WO2010048792A1

WO2010048792A1 - Method and system for bandwidth allocation in passive optical network

Info

Publication number: WO2010048792A1
Application number: PCT/CN2009/070118
Authority: WO
Inventors: 海德杰尼·马瑞克; 张伟良
Original assignee: 中兴通讯股份有限公司
Priority date: 2008-10-31
Filing date: 2009-01-13
Publication date: 2010-05-06
Also published as: CN101729939A; CN101729939B

Abstract

The present invention provides a method and a system for bandwidth allocation in passive optical network (PON), the method includes: when Optical Line Terminal (OLT) allocates upstream bandwidth for Optical Network Unit (ONU), the flag of allocation type is carried in upstream bandwidth allocation information to indicate the type of bandwidth allocated for ONU; ONU receives the bandwidth allocation information, and then maintains and uses the corresponding upstream bandwidth according to the flag of allocation type. For bandwidth allocated in fixed bandwidth allocation type, the present invention enables that a new bandwidth allocation will be processed only when previously allocated bandwidth of related T-CONT needs to be changed, alleviating the load of OLT for allocating the upstream bandwidth, reducing the occupation for downstream bandwidth.

Description

Passive optical network bandwidth allocation method and system

The present invention relates to the field of Passive Optical Network (PON) communication technologies, and in particular, to a method and system for bandwidth allocation of a passive optical network.

Background technique

The PON system usually consists of an OLT (Optical Line Terminal), an ONU (Optical Network Unit), and an Optical Distribution Network (ODN). The ODN is usually a point-to-multipoint structure, and one OLT connects multiple ONUs through an ODN. Such as the ITU-T G.984 series of GPON (Gigabit Passive Optical Network) systems, FSAN GPON-based NG-PON (Next Generation PON) systems.

In a PON system based on TDMA (Time Division Multiplex Access) (such as GPON and NG-PON systems), the ONU needs to be authorized by the OLT to send data in the uplink direction. The OLT passes the DBA (Dynamic Bandwidth Assignment). The Dynamic Bandwidth Allocation feature allocates upstream bandwidth to the ONU. The DBA function divides each T into a number of time intervals and allocates them to the ONUs in a time interval T, and the ONU transmits data in the uplink direction within a specified time interval.

GPON transmission GTC (GPON Transmission Convergence, GPON transmission convergence layer) The frame structure and DBA format are shown in Figure 1. The downstream GTC frame consists of the frame header PCBd and the payload, and the DBA format US in the downstream GTC frame header. BWma is the uplink bandwidth allocation content, including N uplink bandwidths. Each uplink bandwidth includes Alloc-ID, Flags, SStart, SStop, and CRC fields. Alloc-ID represents T-CONT (transport container) in the ONU, and uplink bandwidth allocation. For T-CONT, Flags indicates some attributes related to the upstream bandwidth. The domain 11-7 bits are already used, 6-0 bits are reserved for future use, SStart is the start time of the upstream bandwidth, and SStop is the end time of the upstream bandwidth. The CRC is a cyclic redundancy check code used to protect the correct transmission of the upstream bandwidth content.

The T period in the GPON system is 125 microseconds. When the upper behavior is 1.24416 Gbit/s, 19440 bytes can be transmitted in each cycle. When the upper behavior is 2.48832 Gbit/s, it can be transmitted in each cycle. 38,880 bytes. In the DBA format byte allocation of Figure 1, the upstream bandwidth associated with a T-CONT occupies 8 bytes, with a split ratio of 1:64, each ONU supports 4 T-CONT calculations, and one downstream GTC frame. The DBA overhead is 64 X 4 X 8=2048 bytes, which occupies the downstream GTC frame overhead up to 2048/38880=5.27% (2.44832 Gbit/s) or even 2048/19440=10.27% (1.24416 Gbit/s). In the research of GPON-based next-generation PON, it may be necessary to increase the value of some domains in the DBA format, such as expanding the range of Alloc-ID to support more T-CONT, and the next generation based on GPON. PON may have a higher uplink rate, the above line rate is 9,95328 Gbit/s, and the split ratio is 1:128. Each ONU supports 8 T-CONT calculations. The DBA overhead in a downlink GTC frame is 128 X 8 X. 8 = 8192 bytes, the overhead ratio is also 5.27%. If the DBA overhead can be effectively reduced, it will help to improve the utilization of downlink GTC frames and improve the utilization of downlink bandwidth.

