Abstract: A method and apparatus for receiving system information from a Base Station (BS) in a Mobile Station (MS) in a mobile communication system are provided, in which it is determined whether there is buffered system information in a buffer, if current system information has an error, it is determined whether a combining condition is satisfied, in the presence of the buffered system information, the combining condition being defined by at least one of a Master Information Block (MIB) value tag, a System Information Block (SIB) value tag, and modification time information that are associated with the current system information, and the current system information is combined with the buffered system information, if the combining condition is satisfied.

Abstract: A method and an apparatus for transmitting/receiving a MAC header in a mobile communication system supporting high-speed data communication are provided, which can reduce signaling overhead and increase system throughput by decreasing the size of the MAC header. A LEN unit of the MAC packet header is set to 1 byte when a TB size is less than or equal to a first predetermined threshold value. The LEN unit is set to 2 bytes when the TB size is greater than the first predetermined threshold value and is less than or equal to a second predetermined threshold value.