actual bandwidth request and the preset bandwidth upper limit in the REPORT message corresponding to each transmission container, the transmission time slot corresponding to each transmission container is obtained;

[0017] Get the end time of all subcarriers, sort all subcarriers from early to late, and allocate subcarrier bandwidth to all transmission containers of this type based on the earliest idle time principle.

[0018] And calculate the total remaining bandwidth for updates of this type.

[0019] Preferably, allocating subcarrier bandwidth to all transmission containers of the type and calculating the updated remaining total bandwidth of the type further includes:

[0020] If the actual bandwidth request of the transmission container is not greater than the preset bandwidth upper limit, the subcarrier bandwidth allocation for the transmission container is completed;

[0021] If the actual bandwidth request of the transmission container is greater than the preset bandwidth upper limit, based on the equal distribution principle, the updated remaining total bandwidth of the type corresponding to the transmission container is evenly distributed to all transmission containers whose actual bandwidth requests are greater than the preset bandwidth upper limit, thereby completing the subcarrier bandwidth allocation for the transmission container.

[0022] Preferably, the subcarrier bandwidth allocated to the transmission container is expressed as:

[0023] If the actual bandwidth request of the jth type of transmission container in the i-th optical network unit is not greater than the preset bandwidth upper limit, the subcarrier bandwidth allocated to it is expressed as: G i,j =min(R i,j ,AB j );

[0024] If the actual bandwidth request of the jth type of transmission container in the i-th optical network unit is greater than the preset bandwidth upper limit, the subcarrier bandwidth allocated to it is expressed as:

[0025] Among them, R i,j represents the actual bandwidth request of the j-th transport container, AB j represents the preset bandwidth upper limit of the j-th type of transmission container, |U j | indicates the total number of transmission containers whose actual bandwidth request is greater than the preset bandwidth upper limit, BL j Indicates the updated remaining total bandwidth of the type corresponding to the j-th transport container.

[0026] Preferably, the total available bandwidth of the transport container is expressed as:

[0027] BM j =S j ×AB j ;

[0028] Among them, BM j represents the total available bandwidth of the jth type of transport container, S j represents the total number of optical network units containing the jth type of transmission container, AB j Indicates the preset bandwidth upper limit of the j-th type of transmission container.

[0029] Preferably, the end time of the subcarrier is expressed as:

[0030] F m =ST i,j +G i,j +T g ;

[0031] Among them, F m Indicates the end time of the mth subcarrier, 1≤m≤M, M represents the total number of subcarriers in the TFD-CPON; ST i,j represents the start time of the jth type of transmission container in the i-th optical network unit, G i,j represents the subcarrier bandwidth allocated to the jth type of transmission container in the i-th optical network unit, T g Indicates the preset protection time.

[0032] Preferably, based on the round-trip propagation time from the optical network unit to the optical line terminal and the end time of the subcarrier, the start time of the j-th type of transmission container in the ith optical network unit is updated, expressed as:

[0033] ST i,j =max(t+RTT i ,F m );

[0034] Where t represents the authorization time of the jth type of transmission container in the i-th optical network unit, RTT i represents the round-trip propagation time from the ith optical network unit to the optical line terminal, F m Indicates the end time of the mth subcarrier.

[0035] This embodiment provides a dynamic subcarrier bandwidth resource allocation device, including:

[0036] A bandwidth request acquisition module is used to obtain actual bandwidth requests in REPORT messages of all optical network units in the time-frequency division multiplexing coherent passive optical network where the optical line terminal is located;

[0037] A type acquisition module, used to select a transmission container type corresponding to each service type in a REPORT message corresponding to each actual bandwidth request; the transmission container types include a fixed bandwidth type, a guaranteed bandwidth type, a non-guaranteed bandwidth type and a best-effort bandwidth type;

[0038] The subcarrier bandwidth allocation module is used to allocate fixed subcarrier bandwidth to fixed bandwidth transmission containers on all optical network units, and then allocate subcarrier bandwidth to each transmission container of each type in turn according to the order of guaranteed bandwidth type, non-guaranteed bandwidth type and best effort bandwidth type, based on the earliest idle time principle and the preset bandwidth upper limit corresponding to each type of transmission container, to complete the subcarrier bandwidth resource allocation for all bandwidth requests in the time-frequency division multiplexing coherent passive optical network.

[0039] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps in the dynamic subcarrier bandwidth resource allocation method as described above are implemented.

