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At the moment, two mainstream technical directions taking up the field of 200G optics: one is the economical 8x25G NRZ, the other one is the 4x50G PAM4. In the article, the 200G NRZ series will be emphatically introduce. With its features, relative advantages and available application scenarios being shown, the users will learn how to make targeted and optimum decisions when optical interconnection solutions are required.
Compared with PAM4, NRZ series features better signal integrity, lower latency and easy deployment. Meantime, due to NRZ technology and its matched chips and units are of better maturity, the products based on NRZ modulation technique are generally of better manufacturability.
Based on mature NRZ technology,GIGALIGHT 200G NRZ products are of superior signal integrity, and can achieve zero error rate without FEC, thereby largely reducing latency.
With the above advantages, 200G NRZ can realize comprehensively efficient and reliable optical interconnection, especially when handling with some special scenarios or cases requiring lower latency, better cost management and efficient deployment. Through long-term and deep digging in the field of 200G optical interconnection and NRZ modulation technique ,GIGALIGHT has developed a whole 200G NRZ product portfolio to offer pointed solutions for corresponding application scenarios which demand for ultra-low latency, such as HPC and HFT data centers and 5G backhaul.
GIGALIGHT 200G NRZ Series Product Portfolio:
类型 | 名称 | 距离 | 波长 | 发射器 | 接收器 | 功耗 |
---|---|---|---|---|---|---|
Optical transceivers | 200G QSFP-DD SR8 | 100m | 850nm | VCSEL | PIN | 4W |
200G QSFP-DD PSM8 | 2/10km | 1310nm | DML | PIN | 6W(2km)/6.5W(10km) | |
200G QSFP-DD LR8 | 10/20km | 1310nm | DML LWDM | PIN | 7.5W | |
AOC | 200G QSFP-DD AOC | 100m | 850nm | VCSEL | PIN | < 4W |
200G QSFP-DD转2×100G QSFP28 AOC | 100m | 850nm | VCSEL | PIN |
< 4W (200G QSFP-DD)
< 2W (100G QSFP28) |
|
200G QSFP-DD至4×50G QSFP28 AOC | 100m | 850nm | VCSEL | PIN |
< 4W (200G QSFP-DD)
< 1W (50G QSFP28) |
|
DAC | 200G QSFP-DD PCC | 3m | / | / | / | / |
As high-speed development of internet technology and explosive growth of data exchange, some typical data centers have raised further requirements for low-latency data transmission and exchange. The two fast-developing scenarios: high-frequency trading (HFT) and high performance computing (HPC) data centers, are typical examples. Under HFT scenario, countless users operate simultaneously, which requires the data center to transact a large number of orders in fractions of a second and thus the latency must be extremely low. HPC, as a field dedicated to computers aimed at performing a high volume of calculation in a short amount of time, also has strict demand for the latency of the whole network.Main Application Scenario One — HPC & HFT Data Centers
GIGALIGHT 200G NRZ series products, based on mature NRZ technology, features superior signal integrity and can achieve zero error rate without FEC, thus the delay reduction reaches ultra high level; plus supporting both 200G Ethernet and InfiniBand protocols, they've showed extremely strong performance in HFT and HPC data centers.
For mainstream data centers, GIGALIGHT gives out corresponding solutions respectively:
Taking GIGALIGHT 200G NRZ series, the whole series including short reach and long reach optical transceivers, 200G AOC & DAC. The whole portfolio can cover the whole optical interconnection network construction needs of a large 200G data center. 200G QSFP-DD LR8/PSM8 are usually used for the tier one and tier two interconnection, undertaking the data transmission work between core routers, core switches and aggregation switches. 200G QSFP-DD SR8 can better fit for short distance data transmission, such as the interconnection between aggregation switches and access switches. 200G DAC & AOC are generally deployed between access switches and servers.
Optical transceivers deployed in Data Centers
Under the spine-leaf architecture, 200G QSFP-DD SR8/PSM8 optical modules are usually applied between core-aggregation switches interconnection, which generally require the transmission distance of 2~10km, and when it turns to aggregation-access switches interconnection, the 200G QSFP-DD SR8 optical transceiver can better fit the usual transmission distance of about 100m. 200G QSFP-DD DAC and 200G QSFP28 AOC are generally used in the interconnection between access switches and servers to provide short distance and low latency data transmission.
When it's detailed to the bottom layer — interconnection between access switches and servers, the 200G to 4×50G or 2×100G AOC/DAC products give out more flexible solutions for different switch-server interconnection methods, which are shown as below:
AOC/DAC deployed in switch-server interconnection
Apart from data centers requiring ultra-low latency, 5G Backhaul is another important applicable scenario. The network slicing, as an obvious feature of 5G service, enables it better fit to users' diversified and targeted needs. Correspondingly, the 200G NRZ long reach optical transceiver can especially fit for the low-latency high-reliability slicing network branch, which demands additional lower latency such as self-driving and live streaming.
Generally, GIGALIGHT 200G QSFP-DD LR8 can be deployed between the CU/DU and 5G Core (5GC) in 5G network construction to offer high-speed, low latency and reliable network interconnection.
5G network deployment architecture