Bandwidth resource allocation method and system based on GPON optical access network

Abstract

The present invention discloses a bandwidth resource allocation method and system based on a GPON optical access network. The method is as follows: (1) OLT stores the bandwidth demand of FTTH ONU, the time and bandwidth of the front-end data arriving at FH ONU in a vector; (2) before sending BWmap information, first calculate the reference period, and then calculate the maximum bandwidth that can be allocated to the ONU delay-insensitive service in the upstream frame; OLT allocates bandwidth according to the situation: including allocating bandwidth to FH ONU or FTTH ONU, judging whether the time exceeds the upstream frame duration, calculating the transmission end time, etc., and updating the corresponding vector, the scheduled upstream occupancy time and other parameters according to different rules; (3) generating and sending the BWmap of the upstream frame, updating the scheduled upstream occupancy time to 0 and then entering the next upstream frame bandwidth allocation; (4) ONU transmits according to the allocation and reports the demand. The present invention realizes the low latency target of FH service in a time-division multiplexing passive optical network system and meets the latency requirements of FTTH delay-sensitive services, thereby reducing the latency of the optical access network and ensuring stable and efficient operation of the system.

Description

Technical Field

[0001] The invention belongs to the technical field of time division multiplexing passive optical network access network, and in particular relates to a bandwidth resource allocation method and system based on GPON optical access network. Background Art

[0002] Time-division multiplexing passive optical networks are widely used in many scenarios such as mobile fronthaul (FH) and fiber to the home (FTTH). Based on different requirements, the optical link terminal (OLT) executes different dynamic bandwidth allocation algorithms to perform corresponding bandwidth resource scheduling. The allocated bandwidth information is encapsulated and transmitted to the corresponding optical network unit (ONU) through downlink frames. Coordinated dynamic bandwidth allocation (CO-DBA) is one of the key measures to ensure low latency of FH services in time-division multiplexing passive optical networks, and is of great significance to the efficient operation of FH services. Status report dynamic bandwidth allocation (SR-DBA) is one of the preferred solutions for traditional FTTH services to maintain high bandwidth efficiency. The combination of the two provides an effective way to integrate fixed services with mobile services. However, with the commissioning of the emerging 5G new radio interface (NR), problems also arise. In 5G NR networks, due to the introduction of mini-slots, the CO-DBA cycle of FH services is shorter than the SR-DBA cycle of traditional FTTH services, resulting in conflicts between FH services and FTTH services in resource allocation within a polling cycle, which in turn causes serious delays. This is a huge challenge for FH services because it cannot meet the stringent requirements of FH services for low latency.

[0003] At present, people's demand for information transmission speed has reached a new height. For 5G NR-related services, low latency is the key. How to effectively reduce the latency of FH services while meeting the latency requirements of FTTH latency-sensitive services, improve the performance and efficiency of the entire optical access network, and provide reliable technical support for the integrated transmission of FH and FTTH services. The relevant design solutions are still in the active exploration stage and are also a difficult problem that needs to be solved urgently in this field. Summary of the invention

[0004] Focusing on an optical access network based on GPON (Gigabit Passive Optical Network) time division multiplexing passive optical network technology, and aiming at how to effectively reduce the delay of FH services while meeting the delay requirements of FTTH delay-sensitive services, and improve the performance and efficiency of the entire optical access network, the present invention discloses a bandwidth resource allocation method and system for an optical access network based on GPON. The present invention can effectively achieve low delay in an optical access network with FH service propagation delay, and at the same time meet the delay requirements of FTTH delay-sensitive services as much as possible.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical scheme:

[0006] Based on the GPON optical access network bandwidth preemption resource allocation method, it follows the following steps:

[0007] (1) The optical link terminal OLT stores the bandwidth requirement of the fiber-to-the-home optical network unit FTTH ONU, the time and bandwidth of the fronthaul data arriving at the mobile fronthaul optical network unit FH ONU in a vector;

[0008] (2) Before the OLT sends the BWmap information of the upstream frame, it first calculates the reference period and then calculates the maximum bandwidth that can be allocated to an optical network unit (ONU) for delay-insensitive services in the upstream frame. The OLT allocates bandwidth according to different situations, including allocating bandwidth to FH ONU or FTTH ONU, determining whether the time exceeds the upstream frame duration, calculating the transmission end time, and updating the corresponding vector and the scheduled upstream occupancy time according to different rules;

[0009] (3) Generate and send the BWmap of the upstream frame to each ONU, and proceed to step (4); at the same time, update the scheduled upstream occupancy time to 0, and return to step (2) to allocate the bandwidth of the next upstream frame; after the bandwidth is allocated, use the GPON frame encapsulation structure for transmission;

[0010] (4) The ONU transmits as allocated and reports bandwidth requirements.

