The GXClok-500 is a smart, low cost, ultra small GPS/GNSS-disciplined OCXO clock module (GPSDO) or a fully GPS/GNSS-integrated OCXO clock module, using the advanced u-Blox's 50-channel LEA-6T GPS receiver with a 6-position engine and anti-jamming technology. It uses the auto-adaptive SmarTiming+ technology, disciplining the GPS/GNSS reference from 1 to 100,000 seconds at 1ns resolution, depending on the GPS' 1PPS reference noise and signal-impairment level. It provides a host of complex time and frequency features in a single module, while achieving state-of-the-art performance, reliability and extended lifetime