KR20090119856A - A dynamic bandwidth allocation device for a passive optical network system and the method implemented - Google Patents

Abstract

A dynamic bandwidth allocation device and method for a passive optical network system, the said device comprises:a bandwidth allocation unit for allocating a total number of transmission bytes for each of the transmission containers in a passive optical network system in turn in each of the schedule periods, and saving a transmission container bandwidth allocation list generated; and a bandwidth allocation policy control unit for reading the transmission container bandwidth allocation list in each of the schedule periods, then allocating the total number of transmission bytes to each individual time frame in the schedule periods, and eventually generating the bandwidth allocation map.

Description

A dynamic bandwidth allocation device and its implementation method for a passive optical subscriber network system {A DYNAMIC BANDWIDTH ALLOCATION DEVICE FOR A PASSIVE OPTICAL NETWORK SYSTEM AND THE METHOD IMPLEMENTED}

TECHNICAL FIELD The present invention relates to the field of communications, and more particularly, to dynamic bandwidth allocation (DBA) for realization of a passive optical subscriber network system (XPON) such as a gigabit passive optical network (GPON). bandwidth assignment) and an implementation method thereof.

GPON technology is a new broadband passive optical subscriber network technology that supports gigabit rates. GPON is a point to multi-point structure in physical topology, but logically a point-to-point structure. The downlink data transmission is in broadcast format and all optical network terminals (ONTs) can receive all downlink data frames at the physical PON port. In contrast, uplink is a time division multiplex (TDMA) method, and each ONT can transmit uplink data only within an uplink authorization time slot allocated by an optical line terminal (OLT).

In GPON, the authorization target of bandwidth allocation is a "transmission container" (T-CONT). One ONT may include multiple T-CONTs. There are five types of T-CONT, such as T-CONT1, T-CONT2, T-CONT3, T-CONT4, and T-CONT5. Among them, T-CONT type 1 is a fixed bandwidth type and does not need to participate in dynamic bandwidth allocation, and all other types of T-CONT can obtain bandwidth through dynamic bandwidth allocation. In OLT, a functional unit that allocates an uplink bandwidth to each T-CONT is called dynamic bandwidth allocation (DBA). GPON's DBAs include two status reporting DBAs (SR-DBA) and a stateless reporting DBA (NSR-DBA). The bandwidth utilization is high because SR-DBA can respond more accurately to the bandwidth demands of T-CONT. When using SR-DBA, the bandwidth claim (DSRu) reported by each T-CONT must be taken into account when allocating an uplink bandwidth to the T-CONT, and the service level agreement (SLA) installed by the network administrator on each T-CONT. Consideration should also be given to service level agreement parameters. The contents of these parameters are different depending on the type of T-CONT.

As one of the core technologies of GPON, the realization of DBA should be carefully planned with consideration of each aspect. Bandwidth allocation generally requires throughput, time delay, jitter, and fairness. As for algorithms, there is a demand for efficiency and resource occupancy of the algorithm. In addition, the DBA is a very active part of the GPON system. Therefore, it is necessary to consider scalability in the design of the DBA device because the DBA must be adjusted normally by affecting the quality of service (Qos). Currently, there are relatively few studies on GPON DBAs, most of them focused on algorithms, and very little research on DBA realization design. As already reported, the DBA design proposal was submitted to "Efficient medium arbitration of FSAN-compliant GPONs" published by H.C.Leliguo, Int.J.Commum.Syst 2006; 19: 603-617. One of the salient features of the scheme is that the algorithm realizes the allocation of bandwidth and location and length of time slots in the bandwidth allocation map (BWMap). This presents a problem of low scalability due to the strong coupling of both. Therefore, it is necessary to study how to realize a new DBA.

(Challenge to be solved)

In order to solve the above problems, an object of the present invention is to provide a dynamic bandwidth allocation apparatus and its implementation method used in a passive optical subscriber network system.

