Low frequency waves (ULF & VLF) to establish Communication in Places where Wireless (WIFI) does not function

Technology has made giant strides particularly in the field of communication. Day by day new advances are being reported there making communication even more potent.Take for example WIFI which revolutionized the field of data transfer. 

However, even with Wifi, there are potential limitations. In wifi radiosignals transfer from transmitter to receiver as electromagnetic waves. However, the principle of radio waves pose limitations  particularly in the case of defense. These waves get blocked when they hit the water,  soil or any stone. Therefore scuba divers mainly depend on sign language in tunnels and caves.

Dr. Troy Olson program manager for DARPA (Defence advanced research project agency) announced AMEBA ( A Mechanically Based Antenna) project in which Olson is planning to use ULF(ultra low frequency) electromagnetic waves and Very low-frequency waves  (VLF)which can penetrate any obstacle that comes in its path.

The team is planning to develop antennas for transmitting ULF (1Hz to 3kHz)and VLF (3kHz to 30kHz) waves that could penetrate water walls or even a stone with minimum usage of data.

However, as the wavelengths used are longer it also becomes a necessity to build enormous and costly transmitter structures.This can be evident from the VLF antennae built by the navy in the remote peninsula in cutler maine during cold war, where the gargantuan transmitter complex occupied 2000 acres and featured 26 towers up to 1000 feet high and operated with megawatt levels of power.

The challenge here is to pack the necessary electro magnetic waves into small space since it involves physical movement of materials with strong electrical and magnetic fields rather than relying on circuits and amps. This would involve integrated innovations in the field of chemistry and materials,  design (shapes and packing geometries of materials) and mechanical engineering.

Olson opined that if the project is successful then scuba divers may be able to use the ULF channel to communicate via text messages to nearby submarines or ships. Like wise, ground communication can also even be estabilished in remote locations like tunnels, mines, and caves. He also said that, due to  atmospheric wave guide effect, direct soldier to soldier communication via text and voice will be possible across continents and oceans.

Source: darpa