Chirp Spread Spectrum (CSS) is a customized application of MDMA for the requirements of battery¡Vpowered applications, where the reliability of the transmission as well as low power consumption are of special importance. CSS forms the basis of the nanoLOC TRX Transceiver which was developed for medium data rate applications. CSS consists of Chirp pulses, an Upchirp and a Downchip, as illustrated below.