The measurements have shown that it is possible to achieve delays in the millisecond range in a 5G network. This shows that 5G technology is also superior to LTE technology in terms of latency.
One of the most important fields of application for 5G is ultra-reliable low latency communication (URLLC). URLLC plays an important role for advanced applications in V2X communication; in particular, it is regarded as an enabling technology for autonomous driving. As part of a joint project, Huawei and Rohde & Schwarz used a precise end-to-end runtime measurement system in field tests. Over-the-air IP transmissions in 5G-V2X communication in a moving car were investigated for the specific application case of cooperative driving. A measurement accuracy of less than 2 µs was achieved for each IP packet transmitted. The transmitted data comprised various IP data streams including video, lidar and control data (ITS messages) for a remote-controlled vehicle. The accuracy of the absolute times on both sides was ensured using two independent GPS receivers.
While the test in Munich focused on vehicle remote control, the tests at the test site in Shanghai focused on V2X communication for so-called platooning – in which several vehicles networked via radio communication are moved in a network. The measurement of the transmission time from the source via the air interface to a (mobile) receiver (sink) must include all transit times of an IP packet – the delay caused by the radio transmitter, the propagation delay and the delay caused by the radio receiver.
Since latency is one of the most important performance indicators for 5G and safety applications, such measurements could become an important criterion for future certification tests.