Definition of a combined bandwidth is disclosed. Bandwidths for components of a combined bandwidth can be defined by selecting configurations for the bandwidths from a group of available bandwidth configurations. The bandwidths are combined to define a contiguously combined bandwidth in a resource block unit. At least one set of coefficients corresponding to the available bandwidth configurations are used. The contiguously combined bandwidth shall not exceeds a predefined maximum bandwidth. A transmission bandwidth can be defined. A channel bandwidth can be defined based on the defined transmission bandwidth.