As is apparent from the above embodiments, measurement of timing is critical to establishment of distance estimation. Errors in timing can reduce accuracy of distance estimation. Timing errors often exist within wireless systems. For example, automatic gain control (AGC) is commonly used to ensure robust receiver operation for signals of varying signal strength. During operation, AGC stages may have delays that vary based on the gain. As such, these variations in delay can add to the uncertainty of TOF estimation. In one embodiment, this error can be minimized through calibration. The delay as a function of AGC stage gain may be pre-measured and used to correct the timing during the actual TOF measurement, by subtracting such deviations from the baseline delay. FIG. 9 illustrates RF circuitry having automatic gain control in accordance with one embodiment. The RF circuitry 900 (e.g., 1550, 1670, 1692, 1770, 1870, etc.) can be included in any wireless node (e.g., hub, sensor node) as described in embodiments of the present disclosure. The RF circuitry 900 includes a low noise amplifier to receive a RF signal and to generate an amplified signal sent to an in-phase quadrature (I/Q) downconversion unit 920 to downconvert RF signals to a desired intermediate frequency. A variable gain amplifier 930 amplifiers the intermediate frequency signal and then an analog to digital converter (ADC) converts the amplified signal into a baseband signal. The AGC 950 is a closed-loop feedback regulating circuit that provides a controlled signal amplitude at its output 952 despite variation of the amplitude in its input 942. As discussed above, the delay as a function of AGC stage gain (e.g., AGC 950) may be pre-measured and used to correct the timing during the actual TOF measurement, by subtracting such deviations from a baseline pre-measured delay. Similarly, other calibrated system configurations such as filter delay may be pre-measured and deducted as well.