Source: {"pile_set_name": "USPTO Backgrounds"}

(a) Field of the Invention
The present invention relates to a mobile communication system, and more particularly, to a repeater and a ranging method using the repeater.
(b) Description of the Related Art
Generally, in a portable Internet system, which is one of mobile communication systems, a mobile terminal performs an initial ranging operation and a handover ranging operation to access a base station, using a repeater for increasing coverage and data throughput. When the initial ranging and handover ranging operations are performed, the mobile terminal performs a timing offset control operation and a power offset control operation between the mobile terminal and the base station.
In this case, since timing offset and power offset of the mobile terminal are established based on the base station even when the mobile terminal accesses the repeater, the mobile terminal may be disconnected from the repeater.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention. Applicants have made no determination and make no assertion or admission as to whether or not any of the above information might qualify with regard to the present application as prior art that is already known in this country to a person of ordinary skill in the art.