What are the main challenges and points need to be considered for 5G SA to 4G IRAT?

Main Challenges:

  1. Interoperability strategy tuning between E-UTRAN and NG-RAN
  2. High EPS Fallback delay due to N26 Interfaces issues
  3. SIB24 Activation

Interoperability settings are similar to 4G to 3G parameters; all the following need to be checked and tuned during the initial phase of the network to ensure a smooth transition between 4G & 5G for Idle, Connected, and Fallback services.

  1. 4G/5G Priority to be tuned, and it is preferred to give higher priority to NR.
  2. EPS Fallback settings-related parameters must be tuned to minimize the transition timing.
  3. Reselection, Redirection, and Fast Return settings to be verified and tuned based on network coverage conditions.
  4. A3 offset and time to trigger for intra-frequency handovers to be tuned based on network requirements.
  5. N26 Interfaces issue is to be checked and raised to the Core team to avoid additional call setup time.
  6. SIB24 is to be enabled to ensure cell reselection works from 4G to 5G; however, some devices do not support SIB24.
  7. Idle/Coverage-based redirection/HO thresholds to be tuned properly to avoid ping-pong reselections/handovers

LinkedIn: :point_down:

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