(Solution Solution)

According to an aspect of the present invention, in a dynamic bandwidth allocation apparatus used for a passive optical subscriber network system, the total number of bytes transmitted is sequentially assigned to each transport container in the passive optical subscriber network system within each dispatching period. A bandwidth allocation subunit that preserves the allocated and generated transport container bandwidth allocation list, and after reading the transport container bandwidth allocation list in each dispatch period, allocate the total number of transmitted bytes to each timing frame in the dispatch period and finally bandwidth allocation A dynamic bandwidth allocation device including a bandwidth distribution strategy control subunit for generating a map is provided.

In the dynamic bandwidth allocation apparatus, the bandwidth allocation subunit and the bandwidth distribution strategy controlling subunit are independent of each other and perform different algorithms.

In the dynamic bandwidth allocation apparatus, the bandwidth allocation subunit performs a bandwidth allocation algorithm to calculate the total number of transmitted bytes based on the uplink bandwidth request information and the transport container service level agreement information installed by the user.

In the dynamic bandwidth allocation apparatus, the bandwidth distribution strategy control subunit applies the bandwidth distribution strategy installed by the network manager under the consideration of the overhead arrangement, and allocates the total number of bytes to each timing frame to each timing frame. Get the time slot position and length of the frame.

In the above-described dynamic bandwidth allocation apparatus, the uplink bandwidth request information transmitted from each transport container in the previous period and received by the optical fiber terminator is examined, and the idler actually transmitted by each transport container in the previous period. A bandwidth billing and statistical investigation subunit which preserves through the interface provided by the data maintenance subunit for use by the bandwidth allocation subunit after the processing of the statistics of the byte count and the investigation result; Provides an interface to the Bandwidth Billing and Statistics Survey subunit for preserving uplink bandwidth billing information, provides an interface to the Bandwidth Assignment subunit for preserving transport container bandwidth allocation list, and accesses the Transport Container Bandwidth Allocation List. Bandwidth distribution maneuver to help And a data maintenance subunit providing an interface to the subunit, and a timing service subunit providing timing service to each subunit of the dynamic bandwidth allocation apparatus.

An apparatus for dynamic bandwidth allocation, comprising: an interface installation subunit providing an interface for installing dynamic bandwidth allocation related parameters, transport container service level agreement parameters and bandwidth distribution strategies to a user, and total available bandwidth within one dispatch period; The apparatus further includes an overhead processing subunit that calculates an overhead overhead to be transmitted by each frame within the same period.

In the dynamic bandwidth allocation apparatus, the passive optical subscriber network system is a gigabit passive optical subscriber network system.

According to another aspect of the present invention, a bandwidth allocation subunit, a bandwidth distribution strategy control subunit, an interface installation subunit, an overhead processing subunit, a bandwidth claim and A method of realizing a dynamic bandwidth allocation apparatus including a statistical investigation subunit, a data maintenance subunit, and a timing service subunit, wherein the timing service subunit provides a timing interruption to form a period, the bandwidth claim and the statistical investigation. A subunit is sent from each transport container within each dispatch period to examine the uplink bandwidth billing information received by the ray interrupter, and statistics on the number of idle bytes actually transmitted by each transport container within the entire period. Data processing after processing the data Through the interface provided by the nonce subunit, the bandwidth allocation subunit is stored and used by the bandwidth allocation subunit. The bandwidth allocation subunit sequentially allocates the total number of transmitted bytes to each transport container in the passive optical subscriber network system within each dispatch period. The generated transport container bandwidth allocation list is preserved, and the bandwidth distribution strategy control subunit reads the transport container bandwidth allocation list in each dispatch period and then allocates the total number of transmitted bytes to each timing frame in the dispatch period to finally allocate bandwidth. Generates a map, and within each dispatch period, the dynamic bandwidth allocation device notifies the bottom layer MAC hardware that the bandwidth allocation map has already been updated, and the MAC hardware transmits the bandwidth allocation map through each downlink frame. And a step of transmitting to the work station.

In the above implementation method, the bandwidth allocation subunit and the bandwidth distribution strategy controlling subunit are independent of each other and perform different algorithms.

In the above-described realization method, the bandwidth distribution strategy control subunit applies the bandwidth distribution strategy installed by the network administrator under the circumstances in consideration of overhead arrangement and allocates the total number of transmitted bytes to each timing frame.

