Recently, CTTL Terminal Labs (hereafter referred as CTTL-T), together with Keysight Technologies, ETS-Lindgren, UNISOC and other enterprises, successfully completed the first OTA (air interface) system integration and testing and verification based on NB-IoT NTN (non-terrestrial network) technology in China. In OTA signaling mode, it supports the radio transceiver capability test of terminal equipment based on 3GPP IoT NTN, which lays a good foundation for the inspection and testing of NTN and the development of satellite Internet terminals in the future.

Terminal OTA performance test is one of the mainstream methods of mobile communication performance testing, which evaluates the transmitting and receiving performance of terminals through the whole machine test. Satellite terminals such as mobile phones and Internet of Things devices connect satellites as far as tens of thousands of kilometers on the ground to achieve communication, and the space signal transmission and reception capability of the terminal is very important, and its indicators directly affect the stable connection of the network, the design of terminal products, the network data capacity and the user experience. The International Organization for Standardization, 3GPP and the China Communications Standards Association CCSA have carried out research on the OTA technical requirements and test methods of NTN equipment, and discussed the form of NTN OTA test indicators. Therefore, the NTN terminal test environment based on signaling conditions is of great significance for standard formulation and product development.

Based on the multi-probe anechoic chamber test system, the NB-IoT NTN terminal OTA test system was built, and the typical OTA index tests such as total isotropic radiated power (TRP), total isotropic received sensitivity (TRS), equivalent isotropic radiated power (EIRP), and equivalent isotropic sensitivity (EIS) were successfully completed.

Figure 1: The signal connection between the terminal and the tester is completed

Figure 2: IoT NTN OTA test results (non-commercial devices).

The test results show that the automated test system of the CTTL-T can be effectively compatible with the NB-IoT NTN test platform, realize automatic feeding and discharging and digital signaling OTA testing, and support the OTA test of the terminal under the human head and hand model.

With the gradual maturity of NTN standards and products, CTTL-T will continue to carry out the integration of OTA test system based on NR NTN, as well as NTN terminal testing based on regenerative forwarding mode in the future, to support the needs of international and domestic standardization and product verification. The CTTL-T will also open the NTN-based terminal OTA test platform to the industry to provide testing services for the R&D and verification work of the entire industry.

Contact:

Wang Peng 18810815023

wangpeng5@caict.ac.cn