Question: What is the primary purpose of the "dataInactMon-r14" field in a User Equipment's (UE) radio access capabilities, as related to E-UTRA specifications?
Option 1: To indicate UE support for enhanced voice services over LTE.
Option 2: To specify UE's maximum data transmission rate in idle mode.
Option 3: To determine the UE's ability to perform handovers between different E-UTRAN frequencies.
Option 4: To define whether the UE supports monitoring of data inactivity, as outlined in the MAC protocol specification.
Explanation: The correct answer is Option 4 because the "dataInactMon-r14" field specifically pertains to the UE's capability regarding data inactivity monitoring. This feature is crucial for managing and optimizing network resources by tracking periods of user inactivity, which is a detail of the Medium Access Control (MAC) protocol as specified in TS 36.321. This understanding requires knowledge of how UEs interact with E-UTRA networks at a protocol level, particularly concerning resource allocation and efficiency measures.