Method, device, equipment, terminal and storage medium for dynamic bandwidth allocation

Abstract

The present invention discloses a method, device, equipment, terminal and storage medium for dynamic bandwidth allocation, which belongs to the field of power system communication technology. The method includes the following steps: real-time online acquisition of bandwidth demand information of each ONU in the PON system, the bandwidth demand information including the priority of each service in the ONU and its bandwidth demand; based on the bandwidth demand information, allocating and granting bandwidth to each service in all ONUs; based on the size of the bandwidth allocated to each service in the ONU, dynamically allocating the transmission window of the next cycle to each service in all ONUs. The present invention performs group scheduling on the data received by the optical terminal and the wireless terminal, which solves the problem that it is difficult to simultaneously meet the differences in the demands of multiple types of services in the distributed photovoltaic scenario and it is difficult to guarantee the deterministic delay of control services, so that the deterministic delay of control services can be guaranteed in priority while reducing the impact of different types of services such as burst traffic on the transmission performance of subsequent services.

Description

Technical Field

[0001] The present invention relates to a method, device, equipment, terminal and storage medium for dynamic bandwidth allocation, and in particular to a method and device for dynamic bandwidth allocation by integrating PON and wireless resources in a distributed photovoltaic scenario, belonging to the technical field of power system communication. Background Art

[0002] With the continuous grid connection of distributed renewable energy containing power electronic equipment, the operation mechanism and balance mode of the power grid have undergone profound changes.

[0003] First, the deployment environment of distributed photovoltaics is complex. Most distributed new energy construction is deployed in vast rural areas. The cost of directly accessing low-voltage distributed photovoltaics by optical fiber is extremely high. Secondly, distributed terminal access has the characteristics of diversified services, diversified communications, and local high-density services. When diversified services are carried, the communication requirements of different collection services and control services vary greatly, and differentiated communication services need to be provided. In addition, distributed resources under different distribution conditions in different regions have problems such as business volatility, resource heterogeneity, and difficulty in ensuring QoS.

[0004] How to reasonably schedule distributed resources with different network scales and different business characteristics is the main problem facing distributed networks. Therefore, how to reasonably schedule distributed resources in multi-business scenarios so that the network can meet the needs of various businesses at a lower cost is of great significance to distributed photovoltaic grid connection. Passive Optical Network (PON) has many advantages such as high bandwidth, easy expansion, and low cost due to its use of optical fiber transmission and unique passive characteristics, and has become one of the most popular communication methods in distributed photovoltaic communication networks. Therefore, the present invention relies on the architecture of passive optical networks and designs a method, device, equipment, terminal and storage medium for dynamic bandwidth allocation. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a method, device, equipment, terminal and storage medium for dynamic bandwidth allocation, which can meet the needs of low-cost and efficient transmission of diversified power services in different regions under the hybrid access mode of wireless and PON, and ensure the smoothness of data transmission and the stability of services.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] In a first aspect, an embodiment of the present invention provides a method for dynamic bandwidth allocation, comprising the following steps:

[0008] Obtaining bandwidth demand information of each ONU in the PON system in real time online, wherein the bandwidth demand information includes the priority of each service in the ONU and its bandwidth demand;

[0009] Based on the bandwidth demand information, allocating and granting bandwidth to each service in all ONUs;

[0010] Based on the size of the bandwidth allocated to each service in the ONU, the transmission window of the next cycle is dynamically allocated to each service in all ONUs.

[0011] As a possible implementation method of this embodiment, the services in the ONU include periodic delay-sensitive services, non-periodic delay-sensitive services and non-delay-sensitive services, the periodic delay-sensitive services and non-periodic delay-sensitive services are control services, and the non-delay-sensitive services are collected data services.

[0012] As a possible implementation of this embodiment, allocating and granting bandwidth to each service in all ONUs based on the bandwidth demand information includes:

[0013] For non-periodic delay-sensitive services, the size of the data packets that may arrive in the next DBA cycle is predicted based on the spatiotemporal traffic prediction method, and the bandwidth is allocated based on the prediction results;

[0014] For periodic delay-sensitive services, the bandwidth is allocated by static bandwidth allocation based on the bandwidth demand information;

[0015] For non-delay-sensitive services, bandwidth is granted in a dynamic bandwidth allocation manner based on the bandwidth demand information.

[0016] As a possible implementation of this embodiment, the method based on the spatiotemporal traffic prediction predicts the size of the data packet that may arrive in the next DBA cycle, and allocates the granted bandwidth according to the prediction result, including:

[0017] The bandwidth demand of the ONU in the n-1th DBA (Dynamically Bandwidth Assignment) cycle is brought into the spatiotemporal traffic prediction model to obtain the value of the size of the data packet that may arrive in the nth DBA cycle. This allows the data that may arrive in the ONU in the nth DBA cycle to be allocated in advance, thereby achieving bandwidth allocation.

[0018] As a possible implementation of this embodiment, the dynamically allocating the transmission window of the next cycle for each service in all ONUs based on the size of the bandwidth granted to each service in the ONU includes:

[0019] A DBA cycle is divided into independent sub-cycles, and different methods are used to allocate transmission windows for services within each sub-cycle; the head sub-cycle of the DBA cycle is sub-cycle 1, which is used to transmit delay-sensitive services, and the tail sub-cycle of the DBA cycle is sub-cycle 2, which is used to transmit non-delay-sensitive services. A spare sub-cycle is set between the delay-sensitive service transmission window and the non-delay-sensitive service transmission window to transmit non-periodic delay-sensitive services that are not fully transmitted in the delay-sensitive transmission window;

[0020] In sub-period 1, the ONUs are grouped according to the bandwidth requirements of the non-periodic delay-sensitive services, and transmission time slots are allocated to the delay-sensitive services in the ONUs according to the grouping results;

[0021] In sub-period 2, non-delay-sensitive services are transmitted according to the default transmission order, and periodic delay-sensitive services arriving in sub-period 2 are directly transmitted based on preemption.

[0022] As a possible implementation method of this embodiment, in sub-cycle 1, the transmission order of non-periodic delay-sensitive services is changed in a grouping manner. The group scheduling method of non-periodic delay-sensitive services is completed based on an improved genetic algorithm, and the ONUs in sub-cycle 1 are grouped according to the required bandwidth size of the non-periodic delay-sensitive services in each ONU in the historical K DBA cycles.

[0023] As a possible implementation of this embodiment, the packet scheduling method of the non-periodic delay-sensitive service is implemented based on an improved genetic algorithm, including:

[0024] The dynamic programming algorithm is used to narrow the scope of the genetic algorithm solution. After adding a certain amount of jitter to the optimal solution generated by the dynamic programming algorithm, it is brought into the genetic algorithm to form the optimal grouping method, which is as follows:

[0025] The ONUs are grouped by using a dynamic programming algorithm. Specifically, for each group, an ONU that has not joined the group is randomly selected as the initial value in the current group. The stability coefficient of the group is calculated in sequence when any ONU that has not joined the group is added to the current group in the current state. The ONU added when the stability coefficient is the smallest is selected as the ONU newly added to the group. The above ONU grouping process is repeated until the number of ONUs in the group reaches N / L, where N is the number of ONUs participating in the scheduling, and L is the number of ONU groups in sub-period 1.

[0026] After adding a certain jitter to the optimal grouping method generated by the dynamic programming algorithm, it is brought into the genetic algorithm as the initial input to find the grouping method with the smallest average stability coefficient of all groups in the non-uniform grouping, which is taken as the optimal grouping method. This grouping method is used as the transmission order of non-periodic services in sub-period 1.

[0027] As a possible implementation of this embodiment, allocating transmission time slots for delay-sensitive services in the ONU according to the grouping result includes:

[0028] According to the grouping result, sub-period 1 is divided into N / L transmission time slots. In K DBA cycles, the size of each transmission time slot remains unchanged.

[0029] In sub-period 1, the transmission time slot of the non-periodic delay-sensitive service in each group is before the transmission time slot of the periodic delay-sensitive service;

[0030] In each DBA cycle, the service transmission window is adjusted according to the service requirements of the current cycle.

[0031] As a possible implementation of this embodiment, in each DBA cycle, adjusting the transmission window of the service according to the service demand of the current cycle includes:

[0032] If the bandwidth required by all delay-sensitive services in the current DBA cycle is greater than the maximum bandwidth that can be transmitted in the transmission window, whether the transmission start time of the next packet needs to be changed is determined based on whether the delay demand of the ONU in the next DBA cycle can be met. If the delay demand of the ONU in the next DBA cycle still cannot be met after increasing the incremental bandwidth, the demand of the periodic delay-sensitive services in the group is prioritized;

[0033] If the required bandwidth of all delay-sensitive services in the current DBA period is less than the maximum bandwidth that the transmission window can transmit, the transmission start time of the next packet will not be changed. Instead, the transmission start time of the periodic delay-sensitive services and non-periodic delay-sensitive services in the current group can be changed according to the required bandwidth.

[0034] As a possible implementation of this embodiment, the principle of adjusting the transmission window of the delay-sensitive service is as follows: ensure that the size of the transmission window Unchanged, flexible adjustment based on the needs of latency-sensitive services and The size of is the transmission window size of non-periodic delay-sensitive services, which is determined by the average bandwidth required by non-periodic delay-sensitive services from period eK to period e-1. The transmission window size for periodic delay-sensitive services is determined by the delay and jitter requirements of the service.