In addition, in the GPON system, the OLT needs to reallocate the uplink bandwidth every cycle, which is a heavy burden for the OLT, especially in the GPON-based NG-PON system, with the increase of the uplink rate, T- The increase in the total number of CONTs will undoubtedly increase the burden of the OLT's upstream bandwidth allocation work.

Considering QoS, the T-CONT in GPON ONU includes five types, Type 1, Type 2, Type 3, Type 4, and Type 5, which can be divided into large categories from the perspective of bandwidth usage:

The fixed bandwidth T-CONT, always allocated to a fixed length of upstream bandwidth, is independent of network status and other T-CONT bandwidth conditions.

Dynamic Bandwidth T-CONT, which allocates a certain number of but not fixed upstream bandwidths per cycle, related to network status and other T-CONT bandwidth conditions.

In addition, type 5 T-CONT is special and can be configured as T-CONT of type 1, 2, 3, 4. For the fixed bandwidth T-CONT, the allocated bandwidth length is fixed, but in the existing GPON standard, the OLT still needs to re-allocate the uplink bandwidth every cycle, which undoubtedly causes unnecessary repeated allocation, thus a certain degree The downstream bandwidth is wasted.

Therefore, from the perspective of DBA overhead, OLT processing burden, and fixed bandwidth re-allocation, GPON systems and even NG-PON systems need to provide a more efficient uplink bandwidth allocation mechanism. Summary of the invention

The technical problem to be solved by the present invention is to provide a passive optical network bandwidth allocation method and system to reduce the repeated allocation of uplink bandwidth and reduce the burden of 0LT bandwidth allocation work.

According to an aspect of the present invention, a method for allocating a bandwidth of a passive optical network is provided. The method includes: when an optical line terminal allocates an uplink bandwidth to an optical network unit, carrying an allocation type flag in the uplink bandwidth allocation information, where The type of bandwidth allocated by the optical network unit; after receiving the bandwidth allocation information, the optical network unit maintains and uses the corresponding uplink bandwidth according to the allocation type flag.

The type of bandwidth allocation indicated by the allocation type flag includes: a fixed bandwidth allocation type, and a dynamic bandwidth allocation type.

The optical line terminal allocates the same bandwidth of the fixed bandwidth allocation type only once in a continuous period; when the optical network unit receives the allocation type flag indicating the fixed bandwidth allocation type, the bandwidth allocation information is stored for a long time and used for a long time. Upstream bandwidth until new bandwidth allocation information from the optical line terminal is received.

When the optical network unit receives the allocation type flag indicating the dynamic bandwidth allocation type, the bandwidth allocation information is deleted after the uplink burst packet is sent through the uplink bandwidth, and the optical bandwidth terminal re-allocates the uplink bandwidth of the next period. .

The optical line terminal reclaims the uplink bandwidth of the original fixed bandwidth allocation type by issuing new bandwidth allocation information, and the new bandwidth allocation information includes: carrying a new bandwidth allocation type, a new bandwidth size, and/or a new start. And bandwidth allocation information at the end time, or special bandwidth allocation information whose start time is equal to the end time.

The optical line terminal determines to allocate a fixed bandwidth or a dynamic bandwidth to the transmission container according to the type of the transmission container of the optical network unit.

Wherein, in the case that the optical network unit is restarted, or the optical line terminal loses contact with the optical network unit, the optical line terminal reclaims the original uplink bandwidth.

Among them, the allocation type tag occupies 1 bit.

According to another aspect of the present invention, a passive optical network bandwidth allocation system is provided, including an optical line terminal and an optical network unit, the optical line terminal is configured to allocate an uplink bandwidth to the optical network unit, and carry the uplink bandwidth allocation information. Assignment type tag, where the assignment type tag is used to indicate The type of bandwidth allocated for the optical network unit; the optical network unit is used to maintain and use the corresponding upstream bandwidth according to the allocation type flag.

The optical line terminal specifically includes:

a type identifying unit, configured to allocate a fixed bandwidth or a dynamic bandwidth to the transport container according to the transport container type of the optical network unit, and set a corresponding allocation type identifier in the bandwidth allocation information; and a sending unit, configured to carry the allocation type identifier The bandwidth allocation information is sent to the optical network unit, and the analyzing unit is configured to determine whether to send the next bandwidth allocation information and the time interval for transmitting the next bandwidth allocation information according to the allocation type flag, or the allocation type flag, and the presence or absence of new bandwidth allocation information.