[0011] Preferably, in step (1), the system includes an OLT and n + k ONUs, of which, n The first ONU is a FTTH ONU. k The ONU is an FH ONU. There are two types of services in FTTH ONU. One is the target delay of DM The OLT stores the bandwidth requirements of each FTTH ONU’s delay-sensitive service and delay-insensitive service in the vector A and vector B In which, the vector A Storage latency-sensitive business bandwidth requirements, vector B Storage latency-insensitive service bandwidth requirements. Vector A and B Each is 1 line n Each FTTH ONU corresponds to one column. …in a circular manner to poll each FTTH ONU. When the OLT receives bandwidth demand information for a service of a certain FTTH ONU, it immediately updates the bandwidth demand of the corresponding service of the ONU in the corresponding vector. During network operation, the OLT receives the fronthaul allocation information of the DU and combines it with the mini-slot information to continuously obtain the time and corresponding bandwidth of the fronthaul data arriving at each FH ONU using the collaborative dynamic bandwidth allocation technology. Each time the time when the fronthaul data arrives at a certain FH ONU is obtained, the OLT adds the propagation delay of the corresponding FH ONU to the time and adds the result to the one-dimensional vector C At the end of , the corresponding bandwidth is added to the one-dimensional vector D The end of the vector C and D The initial value of is empty.

[0012] Before sending the BWmap information corresponding to each upstream frame, the OLT reads the vector A , B , C and D , and allocate the bandwidth of the upstream frame and the start and end time of the upstream transmission of the relevant ONU according to the following rules. The bandwidth allocation of the upstream frame m is used as an example for explanation. The time unit is microsecond.

[0013] Preferably, step (2) is specifically as follows:

[0014] Step (2.1), before the OLT sends the BWmap information of the upstream frame m, the OLT first calculates the BWmap information by the formula ( DM -3 *TP ) / 2 Calculate the reference cycle T max ,in TP is the maximum propagation delay of FTTH ONU. T max After that, OLT uses the vector A Total bandwidth requirement of all FTTHONU delay-sensitive services BS , by formula Calculate the maximum bandwidth that can be allocated to an ONU delay-insensitive service in upstream frame m BN max ,in, TR is the link transmission rate, TF is the frame interval, TGAP It is the ONU transmission protection interval.

[0015] Step (2.2), record the start time of receiving the upstream frame m on the OLT side as T 0 , iis the number of the first FTTH ONU that the OLT plans to poll in the upstream frame m. The upstream occupancy time that the OLT has scheduled in the upstream frame m is TOC .

[0016] Step (2.3), OLT search vector C The time when the forward data currently stored in arrives at the OLT, if the vector C The minimum value in j Item) is less than or equal to T 0 +TOC , then proceed to step (2.4); if the vector C The minimum value in j Item) is greater than T 0 +TOC , then proceed to step (2.5).

[0017] Step (2.4), OLT reads vector C The minimum value in j The vector corresponding to D The bandwidth in (i.e., reading vector D The j term), and record the vector D Middle j The value of the item is FH bw At this time, if TOC+FH bw / TR Less than or equal to 125 μs , OLT plans to convert the upstream frame m T 0 +TOC to T 0 +TOC+FH bw / TR The bandwidth of the time is allocated to the corresponding FH ONU and updated TOC for TOC+FH bw / TR+TGAP , and the vector C and vector D The j Item is removed, and then step (2.3) is executed again; if TOC+ FH bw / TR Greater than 125 μs , then OLT plans to convert the upstream frame m T 0 +TOC to T0 The bandwidth corresponding to the +125 time (denoted as P fh ) to the corresponding FH ONU, and the vector D The j Item updated to FH bw -P fh , and at the same time, the allocation of uplink frame m is completed, and then jumps to and executes step (3).

[0018] Step (2.5), OLT reads vector A FTTH ONU with storage i Bandwidth requirements for latency-sensitive services X i , and by the formula T 0 +TOC+X i / TR+H Calculate the end time of delay-sensitive service transmission on the OLT side DSE ,in H is the time required for REPORT. DSE-T 0 Less than or equal to 125 μs , then proceed to step (2.6). DSE-T 0 Greater than 125 μs , then execute step (2.7).

[0019] Step (2.6), OLT search vector C , if the vector C The minimum value in j Item, whose value is recorded as C fh ) is less than or equal to T 0 +TOC+X i / TR+H+TGAP , then OLT plans to convert the upstream frame m T 0 +TOC to C fh -TGAP The bandwidth corresponding to the time is allocated to the FTTH ONU i The bandwidth value of the specific allocation is BW ds Can be obtained by TR*(C fh -T 0 -TOC-H-TGAP) Calculated, and OLT vectorA Medium FTTH ONU i Reduced bandwidth requirements BW ds , the vector B Medium FTTH ONU i The bandwidth requirement is updated to 0. TOC Updated to C fh - T 0 , then OLT executes step (2.3) again; if C fh Greater than T 0 +TOC+X i / TR+H+ TGAP , then OLT plans to convert the upstream frame m T 0 +TOC to T 0 +TOC+X i / TR+H The bandwidth of the time is allocated to the ONU i For delay-sensitive services, the specific allocated bandwidth value is X i , then the OLT will vector A Medium ONU i The bandwidth requirement is updated to 0, and the TOC for TOC+X i / TR+H+TGAP , then perform step (2.8).

