CNWhat are the differences and connections between 25G/50G/100G technologies(2)
50G Technologies
With the maturity of 25G technology and users' requirements for higher speed, the industry has a strong expectation for 50G. In 2018, IEEE launched the 50G Ethernet standard, which is the same as the 400G/200G Ethernet standard architecture. This standard adopts PAM4 technology, which can effectively improve bandwidth utilization efficiency. The next solution for connecting servers and data centers at high speed.
Since 50G can reuse 25G of existing 100G network components, it can effectively reduce costs. Meanwhile, 50GB costs half as much as 40GB, but its performance is 25% better.
Because PAM4 technology maps paired bits into a single symbol, the total baud rate for each 50Gbit/s channel is 26.5625 Gbaud. The 50Gbaud PAM4 provides a 100G transmission rate with a 1*2*50 Gbaud architecture (requiring only one laser), which represents a tenfold increase in transmission rates from 10Gbps to 100Gbps using a single laser.
PAM4 technology is widely used in high-speed signal interconnection because it provides higher transmission efficiency at a lower cost than earlier NRZ technologies.
100G Technologies
100G Ethernet was officially released in 2010, and extensive changes were made to meet the needs of high speeds, long distances, and some special scenarios. Due to the continuous optimization of standards, the unification of technical solutions, the development of industrial chain and the higher transmission rate and longer transmission distance (DWDM technology), 100G is gradually replacing 40G.
100G DWDM technology can realize long-distance high-capacity signal transmission at a single wavelength, especially suitable for high-speed optical communication. Among them, the coherent CFP DWDM optical transceiver is especially suitable for 100G metropolitan area network (MAN) or up to 80 km data center interconnection (DCI) or transmission distance of more than 1000 km ultra-long links. At present, over 100G DWDM technology has also been used commercially in DCI scenarios.
In addition, in the case of multi-rate and multi-protocol networks (such as 10G/40G/100G Ethernet protocol and rate), the use of 100G and over 100G DWDM multiplexing transponders can effectively avoid the redesign and planning of network architecture. It can directly combine signals of different protocols and rates into a single wavelength of up to 100G/200G/400G for transmission, providing a flexible and cost-effective solution.
