Complementary band-splitter and band-combiner devices and methods of operation of both are disclosed. Embodiments of the invention may allow wideband and narrowband functions and services to operate seamlessly by band-splitting wideband data into low-band data and high-band data. Narrowband data may include only low-band data. Wideband services may operate on both low-band and high-band data, while narrowband services may operate only on low-band data. Another embodiment may include computer-readable storage having stored thereon a computer program having a plurality of code sections executable by a processor for causing the processor to perform the foregoing.