Method for configuring a transmission chain in a 3GPP2 system for supporting a flexible or variable data rate of an information bitstream in a process for mapping an information bitstream of a data rate on a physical layer, including the steps of (1) channel coding the information bitstreams with bit rates different from each other into turbo codes or convolution codes having a value inverse of 1/coding rate, and (2) repeating coded bitstream when the channel coded bitstream is smaller than a desired interleaving size, and puncturing the coded bitstream when the channel coded bitstream is greater than the desired interleaving size, for matching the channel coded bitstream to the interleaving size.