Wireless Underground Communication Networks (WUCNs)
Wireless Underground Communication Networks (WUCNs) constitute one of the promising application areas of the recently developed wireless networking techniques. The WUCNs consist of wireless devices that operate below the ground surface. These devices are either (i) buried completely under dense soil or (ii) placed within a bounded open underground space such as underground mines and road/subway tunnels.
In the former case, networks of wireless nodes are buried underground and communicate through soil. In this case, the WUCNs promise a wide variety of novel applications, including intelligent irrigation, environmental monitoring, infrastructure monitoring, localization, and border patrol. Since the major applications of WUCNs in the soil medium are sensing and monitoring, our scope in this environment is focused on wireless underground sensor networks (WUSNs).
|Figure 1 - Installation of an underground sensor for agriculture using existing wired technology. WUSNs can eliminate surface equipment such as the portion of this sensor which extends above the surface.||Figure 2 - Example of a WUSN in use for monitoring turf conditions at a golf course. Underground sensors do not interfere with play on the surface.|
|Figure 3 - In the largest oil spill occurred on the tundra of Alaska's North Slope, 270 K gallons of thick crude oil spilled over two acres. WUCNs can be utilized to monitor the underground plumbing for leaks.|
In the latter case, although the network is located underground, the communication takes place through the air, i.e., through the voids that exist underground. In this case, the WUCNs are necessary to improve the safety and productivity in underground mines, to realize convenient communication for drivers and passengers in road/subway tunnels, and to avoid attacks by continuously monitoring these vulnerable areas.
|Figure 4 - Mine disasters happen every year all over the world, causing the death of thousands of people. Sensors can be deployed in mines to monitor the gas density and water leakage to prevent gas explosion and mine flood.||Figure 5 - The London subway terroristic explosion exposed that the road tunnels and subways are vulnerable areas to terrorists. WUCNs are needed to surveil the human activity in such tunnels.|
The main difference between the WUCNs and the terrestrial wireless networks is the communication medium. In this project, we first investigate the wireless channel characteristics in soil medium, underground mines and road tunnels. Then based on the analysis, the network, data link and physical layer protocols are developed to realize practical underground wireless communication systems.