[0020] Step (2.7), OLT search vector C , if the vector C The minimum value in j Item, whose value is recorded as C fh ) is less than or equal to T 0 +125, then execute step (2.6); if C fh Greater than T 0 +125, then the OLT plans to convert the upstream frame m into T 0 +TOC to T 0 + 125 The bandwidth corresponding to the time (denoted as P ftth ) allocated to FTTH ONUi For delay-sensitive services, the specific allocated bandwidth value can be expressed as TR*(125-TOC-H-TGAP) After calculation, OLT will vector A Medium FTTH ONU i Reduced bandwidth requirements P ftth , and at the same time, the allocation of uplink frame m is completed, and then jumps to and executes step (3).

[0021] Step (2.8), OLT reads vector B FTTH ONU with storage i Bandwidth requirements for latency-insensitive services Z i , and by min ( Z i , BN max ) Calculate FTTH ONU i Expected bandwidth allocation for delay-insensitive services Y i After that, the OLT is T 0 + TOC+Y i / TR+H Calculate the end time of delay-insensitive service transmission on the OLT side DNE ,in H is the time required for REPORT. DNE-T 0 Less than or equal to 125 μs , then execute step (2.9). DNE-T 0 Greater than 125 μs , then execute step (2.10).

[0022] Step (2.9), OLT search vector C , if the vector C The minimum value in j Item, whose value is recorded as C fh ) is less than or equal to T 0 +TOC+Y i / TR+H , then OLT plans to convert the upstream frame m T 0 +TOC to C fh The bandwidth corresponding to the time is allocated to the FTTH ONU i The bandwidth value allocated for latency-insensitive services isBW dn Can be obtained by TR*(C fh -T 0 -TOC-H) Calculated, and OLT vector B Medium FTTH ONU i The bandwidth requirement is updated to Y i - BW dn ,Will TOC Updated to TOC+BW dn / TR+H , then the OLT will i Updated to i +1 (if i +1 greater than n Then i Update to 1) and execute step (2.3) again; if C fh Greater than T 0 +TOC+Y i / TR+H , then OLT plans to convert the upstream frame m T 0 +TOC to T 0 +TOC+Y i / TR+H The bandwidth of the time is allocated to the FTTH ONU i For latency-insensitive services, the specific allocated bandwidth value is Y i , then the OLT will vector B Medium ONU i The bandwidth requirement is updated to 0, and the TOC for TOC+Y i / TR+H,i Updated to i +1 (if i +1 greater than n Then i is updated to 1), and then the OLT executes step (2.3) again.

[0023] Step (2.10), OLT search vector C , if the vector C The minimum value in j Item, whose value is recorded as C fh ) is less than or equal to T 0+125, then execute step (2.9); if it is greater than T 0 +125, then the OLT plans to convert the upstream frame m into T 0 +TOC to T 0 + 125 The bandwidth corresponding to the time (denoted as P ftthn ) allocated to FTTH ONU i For delay-insensitive services, the specific allocated bandwidth value can be expressed as TR*(125-TOC-H) After calculation, OLT will vector B Medium FTTH ONU i Reduced bandwidth requirements P ftthn ,Will i Updated to i +1 (if i +1 greater than n Then i Updated to 1), and the allocation of uplink frame m is ended, and then jumps to and executes step (3).

[0024] Preferably, step (3) is as follows: generating a BWmap of the upstream frame m, and then sending the BWmap of the upstream frame m to each ONU. TOC Update to 0, then enter the next uplink frame m+1 and execute step (2) again.

[0025] Preferably, step (4) is specifically as follows: the ONU transmits according to the bandwidth and transmission start time allocated by the OLT and reports the bandwidth demand of the corresponding service at the end of the transmission.

[0026] The present invention also discloses a bandwidth resource allocation system based on GPON optical access network, which is used to execute the above method and includes the following modules:

[0027] Storage module: The optical link terminal OLT stores the bandwidth requirements of the fiber-to-the-home optical network unit FTTH ONU, the time and bandwidth of the fronthaul data arriving at the mobile fronthaul optical network unit FH ONU in the vector;

[0028] Bandwidth allocation determination module: before OLT sends bandwidth mapping information of the upstream frame, it first calculates the reference period, and then calculates the maximum bandwidth that can be allocated to an optical network unit (ONU) delay-insensitive service in the upstream frame. OLT allocates bandwidth according to different situations; the situations include allocating bandwidth to FH ONU or FTTH ONU, determining whether the time exceeds the upstream frame duration, calculating the transmission end time, updating the corresponding vector according to different rules, and the scheduled upstream occupancy time;

[0029] Sending and updating module: Generates and sends the BWmap of the upstream frame to each ONU, which is executed by the transmission module; at the same time, the scheduled upstream occupancy time is updated to 0, and the bandwidth allocation module allocates the bandwidth of the next upstream frame;

[0030] Transmission module: ONU transmits according to allocation and reports bandwidth requirements.

