Question: In a UMTS network, during an inter-cell soft handover involving cells defined by the Radio Link Set (RLS), what is the primary purpose of transmitting E-HICH (Enhanced-Harq Indicator Channel) using 3 consecutive slots in Cell 1 (containing the Serving E-DCH cell)?
Option 1: To increase the transmission power for voice calls
Option 2: To enhance security by encrypting ACK/NACK signals
Option 3: To synchronize the handover process between Cell 1 and Cell 2
Option 4: To verify that missed and false ACK probabilities do not exceed specified thresholds
Explanation: The correct answer, Option 4, reflects the test purpose mentioned in the context. Transmitting E-HICH using 3 consecutive slots during an inter-cell soft handover is specifically aimed at evaluating the reliability of the Hybrid Automatic Repeat Request (HARQ) process. This is done by measuring the average probabilities of missed ACK (Acknowledgment) and false ACK, ensuring these error rates remain within defined limits to maintain network performance and user experience. The other options are incorrect as they do not relate to the primary purpose of E-HICH transmission in this specific context.