The optical network unit specifically includes:

a receiving unit, configured to receive bandwidth allocation information, and extract an allocation type identifier therein; and a bandwidth maintenance unit, configured to perform corresponding bandwidth allocation information storage and uplink bandwidth usage according to the allocation type flag for the corresponding transmission container.

The analyzing unit sends the bandwidth allocation information once every period in the case that the allocation type flag indicates that the dynamic bandwidth is allocated; and in the case that the allocation type flag indicates that the fixed bandwidth is allocated and there is new bandwidth allocation information, the instruction is sent. The unit immediately sends new bandwidth allocation information.

The bandwidth maintenance unit deletes the bandwidth allocation information immediately after the uplink burst packet is sent through the uplink bandwidth, if the allocation type flag indicates that the dynamic bandwidth is allocated; and allocates the bandwidth when the allocation type flag indicates that the fixed bandwidth is allocated. The information is stored for a long time and the upstream bandwidth is used for a long time until the new bandwidth allocation information sent by the optical line terminal is received.

The new bandwidth allocation information includes: bandwidth allocation information carrying a new bandwidth allocation type, a new bandwidth size, and/or a new start and end time, or special bandwidth allocation information whose start time is equal to the end time. The present invention carries the allocation type flag in the allocated uplink bandwidth allocation information, and the bandwidth used in the fixed bandwidth allocation type can make the bandwidth allocation of the relevant T-CONT only after the bandwidth needs to be changed, and the new bandwidth allocation is reduced. The OLT allocates the burden of the uplink bandwidth and reduces the occupation of the downlink bandwidth. BRIEF abstract

1 is a schematic diagram of a DBA format of a GPON system in the prior art;

Figure 2 is a flow chart of an embodiment of the method of the present invention;

3 is a schematic structural view of an embodiment of a system of the present invention;

FIG. 4 is a schematic diagram of bandwidth allocation according to an embodiment of the present invention.

Preferred embodiment of the invention

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The present invention relates to a frame header portion of a downlink GTC frame and a DBA format in a downlink GTC frame header

US BWmap„

Method embodiment

A method for bandwidth allocation of a passive optical network according to the present invention is shown in FIG. 2 for a flowchart. The method includes:

In the step S202, when the OLT allocates the uplink bandwidth to the ONU, the uplink bandwidth allocation information carries an allocation type flag, which is used to indicate the bandwidth type allocated for the ONU.

When the OLT allocates the uplink bandwidth to the ONU, an allocation type flag is added to the DBA format for the related uplink bandwidth, which is used to indicate the bandwidth allocation type. The bandwidth allocation type indicated by the allocation type flag includes: fixed bandwidth allocation type and dynamic bandwidth allocation. Types of.

Fixed Bandwidth Allocation Type: For this type of bandwidth, the OLT will not repeat the allocation after the assignment. If the bandwidth of the fixed bandwidth allocation type is to be modified, the modification can be implemented by issuing new bandwidth allocation information, and the original bandwidth is automatically reclaimed; the new bandwidth allocation information can also be a special bandwidth allocation information whose start time is equal to the end time. To reclaim the bandwidth of the fixed bandwidth allocation type. If the ONU is restarted or the OLT loses contact with the ONU, the OLT will reclaim the bandwidth of the associated fixed bandwidth allocation type.

Dynamic Bandwidth Allocation Type: For bandwidth of the dynamic bandwidth allocation type, the OLT is reassigned every cycle. The OLT determines to allocate a fixed bandwidth or a dynamic bandwidth to each T-CONT according to the T-CONT type of the ONU. Table 1 shows the relationship between the T-CONT type and the bandwidth allocation type. Different types of T-CONTs can accept different types of bandwidth allocation. Table 1 Relationship between T-CONT type and bandwidth allocation type

In Table 1, the type 1 T-CONT uses a fixed bandwidth and only supports the bandwidth of the fixed bandwidth allocation type. The OLT does not allocate the bandwidth of the fixed bandwidth allocation type once for the type 1 T-CONT. The bandwidth of -CONT can be achieved by redistributing the bandwidth of the fixed bandwidth allocation type, or by setting the special bandwidth with the end time equal to the start time to cancel the bandwidth of the Type 1 T-CONT.

