Low latency, high channel period wireless protocols
The IEEE 802.11 protocol (Wi-Fi) can support lower latency, but you may find that common implementations will not be much lower than a few milliseconds.  Latency is a function of delay to access the channel, packet length, and the delay through the protocol stack.  If only one device is transmitting on the channel, the channel access delay will be less than 100 microseconds.  802.11 also supports packet lengths that are less than 100 microseconds.  So, if you can find the right implementation, you might be able to set the parameters to achieve a total latency of a millisecond or so.