Question: Under what condition(s) can an additional sidelink RLC bearer modification be initiated for an already established NR sidelink communication?
Option 1: When a new UE joins the sidelink groupcast/broadcast transmission.
Option 2: If any of the additional sidelink RLC bearer related parameters is changed by dedicated or broadcast configurations, or through reconfiguration messages for one established additional sidelink RLC bearer.
Option 3: When the UE switches from unicast to groupcast/broadcast mode for a sidelink DRB.
Option 4: If the SL-TxProfile of all associated QoS flows for a sl-ServedRadioBearer indicates backwardsIncompatible and the UE decides to use PDCP duplication for an existing bearer.
Explanation: An additional sidelink RLC bearer modification is initiated only if there are changes to related parameters in dedicated or broadcast configurations, or through reconfiguration messages for an already established additional sidelink RLC bearer, ensuring modifications are made in response to explicit updates.