Type 2-4 The bandwidth used by T-CONT can be dynamically changed, thus supporting the bandwidth of the fixed bandwidth allocation type and the bandwidth of the dynamic bandwidth allocation type. For Type 2-4 T-CONT, the bandwidth can be used in a certain time range by combining the bandwidth of the fixed bandwidth allocation type and the bandwidth of the dynamic bandwidth allocation type, that is, first allocate a fixed bandwidth allocation type bandwidth, and then allocate it after a period of time. A bandwidth of a dynamic bandwidth allocation type.

Type 5 T-CONT is configured as Type 1 to support only the bandwidth of the fixed bandwidth allocation type. When configured as Type 2 or Type 3 or Type 4, it supports the bandwidth of the fixed bandwidth allocation type and the bandwidth of the dynamic bandwidth allocation type.

Accordingly, the OLT should keep track of the type of bandwidth being allocated and should be able to distinguish which bandwidth It is a fixed bandwidth allocation type, and which bandwidth is a dynamic bandwidth allocation type. At the same time, the OLT should also provide an efficient bandwidth allocation method. For example, the bandwidth of the fixed bandwidth allocation type should be continuously allocated at the forefront of the total bandwidth, and the fixed bandwidth can be monitored at any time. The recovery of the allocation type bandwidth, etc., to effectively prevent the generation of bandwidth fragments. If sufficient bandwidth fragmentation is generated, the relevant bandwidth needs to be reclaimed for reallocation.

Step S204: After receiving the bandwidth allocation information, the ONU maintains and uses the corresponding uplink bandwidth according to the allocation type flag.

Correspondingly, the ONU needs to maintain the upstream bandwidth of each T-CONT locally, and the T-CONT related uplink bandwidth is stored according to the start time. For the bandwidth of the dynamic bandwidth allocation type, the ONU deletes the bandwidth allocation information after sending the uplink burst packet through the uplink bandwidth. For the bandwidth of the fixed bandwidth allocation type, the bandwidth allocation information will be stored by the ONU for a long time. The ONU uses the bandwidth as the uplink bandwidth of the relevant T-CONT until it receives the new bandwidth allocation information.

The new bandwidth allocation information includes changing the size or initial end time of the fixed bandwidth allocation type bandwidth, changing the fixed bandwidth allocation type to the dynamic bandwidth allocation type, and reclaiming the fixed bandwidth allocation type bandwidth (by setting the end time equal to the start time), etc. Bandwidth allocation information. The special bandwidth allocation information for recovering the bandwidth of the fixed bandwidth allocation type is required to be equal to the start time or the end time of the originally allocated bandwidth. When a T-CONT supports multiple upstream bandwidths, the start time and end time included in the new bandwidth allocation information need to be equal to the start time or end time of the originally allocated bandwidth.

In the above method, the allocation type flag can be designed to occupy 1 bit, represented by 0 or 1.

System embodiment

A schematic diagram of a system for implementing a passive optical network bandwidth allocation system according to the present invention is shown in FIG. 3.

Referring to FIG. 3, the system of the present invention includes an OLT 30 and an ONU 31. The OLT 30 is configured to allocate an uplink bandwidth to the ONU 31, and carry an allocation type flag in the uplink bandwidth allocation information, that is, add an allocation type flag in the DBA format, where the allocation type flag is used. Indicate the bandwidth allocated for ONU31 Type; ONU31 is used to maintain and use the corresponding upstream bandwidth according to the allocation type tag.

The OLT 30 specifically includes:

The type identifying unit 301 is configured to allocate a fixed bandwidth or a dynamic bandwidth to the T-CONT according to the T-CONT type of the ONU 31, and set a corresponding allocation type flag in the bandwidth allocation information. The sending unit 302 is configured to carry the allocation type. The marked bandwidth allocation information is sent to the ONU 31. The analyzing unit 303 is configured to determine whether to send the next bandwidth allocation information and the time interval for transmitting the next bandwidth allocation information according to the allocation type flag, or the allocation type flag, and the presence or absence of new bandwidth allocation information. .

The analyzing unit 303, in the case where the allocation type flag indicates the allocation of the dynamic bandwidth, the instruction transmitting unit 302 transmits the bandwidth allocation information once per cycle; and in the case where the allocation type flag indicates that the fixed bandwidth is allocated and there is new bandwidth allocation information, the instruction The transmitting unit 302 immediately transmits new bandwidth allocation information.

The ONU 31 specifically includes:

The receiving unit 311 is configured to receive the bandwidth allocation information, and extract the allocation type identifier therein. The bandwidth maintenance unit 312 is configured to perform corresponding bandwidth allocation information storage and uplink bandwidth usage according to the allocation type flag for the corresponding T-CONT.