In the above-described realization method, the method further includes installing service level agreement parameters, dynamic bandwidth allocation device parameters, and bandwidth distribution strategy of each transport container through the installation of an interface.

In the above realization method, the passive optical subscriber network system is a gigabit passive optical subscriber network system.

Accordingly, the method and apparatus according to the present invention can improve the activity and expandability of the DBA function installation in XPON, for example, GPON. Other features and advantages of the invention will be set forth in detail in the description which follows, and in part will be obvious by reference to the description or may be understood by practice of the invention. The objects and other advantages of the present invention can be realized and obtained through the structures particularly pointed out in the specification, claims and drawings.

(effect)

According to the method and apparatus of the present invention, since the bandwidth allocation portion and the bandwidth distribution control portion within the dispatch period can be divided, independent adjustment of the bandwidth allocation algorithm and the bandwidth distribution scheme algorithm is provided and an interface for installing DBA related parameters is provided. The method is simple to implement, not only hardware but also software. By adopting the above DBA realization method, it is possible to improve the activity and expandability of the DBA function installation in XPON, for example, GPON.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings described herein are for further understanding of the present invention and are part of the present invention and for the purpose of interpreting the present invention, together with the embodiments described herein, but not for limiting the present invention.

1 is a GPON topology diagram according to an embodiment of the present invention,

2 is a structural guide diagram of a DBA functional unit according to an embodiment of the present invention,

1 is a flowchart of a DBA device according to an embodiment of the present invention.

(Specific contents for implementation of the invention)

Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

The technical problem to be solved by the present invention is to provide a method for realizing the DBA function of GPON that solves the disadvantages of low current and low expandability existing in the current technology.

The method of realizing DBA function of GPON according to the present invention is as follows:

In the first step, the DBA function unit includes a bandwidth allocation subunit, a bandwidth distribution strategy control subunit, an interface installation subunit, an overhead processing subunit, a DBRu and a statistical inquiry subunit, and data maintenance ( maintenance) and the timing service subunit.

In the second step, the DBA device operates periodically. When the timing provided by the timing service subunit is interrupted, the DBRu and the statistical investigation subunit first examines the upstream DBRu information received by the OLT received from all T-CONTs in the previous period and performs processing thereon. Then, it is preserved through the access interface provided by the data maintenance subunit to be used by the bandwidth allocation subunit. In addition, during the previous period, each T-CONT examines the statistics of the number of non-idle bytes actually transmitted, performs processing thereon, and preserves them through the access interface provided by the data maintenance subunit, thereby allowing the bandwidth allocation subunit to use them. Let's do it.

In a third step, the DBA bandwidth allocation subunit performs a bandwidth allocation algorithm. Based on the DBRu information and the T-CONT SLA information installed by the user, the total number of transmitted bytes is allocated to each T-CONT within the dispatch cycle, and the data maintenance subunit provides the generated T-CONT bandwidth allocation list. Save through the interface.

Step 4, The Bandwidth Distribution Strategy Control Subunit Follows, Reads the List of Bandwidth Allocations Generated by the Bandwidth Allocation Subunit Through the Access Interface Provided by the Data Maintenance Subunit, and then Displays the Network Manager on the Basic Considering Overhead Arrangement BWMap is finally generated by allocating the total transmission bytes of each T-CONT to each 125us frame in the dispatch period by applying the bandwidth distribution strategy installed by the.

In the fifth step, the DBA device notifies the lower layer MAC hardware that the BWMap has already been updated, and the MAC transmits the BWMap to the ONT through the downlink frame.

The sixth step and the sixth step from the third step are repeated.

In the seventh step, the network manager can install the SLA of each T-CONT and the DBA device's own parameters and bandwidth distribution strategy through the deployment interface.

Among them, the first step further includes the following steps.

1, the bandwidth allocation subunit performs a bandwidth allocation algorithm to allocate the total number of bytes that can be transmitted to each T-CONT in one dispatch period.