[0035] As a possible implementation of this embodiment, the transmission window of the service is adjusted as follows:

[0036] If the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle is less than the size of the transmission window , then in this DBA cycle, the transmission window sizes of the periodic delay-sensitive services and non-periodic delay-sensitive services in this group remain unchanged;

[0037] If the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle is greater than the size of the transmission window , then first calculate the maximum delay increment that the non-periodic delay-sensitive services in the ONU in the next DBA cycle can tolerate. If the required bandwidth of the delay-sensitive services in the ONUs included in group j in a DBA cycle exceeds the size of the transmission window If the delay caused by the partial bandwidth of is less than the maximum delay increment it can tolerate, then the start time of group j+1 is adjusted to:

[0038] ,

[0039] in, is the start time of transmission of packet j+1, It means that the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle exceeds the size of the transmission window. The delay increment caused by the part.

[0040] As a possible implementation of this embodiment, in the process of dynamically allocating the transmission window of the next cycle for each service in all ONUs, the restrictions on the transmission window include:

[0041] The first restriction is that after increasing the transmission window of periodic delay-sensitive services, the delay of non-periodic delay-sensitive services cannot exceed the maximum delay that they can tolerate, that is:

[0042] ,

[0043] in, To consider the delay of subsequent services during the transmission window of periodic delay-sensitive services, In order to ignore the delay of subsequent services during the transmission window of periodic delay-sensitive services, It is the difference between the upper limit of the subsequent service delay and the delay of the subsequent service when the transmission window of the periodic delay-sensitive service is not considered;

[0044] The second restriction is that after increasing the transmission window of periodic delay-sensitive services, the jitter of non-periodic delay-sensitive services must be lower than the maximum jitter that they can tolerate, that is:

[0045] ,

[0046] in, To consider the jitter of subsequent services during the transmission window of periodic delay-sensitive services, It is the jitter upper limit of non-periodic delay-sensitive services;

[0047] The third restriction is that the increased periodic delay-sensitive service transmission window size must be able to transmit at least one periodic delay-sensitive service data packet, that is:

[0048] ,

[0049] in, is the transmission window size for periodic delay-sensitive services, To protect bandwidth, It is the minimum packet size for periodic delay-sensitive services;

[0050] Under the condition that the first restriction, the second restriction and the third restriction are satisfied, The size of is the maximum value of the upper limit of the periodic delay-sensitive service transmission window size calculated under the third constraint condition.

[0051] In a second aspect, an embodiment of the present invention provides a device for dynamically allocating bandwidth, including:

[0052] A data acquisition module is used to obtain the bandwidth demand information of each ONU in the PON system in real time online, wherein the bandwidth demand information includes the priority of each service in the ONU and its bandwidth demand;

[0053] A bandwidth submodule, used for allocating and granting bandwidth to each service in all ONUs based on the bandwidth demand information;

[0054] The transmission window allocation module is used to dynamically allocate the transmission window of the next cycle for each service in all ONUs based on the size of the bandwidth allocated to each service in the ONU.

[0055] As a possible implementation method of this embodiment, the services in the ONU include periodic delay-sensitive services, non-periodic delay-sensitive services and non-delay-sensitive services, the periodic delay-sensitive services and non-periodic delay-sensitive services are control services, and the non-delay-sensitive services are collected data services.

[0056] As a possible implementation of this embodiment, allocating and granting bandwidth to each service in all ONUs based on the bandwidth demand information includes:

[0057] For non-periodic delay-sensitive services, the size of the data packets that may arrive in the next DBA cycle is predicted based on the spatiotemporal traffic prediction method, and the bandwidth is allocated based on the prediction results;

[0058] For periodic delay-sensitive services, the bandwidth is allocated by static bandwidth allocation based on the bandwidth demand information;

[0059] For non-delay-sensitive services, bandwidth is granted in a dynamic bandwidth allocation manner based on the bandwidth demand information.

[0060] As a possible implementation of this embodiment, the method based on the spatiotemporal traffic prediction predicts the size of the data packet that may arrive in the next DBA cycle, and allocates the granted bandwidth according to the prediction result, including:

[0061] The required bandwidth of the ONU in the n-1th DBA cycle is brought into the spatiotemporal traffic prediction model to obtain the value of the data packet size that may arrive in the nth DBA cycle, so as to realize the advance allocation of the data that may arrive in the ONU in the nth DBA cycle, thereby realizing bandwidth allocation.

[0062] As a possible implementation of this embodiment, the dynamically allocating the transmission window of the next cycle for each service in all ONUs based on the size of the bandwidth granted to each service in the ONU includes:

[0063] A DBA cycle is divided into independent sub-cycles, and different methods are used to allocate transmission windows for services within each sub-cycle; the head sub-cycle of the DBA cycle is sub-cycle 1, which is used to transmit delay-sensitive services, and the tail sub-cycle of the DBA cycle is sub-cycle 2, which is used to transmit non-delay-sensitive services. A spare sub-cycle is set between the delay-sensitive service transmission window and the non-delay-sensitive service transmission window to transmit non-periodic delay-sensitive services that are not fully transmitted in the delay-sensitive transmission window;

[0064] In sub-period 1, the ONUs are grouped according to the bandwidth requirements of the non-periodic delay-sensitive services, and transmission time slots are allocated to the delay-sensitive services in the ONUs according to the grouping results;

[0065] In sub-period 2, non-delay-sensitive services are transmitted according to the default transmission order, and periodic delay-sensitive services arriving in sub-period 2 are directly transmitted based on preemption.

[0066] As a possible implementation method of this embodiment, in sub-cycle 1, the transmission order of non-periodic delay-sensitive services is changed in a grouping manner. The group scheduling method of non-periodic delay-sensitive services is completed based on an improved genetic algorithm, and the ONUs in sub-cycle 1 are grouped according to the required bandwidth size of the non-periodic delay-sensitive services in each ONU in the historical K DBA cycles.

[0067] As a possible implementation of this embodiment, the packet scheduling method of the non-periodic delay-sensitive service is implemented based on an improved genetic algorithm, including:

[0068] The dynamic programming algorithm is used to narrow the scope of the genetic algorithm solution. After adding a certain amount of jitter to the optimal solution generated by the dynamic programming algorithm, it is brought into the genetic algorithm to form the optimal grouping method, which is as follows:

[0069] The ONUs are grouped by using a dynamic programming algorithm. Specifically, for each group, an ONU that has not joined the group is randomly selected as the initial value in the current group. The stability coefficient of the group is calculated in sequence when any ONU that has not joined the group is added to the current group in the current state. The ONU added when the stability coefficient is the smallest is selected as the ONU newly added to the group. The above ONU grouping process is repeated until the number of ONUs in the group reaches N / L, where N is the number of ONUs participating in the scheduling, and L is the number of ONU groups in sub-period 1.

[0070] After adding a certain jitter to the optimal grouping method generated by the dynamic programming algorithm, it is brought into the genetic algorithm as the initial input to find the grouping method with the smallest average stability coefficient of all groups in the non-uniform grouping, which is taken as the optimal grouping method. This grouping method is used as the transmission order of non-periodic services in sub-period 1.

[0071] As a possible implementation of this embodiment, allocating transmission time slots for delay-sensitive services in the ONU according to the grouping result includes:

[0072] According to the grouping result, sub-period 1 is divided into N / L transmission time slots. In K DBA cycles, the size of each transmission time slot remains unchanged.

[0073] In sub-period 1, the transmission time slot of the non-periodic delay-sensitive service in each group is before the transmission time slot of the periodic delay-sensitive service;

[0074] In each DBA cycle, the service transmission window is adjusted according to the service requirements of the current cycle.

[0075] As a possible implementation of this embodiment, in each DBA cycle, adjusting the transmission window of the service according to the service demand of the current cycle includes:

[0076] If the bandwidth required by all delay-sensitive services in the current DBA cycle is greater than the maximum bandwidth that can be transmitted in the transmission window, whether the transmission start time of the next packet needs to be changed is determined based on whether the delay demand of the ONU in the next DBA cycle can be met. If the delay demand of the ONU in the next DBA cycle still cannot be met after increasing the incremental bandwidth, the demand of the periodic delay-sensitive services in the group is prioritized;

[0077] If the required bandwidth of all delay-sensitive services in the current DBA period is less than the maximum bandwidth that the transmission window can transmit, the transmission start time of the next packet will not be changed. Instead, the transmission start time of the periodic delay-sensitive services and non-periodic delay-sensitive services in the current group can be changed according to the required bandwidth.

[0078] As a possible implementation of this embodiment, the principle of adjusting the transmission window of the delay-sensitive service is as follows: ensure that the size of the transmission window Unchanged, flexible adjustment based on the needs of latency-sensitive services and The size of is the transmission window size of non-periodic delay-sensitive services, which is determined by the average bandwidth required by non-periodic delay-sensitive services from period eK to period e-1. The transmission window size for periodic delay-sensitive services is determined by the delay and jitter requirements of the service.

