Wireless networking protocols may very precise time synchronization at the PHY/MAC layer. Generally, wireless technologies like WiMAX or LTE divide time into frames (e.g. LTE is 10 ms). Then depending on whether you're frequency duplexing (FDD) or TDD (time duplexing), the frames are divided into subframes with defined meaning. If different radios on the network don't agree as to frame start/end times, interference occurs.

Here's an interesting paper describing the software implementation of certain features that are usually handled by the hardware (well, by software running on the baseband processor): http://people.freebsd.org/~sam/FreeBSD_TDMA-20090921.pdf.