I looked at the RRC Inactive state back in 2017, but the standards were not completely defined. In the meantime standards have evolved and commercial 5G networks are rolling out left, right and centre. I made a short technical introduction to the RRC_INACTIVE state, comparing it with the 4G states in RRC and NAS. I also looked at some basic signalling examples and there are lots of relevant references at the end. Video and slides embedded below.
- The 3G4G Blog: Comparison Layer 2 Measurements LTE vs. 5G NR
- The 3G4G Blog: A Look into 5G Virtual/Open RAN – Part 3: Connection Release and Suspend
- The 3G4G Blog: How LTE RRC (4G) and NR RRC (5G) Protocols are used in Parallel in EN-DC (5G NSA)
- The 3G4G Blog: EPS Fallback in 5G Standalone Deployments
- The 3G4G Blog: RRC states in 5G