KR101001515B1 - Media access control method for weighted fairness guarantee scheduling in ethernet passive optical network - Google Patents

Abstract

The present invention relates to a scheduling method of an Ethernet passive optical network (EPON) system. The present invention relates to a method for equally multiplexing an uplink from an optical network unit (ONU) to an optical line terminal (OLT) in an Ethernet passive optical network system. A method of controlling access to a medium in an Ethernet passive optical network (EPON) having an optical network unit (ONU) and a specific optical line terminal (OLT) of the optical network terminal (ONU). A first step of allocating a traffic transmission amount that can be transmitted in one cycle to an optical line terminal in proportion to the weight between the plurality of optical network termination devices; and the specific optical data for transmitting the allocated traffic transmission amount to the plurality of optical network termination devices. A second step of setting a traffic transmission algorithm of a line terminal device; A third step of transmitting the maximum amount of traffic to a specific optical line terminal as long as there is traffic in each cycle according to a predetermined traffic transmission algorithm, and a fourth step of using the remaining quota for the next cycle if the traffic quota is not met. It comprises a medium access control method for ensuring the weight fairness of the Ethernet passive optical network characterized in that.

Description

 MEDIA ACCESS CONTROL METHOD FOR WEIGHTED FAIRNESS GUARANTEE SCHEDULING IN ETHERNET PASSIVE OPTICAL NETWORK}             

1 is a network diagram of an Ethernet passive optical network system,

FIG. 2 is a sequence diagram showing step by step an embodiment of a medium access control method for ensuring weight fairness in an Ethernet passive optical network according to the present invention; FIG.

The present invention relates to a scheduling method of an Ethernet passive optical network (EPON) system, and more particularly, to an optical line terminal (OLT :) from a plurality of optical network units (ONUs) of an Ethernet passive optical network system. The present invention relates to a scheduling scheme required for media access control by using multiplexing uplinks to an optical line terminal.

FIG. 1 is a network diagram of an Ethernet passive optical network system including an optical line terminal 100, an optical splitter 150, and a plurality of optical network termination devices 110, 120, 130.

In the figure, a single optical line terminal 100 is connected to a plurality of optical end devices 110, 120, 130 through an optical splitter 150 to use an Ethernet-based frame as a data transmission unit. do.

In order to provide the same speed to each fiber terminator in an Ethernet passive optical network system, the conventional method is to allocate time slots for each fiber terminator, and packets arriving at the fiber terminator wait in a buffer and then come to their time slot. A time division multiple access (TDMA) scheme for transmitting in an upward direction,

At the end of the allotted transmission time to the fiber terminator, a request frame is sent for the amount of traffic to be transmitted in the next cycle. There is an Interleaved Plooing with Adaptive Cycle Time (IPACT) scheme that controls the transmission of fiber termination devices by sending specified grant frames.

However, the TDMA scheme has a disadvantage in that the average residual bandwidth that is not used is large and the data traffic having self similarity has a large delay time and a low traffic throughput rate.

 The IPACT method has the advantage of being able to send a certain amount of data from the fiber termination device and transmit it in proportion to the amount of data in the buffer, but it does not include a function to ensure that data is delivered fairly by each fiber termination device. It has a disadvantage.

As described above, the conventional method has to provide the same service to the subscribers who pay the same fee regardless of the traffic pattern or the current network condition. Have.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and provides the bandwidth of traffic in proportion to the corresponding weight of each optical fiber termination device to reduce the remaining bandwidth wasted in the conventional Ethernet passive optical network medium access control. There is this.

In order to achieve the above object, the present invention provides a medium access control in an Ethernet passive optical network (EPON) having a plurality of optical network units (ONUs) and specific optical line terminals (OLTs). A method, comprising: a first step of allocating a traffic transmission amount that can be transmitted in one cycle from the plurality of optical network terminators to the specific optical line terminal in proportion to a weight between the plurality of optical network terminators; A second step of setting a traffic transmission algorithm of the specific optical line terminal device for transmission to a plurality of optical network terminators, and as long as the plurality of optical network terminators have traffic in one cycle according to the set traffic transmission algorithm, respectively 3 steps to send the maximum amount of traffic to a specific optical line terminal and fail to meet the traffic quota Wu and the remaining quota characterized by the media access control method for ensuring fairness weight of an Ethernet passive optical network comprising the step of using four handed over to the next cycle.

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

2 is a sequence diagram showing step by step an embodiment of a medium access control method for ensuring weight fairness in an Ethernet passive optical network according to the present invention;

The optical line terminal 330 allocates and allocates the amount of traffic transmission that each optical fiber terminator 340, 350 can transmit in one cycle, in proportion to the transmission weights that are serviced for each optical fiber terminator 340,350. Step 1 of setting a traffic algorithm of the optical line terminal device 330 for transmission of traffic volume;

The optical network terminator 340, 350 transmits a request frame for the amount of traffic to be transmitted in the next cycle (304, 306) in the last part of the transmission time allocated to it (step 304, 306),

The optical line terminal 330 receiving the request frame transmission 304, 306 transmits a grant frame specifying the traffic allocation allowed to the corresponding fiber terminator 340, 350 in the next cycle ( 301) (302) step 3,

The optical network terminator 340, 350, which has received the traffic quota from the optical line terminal 330, transmits the traffic by the allocated amount (303) (305), and if the quota is not met, the remaining quota is used for the next cycle. There are four steps.

(304)라고 했을 때

(304)는 수학식 1과 같이 계산되어 진다.The calculation formula for the request frame for the amount of traffic to be transmitted in the next cycle in step 2 is the amount of traffic that the i-th optical end device requests transmission to the optical line terminal using the request frame in the j-th cycle.