The bandwidth maintenance unit 312 deletes the bandwidth allocation information immediately after the uplink burst packet is sent through the uplink bandwidth, if the allocation type flag indicates that the dynamic bandwidth is allocated; and allocates the bandwidth when the allocation type flag indicates that the fixed bandwidth is allocated. The information is stored for a long time and the upstream bandwidth is used for a long time until the new bandwidth allocation information sent by the OLT 30 is received.

The new bandwidth allocation information includes: bandwidth allocation information carrying a new bandwidth allocation type, a new bandwidth size, and/or a new start and end time; or special bandwidth allocation information whose start time is equal to the end time, The OLT 30 is used to recover the original upstream bandwidth. The special bandwidth allocation information for reclaiming the bandwidth of the fixed bandwidth allocation type is required to be equal to the start time or the end time of the originally allocated bandwidth. When a T-CONT supports multiple uplink bandwidths, the start time and end time included in the new bandwidth allocation information need to be equal to the start time or end time of the originally allocated bandwidth. Take the existing GPON system as an example.

The uplink bandwidth allocation format of the GPON system is shown in Figure 1. The 6-0 bits of the Flags field are reserved. In this embodiment, the bit 6 of the reserved field is used as the allocation type. The bits 6 of the Flags field are designed as follows:

1 : fixed bandwidth allocation type;

0: Dynamic bandwidth allocation type.

An example of bandwidth allocation is shown in Figure 4, where the shaded block represents the bandwidth of the fixed bandwidth allocation type, the grid block represents the bandwidth of the dynamic bandwidth allocation type, and the vertical bar represents the bandwidth that continues to be used without allocation. The first column example is the fixed bandwidth T-CONT, which is allocated to the fixed bandwidth allocation type of 10 KB in the first period, and the new bandwidth allocation is not received in the second period, and the bandwidth of the fixed bandwidth allocation type of 10 KB is continued. The cycle receives the bandwidth of the new fixed bandwidth allocation type and replaces the used bandwidth with 15 KB. The subsequent fourth ninth ninth cycle does not receive the new bandwidth allocation and continues to use the fixed bandwidth allocation type of 15 KB. The second column example is the dynamic bandwidth T-CONT, which receives 11KB of dynamic bandwidth allocation type bandwidth in the first cycle and uses one cycle. The second cycle receives 12KB of dynamic bandwidth allocation type bandwidth and uses one cycle, third. Receives 5 KB of dynamic bandwidth allocation type bandwidth and uses one cycle. The fourth cycle receives 11 KB of dynamic bandwidth allocation type bandwidth and uses one cycle. The fifth cycle receives 11 KB of fixed bandwidth allocation type bandwidth. In the eighth period, the new bandwidth allocation is not received and the bandwidth of the fixed bandwidth allocation type is continued to be 11 KB. The ninth period receives the new dynamic bandwidth allocation type bandwidth of 5 KB and uses one cycle, and simultaneously allocates the bandwidth of the previous fixed bandwidth allocation type. cancel.

Obviously, those skilled in the art should understand that the above-mentioned modules or steps of the present invention can be implemented by program code executable by a computing device, so that they can be stored in a storage device by a computing device, or They are fabricated as individual integrated circuit modules, or a plurality of modules or steps thereof are fabricated as a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Industrial applicability

In summary, the present invention carries the allocation type flag in the allocated uplink bandwidth allocation information, and the bandwidth of the fixed bandwidth allocation type can be used to make the bandwidth of the relevant T-CONT only after the bandwidth needs to be changed. The bandwidth allocation, thereby reducing the repeated allocation of the uplink bandwidth, reduces the burden on the OLT to allocate the uplink bandwidth; reducing the occupation of the downlink bandwidth by reducing the number of transmissions of the US Bwmap.

Claims

Claim

A method for allocating a bandwidth of a passive optical network, the method comprising: when an optical line terminal allocates an uplink bandwidth to an optical network unit, carrying an allocation type flag in the uplink bandwidth allocation information, where the indication is The type of bandwidth allocated by the optical network unit;

After receiving the bandwidth allocation information, the optical network unit maintains and uses a corresponding uplink bandwidth according to the allocation type flag.

The bandwidth allocation method of the passive optical network according to claim 1, wherein the bandwidth allocation type indicated by the allocation type flag comprises: a fixed bandwidth allocation type and a dynamic bandwidth allocation type.