[0079] As a possible implementation of this embodiment, the transmission window of the service is adjusted as follows:

[0080] If the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle is less than the size of the transmission window , then in this DBA cycle, the transmission window sizes of the periodic delay-sensitive services and non-periodic delay-sensitive services in this group remain unchanged;

[0081] If the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle is greater than the size of the transmission window , then first calculate the maximum delay increment that the non-periodic delay-sensitive services in the ONU in the next DBA cycle can tolerate. If the required bandwidth of the delay-sensitive services in the ONUs included in group j in a DBA cycle exceeds the size of the transmission window If the delay caused by the partial bandwidth of is less than the maximum delay increment it can tolerate, then the start time of group j+1 is adjusted to:

[0082] ,

[0083] in, is the start time of transmission of packet j+1, It means that the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle exceeds the size of the transmission window. The delay increment caused by the part.

[0084] As a possible implementation of this embodiment, in the process of dynamically allocating the transmission window of the next cycle for each service in all ONUs, the restrictions on the transmission window include:

[0085] The first restriction is that after increasing the transmission window of periodic delay-sensitive services, the delay of non-periodic delay-sensitive services cannot exceed the maximum delay that they can tolerate, that is:

[0086] ,

[0087] in, To consider the delay of subsequent services during the transmission window of periodic delay-sensitive services, In order to ignore the delay of subsequent services during the transmission window of periodic delay-sensitive services, It is the difference between the upper limit of the subsequent service delay and the delay of the subsequent service when the transmission window of the periodic delay-sensitive service is not considered;

[0088] The second restriction is that after increasing the transmission window of periodic delay-sensitive services, the jitter of non-periodic delay-sensitive services must be lower than the maximum jitter that they can tolerate, that is:

[0089] ,

[0090] in, To consider the jitter of subsequent services during the transmission window of periodic delay-sensitive services, It is the jitter upper limit of non-periodic delay-sensitive services;

[0091] The third restriction is that the increased periodic delay-sensitive service transmission window size must be able to transmit at least one periodic delay-sensitive service data packet, that is:

[0092] ,

[0093] in, is the transmission window size for periodic delay-sensitive services, To protect bandwidth, It is the minimum packet size for periodic delay-sensitive services;

[0094] Under the condition that the first restriction, the second restriction and the third restriction are satisfied, The size of is the maximum value of the upper limit of the periodic delay-sensitive service transmission window size calculated under the third constraint condition.

[0095] In a third aspect, an embodiment of the present invention provides a device for dynamically allocating bandwidth, including an OLT and an ONU, wherein the OLT is communicatively connected with a plurality of ONUs, and the OLT includes the above-mentioned device for dynamically allocating bandwidth.

[0096] In a fourth aspect, an embodiment of the present invention provides a terminal, including: at least one processor; and

[0097] a memory communicatively connected to the at least one processor; wherein,

[0098] The memory stores instructions that can be executed by the at least one processor. The instructions are executed by the at least one processor so that the at least one processor can perform the above-mentioned method for dynamic bandwidth allocation.

[0099] In a fifth aspect, an embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the method for dynamic bandwidth allocation is implemented.

[0100] The beneficial effects of the technical solution of the embodiment of the present invention are as follows:

[0101] The present invention performs group scheduling on the data received by the optical terminal and the wireless terminal, so that the services in the same group change only within the group within a period of time, solving the problem that the differences in the requirements of multiple types of services in the distributed photovoltaic scenario are difficult to meet at the same time and the deterministic delay of the control services is difficult to guarantee, so that the deterministic delay of the control services can be guaranteed first while reducing the impact of different types of services such as burst traffic on the transmission performance of subsequent services. In the mode of wireless and PON hybrid access, the present invention meets the needs of low-cost and efficient transmission of diversified power services in different regions, ensuring the smoothness of data transmission and the stability of services.

[0102] The present invention takes into account the coexistence of diverse services in a distributed photovoltaic scenario, analyzes the needs of different services, and allocates corresponding transmission windows for different services, thereby improving bandwidth utilization while meeting the needs of various services.

[0103] For non-periodic delay-sensitive services, the present invention utilizes a grouping approach to reduce the impact of a single service's highly volatile bandwidth demand on subsequent services, thereby ensuring the certainty of the service's delay.

[0104] For periodic delay-sensitive services, the present invention utilizes the single-frame multi-burst feature of 50G-PON to flexibly increase the transmission window, thereby avoiding as much as possible the high jitter problem caused by the mismatch between the service arrival time interval and the DBA period when allocating a static transmission window. BRIEF DESCRIPTION OF THE DRAWINGS

[0105] Figure 1 is a flow chart of a method for dynamic bandwidth allocation according to an exemplary embodiment;

[0106] Figure 2 is a structural schematic diagram of a device for dynamic bandwidth allocation according to an exemplary embodiment;

[0107] Figure 3 The figure is a schematic diagram of a transmission window within a DBA cycle according to an exemplary embodiment. DETAILED DESCRIPTION

[0108] In order to more clearly illustrate the technical features of the solution of the present invention, the present invention is described in detail below through specific implementation methods and in conjunction with the accompanying drawings.

[0109] Aiming at the problems of large business volatility, heterogeneous resources, and difficulty in ensuring QoS after distributed photovoltaic grid connection, the present invention studies the current distributed resource communication mode, combines optical communication with wireless communication, and proposes a method for dynamic bandwidth allocation. The data received by optical terminals and wireless terminals are grouped and scheduled, so that the services in the same group only change within the group within a period of time. The problem that it is difficult to simultaneously meet the differences in multi-type business requirements in distributed photovoltaic scenarios and that it is difficult to ensure the deterministic delay of control services is solved. The deterministic delay of control services can be guaranteed first, while reducing the impact of different types of services such as burst traffic on the transmission performance of subsequent services.

[0110] like Figure 1 As shown, a method for dynamic bandwidth allocation provided by an embodiment of the present invention includes the following steps:

[0111] Obtaining bandwidth demand information of each ONU in the PON system in real time online, wherein the bandwidth demand information includes the priority of each service in the ONU and its bandwidth demand;

[0112] Based on the bandwidth demand information, allocating and granting bandwidth to each service in all ONUs;

[0113] Based on the size of the bandwidth allocated to each service in the ONU, the transmission window of the next cycle is dynamically allocated to each service in all ONUs.

[0114] As a possible implementation method of this embodiment, the services in the ONU include periodic delay-sensitive services, non-periodic delay-sensitive services and non-delay-sensitive services, the periodic delay-sensitive services and non-periodic delay-sensitive services are control services, and the non-delay-sensitive services are collected data services.

[0115] As a possible implementation of this embodiment, allocating and granting bandwidth to each service in all ONUs based on the bandwidth demand information includes:

[0116] For non-periodic delay-sensitive services, the size of the data packets that may arrive in the next DBA cycle is predicted based on the spatiotemporal traffic prediction method, and the bandwidth is allocated based on the prediction results;

[0117] For periodic delay-sensitive services, the bandwidth is allocated by static bandwidth allocation based on the bandwidth demand information;

[0118] For non-delay-sensitive services, bandwidth is granted in a dynamic bandwidth allocation manner based on the bandwidth demand information.

[0119] As a possible implementation of this embodiment, the method based on the spatiotemporal traffic prediction predicts the size of the data packet that may arrive in the next DBA cycle, and allocates the granted bandwidth according to the prediction result, including:

[0120] The required bandwidth of the ONU in the n-1th DBA cycle is brought into the spatiotemporal traffic prediction model to obtain the value of the data packet size that may arrive in the nth DBA cycle, so as to realize the advance allocation of the data that may arrive in the ONU in the nth DBA cycle, thereby realizing bandwidth allocation.

[0121] As a possible implementation of this embodiment, the dynamically allocating the transmission window of the next cycle for each service in all ONUs based on the size of the bandwidth granted to each service in the ONU includes:

[0122] A DBA cycle is divided into independent sub-cycles, and different methods are used to allocate transmission windows for services within each sub-cycle; the head sub-cycle of the DBA cycle is sub-cycle 1, which is used to transmit delay-sensitive services, and the tail sub-cycle of the DBA cycle is sub-cycle 2, which is used to transmit non-delay-sensitive services. A spare sub-cycle is set between the delay-sensitive service transmission window and the non-delay-sensitive service transmission window to transmit non-periodic delay-sensitive services that are not fully transmitted in the delay-sensitive transmission window;

[0123] In sub-period 1, the ONUs are grouped according to the bandwidth requirements of the non-periodic delay-sensitive services, and transmission time slots are allocated to the delay-sensitive services in the ONUs according to the grouping results;

[0124] In sub-period 2, non-delay-sensitive services are transmitted according to the default transmission order, and periodic delay-sensitive services arriving in sub-period 2 are directly transmitted based on preemption.

[0125] As a possible implementation method of this embodiment, in sub-cycle 1, the transmission order of non-periodic delay-sensitive services is changed in a grouping manner. The group scheduling method of non-periodic delay-sensitive services is completed based on an improved genetic algorithm, and the ONUs in sub-cycle 1 are grouped according to the required bandwidth size of the non-periodic delay-sensitive services in each ONU in the historical K DBA cycles.

[0126] As a possible implementation of this embodiment, the packet scheduling method of the non-periodic delay-sensitive service is implemented based on an improved genetic algorithm, including:

[0127] The dynamic programming algorithm is used to narrow the scope of the genetic algorithm solution. After adding a certain amount of jitter to the optimal solution generated by the dynamic programming algorithm, it is brought into the genetic algorithm to form the optimal grouping method, which is as follows:

[0128] The ONUs are grouped by using a dynamic programming algorithm. Specifically, for each group, an ONU that has not joined the group is randomly selected as the initial value in the current group. The stability coefficient of the group is calculated in sequence when any ONU that has not joined the group is added to the current group in the current state. The ONU added when the stability coefficient is the smallest is selected as the ONU newly added to the group. The above ONU grouping process is repeated until the number of ONUs in the group reaches N / L, where N is the number of ONUs participating in the scheduling, and L is the number of ONU groups in sub-period 1.