2, the bandwidth distribution strategy control subunit allocates the time slot position and length in each 125us frame in each dispatch period of each T-CONT by applying the bandwidth allocation strategy.

3, the interface installation subunit provides the user with an interface for installing DBA related parameters, T-CONT SLA parameters and bandwidth distribution strategy.

4, overhead processing subunit calculates the overhead overhead that each frame should transmit in the same period as the total available bandwidth in one dispatch period.

5, DBRu and Inquiry The subunit examines and summarizes the statistics of its rank occupancy and actual upstream transmissions reported by each T-CONT.

6, the data maintenance subunit maintains the data list required for the other subunits and provides an access interface.

7, timing service subunit provides timing synchronization service required for other subunits.

Hereinafter, the basic idea of the present invention will be described in detail with reference to FIGS. 1 to 3. 1 is a GPON network topology diagram associated with the method of the present invention.

A plurality of ONTs may be connected to one OLT PON port through a spectrometer as shown in FIG. 1. The downlink data transmission format from the OLT to the ONT is a time division multiple access and physical layer broadcast format, that is, each downlink frame is transmitted to the PON ports of all ONTs. The uplink data transmission format from ONT to OLT is TDMA format. Each ONT contains a number of T-CONTs, and the allocation of upstream bandwidth is realized through the DBA functional unit of the OLT, and the T-CONT is authorized.

2 is a structural guide diagram of the DBA apparatus 200 according to the method of the present invention. As shown in FIG. 2, the DAB apparatus 200 includes a bandwidth allocation subunit 202, a bandwidth distribution strategy control subunit 204, an interface installation subunit 206, and an overhead processing subunit 208. And the DBRu and the statistical investigation subunit 210, the data maintenance subunit 212, and the timing service subunit 214.

The function of each sub unit is as follows.

(1) The bandwidth allocation subunit 202 allocates the total number of bytes (number?) That can be transmitted to each T-CONT in one dispatch period. Parameters input by this include total bandwidth available, SLA of each T-CONT, DBRu information, type, statistical information of the previous cycle and bandwidth allocation granularity, and the like. Its output is the total number of bytes that each T-CONT gets in this dispatch cycle and is called the "T-CONT bandwidth allocation list" and the list item is the total number of bytes that T-CONT can transmit in this cycle. In this embodiment, the bandwidth allocation algorithm used by the bandwidth allocation subunit 202 can be provided as a dynamic link library independent of the realization of the overall DAB apparatus 200.

(2) The bandwidth distribution strategy control subunit 204 allocates the total number of transmittable bytes of T-CONT generated by the bandwidth allocation subunit to each frame within the dispatch period according to the specified distribution strategy, and the overhead processing subunit 208 ) Combines with the overhead distribution specified by the) and the window distribution situation found by the ONT to form a BWMap compliant with the ITU-T G.984.3 standard and notifies the OLT MAC 216 to send a new BWMap to each ONT in the downlink frame. . The bandwidth distribution strategy here is actually a Qos realization strategy that can be installed by the network administrator. For example, when employing a distribution strategy of "throughput priority", the transmission time slots of T-CONTs belonging to one ONT should be arranged in one place to reduce overhead as much as possible. Other strategies include "time delay priority" or "jitter priority". The sub-unit is the most active part of the overall DAB apparatus 200, and its maneuvering algorithm can also be provided as a dynamic link library to bring convenience in updating and maintenance.

(3) The interface installation subunit 206 provides an interface for installing a DBA and a T-CONT SLA to a user who is a network administrator.

A. T-CONT SLA: Fixed Bandwidth, Assured Bandwidth, Non-Assured Bandwidth, Best Effort Bandwidth, Maximum Burst Packet Size and Weight weight, etc .;

B. DBA device parameters: dispatch cycle, bandwidth allocation granularity, frequency of processes found by ONT, maximum bandwidth available, and the like;

C. Bandwidth distribution strategy.

(4) The overhead processing subunit 208 processes the overhead overhead transmission request provided by the GPON OLT state machine. Based on this, the total amount of available upstream bandwidth in the dispatch period is calculated and the result is sent to the bandwidth allocation subunit 202. In addition, an overhead transmission request is provided to the bandwidth distribution strategy control subunit 204 to provide a transmission time slot for overhead in the BWMap.

