Markt&Technik: Everyone is talking about 5G, but what is the current situation with regard to the standardization of 5G?
Meik Kottkamp, Rohde & Schwarz: As the responsible standardization body, 3GPP completed the first release of its specification for 5G NR technology in June 2018, and therefore a comprehensive description of the technology is available. The description of the protocol stack for terminal devices was completed in September 2018, with further amendments expected by the end of the year. Late drop milestones have also been defined, and they will be completed by the end of the year. It will take more time to finalize the test specifications, especially for the relatively complex over-the-air (OTA) test scenarios. To date, you can say that the entire industry has achieved a major milestone and is currently focusing on the remaining work packages.
What specific challenges does 5G pose for test and measurement equipment?
For 5G, manufacturers of test and measurement equipment can draw on many years of experience with the 2G to 4G wireless communications generations. Like 4G, 5G is based on an OFDM data transmission method, so there are synergies with existing test and measurement equipment. The special challenges result from the introduction of new frequency bands. The implementation of components, chipsets, modules, wireless devices and base stations in the 28 GHz or 39 GHz band allows higher integration density and requires the use of active antenna systems. This means that over-the-air (OTA) test solutions will have to be rolled out to replace existing conducted measurement methods. Additional shielded chambers will be needed, and the test setup will have to be carefully calibrated. 5G gives network operators more flexibility when it comes to network configuration (network slicing) and configuration of over-the-air data transmission in order to cover various services such as enhanced mobile broadband (eMBB), massive connectivity and ultra reliable low latency communication (URLLC). That requires flexible and intuitive measurement solutions.
Does that mean new test and measurement equipment? Or can existing equipment still be used? If so, are upgrades necessary – or even possible?
An essential 5G network architecture component that the majority of network operators favor for the first rollout requires an LTE anchor, which means that most of the signaling is implemented in the LTE base station and a 5G base station can dynamically improve data transmission. 4G LTE is therefore a very important component in the rollout of 5G, and the solutions used there serve as the basis for the new technology. Most of our test and measurement equipment can handle this task with suitable software modifications. Existing signal generators and spectrum and signal analyzers can be upgraded with software extensions. However, simultaneous testing of LTE and 5G terminal devices in particular also requires hardware enhancements, in part because OTA measurement solutions need additional shielded chambers.