[0129] After adding a certain jitter to the optimal grouping method generated by the dynamic programming algorithm, it is brought into the genetic algorithm as the initial input to find the grouping method with the smallest average stability coefficient of all groups in the non-uniform grouping, which is taken as the optimal grouping method. This grouping method is used as the transmission order of non-periodic services in sub-period 1.

[0130] As a possible implementation of this embodiment, allocating transmission time slots for delay-sensitive services in the ONU according to the grouping result includes:

[0131] According to the grouping result, sub-period 1 is divided into N / L transmission time slots. In K DBA cycles, the size of each transmission time slot remains unchanged.

[0132] In sub-period 1, the transmission time slot of the non-periodic delay-sensitive service in each group is before the transmission time slot of the periodic delay-sensitive service;

[0133] In each DBA cycle, the service transmission window is adjusted according to the service requirements of the current cycle.

[0134] As a possible implementation of this embodiment, in each DBA cycle, adjusting the transmission window of the service according to the service demand of the current cycle includes:

[0135] If the bandwidth required by all delay-sensitive services in the current DBA cycle is greater than the maximum bandwidth that can be transmitted in the transmission window, whether the transmission start time of the next packet needs to be changed is determined based on whether the delay demand of the ONU in the next DBA cycle can be met. If the delay demand of the ONU in the next DBA cycle still cannot be met after increasing the incremental bandwidth, the demand of the periodic delay-sensitive services in the group is prioritized;

[0136] If the required bandwidth of all delay-sensitive services in the current DBA period is less than the maximum bandwidth that the transmission window can transmit, the transmission start time of the next packet will not be changed. Instead, the transmission start time of the periodic delay-sensitive services and non-periodic delay-sensitive services in the current group can be changed according to the required bandwidth.

[0137] As a possible implementation of this embodiment, the principle of adjusting the transmission window of the delay-sensitive service is as follows: ensure that the size of the transmission window Unchanged, flexible adjustment based on the needs of latency-sensitive services and The size of is the transmission window size of non-periodic delay-sensitive services, which is determined by the average bandwidth required by non-periodic delay-sensitive services from period eK to period e-1. The transmission window size for periodic delay-sensitive services is determined by the delay and jitter requirements of the service.

[0138] As a possible implementation of this embodiment, the transmission window of the service is adjusted as follows:

[0139] If the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle is less than the size of the transmission window , then in this DBA cycle, the transmission window sizes of the periodic delay-sensitive services and non-periodic delay-sensitive services in this group remain unchanged;

[0140] If the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle is greater than the size of the transmission window , then first calculate the maximum delay increment that the non-periodic delay-sensitive services in the ONU in the next DBA cycle can tolerate. If the required bandwidth of the delay-sensitive services in the ONUs included in group j in a DBA cycle exceeds the size of the transmission window If the delay caused by the partial bandwidth of is less than the maximum delay increment it can tolerate, then the start time of group j+1 is adjusted to:

[0141] ,

[0142] in, is the start time of transmission of packet j+1, It means that the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle exceeds the size of the transmission window. The delay increment caused by the part.

[0143] As a possible implementation of this embodiment, in the process of dynamically allocating the transmission window of the next cycle for each service in all ONUs, the restrictions on the transmission window include:

[0144] The first restriction is that after increasing the transmission window of periodic delay-sensitive services, the delay of non-periodic delay-sensitive services cannot exceed the maximum delay that they can tolerate, that is:

[0145] ,

[0146] in, To consider the delay of subsequent services during the transmission window of periodic delay-sensitive services, In order to ignore the delay of subsequent services during the transmission window of periodic delay-sensitive services, It is the difference between the upper limit of the subsequent service delay and the delay of the subsequent service when the transmission window of the periodic delay-sensitive service is not considered;

[0147] The second restriction is that after increasing the transmission window of periodic delay-sensitive services, the jitter of non-periodic delay-sensitive services must be lower than the maximum jitter that they can tolerate, that is:

[0148] ,

[0149] in, To consider the jitter of subsequent services during the transmission window of periodic delay-sensitive services, It is the jitter upper limit of non-periodic delay-sensitive services;

[0150] The third restriction is that the increased periodic delay-sensitive service transmission window size must be able to transmit at least one periodic delay-sensitive service data packet, that is:

[0151] ,

[0152] in, is the transmission window size for periodic delay-sensitive services, To protect bandwidth, It is the minimum packet size for periodic delay-sensitive services;

[0153] Under the condition that the first restriction, the second restriction and the third restriction are satisfied, The size of is the maximum value of the upper limit of the periodic delay-sensitive service transmission window size calculated under the third constraint condition.

[0154] like Figure 2 As shown, an embodiment of the present invention provides a device for dynamically allocating bandwidth, including:

[0155] A data acquisition module is used to obtain the bandwidth demand information of each ONU in the PON system in real time online, wherein the bandwidth demand information includes the priority of each service in the ONU and its bandwidth demand;

[0156] A bandwidth submodule, used for allocating and granting bandwidth to each service in all ONUs based on the bandwidth demand information;

[0157] The transmission window allocation module is used to dynamically allocate the transmission window of the next cycle for each service in all ONUs based on the size of the bandwidth allocated to each service in the ONU.

[0158] As a possible implementation method of this embodiment, the services in the ONU include periodic delay-sensitive services, non-periodic delay-sensitive services and non-delay-sensitive services, the periodic delay-sensitive services and non-periodic delay-sensitive services are control services, and the non-delay-sensitive services are collected data services.

[0159] As a possible implementation of this embodiment, allocating and granting bandwidth to each service in all ONUs based on the bandwidth demand information includes:

[0160] For non-periodic delay-sensitive services, the size of the data packets that may arrive in the next DBA cycle is predicted based on the spatiotemporal traffic prediction method, and the bandwidth is allocated based on the prediction results;

[0161] For periodic delay-sensitive services, the bandwidth is allocated by static bandwidth allocation based on the bandwidth demand information;

[0162] For non-delay-sensitive services, bandwidth is granted in a dynamic bandwidth allocation manner based on the bandwidth demand information.

[0163] As a possible implementation of this embodiment, the method based on the spatiotemporal traffic prediction predicts the size of the data packet that may arrive in the next DBA cycle, and allocates the granted bandwidth according to the prediction result, including:

[0164] The required bandwidth of the ONU in the n-1th DBA cycle is brought into the spatiotemporal traffic prediction model to obtain the value of the data packet size that may arrive in the nth DBA cycle, so as to realize the advance allocation of the data that may arrive in the ONU in the nth DBA cycle, thereby realizing bandwidth allocation.

[0165] As a possible implementation of this embodiment, the dynamically allocating the transmission window of the next cycle for each service in all ONUs based on the size of the bandwidth granted to each service in the ONU includes:

[0166] A DBA cycle is divided into independent sub-cycles, and different methods are used to allocate transmission windows for services within each sub-cycle; the head sub-cycle of the DBA cycle is sub-cycle 1, which is used to transmit delay-sensitive services, and the tail sub-cycle of the DBA cycle is sub-cycle 2, which is used to transmit non-delay-sensitive services. A spare sub-cycle is set between the delay-sensitive service transmission window and the non-delay-sensitive service transmission window to transmit non-periodic delay-sensitive services that are not fully transmitted in the delay-sensitive transmission window;

[0167] In sub-period 1, the ONUs are grouped according to the bandwidth requirements of the non-periodic delay-sensitive services, and transmission time slots are allocated to the delay-sensitive services in the ONUs according to the grouping results;

[0168] In sub-period 2, non-delay-sensitive services are transmitted according to the default transmission order, and periodic delay-sensitive services arriving in sub-period 2 are directly transmitted based on preemption.

[0169] As a possible implementation method of this embodiment, in sub-cycle 1, the transmission order of non-periodic delay-sensitive services is changed in a grouping manner. The group scheduling method of non-periodic delay-sensitive services is completed based on an improved genetic algorithm, and the ONUs in sub-cycle 1 are grouped according to the required bandwidth size of the non-periodic delay-sensitive services in each ONU in the historical K DBA cycles.

[0170] As a possible implementation of this embodiment, the packet scheduling method of the non-periodic delay-sensitive service is implemented based on an improved genetic algorithm, including:

[0171] The dynamic programming algorithm is used to narrow the scope of the genetic algorithm solution. After adding a certain amount of jitter to the optimal solution generated by the dynamic programming algorithm, it is brought into the genetic algorithm to form the optimal grouping method, which is as follows:

[0172] The ONUs are grouped by using a dynamic programming algorithm. Specifically, for each group, an ONU that has not joined the group is randomly selected as the initial value in the current group. The stability coefficient of the group is calculated in sequence when any ONU that has not joined the group is added to the current group in the current state. The ONU added when the stability coefficient is the smallest is selected as the ONU newly added to the group. The above ONU grouping process is repeated until the number of ONUs in the group reaches N / L, where N is the number of ONUs participating in the scheduling, and L is the number of ONU groups in sub-period 1.