[0031] The present invention also discloses a bandwidth allocation scheme for downlink frames, that is, in the above technical scheme, the uplink frames are replaced by downlink frames. Compared with the prior art, the present invention has significant beneficial effects:

[0032] In the case of resource allocation conflicts, the existing technology places all conflicting parts of FTTH services after the end of the cycle, without considering the delay requirements of FTTH delay-sensitive services. However, the present invention can effectively reduce the delay of FH services while meeting the delay requirements of FTTH services, improve the performance and efficiency of the entire optical access network, provide reliable technical support for the integrated transmission of FH services and FTTH services, and help promote the application and development of time-division multiplexing passive optical networks in 5G and future communication scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram of network data flow in a preferred embodiment of the present invention;

[0034] Figure 2 The present invention is a block diagram of a bandwidth resource allocation system based on a GPON optical access network according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to make the present invention more thoroughly understood, including its purpose, technical solutions and advantages, the present invention will be further described in detail in conjunction with specific embodiments and with reference to the accompanying drawings. The present invention is based on the technical background of time division multiplexing passive optical network. The polling and bandwidth allocation process of OLT to FTTH ONU and FH ONU is detailed below.

[0036] Embodiment 1:

[0037] like Figure 1 As shown, this embodiment discloses a method for allocating bandwidth resources based on a GPON optical access network, which comprises the following steps:

[0038] Step (1), the system includes an OLT and n + k ONUs, of which, n The first ONU is a FTTH ONU. k The first ONU is FHONU. There are two types of services in FTTH ONU. One is the target delay of DMThe OLT stores the bandwidth requirements of each FTTH ONU’s delay-sensitive service and delay-insensitive service in the vector A and vector B In which the vector A Storage latency-sensitive business bandwidth requirements, vector B Storage latency-insensitive service bandwidth requirements. Vector A and B Each is 1 line n During network operation, OLT …in a circular manner to poll each FTTH ONU. When the OLT receives bandwidth demand information for a service of a certain FTTH ONU, it immediately updates the bandwidth demand of the corresponding service of the ONU in the corresponding vector. During network operation, the OLT receives the forward transmission allocation information of the DU and combines it with the mini-slot information to continuously obtain the time and corresponding bandwidth of the forward transmission data arriving at each FH ONU using CO-DBA technology. Each time the time of the forward transmission data arriving at a certain FH ONU is obtained, the OLT adds the propagation delay of the corresponding FH ONU to the time and adds the result to the one-dimensional vector C At the end of , the corresponding bandwidth is added to the one-dimensional vector D The end of the vector C and D The initial value of is empty.

[0039] Before sending the BWmap information corresponding to each upstream frame, the OLT reads the vector A , B , C and D , and allocate the bandwidth of the upstream frame and the start and end time of the upstream transmission of the relevant ONU according to the following rules. The bandwidth allocation of the upstream frame m is used as an example for explanation. The time unit is microsecond.

[0040] Step (2) is as follows: Figure 1 As shown:

[0041] Step (2.1), before the OLT sends the BWmap information of the upstream frame m, the OLT first calculates the BWmap information by the formula ( DM -3 *TP ) / 2 Calculate the reference cycle T max ,in TP is the maximum propagation delay of FTTH ONU. T max After that, OLT uses the vector A Total bandwidth requirement of all FTTHONU delay-sensitive servicesBS , by formula Calculate the maximum bandwidth that can be allocated to an ONU delay-insensitive service in upstream frame m BN max ,in, TR is the link transmission rate, TF is the frame interval, TGAP It is the ONU transmission protection interval.

[0042] Step (2.2), record the start time of receiving the upstream frame m on the OLT side as T 0 , i is the number of the first FTTH ONU that the OLT plans to poll in the upstream frame m. The upstream occupancy time that the OLT has scheduled in the upstream frame m is TOC .

[0043] Step (2.3), OLT search vector C The time when the forward data currently stored in arrives at the OLT, if the vector C The minimum value in j Item) is less than or equal to T 0 +TOC , then proceed to step (2.4); if the vector C The minimum value in j Item) is greater than T 0 +TOC , then proceed to step (2.5).

[0044] Step (2.4), OLT reads vector C The minimum value in j The vector corresponding to D The bandwidth in (i.e., reading vector D The j term), and record the vector D Middle j The value of the item is FH bw At this time, if TOC+FH bw / TR Less than or equal to 125 μs , OLT plans to convert the upstream frame m T 0 +TOC to T 0 +TOC+FH bw / TR The bandwidth of the time is allocated to the corresponding FH ONU and updated TOC for TOC+FHbw / TR+TGAP , and the vector C and vector D The j Item is removed, and then step (2.3) is executed again; if TOC+ FH bw / TR Greater than 125 μs , then OLT plans to convert the upstream frame m T 0 +TOC to T 0 The bandwidth corresponding to the +125 time (denoted as P fh ) to the corresponding FH ONU, and the vector D The j Item updated to FH bw -P fh , and at the same time, the allocation of uplink frame m is completed, and then jumps to and executes step (3).

[0045] Step (2.5), OLT reads vector A FTTH ONU with storage i Bandwidth requirements for latency-sensitive services X i , and by the formula T 0 +TOC+X i / TR+H Calculate the end time of delay-sensitive service transmission on the OLT side DSE ,in H is the time required for REPORT. DSE-T 0 Less than or equal to 125 μs , then proceed to step (2.6). DSE-T 0 Greater than 125 μs , then execute step (2.7).

