RuBee is a long wavelength IEEE (1902.1) wireless peer-to-peer, packet standard, based on magnetic waves. RuBee works in harsh environment visibility applications...
RuBee uses a low frequency (131Kz) and has a wavelength of 2,289 Meters, or about 1.25 miles. Unlike LF, HF, or UHF, RFID RuBee is an on-demand packet based protocol, similar to WiFi, Bluetooth and Zigbee. All active and passive RFID tags are transponders and reflect radio signals for data communication. RFID tags use the same signal for timing and power.
In contrast, RuBee works as a transceiver, similar to a two way walkie-talkie but uses magnetic waves rather than radio waves (see Maxwell's Equation below). RuBee tags have a crystal and can keep track of time, they also have a battery and static memory. RuBee tags can also have sensors and the ability to data log or store sensor information. Because RuBee uses such a low frequency, it does not consume much power (see Planck's Law below) and has a five to fifteen year battery life using simple Li coin size batteries with a range of 1" to 50 feet. RuBee tags overcome many of the technological problems seen with RF near steel and water, and is field proven in harsh environments. To learn more about the differences between RuBee and RF see RuBee vs RFID Summary.
Barcodes and RF systems are line-of-sight in harsh environments. RuBee is not line-of-sight in harsh environments; RuBee antennas produce 3D volumetric magnetic waves that go through steel and water. That means RuBee delivers reliable, real-time asset visibility with no Change In Process.
The Physics of RuBee
Maxwell’s equations quantified the relationship between E the electric field, and H, the magnetic field produced by an electron moving down a conductor. The two photons E and H are linked and impossible to disconnect. A simplified explanation is found at this URL: Elementary Particles. However, RuBee breaks this rule and has no significant electric field. RuBee antennas work like light bulbs, to illuminate a 3D volume with “magnetic light”.
A standard RuBee antenna produces about 600 mGauss and the tag produces about 50 mGauss. To put that in perspective, the Earth’s magnetic field is about 500 to 700 mGauss. Magnetic fields from earth or a permanent magnet do not have any effect on RuBee because they do not vary in time. When a magnetic field does vary in time (possible noise source), it usually has only short range effects on RuBee since signal strength drops off fast (see below). Typical RuBee noise sources are LCD projectors, plasma panel displays, switching power supplies, large transformers and lighting storms. However, RuBee demos and RuBee systems work in the same room with all of these noise sources, because the signal drop off so quickly.
In 1856 James Clark Maxwell created his equations that described the relationship between the electric field (E) and magnetic field (H) produced by a moving electron. These equations are in effect "Ohms law" for moving electrons and describe the relationship between emitted radio waves (Voltage) and emitted magnetic waves (Current). The impedance or resistance of free space is 377 ohms. This is a universal constant and makes it possible to calculate the electric field (E) from the magnetic field (H) or vice versa. The electric field is given in Volts/meter and the magnetic field is given in Amps/meter and the ratio is E=H*377 in the "far field". This 377 ohm value (Z) is used by the FCC for example to calculate emitted power for all RF systems. The impedance of space Z in the is the ratio of the electric field to the magnetic field.
However, when emitted energy is measured at a distance of 1/10th of a wavelength or less it is in what is known as the "near field" and the 377 ohm constant goes out the window. RuBee has a wavelength of 7,511 feet, but tags are typically read in the 10 to 20 foot range or about 1/700th of a wavelength. The impedance of space seen by a RuBee tag is well under 0.00001 ohm not 377 ohms. That is why E becomes so small in near field (E = H * .00001). You would have to have a RuBee antenna about ¼ of a mile long and measure E and H about 1,000 feet away, before the impedance gets back up to 377 ohms. In other words, with a RuBee system (or any near field system) you cannot calculate E from H using 377 ohms; they are decoupled. Good news is magnetic waves, or magnetic photons are not stopped by steel or water.