Question: In the context of Evolved Universal Terrestrial Radio Access Network (E-UTRAN), which of the following accurately describes the mechanisms through which RACH (Random Access Channel) Optimisation is supported?
Option 1: Solely by UE (User Equipment) reported information, without any inter-cell parameter exchange.
Option 2: Exclusively through RACH parameters exchanged between E-UTRA cells only.
Option 3: By a combination of UE reported information and RACH parameters exchanged between both E-UTRA cells and NR (New Radio) cells, specifically in the case of EN-DC (E-UTRA-NR Dual Connectivity).
Option 4: Through direct RACH parameter exchange between UEs in the same network.
Explanation: This is correct because RACH Optimisation leverages both the insights provided by User Equipment (UE) reports and the coordinated management enabled by exchanging RACH parameters. This exchange isn't limited to E-UTRA cells; it also involves NR cells when the network operates in EN-DC mode, enhancing flexibility and performance across different radio access technologies.