[0046] Step (2.6), OLT search vector C , if the vector C The minimum value in j Item, whose value is recorded as C fh ) is less than or equal to T 0 +TOC+X i / TR+H+TGAP , then OLT plans to convert the upstream frame mT 0 +TOC to C fh -TGAP The bandwidth corresponding to the time is allocated to the FTTH ONU i The bandwidth value of the specific allocation is BW ds Can be obtained by TR*(C fh -T 0 -TOC-H-TGAP) Calculated, and OLT vector A Medium FTTH ONU i Reduced bandwidth requirements BW ds , the vector B Medium FTTH ONU i The bandwidth requirement is updated to 0. TOC Updated to C fh - T 0 , then OLT executes step (2.3) again; if C fh Greater than T 0 +TOC+X i / TR+H+ TGAP , then OLT plans to convert the upstream frame m T 0 +TOC to T 0 +TOC+X i / TR+H The bandwidth of the time is allocated to the ONU i For delay-sensitive services, the specific allocated bandwidth value is X i , then the OLT will vector A Medium ONU i The bandwidth requirement is updated to 0, and the TOC for TOC+X i / TR+H+TGAP , then perform step (2.8).

[0047] Step (2.7), OLT search vector C , if the vector C The minimum value in j Item, whose value is recorded as C fh ) is less than or equal to T0 +125, then execute step (2.6); if C fh Greater than T 0 +125, then the OLT plans to convert the upstream frame m into T 0 +TOC to T 0 + 125 The bandwidth corresponding to the time (denoted as P ftth ) allocated to FTTH ONU i For delay-sensitive services, the specific allocated bandwidth value can be expressed as TR*(125-TOC-H-TGAP) Calculate, then OLT will vector A Medium FTTH ONU i Reduced bandwidth requirements P ftth , and at the same time, the allocation of uplink frame m is completed, and then jumps to and executes step (3).

[0048] Step (2.8), OLT reads vector B FTTH ONU with storage i Bandwidth requirements for latency-insensitive services Z i , and by min ( Z i , BN max ) Calculate FTTH ONU i Expected bandwidth allocation for delay-insensitive services Y i After that, the OLT is T 0 + TOC+Y i / TR+H Calculate the end time of delay-insensitive service transmission on the OLT side DNE ,in, H is the time required for REPORT. DNE-T 0 Less than or equal to 125 μs , then execute step (2.9). DNE-T 0 Greater than 125 μs , then execute step (2.10).

[0049] Step (2.9), OLT search vector C , if the vector C The minimum value in j Item, whose value is recorded asC fh ) is less than or equal to T 0 +TOC+Y i / TR+H , then OLT plans to convert the upstream frame m T 0 +TOC to C fh The bandwidth corresponding to the time is allocated to the FTTH ONU i The bandwidth value allocated for latency-insensitive services is BW dn Can be obtained by TR*(C fh -T 0 -TOC-H) Calculated, and OLT vector B Medium FTTH ONU i The bandwidth requirement is updated to Y i - BW dn ,Will TOC Updated to TOC+BW dn / TR+H , then the OLT will i Updated to i +1 (if i +1 greater than n Then i Update to 1) and execute step (2.3) again; if C fh Greater than T 0 +TOC+Y i / TR+H , then OLT plans to convert the upstream frame m T 0 +TOC to T 0 +TOC+Y i / TR+H The bandwidth of the time is allocated to the FTTH ONU i For latency-insensitive services, the specific allocated bandwidth value is Y i , then the OLT will vector B Medium ONU i The bandwidth requirement is updated to 0, and the TOC for TOC+Y i / TR+H,i Updated to i +1 (ifi +1 greater than n Then i is updated to 1), and then the OLT executes step (2.3) again.

[0050] Step (2.10), OLT search vector C , if the vector C The minimum value in j Item, whose value is recorded as C fh ) is less than or equal to T 0 +125, then execute step (2.9); if it is greater than T 0 +125, then the OLT plans to convert the upstream frame m into T 0 +TOC to T 0 + 125 The bandwidth corresponding to the time (denoted as P ftthn ) allocated to FTTH ONU i For delay-insensitive services, the specific allocated bandwidth value can be expressed as TR*(125-TOC-H) Calculate, then OLT will vector B Medium FTTH ONU i Reduced bandwidth requirements P ftthn ,Will i Updated to i +1 (if i +1 greater than n Then i Updated to 1), and the allocation of uplink frame m is ended, and then jumps to and executes step (3).

[0051] Step (3), generate the BWmap of the upstream frame m, then send the BWmap of the upstream frame m to each ONU, and enter step (13); at the same time, TOC Update to 0, then enter the next uplink frame m+1 and execute step (2) again.

[0052] Step (4), the ONU transmits according to the bandwidth and transmission start time allocated by the OLT and reports the bandwidth demand of the corresponding service at the end of the transmission.