[0173] After adding a certain jitter to the optimal grouping method generated by the dynamic programming algorithm, it is brought into the genetic algorithm as the initial input to find the grouping method with the smallest average stability coefficient of all groups in the non-uniform grouping, which is taken as the optimal grouping method. This grouping method is used as the transmission order of non-periodic services in sub-period 1.

[0174] As a possible implementation of this embodiment, allocating transmission time slots for delay-sensitive services in the ONU according to the grouping result includes:

[0175] According to the grouping result, sub-period 1 is divided into N / L transmission time slots. In K DBA cycles, the size of each transmission time slot remains unchanged.

[0176] In sub-period 1, the transmission time slot of the non-periodic delay-sensitive service in each group is before the transmission time slot of the periodic delay-sensitive service;

[0177] In each DBA cycle, the service transmission window is adjusted according to the service requirements of the current cycle.

[0178] As a possible implementation of this embodiment, in each DBA cycle, adjusting the transmission window of the service according to the service demand of the current cycle includes:

[0179] If the bandwidth required by all delay-sensitive services in the current DBA cycle is greater than the maximum bandwidth that can be transmitted in the transmission window, whether the transmission start time of the next packet needs to be changed is determined based on whether the delay demand of the ONU in the next DBA cycle can be met. If the delay demand of the ONU in the next DBA cycle still cannot be met after increasing the incremental bandwidth, the demand of the periodic delay-sensitive services in the group is prioritized;

[0180] If the required bandwidth of all delay-sensitive services in the current DBA period is less than the maximum bandwidth that the transmission window can transmit, the transmission start time of the next packet will not be changed. Instead, the transmission start time of the periodic delay-sensitive services and non-periodic delay-sensitive services in the current group can be changed according to the required bandwidth.

[0181] As a possible implementation of this embodiment, the principle of adjusting the transmission window of the delay-sensitive service is as follows: ensure that the size of the transmission window Unchanged, flexible adjustment based on the needs of latency-sensitive services and The size of is the transmission window size of non-periodic delay-sensitive services, which is determined by the average bandwidth required by non-periodic delay-sensitive services from period eK to period e-1. The transmission window size for periodic delay-sensitive services is determined by the delay and jitter requirements of the service.

[0182] As a possible implementation of this embodiment, the transmission window of the service is adjusted as follows:

[0183] If the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle is less than the size of the transmission window , then in this DBA cycle, the transmission window sizes of the periodic delay-sensitive services and non-periodic delay-sensitive services in this group remain unchanged;

[0184] If the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle is greater than the size of the transmission window , then first calculate the maximum delay increment that the non-periodic delay-sensitive services in the ONU in the next DBA cycle can tolerate. If the required bandwidth of the delay-sensitive services in the ONUs included in group j in a DBA cycle exceeds the size of the transmission window If the delay caused by the partial bandwidth of is less than the maximum delay increment it can tolerate, then the start time of group j+1 is adjusted to:

[0185] ,

[0186] in, is the start time of transmission of packet j+1, It means that the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle exceeds the size of the transmission window. The delay increment caused by the part.

[0187] As a possible implementation of this embodiment, in the process of dynamically allocating the transmission window of the next cycle for each service in all ONUs, the restrictions on the transmission window include:

[0188] The first restriction is that after increasing the transmission window of periodic delay-sensitive services, the delay of non-periodic delay-sensitive services cannot exceed the maximum delay that they can tolerate, that is:

[0189] ,

[0190] in, To consider the delay of subsequent services during the transmission window of periodic delay-sensitive services, In order to ignore the delay of subsequent services during the transmission window of periodic delay-sensitive services, It is the difference between the upper limit of the subsequent service delay and the delay of the subsequent service when the transmission window of the periodic delay-sensitive service is not considered;

[0191] The second restriction is that after increasing the transmission window of periodic delay-sensitive services, the jitter of non-periodic delay-sensitive services must be lower than the maximum jitter that they can tolerate, that is:

[0192] ,

[0193] in, To consider the jitter of subsequent services during the transmission window of periodic delay-sensitive services, It is the jitter upper limit of non-periodic delay-sensitive services;

[0194] The third restriction is that the increased periodic delay-sensitive service transmission window size must be able to transmit at least one periodic delay-sensitive service data packet, that is:

[0195] ,

[0196] in, is the transmission window size for periodic delay-sensitive services, To protect bandwidth, It is the minimum packet size for periodic delay-sensitive services;

[0197] Under the condition that the first restriction, the second restriction and the third restriction are satisfied, The size of is the maximum value of the upper limit of the periodic delay-sensitive service transmission window size calculated under the third constraint condition.

[0198] An embodiment of the present invention provides a device for dynamically allocating bandwidth, comprising an OLT and an ONU. The OLT is communicatively connected with a plurality of ONUs, and the OLT comprises the above-mentioned device for dynamically allocating bandwidth.

[0199] In the embodiment of the present invention, taking a GPON network with 16 ONUs as an example, the specific process of dynamic bandwidth allocation is as follows.

[0200] 1. OLT obtains bandwidth requirement information from each ONU.

[0201] The information of the required bandwidth includes the priority of the service and the bandwidth requirement of the service. According to the service type and service requirement, the services in the power network can be divided into three categories: periodic delay-sensitive services, non-periodic delay-sensitive services, and non-delay-sensitive services. Among them, delay-sensitive services are usually control services. According to whether data is uploaded periodically, delay-sensitive services are further divided into periodic delay-sensitive services and non-periodic delay-sensitive services. Non-delay-sensitive services usually include data services collected by wireless and other means.

[0202] In the upstream frame, the ONU transmits upstream data and the required bandwidth to the OLT. The required bandwidth is the size of the data packet in the current ONU buffer. In GPON, the required bandwidth is encapsulated in the DBRu field in the GPON upstream frame. The OLT receives the upstream data and requested bandwidth sent from the ONU, analyzes the required bandwidth of each service in each ONU in the requested bandwidth, and distinguishes the required bandwidth of periodic delay-sensitive services, non-periodic delay-sensitive services, and non-delay-sensitive services.

[0203] According to the bandwidth requirements of non-periodic delay-sensitive services in each ONU received by the OLT, the spatiotemporal traffic prediction model is used to predict the size of the data packet that may arrive at the ONU in the next cycle, and the transmission window size that can be allocated to the ONU in the next cycle is obtained.

[0204] Here, spatiotemporal traffic prediction means that when training the model, not only the time series traffic characteristics of the service are considered, but also spatial factors such as the distance between nodes are considered, and the next traffic value of the node is predicted by combining the characteristics of time and space. In the DBA process, when predicting, the required bandwidth of the corresponding ONU is brought into the spatiotemporal traffic model to obtain the predicted granted bandwidth, and this bandwidth size is used as the transmission window size of the ONU in the next cycle.

[0205] 2. Based on the collected information on required bandwidth, bandwidth is allocated and granted to each service in each ONU.

[0206] According to the bandwidth requirements of non-delay-sensitive services in each ONU received by the OLT, a cycle is granted for the non-delay-sensitive service. The granted bandwidth is equal to the required bandwidth size of the ONU received by the OLT, that is, the transmission window size that can be allocated to the ONU non-delay-sensitive service in the next cycle is equal to the required bandwidth size.

[0207] Depending on the type of service, the methods for allocating granted bandwidth mainly include:

[0208] For non-periodic delay-sensitive services, the size of data packets that may arrive in the next DBA cycle is predicted based on the spatiotemporal traffic prediction method; for periodic delay-sensitive services, static bandwidth allocation is used to allocate bandwidth; for non-delay-sensitive services, traditional dynamic bandwidth allocation is used to grant bandwidth.

[0209] A bandwidth allocation method for predicting the size of a data packet that may arrive in the next DBA cycle based on a time-space traffic prediction method includes: when predicting the size of a data packet that may arrive in the nth DBA cycle, bringing the required bandwidth of the ONU in the cycle n-1 into the time-space traffic prediction model to obtain the value of the size of the data packet that may arrive in the nth cycle, thereby realizing early allocation of data that may arrive in the ONU.

[0210] 3. Based on the size of the granted bandwidth of each service in each ONU, a transmission window of the next cycle is allocated to each service in each ONU.

[0211] A DBA cycle is divided into independent sub-cycles, and different methods are used to allocate transmission windows for services within each sub-cycle. The head sub-cycle (sub-cycle 1) of the DBA cycle transmits delay-sensitive services, and the tail sub-cycle (sub-cycle 2) of the DBA cycle transmits non-delay-sensitive services. A spare sub-cycle is set between the delay-sensitive service transmission window and the non-delay-sensitive service transmission window to transmit non-periodic delay-sensitive services that are not fully transmitted in the delay-sensitive transmission window, so as to ensure timely transmission of services as much as possible.

[0212] The ONUs are grouped according to the obtained transmission window sizes and historical bandwidths of the non-periodic delay-sensitive services of the corresponding ONUs.

[0213] Here, when grouping, an improved genetic algorithm is used to group the ONUs. According to the bandwidth requirements of each ONU in the historical K DBA cycles, ONUs with similar or complementary requirements are grouped into the same group.

