A single radio wireless communications device is contemplated in which the user equipment (UE) operates according to more than one radio access technology. The UE may operate preferentially according to a first radio access technology, and may switch to a different radio access technology at predetermined intervals to check for incoming calls. An error unit within the UE may provide frequency error estimates to a GPS unit during operation according to the first radio access technology based upon signals received in the first radio access technology, unless any time spent in the different radio access technology is longer that a predetermined duration. In response to the predetermined duration being met, the error unit may provide the frequency error estimation to the GPS unit based upon signals received in the different radio access technology.