[0053] Embodiment 2:

[0054] like Figure 2 As shown, this embodiment discloses a bandwidth resource allocation system based on GPON optical access network, which is used to execute the above method, and includes the following modules:

[0055] Storage module: The optical link terminal OLT stores the bandwidth requirements of the fiber-to-the-home optical network unit FTTH ONU, the time and bandwidth of the fronthaul data arriving at the mobile fronthaul optical network unit FH ONU in the vector;

[0056] Bandwidth allocation determination module: before OLT sends bandwidth mapping information of the upstream frame, it first calculates the reference period, and then calculates the maximum bandwidth that can be allocated to an optical network unit (ONU) delay-insensitive service in the upstream frame. OLT allocates bandwidth according to different situations; the situations include allocating bandwidth to FH ONU or FTTH ONU, determining whether the time exceeds the upstream frame duration, calculating the transmission end time, updating the corresponding vector according to different rules, and the scheduled upstream occupancy time;

[0057] Sending and updating module: Generates and sends the BWmap of the upstream frame to each ONU, which is executed by the transmission module; at the same time, the scheduled upstream occupancy time is updated to 0, and the bandwidth allocation module allocates the bandwidth of the next upstream frame;

[0058] Transmission module: ONU transmits according to allocation and reports bandwidth requirements.

[0059] For other contents of this embodiment, please refer to the above-mentioned embodiment 1.

[0060] The following specifically describes how the present invention is implemented in practical applications by applying the GPON optical access network bandwidth resource allocation method of the present invention in a cell communication network system:

[0061] The system is set to include 1 OLT, 16 FTTH ONUs for residential broadband access, and 4 FH ONUs to support 5G mobile base station signal transmission in the community. In this community, the broadband services provided by the FTTH ONU include high-definition video playback, file downloads, WeChat chats, etc. Among them, the high-definition video playback service is set as a delay-sensitive service, and the target delay is set to 2 ms Other services such as WeChat chatting and web browsing are considered as latency-insensitive services.

[0062] In the existing solution, the OLT collects and organizes the feedback information of 16 FTTH ONUs to calculate the total bandwidth transmission time (assuming 4 ms ), in response to the sudden arrival of FH services, OLT uses a simple preemption method to ensure that FH services can be transmitted immediately after arriving at FH ONU. Due to the mixing of FTTH services, the delay of delay-sensitive services increases when FTTH services are preempted, and system bandwidth resources are wasted. Assume that 2 of the FH ONUs are preempted within the ONU, and 2 are preempted across ONUs, and the protection bandwidth TGAP is set to 1 μs , which can be increased by about 12μs If the first FH ONU arrives earlier, the preempted delay-sensitive service will not be transmitted until the cycle ends, which does not meet the target delay of delay-sensitive services. ms delay requirements.

[0063] In this solution, the OLT can plan the transmission time and size of each ONU before each upstream frame. The ONU transmits and reports the bandwidth requirements according to the allocation, and updates the bandwidth requirements of each FTTH ONU in a timely manner. FTTH services are divided into services without delay requirements, and the maximum polling cycle will not exceed the target delay of delay-sensitive services, so the delay requirements of delay-sensitive services can be guaranteed. This solution adopts a more dynamic bandwidth allocation, so the protection bandwidth for transmitting FH services is increased by about 8 μ s , which reduces bandwidth waste compared to existing solutions.

[0064] Through a simple practical application process, in the communication network of this community, FH services can be transmitted immediately after arrival, and the FH service delay is effectively controlled; at the same time, delay-sensitive services in FTTH services can also run smoothly, meeting the target delay of 2 ms The latency requirement is reduced; the bandwidth resource waste is reduced by about 33%, which greatly improves the network usage experience of the residents in the entire community and verifies the effectiveness and practicality of the present invention in an actual complex network environment.

[0065] In addition, in the present invention, the uplink frames involved in the above embodiments 1 and 2 are replaced by downlink frames to form a bandwidth allocation implementation plan for downlink frames. For other specific contents, please refer to the above embodiments 1 and 2.

[0066] In summary, the present invention provides a technical solution for allocating bandwidth resources of an optical access network for polling scheduling of multi-service transmission priorities in GPON, and the present invention is applied to a time-division multiplexed passive optical access network environment consisting of an OLT and multiple ONUs. The present invention achieves the low latency target of FH services and meets the latency requirements of FTTH delay-sensitive services, reduces the latency of the optical access network, and ensures stable and efficient operation of the system. The above implementation examples are representative examples listed to more clearly illustrate the present invention. In the actual implementation process, the actual parameters such as the start and end time of each ONU's actual data transmission can be dynamically adjusted and calculated in combination with the actual situation, so that the system can operate stably and efficiently.

[0067] The above contents are only a detailed description of the embodiments and principles of the present invention. For ordinary technicians in this field, any omissions, modifications, equivalent substitutions, improvements, etc. made based on the ideas provided by the present invention should be included in the protection scope of this disclosure.