[0040] The above technical solution of the present invention has the following beneficial effects compared with the prior art:

[0041] The dynamic subcarrier bandwidth resource allocation method described in the present invention utilizes the fast switching characteristics of subcarriers in a time-frequency division multiplexing coherent passive optical network, and flexibly allocates subcarrier bandwidth for REPORT messages in all optical network units based on the priority of the transmission container and according to the transmission container granularity; and when allocating subcarrier bandwidth based on the priority of the transmission container, the present application allocates fixed bandwidth to the fixed bandwidth transmission container with the highest priority, which can ensure that key services can always obtain sufficient bandwidth resources, thereby ensuring the service quality of the service; at the same time, the fixed bandwidth allocation method is relatively simple in technology, and since the need for dynamic adjustment is reduced, the complexity and cost of network maintenance are also reduced. The present application is divided by the type of transmission container, and subcarrier bandwidth is allocated to multiple types in turn according to the priority of the transmission container type, so that the data transmission of delay-sensitive services does not require long queue waiting, and the delay performance of delay-sensitive services is significantly improved without sacrificing resource utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein

[0043] Figure 1 It is a schematic diagram of the subcarrier allocation mechanism based on the optical network unit granularity;

[0044] Figure 2 It is a schematic diagram of a subcarrier allocation mechanism based on transmission container granularity provided by the present invention;

[0045] Figure 3 It is a flowchart of the steps of the dynamic subcarrier bandwidth resource allocation method provided by the present invention;

[0046] Figure 4 It is a specific flow chart of subcarrier bandwidth allocation provided by the present invention;

[0047] Figure 5 is a comparison diagram of average frame delays of the present invention and the method based on ONU granularity under different service types provided by the present invention;

[0048] Figure 6 It is a schematic diagram comparing the cumulative distribution function CDF of T2 data frame delay under low network load (0.3) provided by the present invention and the method based on ONU granularity;

[0049] Figure 7 It is a schematic diagram comparing the cumulative distribution function CDF of T2 data frame delay under high network load (0.9) provided by the present invention and the method based on ONU granularity;

[0050] Figure 8 It is a schematic diagram comparing the uplink bandwidth utilization performance of the present invention and the method based on ONU granularity provided by the present invention. DETAILED DESCRIPTION

[0051] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0052] In a single scheduling cycle based on the offline scheduling architecture, the optical line terminal OLT collects the bandwidth request information of all optical network units (ONUs) and then schedules it on four subcarriers. The entire allocation problem can be compared to the problem of splitting items into packets. The four subcarriers are equivalent to four backpacks, which are used to assemble the data of the optical network units (ONUs). The data that all optical network units (ONUs) need to transmit is equivalent to splittable items that can be scheduled on a single or multiple backpacks. However, the transmission of the data of the optical network units (ONUs) on different subcarriers will cause different delay effects. First, the subcarrier allocation problem is modeled and analyzed.

[0053] Reference Figure 1The figure shows a schematic diagram of the subcarrier allocation mechanism based on the optical network unit granularity, where each ONU is allocated a time slot on the subcarrier. The length of the time slot is determined by its demand and weight, and the subcarrier selects the currently available subcarrier with the most remaining time slots based on the First-Fit principle. However, this scheme allocates time slots based on the ONU granularity and does not consider the QoS (quality of service) requirements of different services, which may affect the latency performance of some TS services. Figure 1 In the example, ONU 1-4 is sequentially allocated to four subcarriers (i.e., SC 1-4). Since SC-3 is the first subcarrier to be idle, ONU 5 is allocated to SC-3. However, this solution causes the delay-sensitive data in the buffer of ONU 5 to be transmitted at the end of the polling queue. The data from ONU 5 needs to wait for the time elapsed after the data from ONU 3 is transmitted, i.e., T TS Therefore, the delay-sensitive data in the lagging ONU will experience higher delay, making it difficult to meet its delay requirements, especially when there are a large number of ONUs.

