NTN Timing Relationship – 3GPP TR 38.821 §6.2.1

⬤ Large TA · gNB DL/UL aligned Figure 6.2.1-1 (conceptual)

🛰️ Propagation delay (one‑way) 80 ms

gNB DL / UL (aligned) UE received DL UE transmitted UL (early) TA offset (UE side)

▶ UE applies TA = 2 × propagation delay · UL transmitted early · DL/UL frames aligned at gNB

⏱ NTN Timing Relationship