XBee for Ultrasonic range finder synchronization


I have two ultrasonic transducers non-collocated at few meters distance. I want to calculate the distance between them using time of flight of sound. I have XBee S2Cs, which I plan to use for synchronization of the two transducers through Arduino boards, which both the transducers are mounted on.

I have noticed that there is a lag between transmission and receiver signal of the order of > 10 ms. Since sound can travel more than 3 m in that time, it defeats the purpose of using XBees for synchronization of clocks at the two ultrasonic transducers. So, I had a few questions regarding the XBee S2C I am using:

  1. Is there any way to reduce considerably/eliminate the latency between transmitting and receiving XBee modules?

  2. If not, is there a way to make the latency consistent at least? I noticed on the oscilloscope that the time gap due to latency kept fluctuating from, say 10 ms to 20 ms.

Thanks in advance!