RRC Reporting events or Handover events are sent from RBS or UE to trigger the different handover procedures in the RNC. The genertion of handover events depend on the different RF parameters and thresholds. event 1A: A Primary CPICH enters the reporting range; addition of a radio link. event 1B: A primary CPICH leaves the reporting range; removal of a radio link. event 1C: A non-active primary CPICH becomes better than an active primary CPICH; replacement of the worst cell in AS. event 1D: Change of best cell event 1E: A Primary CPICH becomes better than an absolute threshold event 1F: A Primary CPICH becomes worse than an absolute threshold event 1G: Change of best cell (TDD) event 1H: Timeslot ISCP below a certain threshold (TDD) event 1I: Timeslot ISCP above a certain threshold (TDD) Event 2a: Change of best frequency Event 2b: The estimated quality of the currently used frequency is below a certain threshold and the estimated quality of a non-used frequency is above a certain threshold; handover to inter-freq neighbors Event 2c: The estimated quality of a non-used frequency is above a certain threshold Event 2d: The estimated quality of the currently used frequency is below a certain threshold; start compressed mode to measure inter-freq WCDMA or GSM neighbors. Event 2e: The estimated quality of a non-used frequency is below a certain threshold Event 2f: The estimated quality of the currently used frequency is above a certain threshold; stop compressed mode & stop measure inter-freq WCDMA or GSM neighbors Event 3a: The estimated quality of the currently used UTRAN frequency is below a certain threshold and the estimated quality of the other system is above a certain threshold; handover to GSM neighbors Event 3b: The estimated quality of other system is below a certain threshold Event 3c: The estimated quality of other system is above a certain threshold Event 3d: Change of best cell in other system event 4 A: Transport Channel Traffic Volume becomes larger than an absolute threshold event 4 B: Transport Channel Traffic Volume becomes smaller than an absolute threshold event 5A: A predefined number of bad CRCs is exceeded event 6A: The UE Tx power becomes larger than an absolute threshold; start compressed mode event 6B: The UE Tx power becomes less than an absolute threshold; stop compressed mode event 6C: The UE Tx power reaches its minimum value event 6D: The UE Tx power reaches its maximum value event 6E: The UE RSSI reaches the UE's dynamic receiver range event 6F: The UE Rx-Tx time difference for a RL included in the active set becomes larger than an absolute threshold event 6G: The UE Rx-Tx time difference for a RL included in the active set becomes less than an absolute threshold Event 7a: The UE position changes more than an absolute threshold Event 7b: SFN-SFN measurement changes more than an absolute threshold Event 7c: GPS time and SFN time have drifted apart more than an absolute threshold Measurement report 3G Two types of Measurement reporting is possible in 3G 1. Periodic 2. Event triggered Measurement reporting parameters for both Periodic and Event triggered are set through system information. Measurement report is send by the UE if a specific condition fulfilled. To set the reporting condition, parameters are set in the system information 11 for idle state and system information 12 for connected state. If the parameters are not set in system information, it could be send through Measurement control. Following are the different measurement reporting that UE can Perform:1. Intra-frequency measurements: Parameter: - CPICH Ec/No, CPICH RSCP, pathloss Event 1a: A Primary CPICH enters the reporting range Event 1b: A Primary CPICH leaves the reporting range Event 1c: A non-active primary CPICH becomes better than an active primary CPICH Event 1d: Change of best cell Event 1e: A Primary CPICH becomes better than an absolute threshold Event 1f: A Primary CPICH becomes worse than an absolute threshold 2. Inter-frequency measurements: Parameter :- CPICH Ec/No, CPICH RSCP Event 2a: Change of best frequency Event 2b: The estimated quality of the currently used frequency is below a certain threshold and the estimated quality of a non-used frequency is above a certain threshold. Event 2c: The estimated quality of a non-used frequency is above a certain threshold Event 2d: The estimated quality of the currently used frequency is below a certain threshold Event 2e: The estimated quality of a non-used frequency is below a certain threshold Event 2f: The estimated quality of the currently used frequency is above a certain threshold 3. Inter-RAT measurements: Parameter: - GSM carrier RSSI Event 3a: The estimated quality of the currently used UTRAN frequency