A Test Scheme To Verify The Performance Indicators Of 40Gbps Aoc

With the rapid development of information technology, data centers and high-performance computing (HPC) systems have increasing requirements for data transmission rates. As a new generation of high-speed data transmission solutions, 40Gbps Active Optical Cable (AOC) is gradually replacing traditional copper cable transmission methods with its low latency, high bandwidth, long-distance transmission and low loss. However, in order to ensure the reliability and performance of 40Gbps AOC in practical applications, we need to conduct rigorous testing of its key performance indicators. This article will introduce in detail a comprehensive test scheme designed to verify the performance indicators of 40Gbps AOC such as latency and bit error rate.

1.Test objectives

• Latency test: Measure the latency of  at different transmission distances to evaluate its response speed and real-time communication capabilities.

• Bit error rate test: Under specific conditions, the bit error rate of 40Gbps AOC is detected by sending and receiving a large amount of data to evaluate the accuracy and reliability of its data transmission.

Test equipment and environment

Test equipment:

• Several 40Gbps AOC samples (different lengths, such as 1m, 5m,10m, 50m, etc.)

• High-performance 40Gbps network interface card (NIC)

• Packet generator/receiver

• High-speed oscilloscope

• Bit error rate tester

• Precision timer

• Data recording and analysis software

Test environment:

• Temperature: 20°C ± 5°C

• Humidity: 40%RH ~ 60%RH

• Electromagnetic interference: Low interference environment, avoid the influence of radio waves, large motors and other equipment

• Test platform: Stable workstation or server with high-performance CPU and sufficient memory

2.Test plan

Delay test

Connection setup: 

• Connect the packet generator and receiver to the test platform using a high-performance 40Gbps network interface card.

• Connect the packet generator and receiver through the 40Gbps AOC to ensure a strong connection and stable signal transmission.

Test steps: 

• Set the packet generator to send packets of a specific size and format.

• Accurately record the timestamp of the packet from sending to receiving.

• Repeat the test multiple times and take the average value to reduce the error.

• Perform multiple tests on 40Gbps AOCs of different lengths, record and compare the results.

• Data analysis: Calculate the delay time for each test and analyze its stability.

• Compare the delay time of 40Gbps AOCs of different lengths to evaluate the impact of transmission distance on delay.

• Analyze the test results to determine whether the delay performance indicators of 40Gbps AOC meet the application requirements.

Bit error rate test

Connection setup:

• Use a high-performance 40Gbps network interface card to connect the transmitter and receiver of the bit error rate tester to the test platform.

• Connect the transmitter and receiver of the bit error rate tester through a 40Gbps AOC.

Test steps:

• Set the bit error rate tester to send test data of a specific size and format.

• Set the test time or number of packets to ensure that the test is sufficient.

• During the test, record the data received by the receiver and calculate the bit error rate.

• Perform multiple tests on 40Gbps AOCs of different lengths, record and compare the results.

• Tests can also be performed at different transmission rates, different ambient temperatures, and humidity conditions to evaluate the bit error rate performance of 40Gbps AOC in different environments.

Data analysis: 

• Calculate the bit error rate for each test and analyze its stability.

• Compare the bit error rates of 40Gbps AOCs of different lengths to evaluate the impact of transmission distance on the bit error rate.

• Analyze the test results to determine whether the bit error rate performance indicators of 40Gbps AOC meet the application requirements.

• If the bit error rate is found to be too high, further check the connection quality, signal attenuation and other reasons, and optimize them.

3.Test results and analysis

Delay test results

After multiple tests, we obtained the delay time data of 40Gbps AOCs of different lengths. The following is an example of some test results:

From the test results, we can see that as the length of the 40Gbps AOC increases, the latency also increases slightly. However, even at a length of 50 meters, the latency remains within an acceptable range, meeting the needs of most applications for real-time communication.

Bit error rate test results

After multiple tests, we obtained the bit error rate data of 40Gbps AOCs of different lengths. The following is an example of some test results:

From the test results, it can be seen that as the length of the 40Gbps AOC increases, the bit error rate increases slightly. However, the bit error rate of all test results is much lower than the 1e-11 required by the industry standard, which shows that the 40Gbps AOC maintains extremely high accuracy during data transmission.

4.Further optimization suggestions

• Improve connection quality: Ensure that the connection of the 40Gbps AOC is firm and the signal transmission is stable. You can consider using high-quality connectors, optimizing the connection process, and other methods to improve the connection quality.

• Optimize signal transmission: You can consider using more advanced signal processing technologies, such as adaptive equalization technology, pre-emphasis technology, etc., to optimize signal transmission quality and reduce bit error rate.

• Improve environmental adaptability: Tests are conducted under different ambient temperature and humidity conditions to evaluate the performance of the 40Gbps AOC in different environments. You can consider using technologies such as temperature compensation and humidity control to improve its environmental adaptability.

Conclusion

This paper verifies the reliability and performance of 40Gbps AOC in high-speed data transmission by conducting detailed tests and analysis on performance indicators such as latency and bit error rate of the 40Gbps AOC. The test results show that 40Gbps AOC maintains low latency and extremely low bit error rate at different lengths, meeting the needs of most applications for high-speed and accurate data transmission. In addition, this paper also proposes further optimization suggestions to improve the performance and reliability of 40Gbps AOC. In the future, as technology continues to develop, we can expect 40Gbps AOC to be widely used in more fields, providing higher-performance data transmission solutions for data centers and high-performance computing systems.