1. CRANE Project Wireless Networking Demonstration

2. a)Single-hop transmission b)Multi-hop transmission with a mobile relay node

3. Direct transmission requires high power to maintain the connectivity of a wireless link. Power increases at least quadratically with the increase of transmission distance. 4dB Signal spectrum at receiver

4. Mobile relay enhances the connectivity of the sensor network with the same power consumption 1, or alternatively, keeps the connectivity of the network with less resource consumption. Signal spectrum at receiver 12.5dB 1 For fair comparison, the power consumed in direct transmission is twice of the power consumed in each hop of a two-hop link.

5. Received signal spectrums with different relay locations (distance of two locations around λ/2) of the mobile relay. Multipath fading in wireless channels The mobile relay further takes the advantage of spatial diversity of multipath fading in wireless channels. Compared to the relay at fixed location, transmission reliability can further be increased with slight movement of a relay mote.