Abstract: Disclosed is a wireless communications system having multiple communication channel types in a multi-carrier system. The different channel types, which correspond to different data rates, are allocated depending on the type of session being initialized (its data rate requirements). This is accomplished using different orthogonal code lengths with different carriers and their subcarriers. An orthogonal code length is assigned to a carrier and used with its subcarriers to create a set of assignable channels having differing data rates. The association between a carrier and an orthogonal code length can be dynamically reassigned depending on the needs of active sessions.