(5) The DBRu and the statistical survey subunit (i.e., the DBRu and the statistical survey subunit shown in FIG. 2) 210 are actually divided into the following two parts. One is to calculate the bandwidth usage by checking the number of bytes actually transmitted by each T-CONT every cycle, and the list item outputs the "T-CONT bandwidth utilization list", which is the bandwidth utilization of the T-CONT, and the upstream bandwidth of the T-CONT. We use for monitoring the use situation. The other is to examine the DBRu information received from each T-CONT in the entire period and output a "T-CONT bandwidth request list". The list item is the number of bytes requested for transmission by the T-CONT.

(6) The data maintenance subunit 212 provides an access interface to all parameters and data lists installable in the DBA apparatus and performs mutual exclusion protection processing. However, this subunit is the final output of the DBA device and is not responsible for the maintenance of the BWMap list used for the OLT MAC hardware 216.

(7) Timing service subunit 214 is generally realized in hardware and can be simplified, for example, can provide a timing service of 125us, and stop at the dispatch cycle to start periodic operation of the DBA.

FIG. 3 is a complete process flow diagram within one cycle of a DBA device in accordance with the method of the present invention, in combination with the device 200 shown in FIG. 2 below to describe the method shown in FIG. After receiving the interruption provided from the timing service subunit, as shown in FIG. 3, the DBA starts a cycle of operation.

In step S302, the DBRu and statistics investigation subunit 210 examines the uplink DBRu claim of each T-CONT and the statistics of the actual transmission amount in all cycles through the hardware, and also performs processing to perform "T-CONT bandwidth." Utilization list " and " T-CONT bandwidth application list ". The overhead processing subunit 208 subsequently calculates the total amount of uplink bandwidth available within this period.

In step S304, the bandwidth allocation subunit 202 performs a bandwidth allocation algorithm to allocate the total number of transmittable bytes to each T-CONT and generate a "T-CONT bandwidth allocation list". Thereafter, the bandwidth distribution strategy control subunit 204 first distributes the specific transmission time slot to the overhead that needs to be transmitted within this period.

In step S306, the hardware is notified that an actual transmission time slot has been allocated to each T-CONT within each 125us frame in this period according to the currently specified distribution strategy, and a final BWMap has been constructed and updated.

In step S308, the OLT MAC hardware 216 transmits the same BWMap to all ONTs on the downlink frame.

In addition, the method may further include installing service level agreement parameters, dynamic bandwidth allocation devices, and bandwidth distribution strategies of each transport container through the installation of the interface.

In addition, the bandwidth allocation subunit 202 and the bandwidth distribution strategy control subunit 204 are independent and perform different algorithms. In addition, the bandwidth distribution strategy control subunit 204 applies the bandwidth distribution strategy installed by the network manager under consideration of overhead arrangement, and allocates the total number of transmitted bytes to each timing frame.

As described above, according to the present invention, the following effects can be realized.

According to the method and the apparatus of the present invention, the bandwidth allocation portion and the bandwidth distribution control portion in the dispatch period can be divided to enable independent adjustment of the bandwidth allocation algorithm and the bandwidth distribution scheme and provide an interface for installing DBA related parameters. do. The method is simple to implement, not only hardware but also software. By adopting the above DBA realization method, it is possible to improve the activity and expandability of the DBA function installation in XPON, for example, GPON.

The foregoing is not intended to limit the invention to the optimized embodiments of the invention. Those skilled in the art can bring various changes and changes to the present invention. All the number, equal exchange, improvement, etc. which were performed within the range without deviating from the mind and principle of this invention belong to the protection scope of this invention.