When we said 304

304 is calculated as in Equation 1.

(301)은 j번째 사이클에서 i번째 광망종단장치에게 할당되는 트래픽 전송 허락 양을 나타내며,

는 현재 i번째 광망 종단장치의 큐에 도착해서 저장되어 있는 트래픽을 나타내고,

는 현재 사이클에서 남은 전송량을 나타낸다.In Equation 1

301 represents the traffic transmission permission amount allocated to the i th optical terminator in the j th cycle,

Represents the traffic currently stored in the queue of the i-th fiber terminator,

Indicates the amount of transmission remaining in the current cycle.

In addition, Equation 2 shows the sum of the quota per cycle and the remaining quota not used in the current cycle. That is, by using an amount that is not currently used in the next cycle, weight fairness can be maintained.                     

 In practice, however, the value of Equation 2 is not likely to exactly match the packet boundary, so in order to eliminate the wasted bandwidth, the largest or less than To calculate the integer, we use the equation (3) using lowbound.

(304) = 0로 하고 남은 할당량

도 0으로 만든다.At this time, it is not fair to accumulate and accumulate the unused amount of the unused fiber end device every cycle because there is no packet waiting in the buffer of the i th optical end device.

(304) = 0 and remaining quota

Make it 0.

(304)뿐만 아니라 현재 사이클에서 남은 전송량

도 보내주어 광라인 터미널(330)이 해당 정보를 유지할 수 있도록 해준다. Where the i th optical end device is the request amount for the request frame

304, as well as remaining traffic in the current cycle

It is also sent so that the optical line terminal 330 can maintain the information.

(304)에 대한 프레임을 받은 광라인 터미널(330)은 j+1 번째 사이클에서 허락(Grant) 프레임을 통해 i 번째 광망 종단장치에게 허락하는 할당량 트래픽 양을

(301)라고 했을 때 수학식 4와 같이 계산되어 진다.The amount of traffic requested for the j th cycle in step 3 above

The optical line terminal 330 receiving the frame for 304 receives the amount of quota traffic that is allowed to the i th optical end device through the grant frame in the j + 1 th cycle.

Suppose that (301) is calculated as in Equation 4.

The i-th optical network terminator described above corresponds to the first optical network terminator 340 of FIG. 2. The i + 1 th optical end device corresponds to the second optical end device 350.

While the invention has been described above based on the preferred embodiments thereof, these embodiments are intended to illustrate rather than limit the invention. It will be apparent to those skilled in the art that various changes, modifications, or adjustments to the above embodiments can be made without departing from the spirit of the invention. Therefore, the protection scope of the present invention will be limited only by the appended claims, and should be construed as including all such changes, modifications or adjustments.

 As described above, if the media access control method for guaranteeing the weight fairness according to the present invention is applied to the Ethernet passive optical network system, the allocation bandwidth differentiation function can be implemented among the various optical end devices having different bandwidth requirements. It can effectively meet the requirements of users using different bandwidths. In addition, weighted fairness among optical fiber terminations can be effectively maintained even in a short time period. In addition, since the optical network terminator can request the transmission requirement according to the packet boundary, there is an effect to completely eliminate the unused wasted bandwidth caused by the existing media access control method quota does not match the packet boundary.

Claims (5)

A media access control method in an Ethernet passive optical network (EPON) having a plurality of optical network units (ONUs) and specific optical line terminals (OLTs), A first step of allocating a traffic transmission amount that can be transmitted in one cycle from the plurality of optical network terminators to the specific optical line terminal in proportion to the weights of the plurality of optical network terminators; Setting a traffic transmission algorithm of the specific optical line terminal device to transmit the allocated traffic transmission amount to the plurality of optical network termination devices; Transmitting, by the plurality of optical network terminators, maximum traffic to a specific optical line terminal as long as there is traffic in one cycle according to the set traffic transmission algorithm; If the traffic quota has not been met, the fourth step is to use the remaining quota over the next cycle. Media access control method for ensuring the weight fairness of the Ethernet passive optical network comprising a. The method of claim 1, In step 1, when the plurality of optical network terminators allocate a traffic amount that can be transmitted in one cycle to a specific optical line terminal, requesting a predetermined traffic amount value to prevent the unused bandwidth. The method of claim 1, further comprising a weight fairness of the Ethernet passive optical network. The method of claim 2, The preset traffic transmission value is equal to the following Equation (10). [Equation 10]

However, in Equation 10

Is the amount of traffic that the i-th optical end device requires to transmit to the optical line terminal using a request frame,

Is the amount of traffic allowance allocated to the i th optical terminator in the j th cycle,

Is the traffic stored at the i th optical end device,

Is the amount of transmission remaining in the current cycle. The method of claim 3, wherein And a value of Equation 20 below in Equation (10) to eliminate the unused bandwidth. [Equation 20]

The method of claim 1, In setting the specific optical line terminal and the plurality of optical network terminators, the specific optical line terminal requests the traffic volume to the specific optical line terminal through a request frame in the plurality of optical network terminators. In order to control the transmission of the plurality of optical network end devices by sending a grant frame specifying the traffic quota, the traffic quota sent through the grant frame is equal to the calculated value of Equation 30. A medium access control method that guarantees weight fairness in Ethernet passive optical networks. Equation 30

However, in Equation 30

Is the grant frame at j + 1th cycle,

Is the amount of traffic that the i-th optical end device requests to the optical line terminal to transmit using the request frame, in cycle j,

Is the amount of traffic allowance allocated to the i th optical terminator in the j th cycle,

Is the amount of transfer remaining in the current cycle.

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