The method for allocating a bandwidth of a passive optical network according to claim 2, wherein the optical line terminal allocates the same bandwidth of the fixed bandwidth allocation type only once in a continuous period; the optical network unit receives In the case of indicating the allocation type flag of the fixed bandwidth allocation type, the bandwidth allocation information is stored for a long time and the uplink bandwidth is used for a long time until the new bandwidth allocation information sent by the optical line terminal is received.

The method for allocating a bandwidth of a passive optical network according to claim 2, wherein, when the optical network unit receives the allocation type flag indicating the dynamic bandwidth allocation type, the optical network unit sends the uplink bandwidth through the uplink bandwidth. After the uplink burst packet is completed, the bandwidth allocation information is deleted, and the optical line terminal re-allocates the uplink bandwidth of the next period.

The method for allocating a bandwidth of a passive optical network according to claim 3, wherein the optical line terminal reclaims the uplink bandwidth of the original fixed bandwidth allocation type by issuing new bandwidth allocation information, the new bandwidth. The allocation information includes: bandwidth allocation information carrying a new bandwidth allocation type, a new bandwidth size, and/or a new start and end time, or special bandwidth allocation information whose start time is equal to the end time.

The passive optical network bandwidth allocation method according to any one of claims 2 to 5, wherein the optical line terminal determines to allocate and fix the transmission container according to a transmission container type of the optical network unit. Bandwidth or dynamic bandwidth.

The passive optical network bandwidth allocation method according to claim 3 or 5, wherein the optical network unit is restarted, or the optical line terminal loses contact with the optical network unit Next, the optical line terminal reclaims the original uplink bandwidth.

8. The passive optical network bandwidth allocation method according to claim 1, wherein the allocation type flag occupies 1 bit.

9. A passive optical network bandwidth allocation system, comprising an optical line terminal and an optical network unit, wherein the feature is that

The optical line terminal is configured to allocate an uplink bandwidth to the optical network unit, and carry an allocation type flag in the uplink bandwidth allocation information, where the allocation type flag is used to indicate a bandwidth type allocated to the optical network unit. ;

The optical network unit is configured to maintain and use a corresponding uplink bandwidth according to the allocation type flag.

The passive optical network bandwidth allocation system according to claim 9, wherein the optical line terminal specifically includes:

a type identifying unit, configured to allocate a fixed bandwidth or a dynamic bandwidth to the transport container according to a transport container type of the optical network unit, and set a corresponding allocation type flag in the bandwidth allocation information;

a sending unit, configured to send, to the optical network unit, bandwidth allocation information that carries the allocation type identifier;

And an analyzing unit, configured to determine whether to send the next bandwidth allocation information and the time interval for transmitting the next bandwidth allocation information according to the allocation type flag, or the allocation type flag, and the presence or absence of new bandwidth allocation information.

The passive optical network bandwidth allocation system according to claim 9, wherein the optical network unit specifically includes:

a receiving unit, configured to receive the bandwidth allocation information, and extract an allocation type identifier therein; and a bandwidth maintenance unit, configured to perform, for the corresponding transmission container, corresponding bandwidth allocation information storage and uplink bandwidth usage according to the allocation type identifier.

12. The passive optical network bandwidth allocation system according to claim 10, wherein the analyzing unit instructs the sending unit to send once every period when the allocation type flag indicates that a dynamic bandwidth is allocated. Bandwidth allocation information; and indicating allocation in the allocation type flag In the case where the bandwidth is fixed and there is new bandwidth allocation information, the transmitting unit is instructed to immediately transmit the new bandwidth allocation information.

The bandwidth allocation system of the passive optical network according to claim 11, wherein the bandwidth maintenance unit sends an uplink burst through the uplink bandwidth when the allocation type flag indicates that the dynamic bandwidth is allocated. The bandwidth allocation information is deleted immediately after the packet is sent; and when the allocation type flag indicates that the fixed bandwidth is allocated, the bandwidth allocation information is stored for a long time and the uplink bandwidth is used for a long time until the optical line is received. New bandwidth allocation information sent by the terminal.

The passive optical network bandwidth allocation system according to claim 12 or 13, wherein the new bandwidth allocation information comprises: carrying a new bandwidth allocation type, a new bandwidth size, and/or a new one. Bandwidth allocation information for start and end times, or special bandwidth allocation information with a start time equal to the end time.