Patent ID: 8718018

Claim:
A method for reporting an inter-frequency measurement result using a random access channel (RACH) message by a User Equipment (UE) in a mobile communication system, the method comprising the steps of: receiving a system information block (SIB) comprising an inter-frequency cell information list for non-used frequency cells and a threshold from the system, for inter-frequency measurement reporting; measuring signal strengths of signals received from the non-used frequency cells and comparing the measured signal strengths with the threshold; if there is any signal strength exceeding the threshold, acquiring one or more inter-frequency cell identifiers (IDs) indicating one or more non-used frequency cells having the signal strength exceeding the threshold referring to the inter-frequency cell information list; and transmitting the RACH message to the system, the RACH message including the one or more inter-frequency cell IDs as inter-frequency measurement result information, wherein the inter-frequency measurement result information comprises the one or more inter-frequency cell IDs of non-used frequency cells having the signal strength exceeding the threshold, the one or more inter-frequency cell IDs being ordered according to the signal strength of the non-used frequency cells.