The expansion from 5G non-standalone (NSA) to 5G standalone (SA) is primarily done via software. Michael Lemke, Senior Technology Principal at Huawei Technologies Germany, explained this on February 21, 2020 in an interview with Golem.de. "This is the step towards complete 5G in the core network, whereby 4G can also be operated. Today, in non-standalone mode, the control layer is obtained via 4G and a 5G payload is added." Lemke explained that no network operator would use new hardware for this one year after the introduction.
"5G NSA is an evolutionary step on the way to 5G SA, which then brings 'real' 5G performance beyond 5G New Radio and functionalities like e2e Network Slicing. At 5G NSA, 5G and 4G radio access typically works with one 4G core. Network operators will upgrade this to a full 5G (5G SA) with 5G core over time and according to their own plans. "Nokia spokesman Bernhard Fuckert said Golem.de.
3GPP Release 15 is currently standardized and work is also ongoing. 5G SA will therefore be introduced in a late release 15 drop. Release 16 is expected later this year and release 17 next year. "After that, it will take some time for products to become commercially available. These releases will add important new features to 5G. To unlock the full potential of 5G, more than just upgrading the radio and transport network is required."said Fuckert. A new core is needed to fully exploit the flexibility and capabilities of 5G NR (New Radio), such as end-to-end network slicing to support massive machine connectivity (MMTC) and ultra-low latency (URLLC).