Hope I have understood your question correctly
Part 1: How to collect Measurements?
• Each Measurement Type will define on one or several Measurement Object(s) (Carrier Frequency).
• Reporting Configurations are defined on each Measurement Object (i.e. criteria like Event triggered, periodic or event triggered periodic reporting).
• Measurement quantities and Reporting Configurations are considered separately for each Measurement Type.
• Measurement Object and Measurement Configurations are related with the help of Measurement id.
• eNB configures each Measurement Type using a Measurement Identity and instructs the UE when to report the measurements results.
• Measurement commands are used by eNB to order the UE to start, modify or stop measurements specified by RRC as in UTRAN Measurement_Control.What UE measures?
• After instructions from eNB; UE measures two parameters on reference signal: cell RSSI & CPICH RSCP or CPICH En/lo.
• The handover measurement report triggering are based on cell RSSI & CPICH RSCP in GSM or CPICH Ec/Io for UMTS for inter-RAT.
• Serving Cell’s RSRP is degrading threshold 1, while neighbor cell RSSI or CPICH RSCP or CPICH En/lo increasing threshold 2 will trigger the event.
Call Flow of Inter Rat Handover
Now coming to specifics though measConfig is a optional IE but it is important to tell UE when/how measurement config to be done if operator is supporting it. Please comment if you are looking something different.