Transmission technologies for implementing high-speed, large-volume transfers are centred on PAM (pulse amplitude modulation) methods, which offer both faster symbol rates than earlier NRZ signal methods and increased transmission capacity without increased symbol rates.
This article describes a new measurement platform supporting next-generation network transmission standards such as 100GbE, 200GbE and 400GbE as well as the latest and future high-speed serial interface standards, such as PCIe Gen4 and Gen5, Thunderbolt Gen3 and USB Gen3.1.
Telecom and datacom trends
The trends that are driving the telecom and datacom sectors, and hence the requirements for test and measurement equipment, can be summarised under the following categories:
- Higher speed, smaller size and lower power consumption are key drivers for the optical interfaces of leaf and spine switches on high-end servers and storage devices.
- Enhancements for high-speed inter-equipment interfaces, including advanced semiconductor devices, network interface cards, and optical modules for 25GbE, 50GbE, 100GbE, 200GbE and 400GbE communications.
- The PCIe Gen4 (16GT/s) standard for bus/backplane interfaces in network interface cards, which has just been ratified.
- PAM4 (pulse amplitude modulation) transmission, now becoming widely adopted to increase bandwidth in 50G/200G/400GbE systems and likely to migrate into next-generation solutions for other standard interfaces such as Infiniband, Thunderbolt and PCIe Gen5 in the near future.