[0054] Reference Figure 2 As shown in the figure, it is a schematic diagram of the subcarrier allocation mechanism based on the transmission container granularity; the transmission container T-CONT 1 (i.e., T-1,1, T-2,1, T-3,1, T-4,1, T-5,1) of all ONUs has the highest priority time slot and subcarrier. Subsequently, the transmission containers T-CONT 2, 3, and 4 are allocated in the next round of polling in descending order of priority. In each round of allocation, the subcarrier allocation is still carried out according to the principle of the earliest idle time. It can be found that compared with the allocation mechanism based on the ONU granularity, the subcarrier allocation mechanism based on the transmission container T-CONT granularity has a shorter T TS , so that the delay-sensitive data in ONU 5 can get the transmission opportunity earlier. Therefore, the dynamic subcarrier bandwidth allocation mechanism based on the transmission container T-CONT granularity can provide services for high priority as soon as possible, especially for TS services.

[0055] This embodiment is based on the above-mentioned transmission container granularity, referring to Figure 3 As shown, the step flow chart of the dynamic subcarrier bandwidth resource allocation method provided by the present invention includes:

[0056] S101: Acquire actual bandwidth requests in REPORT messages of all optical network units in a time-frequency division multiplexing coherent passive optical network where an optical line terminal is located;

[0057] S102: Selecting a transmission container type corresponding to each service type in a REPORT message corresponding to each actual bandwidth request; the transmission container types include a fixed bandwidth type, a guaranteed bandwidth type, a non-guaranteed bandwidth type, and a best-effort bandwidth type;

[0058] S103: Allocate a fixed subcarrier bandwidth to fixed bandwidth transmission containers on all optical network units;

[0059] S104: Allocate subcarrier bandwidth to each transmission container of each type in turn according to the order of guaranteed bandwidth type, non-guaranteed bandwidth type and best effort bandwidth type, based on the earliest idle time principle and the preset bandwidth upper limit corresponding to each type of transmission container, and complete the subcarrier bandwidth resource allocation for all bandwidth requests in the time-frequency division multiplexing coherent passive optical network.

[0060] In the embodiment of the present invention, the preset bandwidth upper limit corresponding to each type of transmission container is expressed as:

[0061]

[0062] Among them, AB j represents the preset bandwidth upper limit of the j-th type of transmission container, M represents the total number of subcarriers in the time-frequency division multiplexing coherent passive optical network, T c Indicates the preset polling period, T r Indicates the length of the REPORT message, S j represents the total number of optical network units that require the jth type of transmission container, w j Represents the weight of the j-th transmission container.

[0063] By setting a corresponding preset bandwidth limit for each type of transmission container, it is ensured that a certain type of transmission container does not occupy too much bandwidth, preventing a transmission container from occupying too much bandwidth and affecting the transmission of other transmission containers, thereby ensuring resource utilization.

[0064] Reference Figure 4 As shown, it is a specific flow chart of subcarrier bandwidth allocation; in step S104, subcarrier bandwidth allocation includes: in the order of guaranteed bandwidth waiting type, non-guaranteed bandwidth type and best effort bandwidth type, in each type:

[0065] S104-1: Initialize the remaining total bandwidth to the total available bandwidth of the transport container of this type;

[0066] The total available bandwidth for the transport container, denoted as: BM j =S j ×AB j ; Among them, BM j represents the total available bandwidth of the jth type of transport container, Sj represents the total number of optical network units containing the jth type of transmission container, AB j Indicates the preset bandwidth upper limit of the j-th type of transmission container.

[0067] S104-2: Based on the actual bandwidth request and the preset bandwidth upper limit in the REPORT message corresponding to each transmission container, obtain the transmission time slot corresponding to each transmission container;

[0068] S104-3: Obtain the end time of all subcarriers, sort all subcarriers from early to late, allocate subcarrier bandwidth to all transmission containers of this type based on the earliest idle time principle, and calculate the updated remaining total bandwidth of this type.

[0069] The end time of the subcarrier is expressed as: F m =ST i,j +G i,j +T g Among them, F m Indicates the end time of the mth subcarrier, 1≤m≤M, M represents the total number of subcarriers in the TFD-CPON; ST i,j represents the start time of the jth type of transmission container in the i-th optical network unit, G i,j represents the subcarrier bandwidth allocated to the jth type of transmission container in the i-th optical network unit, T g Indicates the preset protection time.

[0070] Among them, based on the round-trip propagation time from the optical network unit to the optical line terminal and the end time of the subcarrier, the start time of the jth type of transmission container in the ith optical network unit is updated, which is expressed as: ST i,j =max(t+RTT i ,F m );t represents the authorization time of the jth type of transmission container in the i-th optical network unit, RTT i represents the round-trip propagation time from the ith optical network unit to the optical line terminal, F m Indicates the end time of the mth subcarrier.