Claims (10)

A dynamic bandwidth allocation apparatus used for a passive optical subscriber network system, A bandwidth allocation subunit which sequentially allocates the total number of transmitted bytes to each transport container in the passive optical subscriber network system in each dispatch period and keeps the generated transport container bandwidth allocation list; And a bandwidth distribution strategy control subunit which reads the transport container bandwidth allocation list in each dispatch period and then allocates the total number of transmitted bytes to each timing frame in the dispatch period and finally generates a bandwidth allocation map. A dynamic bandwidth allocation device used for a passive optical subscriber network system. The apparatus of claim 1, wherein the bandwidth allocation subunit and the bandwidth distribution strategy control subunit are independent of each other. [4] The passive optical of claim 2, wherein the bandwidth allocation subunit performs a bandwidth allocation algorithm to calculate the total number of transmitted bytes based on uplink bandwidth billing information and user-installed transport container service level agreement information. Dynamic bandwidth allocation device used in subscriber network system. 4. The method of claim 3, wherein the bandwidth distribution strategy controlling subunit is configured to allocate the total number of transmitted bytes to each timing frame by applying a bandwidth distribution strategy installed by a network manager under an overhead arrangement. A dynamic bandwidth allocation device used in a passive optical subscriber network system characterized by obtaining a time slot location and length. 5. The method according to claim 4, wherein the uplink bandwidth request information transmitted from each of the transport containers within the entire period and received by the optical fiber stop device is examined and the number of idle bytes actually transmitted by each of the transport containers within the entire period. A bandwidth billing and statistical survey subunit which inspects statistics and performs processing on the results of the survey and then preserves them through an interface provided by the data maintenance subunit for use by the bandwidth allocation subunit; Provide an interface to the bandwidth billing and statistics investigation subunit to preserve the uplink bandwidth billing information, and provide an interface to the bandwidth allocation subunit to preserve the transport container bandwidth allocation list, the transport container bandwidth A data maintenance subunit providing an interface to the bandwidth distribution strategy controlling subunit to access an allocation list; And a timing service subunit providing timing service to each subunit of the dynamic bandwidth allocation apparatus. The method of claim 5, An interface installation subunit providing an user with an interface for installing dynamic bandwidth allocation related parameters, transport container service level agreement parameters, and bandwidth distribution strategy; And an overhead processing subunit that calculates the total available bandwidth in one dispatch period and the uplink overhead that each frame should transmit within that period. 7. The apparatus of any one of claims 1 to 6, wherein the passive optical subscriber network system is a gigabit passive optical subscriber network system. Used for dynamic bandwidth allocation of passive optical subscriber network system, bandwidth allocation subunit, bandwidth distribution strategy control subunit, interface installation subunit, overhead processing subunit, bandwidth billing and statistical investigation subunit, data In the realization method of the dynamic bandwidth allocation apparatus including a maintenance sub unit and a timing service sub unit, The timing service subunit provides an interruption in timing to form a period, The bandwidth claim and statistical investigation subunit is transmitted from each of the transport containers within the entire cycle within each dispatch period to examine the uplink bandwidth billing information received by the ray interrupter and is actually transmitted by each of the transport containers within the entire cycle. Investigate the statistics of the idle bytes, perform processing on the result of the investigation, and save the data through the interface provided by the data maintenance subunit to make the bandwidth allocation subunit available. The bandwidth allocation subunit sequentially allocates the total number of transmitted bytes to each transport container in the gigabit passive optical subscriber network system within each dispatch period, and preserves the generated transport container bandwidth allocation list, The bandwidth distribution strategy controlling subunit reads the transport container bandwidth allocation list in each dispatch period and then allocates the total number of transmitted bytes to each timing frame in the dispatch period to finally generate a bandwidth allocation map, The dynamic bandwidth allocation device notifies the underlying MAC hardware that the bandwidth allocation map has already been updated in each dispatch period, and wherein the MAC hardware transmits the bandwidth allocation map to each optical network terminal via a downlink frame. A method of realizing a dynamic bandwidth allocation device, characterized by the above-mentioned. 10. The method of claim 8, wherein the bandwidth allocation subunit and the bandwidth distribution strategy controlling subunit are independent of each other and perform different algorithms. 10. The method of claim 8 or 9, wherein the passive optical subscriber network system is a gigabit passive optical subscriber network system.

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