Experimental Demonstration of Nanosecond Accuracy Wireless Network   Synchronization
  Accurate wireless timing synchronization has been an extremely important topic in wireless sensor networks, required in applications ranging from distributed beam forming to precision localization and navigation. However, it is very challenging to realize, in particular when the required accuracy should be better than the runtime between the nodes. This work presents, to our knowledge for the first time, an experimental timing synchronization scheme that achieves a timing accuracy better than 5ns rms in a network with 4 nodes. The experimental hardware is built from commercially available components and based on software defined ultra wideband transceivers. The protocol for establishing the synchronization is based on our recently developed blink protocol that can scale from the small network demonstrated here to larger networks of hundreds or thousands of nodes. 
Marcelo Segura, S. Niranjayan, Hossein Hashemi, Andreas F. Molisch
cs.NI