[0071] In step S104-3, if the actual bandwidth request of the transmission container is not greater than the preset bandwidth upper limit, the subcarrier bandwidth allocation to the transmission container is completed; if the actual bandwidth request of the transmission container is greater than the preset bandwidth upper limit, based on the equal distribution principle, the updated remaining total bandwidth of the type corresponding to the transmission container is evenly distributed to all transmission containers whose actual bandwidth requests are greater than the preset bandwidth upper limit, and the subcarrier bandwidth allocation to the transmission container is completed.

[0072] Specifically, the subcarrier bandwidth allocated to the transmission container is expressed as:

[0073] If the actual bandwidth request of the jth type of transmission container in the i-th optical network unit is not greater than the preset bandwidth upper limit, the subcarrier bandwidth allocated to it is expressed as: G i,j =min(R i,j ,AB j );

[0074] If the actual bandwidth request of the jth type of transmission container in the i-th optical network unit is greater than the preset bandwidth upper limit, the subcarrier bandwidth allocated to it is expressed as:

[0075] Among them, R i,j represents the actual bandwidth request of the j-th transport container, AB j represents the preset bandwidth upper limit of the j-th type of transmission container, |Uj| represents the total number of transmission containers whose actual bandwidth request is greater than the preset bandwidth upper limit, and BL j Indicates the updated remaining total bandwidth of the type corresponding to the j-th transport container.

[0076] The embodiment of the present invention takes into account that the fixed bandwidth type transmission container T-CONT 1 adopts a fixed bandwidth allocation method and lacks the process of reporting buffer status report information, and here the guaranteed bandwidth type T-CONT 2 is taken as the highest priority. The optical line terminal first polls the T-CONT with the highest priority (T-CONT 2), and then polls the non-guaranteed bandwidth type T-CONT 3 and the best effort bandwidth type T-CONT 4 in descending order of priority. In each polling cycle, after receiving all REPORT messages from each ONUs, the OLT will collect the actual bandwidth request of the jth type T-CONT of the i-th ONU and allocate subcarrier bandwidth for it.

[0077] In this embodiment, for each round of subcarrier allocation, DSBA-TG authorizes the earliest idle subcarrier among all available subcarriers, that is, the OLT first selects the subcarrier with the shortest transmission completion time and allocates it to the time slot of the jth T-CONT of the ith ONU; after calculating the time slot of the jth T-CONT of the ith ONU, the remaining bandwidth will be further reused. If the time slot of the jth T-CONT of the ith ONU cannot meet the needs of the T-CONT, the T-CONT is added to the index set of T-CONTs of the same type that meet the request, and then the remaining bandwidth is allocated to it using the equal sharing principle, and updated to the bandwidth allocated to the jth T-CONT in the ith ONU; when allocating bandwidth, all subcarriers are arranged in ascending order according to their start time. If the start time of the subcarrier is earlier than t+RTT i (t is the authorization time, RTT i is the round-trip propagation delay from the ith ONU to the OLT), then we need to calculate the RTTi Adjust to avoid conflicts. If multiple subcarriers have the same start time, the first subcarrier in the subcarrier order will be considered for grant allocation. For subcarrier allocation before each round of bandwidth allocation, the earliest idle subcarrier principle adopted is based on the end time of the subcarrier, and the subcarrier information of the jth T-CONT allocated to the i-th ONU is expressed as: i,j =argmin{F m}; After that, you can prepare to start the next round of subcarrier and bandwidth allocation for the next T-CONT type. The next round of T-CONT allocation follows the same process.

[0078] Based on the above embodiments, in the embodiments of the present invention, Python simulation is used to evaluate the performance of the dynamic subcarrier bandwidth resource allocation method proposed in the present invention, and the allocation algorithm based on ONU granularity is used as a benchmark for comparison.

[0079] The simulation of this embodiment is based on an offline scheduling framework, and considers a 4×25G TFDM-CPON environment consisting of 1 OLT and 512 ONUs, each of which contains 4 different T-CONTs. The physical distance between the ONU and the OLT is set to 20 kilometers. Based on the calculation of 5us per kilometer, the round-trip propagation delay of each ONU is 200us. The processing time is set to 35us. The arrival time of the traffic generated by the ONU follows a Poisson process, and the generated data frames are Ethernet frames. After encapsulation using the XGEM encapsulation method, the size of the XGEM frame is between 72 bytes and 1526 bytes. A protection time of 0.2058us is introduced between two upstream bursts. Due to the fixed bandwidth allocated to T-CONT 1, this type of performance is not evaluated in the simulation. This embodiment increases the traffic received by each T-CONT 2 (T2) in the ONU to 40%, while the other three T-CONTs each account for 20%. TS services are concentrated on T2, and its latency requirement is 0.8ms.