[0214] Taking the GPON system of 16 ONUs as an example, if K is selected as 10, and all ONUs are divided into 4 groups, the grouping algorithm is based on the historical bandwidth of the historical 10 DBA cycles, and the ONUs with complementary bandwidth requirements are divided into one group, so that the sum of the bandwidths of each ONU in the same group tends to a fixed number within K cycles. It should be noted that the grouping is not necessarily uniform. The improved genetic algorithm based on it is firstly to obtain the range of the solution of the genetic algorithm by dynamic programming. When solving it according to the dynamic programming algorithm, an ONU is randomly selected and divided into the first group. The average difference of the bandwidth requirements of the current group in two adjacent cycles within 10 DBA cycles is calculated, and this difference is recorded as the stability coefficient γ1. Subsequently, the stability coefficient of the group is calculated in turn when any ONU is added to the first group in the current state, and the ONU corresponding to the minimum stability is selected as the ONU newly added to the first group. The above process is repeated until the number of ONUs in the group reaches 4. The remaining second, third, and fourth groups are grouped in a similar way to the first group, so that all ONUs have the minimum stability coefficient for each group under the premise of uniform grouping. After adding a certain amount of jitter to this grouping method, this data set is used as the initial input to the genetic algorithm to find the grouping method with the minimum average stability coefficient of all groups when non-uniform grouping occurs. This grouping method is used as the transmission order of non-periodic services in sub-period 1. The objective function of the genetic algorithm is that the average stability coefficient of the first three groups is the smallest, because the period size of the DBA is fixed, and whether the last group is stable has no effect on the subsequent ONUs.

[0215] In sub-cycle 1, ONUs are grouped according to the bandwidth requirements of non-periodic services, and transmission time slots are allocated to delay-sensitive services in ONUs according to the grouping results. In sub-cycle 2, non-delay-sensitive services are transmitted according to the default transmission order, and periodic delay-sensitive services arriving in sub-cycle 2 are directly transmitted based on preemption.

[0216] The transmission order of non-periodic delay-sensitive services is changed by grouping, including:

[0217] The group scheduling method for non-periodic delay-sensitive services is based on an improved genetic algorithm. The ONUs are divided into sub-periods according to the bandwidth requirements of non-periodic delay-sensitive services in each ONU in the historical K DBA cycles, so that all bandwidth requirements within each group are relatively stable within a certain period of time. To measure the stability of each group, the average difference in bandwidth requirements of each group in two adjacent cycles within the K DBA cycles is used as the measurement basis, which is recorded as the stability coefficient γj. The smaller the average difference, the more stable the group is in the K DBA cycles.

[0218] The improved genetic algorithm is to find the grouping method with the smallest average stability coefficient. In the implementation process of the improved genetic algorithm, first, the dynamic programming algorithm is used to narrow the range of the genetic algorithm solution, and the optimal solution generated by the dynamic programming algorithm is added with a certain jitter and then brought into the genetic algorithm to form the optimal grouping method.

[0219] When the dynamic programming algorithm is used to group ONUs, first, an ungrouped ONU is randomly selected as the initial value in group 1, and the stability coefficient of the group is calculated in sequence when any ONU is added to group 1 in the current state. The ONU added when the stability coefficient is the smallest is selected as the ONU newly added to the group, and the above grouping process is repeated until the number of ONUs in the group reaches N / L, where N is the number of ONUs participating in the scheduling. The scheduling method of the remaining groups is similar to that of group 1, so that when the grouping is uniform, the stability coefficient of each group is the minimum value.

[0220] After adding a certain amount of jitter to the optimal grouping method generated by the above dynamic bandwidth algorithm, this data set is brought into the genetic algorithm as the initial input. The genetic algorithm is used to find the grouping method with the smallest average stability coefficient of all groups when the non-uniform grouping is performed. This grouping method is used as the transmission order of the non-periodic services in sub-period 1.

[0221] Allocate transmission time slots for delay-sensitive services in the ONU based on the grouping results, including:

[0222] According to the grouping result, sub-period 1 is divided into N / L transmission time slots. In K DBA cycles, the size of each transmission time slot remains unchanged. In sub-period 1, each group transmits non-periodic delay-sensitive services first and then periodic delay-sensitive services.

[0223] In each DBA cycle, the service transmission window is adjusted according to the service demand of the current cycle, so that the transmission time slots of non-periodic delay-sensitive services in the group can change as much as possible within the group in a long period of time, the bandwidth demand can be met in a short period of time, and the periodic delay-sensitive services can be transmitted in time.

[0224] In each DBA cycle, the business transmission window is adjusted according to the business needs of the current cycle. Including:

[0225] If the required bandwidth of all delay-sensitive services in the current DBA cycle is greater than the maximum bandwidth that the transmission window can transmit, then whether the transmission start time of the next packet needs to be changed is determined based on whether the delay demand of the ONU in the next DBA cycle can be met. If the delay demand of the ONU in the next DBA cycle cannot be guaranteed after increasing the incremental bandwidth, then the demand of the periodic delay-sensitive services in the current DBA cycle is prioritized. If the required bandwidth of all delay-sensitive services in the current DBA cycle is less than the maximum bandwidth that the transmission window can transmit, then the transmission start time of the next packet will not be changed, and the transmission start time of the periodic delay-sensitive services and non-periodic delay-sensitive services in the group can be changed based on the required bandwidth.

[0226] According to the transmission sequence and granted bandwidth between ONUs, a rough transmission window is set for each service in each ONU within a period of time.

[0227] Taking a GPON system with 16 ONUs as an example, if all ONUs are divided into 4 groups, the transmission windows of each service in a DBA cycle are as follows: Figure 3 As shown in the figure, CTS, NTS and TS are periodic delay-sensitive services, non-periodic delay-sensitive services and non-delay-sensitive services respectively. Among them, in sub-period 1, according to the grouping result of step S105, sub-period 1 is divided into 4 independent transmission windows. According to the grouping, these 4 transmission windows are called transmission windows C1, C2, C3 and C4 respectively. In period e-e+K-1, the jth transmission window C j The size is ,in, It is determined by the average bandwidth required by non-periodic delay-sensitive services from period eK to period e-1, which is the transmission window size of non-periodic delay-sensitive services in an ideal situation. Determined by the service's latency and jitter requirements. In K cycles, the total transmission window size of each packet is Remain unchanged, only the service transmission window is flexibly changed and size.

[0228] The three restrictions are:

[0229] 1. After increasing the transmission window for periodic delay-sensitive services, the delay of subsequent non-periodic delay-sensitive services cannot exceed the maximum delay that it can tolerate, that is:

[0230] ,

[0231] in, To consider the delay of subsequent services during the transmission window of periodic delay-sensitive services, In order to ignore the delay of subsequent services during the transmission window of periodic delay-sensitive services, It is the difference between the upper limit of the subsequent service delay and the delay of the subsequent service when the transmission window of periodic delay-sensitive services is not considered.

[0232] 2. After increasing the transmission window for periodic delay-sensitive services, the jitter of subsequent non-periodic delay-sensitive services must be lower than the maximum jitter that they can tolerate, that is:

[0233] ,

[0234] in, To consider the jitter of subsequent services during the transmission window of periodic delay-sensitive services, It is the jitter upper limit of non-periodic delay-sensitive services.

[0235] 3. The increased periodic delay-sensitive service transmission window size must be able to transmit at least one periodic delay-sensitive service data packet, that is:

[0236] ,

[0237] in, To protect bandwidth, It is the minimum data packet size for periodic delay-sensitive services.

[0238] Under the conditions of meeting the above three restrictions, The size is the maximum value of the upper limit calculated under the restriction 3 condition.

[0239] Based on the coarse-grained time window size calculated over a long period of time, the transmission window of each business can be flexibly adjusted according to the current business needs within each DBA cycle. The transmission window adjustment principle of each business is to ensure Unchanged, flexible adjustment based on business needs and The size of the bandwidth can be adjusted to reduce bandwidth waste and provide appropriate transmission bandwidth for each business. The adjustment method is as follows:

[0240] If the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle is less than , then in this DBA cycle, the transmission window sizes of the periodic delay-sensitive services and non-periodic delay-sensitive services in this group remain unchanged.

[0241] If the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle is greater than , then first calculate the maximum delay increment that the non-periodic delay-sensitive service in the ONU can tolerate in the next DBA period. If the delay caused by the excess bandwidth is less than the maximum delay increment that it can tolerate, the start time of the next packet is adjusted to:

[0242] ,

[0243] in, is the transmission start time of packet j-1, means exceeding The delay increment caused by the part.

[0244] If the delay caused by the excess bandwidth is greater than the maximum delay increment that it can tolerate, it means that the delay caused by the increased bandwidth can be tolerated by subsequent services. In this case, the start time of the transmission window for periodic delay-sensitive services in the group is adjusted to prioritize the transmission of periodic delay-sensitive services that arrive after the start time of the transmission window for the group. If there are too many periodic delay-sensitive services in the ONU at this time and they cannot be fully transmitted in the group, a transmission window is allocated to the corresponding ONU in the standby sub-period.

[0245] An embodiment of the present invention provides a terminal, comprising: at least one processor; and

[0246] a memory communicatively connected to the at least one processor; wherein,

[0247] The memory stores instructions that can be executed by the at least one processor. The instructions are executed by the at least one processor so that the at least one processor can perform the above-mentioned method for dynamic bandwidth allocation.

