Virtual Sinks in Action

These two videos show the positive effect a single virtual sink can have on a congested wireless sensor network. The video shows a table top test bed of 48 MICA2 motes, where yellow LEDs blink when their locally measured channel load exceeds the congestion threshold. All nodes are sources at 1 pkt/sec, funnelling packets towards the sink at the right side of the video capture. The first video visually shows congestion with no active virtual sinks. The second video shows the situation when a single virtual sink is activated (the Stargate node in the foreground). Congestion is not eliminated (still a few blinking yellows), but is markedly reduced.