[0080] Reference Figure 5As shown, it is a comparison chart of the average frame delay of the present invention and the method based on ONU granularity under different service types. For T2, it can be seen that the dynamic subcarrier bandwidth resource allocation method DSBA-TG provided by the present invention has a lower delay compared with the benchmark, especially after the load exceeds 0.6. When the load is 0.9, the delay is reduced by 82.23%. For T3 and T4, the delay performance of the two algorithms is basically similar. After the load exceeds 0.7, the delay of DSBA-TG is slightly higher than that of Benchmark. This is because under DSBA-TG, the data frames of T2 obtain an earlier transmission opportunity, while the data frames of T3 and T4 need to wait for the previous T-CONT type before they can start transmission. From the simulation results, DSBA-TG can significantly improve the delay performance of the TS service contained in T2, while the delay performance of T3 and T4 is not significantly affected.

[0081] Reference Figure 6 FIG. 1 is a schematic diagram showing a comparison of the cumulative distribution function CDF of the T2 data frame delay of the present invention and the method based on ONU granularity under low network load (0.3); Figure 7 As shown, it is a schematic diagram comparing the cumulative distribution function CDF of T2 data frame delay under high network load (0.9) between the present invention and the method based on ONU granularity. When the load is 0.3, the performance of the two algorithms is very similar, the delay range of Benchmark is 0.37ms to 1.10ms, and the delay range of DSBA-TG is 0.37ms to 0.88ms. This is because the data frames received by the ONU in each polling cycle can be transmitted immediately in the next polling cycle when the load is 0.3, and the queuing delay is low. When the load is 0.9, the delay range of Benchmark is 0.37ms to 1.91ms, while the delay range of DSBA-TG is 0.38ms to 1.31ms, which results in 81.75% and 98.64% of delay-sensitive data frames meeting their delay requirements under Benchmark and DSBA-TG, respectively. Therefore, combined with Figure 6 and Figure 7 , indicating that DSBA-TG can better support TS services, especially under high load, and the latency performance can be improved by up to 32.5% compared with Benchmark.

[0082] Reference Figure 8As shown, it is a schematic diagram comparing the uplink bandwidth utilization performance of the present invention and the method based on ONU granularity; as the load increases, the bandwidth utilization of both algorithms shows an upward trend, reaching a maximum of about 94%, thereby providing a higher level of system utilization. This is because Benchmark only schedules each ONU once in each scheduling cycle, so each ONU only generates an average protection time overhead. In contrast, DSBA-TG allows multiple rounds of allocation scheduling for each ONU based on T-CONT priority within one scheduling cycle, which increases the protection time overhead. However, the remaining bandwidth allocation strategy in the DSBA-TG algorithm can achieve better bandwidth utilization to a certain extent. Therefore, despite facing more protection time overhead, the bandwidth utilization of DSBA-TG is not lower than that of Benchmark. Therefore, DSBA-TG can be fully adapted to TFDM-CPON with larger user connections.

[0083] Based on the above embodiment, an embodiment of the present invention provides a dynamic subcarrier bandwidth resource allocation device, which may include:

[0084] The bandwidth request acquisition module 100 is used to acquire the actual bandwidth request in the REPORT message of all optical network units in the time-frequency division multiplexing coherent passive optical network where the optical line terminal is located;

[0085] The type acquisition module 200 is used to select a transmission container type corresponding to each service type in the REPORT message corresponding to each actual bandwidth request; the transmission container type includes a fixed bandwidth type, a guaranteed bandwidth type, a non-guaranteed bandwidth type and a best-effort bandwidth type;

[0086] The subcarrier bandwidth allocation module 300 is used to allocate fixed subcarrier bandwidth to fixed bandwidth transmission containers on all optical network units, and then allocate subcarrier bandwidth to each transmission container of each type in turn according to the order of guaranteed bandwidth type, non-guaranteed bandwidth type and best effort bandwidth type, based on the earliest idle time principle and the preset bandwidth upper limit corresponding to each type of transmission container, to complete the subcarrier bandwidth resource allocation for all bandwidth requests in the time-frequency division multiplexing coherent passive optical network.