[0248] Among them, in the embodiment of the present application, the memory and the processor are connected in a bus manner, and the bus may include any number of interconnected buses and bridges, and the bus connects various circuits of one or more processors and memories together. The bus can also connect various other circuits such as peripherals, voltage regulators, and power management circuits together, which are all well known in the art, so this article will not further describe them. The bus interface provides an interface between the bus and the transceiver. The transceiver can be one element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices on a transmission medium. The business data processed by the processor is transmitted on the wireless medium through the antenna, and further, the antenna also receives the business data and transmits the business data to the processor. The processor is responsible for managing the bus and normal processing, and can also provide various functions, including timing, peripheral interfaces, voltage regulation, power management and other control functions. The memory can be used to store the business data used by the processor when performing operations.

[0249] Corresponding to the above-mentioned method for starting the application, 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 above-mentioned method for dynamically allocating bandwidth is implemented.

[0250] Those skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a program, and the program is stored in a storage medium, including several instructions to enable a device (which can be a single-chip microcomputer, chip, etc.) or a processor to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0251] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for dynamic bandwidth allocation, characterized in that: The steps include: Obtaining bandwidth demand information of each ONU in the PON system in real time online, wherein the bandwidth demand information includes the priority of each service in the ONU and its bandwidth demand; Based on the bandwidth demand information, allocating and granting bandwidth to each service in all ONUs; Based on the size of the bandwidth allocated to each service in the ONU, the transmission window of the next cycle is dynamically allocated to each service in all ONUs; The method of dynamically allocating the transmission window of the next cycle for each service in all ONUs based on the size of the bandwidth granted for each service in the ONU includes: A DBA cycle is divided into independent sub-cycles, and different methods are used to allocate transmission windows for services within each sub-cycle; the head sub-cycle of the DBA cycle is sub-cycle 1, which is used to transmit delay-sensitive services, and the tail sub-cycle of the DBA cycle is sub-cycle 2, which is used to transmit non-delay-sensitive services. A spare sub-cycle is set between the delay-sensitive service transmission window and the non-delay-sensitive service transmission window to transmit non-periodic delay-sensitive services that are not fully transmitted in the delay-sensitive transmission window; In sub-period 1, the ONUs are grouped according to the bandwidth requirements of the non-periodic delay-sensitive services, and transmission time slots are allocated to the delay-sensitive services in the ONUs according to the grouping results; In sub-period 2, non-delay-sensitive services are transmitted according to the default transmission order, and periodic delay-sensitive services arriving in sub-period 2 are directly transmitted based on preemption; In sub-cycle 1, the transmission order of non-periodic delay-sensitive services is changed by grouping. The group scheduling of non-periodic delay-sensitive services is completed based on the improved genetic algorithm, and the ONUs in sub-cycle 1 are grouped according to the bandwidth requirements of non-periodic delay-sensitive services in each ONU in the historical K DBA cycles. The packet scheduling method of the non-periodic delay-sensitive service is completed based on an improved genetic algorithm, including: The dynamic programming algorithm is used to narrow the scope of the genetic algorithm solution. After adding a certain amount of jitter to the optimal solution generated by the dynamic programming algorithm, it is brought into the genetic algorithm to form the optimal grouping method, which is as follows: The ONUs are grouped by using a dynamic programming algorithm. Specifically, for each group, an ONU that has not joined the group is randomly selected as the initial value in the current group, and the stability coefficient of the group is calculated in sequence when any ONU that has not joined the group is added to the current group in the current state. The ONU added when the stability coefficient is the smallest is selected as the ONU newly added to the group, and the above ONU grouping process is repeated until the number of ONUs in the group reaches N / L, where N is the number of ONUs participating in the scheduling, L is the number of ONU groups in sub-period 1, and the stability coefficient is the average difference in the required bandwidth of the current group in two adjacent periods; After adding a certain jitter to the optimal grouping method generated by the dynamic programming algorithm, the optimal grouping method is used as the initial input to the genetic algorithm to find the grouping method with the smallest average stability coefficient of all groups in the case of non-uniform grouping, and the optimal grouping method is used as the transmission order of the non-periodic services in sub-period 1. In the process of dynamically allocating the transmission window of the next cycle for each service in all ONUs, the restrictions on the transmission window include: The first restriction is that after increasing the transmission window of periodic delay-sensitive services, the delay of non-periodic delay-sensitive services cannot exceed the maximum delay that they can tolerate, that is: ， in, To consider the delay of subsequent services during the transmission window of periodic delay-sensitive services, In order to ignore the delay of subsequent services during the transmission window of periodic delay-sensitive services, It is the difference between the upper limit of the subsequent service delay and the delay of the subsequent service when the transmission window of the periodic delay-sensitive service is not considered; The second restriction is that after increasing the transmission window of periodic delay-sensitive services, the jitter of non-periodic delay-sensitive services must be lower than the maximum jitter that they can tolerate, that is: ， in, To consider the jitter of subsequent services during the transmission window of periodic delay-sensitive services, It is the jitter upper limit of non-periodic delay-sensitive services; The third restriction is that the increased periodic delay-sensitive service transmission window size must be able to transmit at least one periodic delay-sensitive service data packet, that is: ， in, is the transmission window size for periodic delay-sensitive services, To protect bandwidth, It is the minimum packet size for periodic delay-sensitive services; Under the condition that the first restriction, the second restriction and the third restriction are satisfied, The size of is the maximum value of the upper limit of the periodic delay-sensitive service transmission window size calculated under the third constraint condition.

2. The method for dynamic bandwidth allocation according to claim 1, characterized in that: The services in the ONU include periodic delay-sensitive services, non-periodic delay-sensitive services and non-delay-sensitive services. The periodic delay-sensitive services and non-periodic delay-sensitive services are control services, and the non-delay-sensitive services are collected data services.

3. The method for dynamic bandwidth allocation according to claim 2, characterized in that: The allocating and granting bandwidth to each service in all ONUs based on the bandwidth demand information includes: For non-periodic delay-sensitive services, the size of the data packets that may arrive in the next DBA cycle is predicted based on the spatiotemporal traffic prediction method, and the bandwidth is allocated based on the prediction results; For periodic delay-sensitive services, the bandwidth is allocated by static bandwidth allocation based on the bandwidth demand information; For non-delay-sensitive services, bandwidth is granted in a dynamic bandwidth allocation manner based on the bandwidth demand information.

4. The method for dynamic bandwidth allocation according to claim 3, characterized in that: The method for predicting the time-space traffic flow predicting method predicts the size of the data packet that may arrive in the next DBA cycle, and allocates the granted bandwidth according to the prediction result, including: The required bandwidth of the ONU in the n-1th DBA cycle is brought into the spatiotemporal traffic prediction model to obtain the value of the data packet size that may arrive in the nth DBA cycle, so as to realize the advance allocation of the data that may arrive in the ONU in the nth DBA cycle, thereby realizing bandwidth allocation.

5. The method for dynamic bandwidth allocation according to claim 1, characterized in that: The allocating transmission time slots for delay-sensitive services in the ONU according to the grouping results includes: According to the grouping result, sub-period 1 is divided into N / L transmission time slots. In K DBA cycles, the size of each transmission time slot remains unchanged. In sub-period 1, the transmission time slot of the non-periodic delay-sensitive service in each group is before the transmission time slot of the periodic delay-sensitive service; In each DBA cycle, the service transmission window is adjusted according to the service requirements of the current cycle.

6. The method for dynamic bandwidth allocation according to claim 5, characterized in that: In each DBA cycle, the service transmission window is adjusted according to the service requirements of the current cycle, including: If the bandwidth required by all delay-sensitive services in the current DBA cycle is greater than the maximum bandwidth that can be transmitted in the transmission window, whether the transmission start time of the next packet needs to be changed is determined based on whether the delay demand of the ONU in the next DBA cycle can be met. If the delay demand of the ONU in the next DBA cycle still cannot be met after increasing the incremental bandwidth, the demand of the periodic delay-sensitive services in the group is prioritized; If the required bandwidth of all delay-sensitive services in the current DBA period is less than the maximum bandwidth that the transmission window can transmit, the transmission start time of the next packet will not be changed. Instead, the transmission start time of the periodic delay-sensitive services and non-periodic delay-sensitive services in the current group can be changed according to the required bandwidth.

7. The method for dynamic bandwidth allocation according to claim 5, characterized in that: The principle for adjusting the transmission window for delay-sensitive services is to ensure the size of the transmission window Unchanged, flexible adjustment based on the needs of latency-sensitive services and The size of is the transmission window size of non-periodic delay-sensitive services, which is determined by the average bandwidth required by non-periodic delay-sensitive services from period eK to period e-1. The transmission window size for periodic delay-sensitive services is determined by the delay and jitter requirements of the service.

8. The method for dynamic bandwidth allocation according to claim 5, characterized in that: The transmission window of the service is adjusted as follows: If the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle is less than the size of the transmission window , then in this DBA cycle, the transmission window sizes of the periodic delay-sensitive services and non-periodic delay-sensitive services in this group remain unchanged; If the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle is greater than the size of the transmission window , then first calculate the maximum delay increment that the non-periodic delay-sensitive services in the ONU in the next DBA cycle can tolerate. If the required bandwidth of the delay-sensitive services in the ONUs included in group j in a DBA cycle exceeds the size of the transmission window If the delay caused by the partial bandwidth of is less than the maximum delay increment it can tolerate, then the start time of group j+1 is adjusted to: ， in, is the start time of transmission of packet j+1, It means that the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle exceeds the size of the transmission window. The delay increment caused by the part.

