Rohde & Schwarz & Huawei have conducted cellular-based 5G V2X latency measurements in the field in vehicular environments. The test were carries out in Munich/Shanghai and show that it is possible to achieve delays in the millisecond regime in a 5G network, demonstrating superior latency performance in comparison to LTE.
One of the key use cases of 5G is ultra-reliable low-latency communication (URLLC). Important for advanced vehicle-to-X communication use cases, URLLC will enable automated driving in the future. In a joint project between Huawei and Rohde & Schwarz, a precision end-to-end delay measurement system for over-the-air IP transmissions was applied to 5G V2X communication for cooperative driving applications in field tests in a moving car. A measurement accuracy below 2 µs for each transmitted IP packet was demonstrated. The transmitted data contained various IP traffic streams including video, LIDAR and control data (ITS messages) for a tele-operated vehicle. The precision absolute time standards on both ends were derived from two independent GPS receivers.
While the trial in Munich was related to a tele-operated driving project, the tests in Shanghai were related to a platoon V2X testing site, where a number of vehicles traveling together are electronically connected via wireless communication. The delay for transmission of one IP packet from the source, over-the-air to a (moving) receiver (sink) needs to be measured, spanning all delays introduced by the radio transmitter, propagation delay and radio receiver from/to IP packet level.
As latency is one of the key performance indicators of 5G and crucial for safety applications, such measurements could become an important criterion for future certification testing.
