Patent ID: 8270353

Claim:
An operation method of a base station (BS) for performing load balancing in a broadband communication system in an initial network entry, the method comprising: receiving a ranging request message from a user terminal; determining, upon receipt of the ranging request message, whether to allow the user terminal by taking into account a network load; setting a ranging status to ‘abort’, if the user terminal is not allowed; generating a first ranging response message including the ranging status which is set to ‘abort’ and at least one of a frequency override for a channel on which the user terminal redoes ranging and preamble index override for a preamble index of a target BS where the user terminal redoes ranging; transmitting the first ranging response message to the user terminal in response to the ranging request message; and setting a ranging status to ‘success’ if the user terminal is allowed, generating a second ranging response message to the user terminal in response to the ranging request message including the ranging status which is set to ‘success’, without the frequency override and the preamble index override and transmitting the second ranging response message to the user terminal in response to the ranging request message, wherein when the preamble index override is used with the frequency override, redoing ranging is performed on a downlink channel identified by the preamble index of the target BS.