9. A device for dynamic bandwidth allocation, characterized in that: include: A data acquisition module is used to obtain the bandwidth demand information of each ONU in the PON system in real time online, wherein the bandwidth demand information includes the priority of each service in the ONU and its bandwidth demand; A bandwidth submodule, used for allocating and granting bandwidth to each service in all ONUs based on the bandwidth demand information; The transmission window allocation module is used to dynamically allocate the transmission window of the next cycle for each service in all ONUs based on the size of the bandwidth allocated to each service in the ONU; The method of dynamically allocating the transmission window of the next cycle for each service in all ONUs based on the size of the bandwidth granted for each service in the ONU includes: A DBA cycle is divided into independent sub-periods, and the traffic is allocated in different ways within each sub-period; among them, the head sub-period of the DBA cycle is sub-period 1, which is used to transmit delay-sensitive services, and the tail sub-period of the DBA cycle is sub-period 2, which is used to transmit non-delay-sensitive services. A backup sub-period is set between the delay-sensitive service transmission window and the non-delay-sensitive service transmission window, which is used to transmit non-period delay-sensitive services that are not fully transmitted in the delay-sensitive transmission window; In sub-period 1, the ONUs are grouped according to the bandwidth requirements of the non-periodic delay-sensitive services, and transmission time slots are allocated to the delay-sensitive services in the ONUs according to the grouping results; In sub-period 2, non-delay-sensitive services are transmitted according to the default transmission order, and periodic delay-sensitive services arriving in sub-period 2 are directly transmitted based on preemption; In sub-cycle 1, the transmission order of non-periodic delay-sensitive services is changed by grouping. The group scheduling of non-periodic delay-sensitive services is completed based on the improved genetic algorithm, and the ONUs in sub-cycle 1 are grouped according to the bandwidth requirements of non-periodic delay-sensitive services in each ONU in the historical K DBA cycles. The packet scheduling method of the non-periodic delay-sensitive service is completed based on an improved genetic algorithm, including: The dynamic programming algorithm is used to narrow the scope of the genetic algorithm solution. After adding a certain amount of jitter to the optimal solution generated by the dynamic programming algorithm, it is brought into the genetic algorithm to form the optimal grouping method, which is as follows: The ONUs are grouped by using a dynamic programming algorithm. Specifically, for each group, an ONU that has not joined the group is randomly selected as the initial value in the current group, and the stability coefficient of the group is calculated in sequence when any ONU that has not joined the group is added to the current group in the current state. The ONU added when the stability coefficient is the smallest is selected as the ONU newly added to the group, and the above ONU grouping process is repeated until the number of ONUs in the group reaches N / L, where N is the number of ONUs participating in the scheduling, L is the number of ONU groups in sub-period 1, and the stability coefficient is the average difference in the required bandwidth of the current group in two adjacent periods; After adding a certain jitter to the optimal grouping method generated by the dynamic programming algorithm, the optimal grouping method is used as the initial input to the genetic algorithm to find the grouping method with the smallest average stability coefficient of all groups in the case of non-uniform grouping, and the optimal grouping method is used as the transmission order of the non-periodic services in sub-period 1. In the process of dynamically allocating the transmission window of the next cycle for each service in all ONUs, the restrictions on the transmission window include: The first restriction is that after increasing the transmission window of periodic delay-sensitive services, the delay of non-periodic delay-sensitive services cannot exceed the maximum delay that they can tolerate, that is: ， in, To consider the delay of subsequent services during the transmission window of periodic delay-sensitive services, In order to ignore the delay of subsequent services during the transmission window of periodic delay-sensitive services, It is the difference between the upper limit of the subsequent service delay and the delay of the subsequent service when the transmission window of the periodic delay-sensitive service is not considered; The second restriction is that after increasing the transmission window of periodic delay-sensitive services, the jitter of non-periodic delay-sensitive services must be lower than the maximum jitter that they can tolerate, that is: ， in, To consider the jitter of subsequent services during the transmission window of periodic delay-sensitive services, It is the jitter upper limit of non-periodic delay-sensitive services; The third restriction is that the increased periodic delay-sensitive service transmission window size must be able to transmit at least one periodic delay-sensitive service data packet, that is: ， in, is the transmission window size for periodic delay-sensitive services, To protect bandwidth, It is the minimum packet size for periodic delay-sensitive services; Under the condition that the first restriction, the second restriction and the third restriction are satisfied, The size of is the maximum value of the upper limit of the periodic delay-sensitive service transmission window size calculated under the third constraint condition.

10. The device for dynamic bandwidth allocation according to claim 9, characterized in that: The services in the ONU include periodic delay-sensitive services, non-periodic delay-sensitive services and non-delay-sensitive services. The periodic delay-sensitive services and non-periodic delay-sensitive services are control services, and the non-delay-sensitive services are collected data services.

11. The device for dynamic bandwidth allocation according to claim 10, characterized in that: The allocating and granting bandwidth to each service in all ONUs based on the bandwidth demand information includes: For non-periodic delay-sensitive services, the size of the data packets that may arrive in the next DBA cycle is predicted based on the spatiotemporal traffic prediction method, and the bandwidth is allocated based on the prediction results; For periodic delay-sensitive services, the bandwidth is allocated by static bandwidth allocation based on the bandwidth demand information; For non-delay-sensitive services, bandwidth is granted in a dynamic bandwidth allocation manner based on the bandwidth demand information.

12. The device for dynamic bandwidth allocation according to claim 11, characterized in that: The method for predicting the time-space traffic flow predicting method predicts the size of the data packet that may arrive in the next DBA cycle, and allocates the granted bandwidth according to the prediction result, including: The required bandwidth of the ONU in the n-1th DBA cycle is brought into the spatiotemporal traffic prediction model to obtain the value of the data packet size that may arrive in the nth DBA cycle, so as to realize the advance allocation of the data that may arrive in the ONU in the nth DBA cycle, thereby realizing bandwidth allocation.

13. The device for dynamic bandwidth allocation according to claim 9, characterized in that: The allocating transmission time slots for delay-sensitive services in the ONU according to the grouping results includes: According to the grouping result, sub-period 1 is divided into N / L transmission time slots. In K DBA cycles, the size of each transmission time slot remains unchanged. In sub-period 1, the transmission time slot of the non-periodic delay-sensitive service in each group is before the transmission time slot of the periodic delay-sensitive service; In each DBA cycle, the service transmission window is adjusted according to the service requirements of the current cycle.

14. The device for dynamic bandwidth allocation according to claim 13, characterized in that: In each DBA cycle, the service transmission window is adjusted according to the service requirements of the current cycle, including: If the bandwidth required by all delay-sensitive services in the current DBA cycle is greater than the maximum bandwidth that can be transmitted in the transmission window, whether the transmission start time of the next packet needs to be changed is determined based on whether the delay demand of the ONU in the next DBA cycle can be met. If the delay demand of the ONU in the next DBA cycle still cannot be met after increasing the incremental bandwidth, the demand of the periodic delay-sensitive services in the group is prioritized; If the required bandwidth of all delay-sensitive services in the current DBA period is less than the maximum bandwidth that the transmission window can transmit, the transmission start time of the next packet will not be changed. Instead, the transmission start time of the periodic delay-sensitive services and non-periodic delay-sensitive services in the current group can be changed according to the required bandwidth.

15. The device for dynamic bandwidth allocation according to claim 14, characterized in that: The principle for adjusting the transmission window for delay-sensitive services is to ensure the size of the transmission window Unchanged, flexible adjustment based on the needs of latency-sensitive services and The size of is the transmission window size of non-periodic delay-sensitive services, which is determined by the average bandwidth required by non-periodic delay-sensitive services from period eK to period e-1. The transmission window size for periodic delay-sensitive services is determined by the delay and jitter requirements of the service.

16. The device for dynamic bandwidth allocation according to claim 14, characterized in that: The transmission window of the service is adjusted as follows: If the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle is less than the size of the transmission window , then in this DBA cycle, the transmission window sizes of the periodic delay-sensitive services and non-periodic delay-sensitive services in this group remain unchanged; If the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle is greater than the size of the transmission window , then first calculate the maximum delay increment that the non-periodic delay-sensitive services in the ONU in the next DBA cycle can tolerate. If the required bandwidth of the delay-sensitive services in the ONUs included in group j in a DBA cycle exceeds the size of the transmission window If the delay caused by the partial bandwidth of is less than the maximum delay increment it can tolerate, then the start time of group j+1 is adjusted to: ， in, is the start time of transmission of packet j+1, It means that the bandwidth required by the delay-sensitive services in the ONUs included in group j in a DBA cycle exceeds the size of the transmission window. The delay increment caused by the part.

17. A device for dynamically allocating bandwidth, characterized in that: It comprises an OLT and an ONU, wherein the OLT is communicatively connected with a plurality of ONUs, and the OLT comprises a device for dynamically allocating bandwidth as described in any one of claims 9 to 16.

18. A terminal for dynamically allocating bandwidth, characterized in that: include: at least one processor; as well as, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method for dynamic bandwidth allocation as described in any one of claims 1-8.

19. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, which, when executed by a processor, implements the method for dynamic bandwidth allocation described in any one of claims 1 to 8.

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