O2 Telefonica has made a name for itself this year in the various cutting-edge developments of its 5G network. This week, the German subsidiary of Telefonica is back in the limelight, this time with Ericsson. The pair have run an in-service software upgrade (ISSU) on the operator’s 5G cloud-native Core and claim this is a world-first because the upgrade was in the user plane, while the network was in active operation. Ericsson’s Senior Strategic Product Manager of 5G Core Automation, Brett Kofoed, spoke to Wireless Watch to explain why this exercise was unique. Last month, the vendor and operator tested an ISSU in the Packet Core Gateway (PCG), the cloud-native user plane traffic processing and gateway function in Ericsson’s dual-mode 5G…