5G BTS Conformance Testing | 5G BTS OTA Testing, Equipments
This page covers 5G BTS Conformance Testing. It describes various 5G BTS OTA (Over The Air) test cases performed by 5G BTS (i.e. Base Station) conformance test equipments.
As we know any communication system consists of two parts viz. transmitter and receiver. Signal generated by transmitter is known as transmit signal which gets various impairments (nonlinearities, noise etc.) due to various modules in the transmit chain. Similarly received signal consists of various distortions and impairments.
As both transmit and receive signals are not ideal and consists of impairments, it is necessary to perform testing on the device. Testing is performed throughout the product life cycle. During the development life cycle of the 5G BTS various tests are performed in order to ensure that 5G BTS meets the 3GPP specifications. As a result, there are pre conformance and post conformance tests.
5G BTS (Base Station) is referred as gNB. The specifications are published and maintained by 3GPP. 3GPP conformance tests are categorized into RF, RRM (Radio Resource Management), demodulation and signaling. It is specified in 3GPP TS 38.104, 38.141 part-1 (Conducted conformance testing) and 38.141 part-2 (Radiated conformance testing).
5G BTS Conformance Testing
The table-1 mentions brief of 5G BTS conformance tests. 5G BTS Conformance testing covers all the layers of the 5G protocol stack which include PHY, MAC, RLC, PDCP and RRC. GCF and PTCRB are global device certification groups provide framework for 5G device certification testing.
The 5G Base Stations are designed in various classes viz. type 1-C, type 1-H, type 1-O and type 2-O. These classes are based on distances from 5G UE as defined in 3gpp 38.104. These 5G BTSs are tested under various frequency bands, channel bandwidths (5MHz, 10MHz, 15MHz, 20MHz, 25MHz, 30MHz, 40MHz, 50MHz, 60MHz, 80MHz, 100MHz) and subcarrier spacing (15KHz, 30KHz, 60KHz) in these modes as per 3GPP document.
The table-2 mentions detailed test cases used for 5G base station conformance testing as published in TS 38.104 document. The other OTA measurements performed during R&D stage include 2D/3D beam patten measurements, cross polar isolation measurements, beamstreering or null steering performance.
5G BTS OTA Test Equipments
Following companies are developing 5G OTA (Over-The-Air) test solutions and conformance test equipments.
• EMITE spain provides 5G OTA test solutions along with Reverberation Chambers, Anechoic Chambers and CATR Chambers.
• Anritsu is developing test solution for 5G mobile products.
• ETS Lindgren
• Rohde & Schwarz
• TS 38.104 5G Base Station (BS) radio transmission and reception
• TS 38.141 5G BS conformance testing