[0087] The dynamic subcarrier bandwidth resource allocation device of this embodiment is used to implement the aforementioned dynamic subcarrier bandwidth resource allocation method. Therefore, the specific implementation method of the dynamic subcarrier bandwidth resource allocation device can be seen in the embodiment part of the dynamic subcarrier bandwidth resource allocation method in the previous text. For example, the bandwidth request acquisition module 100 and the type acquisition module 200 are respectively used to implement steps S101 and S102 in the above-mentioned dynamic subcarrier bandwidth resource allocation method; the subcarrier bandwidth allocation module 300 is used to implement steps S103 and S104 in the above-mentioned dynamic subcarrier bandwidth resource allocation method. Therefore, its specific implementation method can refer to the description of the corresponding embodiments of each part, which will not be repeated here.

[0088] Based on the above embodiments, an embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps in the dynamic subcarrier bandwidth resource allocation method as described above are implemented.

[0089] The dynamic subcarrier bandwidth resource allocation method described in the present invention utilizes the fast switching characteristics of subcarriers in a time-frequency division multiplexing coherent passive optical network, and flexibly allocates subcarrier bandwidth for REPORT messages in all optical network units based on the priority of the transmission container and according to the transmission container granularity; and when allocating subcarrier bandwidth based on the priority of the transmission container, the present application allocates fixed bandwidth to the fixed bandwidth transmission container with the highest priority, which can ensure that key services can always obtain sufficient bandwidth resources, thereby ensuring the service quality of the service; at the same time, the fixed bandwidth allocation method is relatively simple in technology, and since the need for dynamic adjustment is reduced, the complexity and cost of network maintenance are also reduced. The present application is divided by the type of transmission container, and subcarrier bandwidth is allocated to multiple types in turn according to the priority of the transmission container type, so that the data transmission of delay-sensitive services does not require long queue waiting, and the delay performance of delay-sensitive services is significantly improved without sacrificing resource utilization.

[0090] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0091] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0092] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0093] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0094] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A method for dynamic subcarrier bandwidth resource allocation, characterized in that: Applied to optical line terminals, including: Obtaining the actual bandwidth request in the REPORT message of all optical network units in the time-frequency division multiplexing coherent passive optical network where the optical line terminal is located; Selecting a transmission container type corresponding to each service type in a REPORT message corresponding to each actual bandwidth request; the transmission container types include a fixed bandwidth type, a guaranteed bandwidth type, a non-guaranteed bandwidth type, and a best-effort bandwidth type; A fixed subcarrier bandwidth is allocated to fixed bandwidth transmission containers on all optical network units, and then subcarrier bandwidth is allocated to each transmission container of each type in turn in the order of guaranteed bandwidth type, non-guaranteed bandwidth type and best effort bandwidth type, based on the earliest idle time principle and the preset bandwidth upper limit corresponding to each type of transmission container, to complete the subcarrier bandwidth resource allocation for all bandwidth requests in the time-frequency division multiplexing coherent passive optical network.

2. The method for dynamic subcarrier bandwidth resource allocation according to claim 1, characterized in that: The preset bandwidth upper limit corresponding to each type of transmission container is expressed as: Among them, AB j represents the preset bandwidth upper limit of the j-th type of transmission container, M represents the total number of subcarriers in the time-frequency division multiplexing coherent passive optical network, T c Indicates the preset polling period, T r Indicates the length of the REPORT message, S j represents the total number of optical network units that require the jth type of transmission container, w j Represents the weight of the j-th transmission container.

3. The method for dynamic subcarrier bandwidth resource allocation according to claim 1, characterized in that: The allocating subcarrier bandwidth to each transmission container of each type in sequence according to the order of guaranteed bandwidth type, non-guaranteed bandwidth type and best effort bandwidth type, based on the earliest idle time principle and the preset bandwidth upper limit corresponding to each type of transmission container, includes: In the order of guaranteed bandwidth type, non-guaranteed bandwidth type, and best-effort bandwidth type, in each type: Initialize the remaining total bandwidth to the total available bandwidth of the transport container of this type; Based on the actual bandwidth request and the preset bandwidth upper limit in the REPORT message corresponding to each transmission container, the transmission time slot corresponding to each transmission container is obtained; Get the end time of all subcarriers, sort all subcarriers from early to late, allocate subcarrier bandwidth to all transmission containers of this type based on the earliest idle time principle, and calculate the updated remaining total bandwidth of this type.

