Question: What triggers a User Equipment (UE) to limit the usage of certain Transport Format Combinations (TFCs) in a UTRA FDD network, specifically for UEs supporting E-DCH and HSDPA?
Option 1: Receipt of a specific RRC signal from the eNodeB indicating reduced power transmission.
Option 2: UE's estimation that a certain TFC and E-TFC would exceed its maximum transmit power.
Option 3: Network congestion detected by the UE, prompting voluntary power reduction.
Option 4: Scheduled maintenance periods indicated by the network to conserve energy.
Explanation: This is correct because a UE must self-regulate its transmit power to prevent exceeding its maximum capability, which could lead to reduced coverage or signal quality. By limiting TFC usage based on power estimations, the UE helps network operators maximize coverage areas without overloading the UE's transmission capabilities.