Claims

1. A method for allocating bandwidth resources based on a GPON optical access network, characterized in that: Follow these steps: S1, the optical link terminal OLT stores the bandwidth requirement of the fiber-to-the-home optical network unit FTTH ONU, the time and bandwidth of the fronthaul data arriving at the mobile fronthaul optical network unit FH ONU in a vector; S2, before the OLT sends the bandwidth mapping BWmap information of the upstream frame, it first calculates the reference period, and then calculates the maximum bandwidth that can be allocated to an optical network unit ONU delay-insensitive service in the upstream frame. The OLT allocates bandwidth according to different situations; the situations include allocating bandwidth to FH ONU or FTTH ONU, judging whether the time exceeds the upstream frame duration, calculating the transmission end time, updating the corresponding vector according to different rules, and the scheduled upstream occupancy time; S3, generate and send the BWmap of the upstream frame to each ONU, and enter step S4; at the same time, update the scheduled upstream occupancy time to 0, return to step S2 to allocate the bandwidth of the next upstream frame; after the bandwidth is allocated, use the GPON frame encapsulation structure for transmission; S4, ONU transmits according to the allocation and reports the bandwidth demand; Step S2 is specifically as follows: S21, before the OLT sends the BWmap information of the upstream frame m, the OLT reads the vectors A, B, C and D; the OLT first calculates the reference period T by the formula (DM-3*TP) / 2 max , where TP is the maximum propagation delay of FTTH ONU; after obtaining T max After that, OLT needs to calculate the total bandwidth demand BS of all FTTH ONU delay-sensitive services in vector A by formula Calculate the maximum bandwidth BN that can be allocated to an ONU delay-insensitive service in the upstream frame m max , where TR is the link transmission rate, TF is the frame interval, and TGAP is the ONU transmission protection interval; S22, the start time of receiving the upstream frame m on the OLT side is recorded as T0, i is the number of the first FTTHONU that the OLT plans to poll in the upstream frame m; the upstream occupation time that the OLT has arranged in the upstream frame m is recorded as TOC; S23, the OLT searches for the time when the forward data currently stored in the vector C arrives at the OLT, and records the minimum value in the vector C as the jth item. If the minimum value in the vector C is less than or equal to T0+TOC, then execute step S24; if the minimum value in the vector C is greater than T0+TOC, then execute step S25; S24, OLT reads the bandwidth in vector D corresponding to the jth item of the minimum value in vector C, and records the value of the jth item in vector D as FH bw ; At this time, if TOC+FH bw / TR is less than or equal to 125μs, OLT plans to convert T0+TOC to T0+TOC+FH in the upstream frame m. bw The bandwidth of the / TR time is allocated to the corresponding FH ONU, and TOC is updated to TOC+FH bw / TR+TGAP, and remove the j-th item in vector C and vector D, and then return to step S23; if TOC+FH bw / TR is greater than 125μs, then OLT plans to allocate the bandwidth P corresponding to the time from T0+TOC to T0+125 in the upstream frame m fh Assign it to the corresponding FH ONU and update the jth item in vector D to FH bw -P fh , and the allocation of uplink frame m is terminated, and then the process jumps to and executes step S3; S25, OLT reads the i-th fiber-to-the-home optical network unit FTTH ONU stored in vector A. i The bandwidth requirement of delay-sensitive services is X i , and by the formula T0+TOC+X i / TR+H calculates the end time DSE of the delay-sensitive service transmission on the OLT side, where H is the time overhead required for reporting; at this time, if DSE-T0 is less than or equal to 125μs, then execute step S26; if DSE-T0 is greater than 125μs, then execute step S27; S26, OLT searches for vector C, records the minimum value in vector C as the jth item, and records the corresponding value as C fh , if the minimum value in vector C is less than or equal to T0+TOC+X i / TR+H+TGAP, then OLT plans to transfer T0+TOC in the upstream frame m to C fh -The bandwidth corresponding to the TGAP time is allocated to the FTTH ONU i For delay-sensitive services, the bandwidth value BW is allocated ds From the formula TR*(C fh -T0-TOC-H-TGAP) is calculated, and OLT sends the FTTH ONU in vector A i The bandwidth requirement is reduced by ds , the FTTH ONU in vector B i Update the bandwidth requirement to 0 and update the TOC to C fh -T0, then OLT returns to execute step S23; if C fh Greater than T0+TOC+X i / TR+H+TGAP, then OLT plans to convert T0+TOC to T0+TOC+X in the upstream frame m. i The bandwidth of the / TR+H time is allocated to the i-th optical network unit ONU i For delay-sensitive services, the bandwidth allocated is X i , then OLT will vector A in ONU i The bandwidth requirement is updated to 0, and TOC is updated to TOC+X i / TR+H+TGAP, then execute step S28; S27, OLT searches vector C. If the minimum value in vector C is less than or equal to T0+125, execute step S26. If C fh If it is greater than T0+125, then the OLT plans to increase the bandwidth P corresponding to the time from T0+TOC to T0+125 in the upstream frame m. ftth Assigned to FTTH ONU i For delay-sensitive services, the allocated bandwidth value is calculated by the formula TR*(125-TOC-H-TGAP). Then the OLT allocates the FTTHONU in vector A to the i The bandwidth requirement is reduced by P ftth , and at the same time, the allocation of uplink frame m is ended, and then the process jumps to and executes step S3; S28, OLT reads the FTTH ONU stored in vector B i The bandwidth requirement of the latency-insensitive service Z i , and min(Z i , BN max )Calculate FTTH ONU i The expected bandwidth allocation for delay-insensitive services is Y i ; After that, OLT is T0+TOC+Y i / TR+H calculates the end time DNE of the delay-insensitive service transmission on the OLT side, where H is the time overhead required for REPORT; at this time, if DNE-T0 is less than or equal to 125μs, then execute step S29; if DNE-T0 is greater than 125μs, then execute step S210; S29, OLT searches vector C, if the minimum value in vector C is less than or equal to T0+TOC+Y i / TR+H, then OLT plans to transfer T0+TOC in the upstream frame m to C fh The bandwidth corresponding to the time is allocated to the FTTH ONU i For latency-insensitive services, the allocated bandwidth value is BW dn From the formula TR*(C fh -T0-TOC-H) is calculated, and OLT sends the FTTH ONU in vector B i The bandwidth requirement is updated to Y i -BW dn , update TOC to TOC+BW dn / TR+H, then OLT updates i to i+1. If i+1 is greater than n, i is updated to 1, and step S23 is executed again. If C fh Greater than T0+TOC+Y i / TR+H, then OLT plans to convert T0+TOC to T0+TOC+Y in the upstream frame m i The bandwidth of the / TR+H time is allocated to the FTTH ONU i For latency-insensitive services, the allocated bandwidth is Y i , then OLT will vector B in ONU i The bandwidth requirement is updated to 0, and TOC is updated to TOC+Y i / TR+H, i is updated to i+1. If i+1 is greater than n, i is updated to 1, and then the OLT executes step S23 again; S210, OLT searches vector C. If the minimum value in vector C is less than or equal to T0+125, then step S29 is executed. If it is greater than T0+125, then OLT plans to increase the bandwidth P corresponding to the time from T0+TOC to T0+125 in the upstream frame m. ftthn Assigned to FTTH ONU i The bandwidth value allocated for delay-insensitive services is calculated by the formula TR*(125-TOC-H). Then the OLT allocates the FTTHONU in vector B to the i The bandwidth requirement is reduced by P ftthn , update i to i+1, if i+1 is greater than n, update i to 1, and end the allocation of uplink frame m, then jump and execute step S3.