is below a certain threshold and the estimated quality of the other system is above a certain threshold. Event 3b: The estimated quality of other system is below a certain threshold Event 3c: The estimated quality of other system is above a certain threshold Event 3d: Change of best cell in other system 4. Traffic Volume Measurements Parameter: - total buffer occupancy (BO) of RLC buffer, average of BOs, variance of BOs Event 4a: Transport Channel Traffic Volume becomes larger than an absolute threshold Event 4b: Transport Channel Traffic Volume becomes smaller than an absolute threshold 5. Quality measurements: Parameter: - BLER (transport channel block error rate) Event 5a: A predefined number of bad CRCs are exceeded 6. UE internal measurements: Parameter: - UTRA carrier RRSI (intra or interfrequency), UE Transmitted power, UE Rx-Tx Time difference Event 6a: The UE Tx power becomes larger than an absolute threshold Event 6b: The UE Tx power becomes less than an absolute threshold Event 6c: The UE Tx power reaches its minimum value Event 6d: The UE Tx power reaches its maximum value Event 6e: The UE RSSI reaches the UE's dynamic receiver range Event 6f: (FDD) The UE Rx-Tx time difference for a RL included in the active set becomes larger than an absolute threshold (1.28 Mcps TDD): The time difference indicated by TADV becomes larger than an absolute threshold Event 6g: The UE Rx-Tx time difference for a RL included in the active set becomes less than an absolute threshold 7. Positioning measurements: Parameter: - UE GPS timing, Synchronization measurements SFN-SFN, SFNCFN, GSM carrier observed time difference Event 7a: The UE position changes more than an absolute threshold Event 7b: SFN-SFN measurement changes more than an absolute threshold Event 7c: GPS time and SFN time have drifted apart more than an absolute threshold Event 7d: GANSS time and SFN time have drifted apart more than an absolute threshold Measurement reports in LTE 1. Event A1 (Serving becomes better than threshold) 2. Event A2 (Serving becomes worse than threshold) 3. Event A3 (Neighbor becomes offset better than serving) 4. Event A4 (Neighbor becomes better than threshold) 5. Event A5 (Serving becomes worse than threshold1 and neighbor becomes better than threshold2) 6. Event B1 (Inter RAT neighbor becomes better than threshold) 7. Event B2 (Serving becomes worse than threshold1 and inter RAT neighbor becomes better than threshold2) Measurement report UMTS and LTE comparison LTE Measurement Events and Description Event A1 - Serving becomes better than threshold Event A2 - Serving becomes worse than threshold Event A3 - Neighbor becomes offset better than serving UMTS Measurement Events and Description e2f - The estimated quality of the currently used frequency is above a certain threshold Comments In LTE this may be used to stop looking for a cell on a different frequency or technology, as e2f is used in UMTS. e2d - The estimated quality of In LTE this may be used to the currently used frequency is start looking for a cell on a below a certain threshold different frequency or technology, as e2d is used in UMTS. e1a - A Primary CPICH enters This comparison is a bit of the reporting range a stretch. The reason I have equated them is because in both cases a neighbor should be considered for a handover, either soft or hard depending on the technology. Event A4 - Neighbor becomes better than threshold Event A5 - Serving becomes worse than threshold1 and neighbor becomes better than threshold2 e1e - A Primary CPICH becomes better than an absolute threshold e2b - The estimated quality of This comparison is good for the currently used frequency is saying that the current cell below a certain threshold and is below an absolute threshold and the new cell the estimated quality of a non- is above a threshold. This would mean that the current used frequency is above a cell is not good enough and certain threshold the new one is good, which is a good reason to do a hard handover (in either technology). Event B1 - Inter RAT e3c - The estimated quality of neighbor becomes better other system is above a than threshold certain threshold Event B2 - Serving e3a - The estimated quality of This comparison is good for becomes worse than the currently used UTRAN saying that the current cell threshold1 and inter RAT frequency is below a certain is below an absolute neighbor becomes better threshold and the new cell than threshold2 on a different technology is threshold and the estimated above a threshold. This quality of the other system is would mean that the current above a certain threshold cell is not good enough and the new one is good, which is a good reason to do a hard handover to the new technology.