4. The method for dynamic subcarrier bandwidth resource allocation according to claim 3, characterized in that: Allocate subcarrier bandwidth for all transport containers of this type and calculate the updated remaining total bandwidth of this type, including: If the actual bandwidth request of the transmission container is not greater than the preset bandwidth upper limit, the subcarrier bandwidth allocation for the transmission container is completed; If the actual bandwidth request of the transmission container is greater than the preset bandwidth upper limit, based on the equal distribution principle, the updated remaining total bandwidth of the type corresponding to the transmission container is evenly distributed to all transmission containers whose actual bandwidth requests are greater than the preset bandwidth upper limit, thereby completing the subcarrier bandwidth allocation for the transmission container.

5. The method for dynamic subcarrier bandwidth resource allocation according to claim 4, characterized in that: The subcarrier bandwidth allocated to the transmission container is expressed as: If the actual bandwidth request of the jth type of transmission container in the i-th optical network unit is not greater than the preset bandwidth upper limit, the subcarrier bandwidth allocated to it is expressed as: G i,j =min(R i,j ,AB j ); If the actual bandwidth request of the jth type of transmission container in the i-th optical network unit is greater than the preset bandwidth upper limit, the subcarrier bandwidth allocated to it is expressed as: Among them, R i,j represents the actual bandwidth request of the j-th transport container, AB j represents the preset bandwidth upper limit of the j-th type of transmission container, |U j | indicates the total number of transmission containers whose actual bandwidth request is greater than the preset bandwidth upper limit, BL j Indicates the updated remaining total bandwidth of the type corresponding to the j-th transport container.

6. The method for dynamic subcarrier bandwidth resource allocation according to claim 3, characterized in that: The total available bandwidth for transport containers, expressed as: BM j =S j ×AB j ; Among them, BM j represents the total available bandwidth of the jth type of transport container, S j represents the total number of optical network units containing the jth type of transmission container, AB j Indicates the preset bandwidth upper limit of the j-th type of transmission container.

7. The method for dynamic subcarrier bandwidth resource allocation according to claim 3, characterized in that: The end time of the subcarrier is expressed as: F m =ST i,j +G i,j +T g ; Among them, F m Indicates the end time of the mth subcarrier, 1≤m≤M, M represents the total number of subcarriers in the TFD-CPON; ST i,j represents the start time of the jth type of transmission container in the i-th optical network unit, G i,j represents the subcarrier bandwidth allocated to the jth type of transmission container in the i-th optical network unit, T g Indicates the preset protection time.

8. The method for dynamic subcarrier bandwidth resource allocation according to claim 7, characterized in that: Based on the round-trip propagation time from the optical network unit to the optical line terminal and the end time of the subcarrier, the start time of the jth type of transmission container in the ith optical network unit is updated, which is expressed as: ST i,j =max(t+RTT i ,F m ); Where t represents the authorization time of the jth type of transmission container in the i-th optical network unit, RTT i represents the round-trip propagation time from the ith optical network unit to the optical line terminal, F m Indicates the end time of the mth subcarrier.

9. A dynamic subcarrier bandwidth resource allocation device, characterized in that: include: A bandwidth request acquisition module is used to obtain actual bandwidth requests in REPORT messages of all optical network units in the time-frequency division multiplexing coherent passive optical network where the optical line terminal is located; A type acquisition module, used to select a transmission container type corresponding to each service type in a REPORT message corresponding to each actual bandwidth request; the transmission container types include a fixed bandwidth type, a guaranteed bandwidth type, a non-guaranteed bandwidth type and a best-effort bandwidth type; The subcarrier bandwidth allocation module is used to allocate fixed subcarrier bandwidth to fixed bandwidth transmission containers on all optical network units, and then allocate subcarrier bandwidth to each transmission container of each type in turn according to the order of guaranteed bandwidth type, non-guaranteed bandwidth type and best effort bandwidth type, based on the earliest idle time principle and the preset bandwidth upper limit corresponding to each type of transmission container, to complete the subcarrier bandwidth resource allocation for all bandwidth requests in the time-frequency division multiplexing coherent passive optical network.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps in the dynamic subcarrier bandwidth resource allocation method according to any one of claims 1 to 8 are implemented.

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