2. The method for allocating bandwidth resources based on GPON optical access network according to claim 1, characterized in that: In step S1, the bandwidth demand and time information recording method is that the OLT stores the bandwidth demand of the FTTH ONU, the time and bandwidth of the fronthaul data arriving at the FH ONU in a vector, involving one OLT and n+k ONUs, wherein n ONUs are FTTH ONUs and k ONUs are FH ONUs; the FTTH ONU has two services, one is a delay-sensitive service with a target delay of DM, and the other is a delay-insensitive service; the OLT stores the bandwidth demand of the delay-sensitive service and the delay-insensitive service of each FTTH ONU in vector A and vector B respectively, and both vectors A and B have 1 row and n columns; the OLT cyclically polls each FTTH ONU in the order of 1→n→1→n…; when the OLT receives the bandwidth demand information of the FTTH ONU, it updates the bandwidth demand of the FTTH ONU in the corresponding vector; the OLT continuously obtains the time and corresponding bandwidth of the fronthaul data arriving at each FH ONU by receiving the fronthaul allocation information of the distribution unit DU and combining the mini-slot information; each time the fronthaul data arriving at the FH After the time of the FH ONU, the OLT adds the time plus the propagation delay of the corresponding FH ONU to the end of the one-dimensional vector C, and at the same time, adds the corresponding bandwidth to the end of the other-dimensional vector D.

3. The method for allocating bandwidth resources based on GPON optical access network according to claim 1, characterized in that: Step S3 is specifically as follows: generate the BWmap of the upstream frame m, then send the BWmap of the upstream frame m to each ONU, and proceed to step S4; at the same time, update the TOC to 0, then proceed to the next upstream frame m+1 and execute step S2.

4. The method for allocating bandwidth resources based on GPON optical access network according to claim 3, characterized in that: Step S4 is specifically as follows: the ONU transmits according to the bandwidth and transmission start time allocated by the OLT and reports the bandwidth demand of the corresponding service at the end of the transmission.

5. The method for allocating bandwidth resources based on GPON optical access network according to any one of claims 1 to 4, characterized in that: Replace the upstream frame with the downstream frame.

6. A GPON optical access network bandwidth resource allocation system, used to execute the method according to any one of claims 1 to 5, characterized in that: Includes the following modules: Storage module: The optical link terminal OLT stores the bandwidth requirements of the fiber-to-the-home optical network unit FTTH ONU, the time and bandwidth of the fronthaul data arriving at the mobile fronthaul optical network unit FH ONU in the vector; Bandwidth allocation determination module: before OLT sends the bandwidth mapping BWmap information of the downstream frame, it first calculates the reference period, and then calculates the maximum bandwidth that can be allocated to an optical network unit ONU delay-insensitive service in the downstream frame. OLT allocates bandwidth according to different situations; the situations include allocating bandwidth to FH ONU or FTTH ONU, judging whether the time exceeds the downstream frame duration, calculating the transmission end time, updating the corresponding vector according to different rules, and the scheduled downstream occupancy time; Sending and updating module: Generates and sends the BWmap of the downstream frame to each ONU, which is executed by the transmission module; at the same time, the scheduled downstream occupancy time is updated to 0, and the bandwidth allocation module performs the bandwidth allocation of the next downstream frame; Transmission module: ONU transmits according to allocation and reports bandwidth requirements.

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