Rx level is the strength

Dear user,

dbm: decibel-milliwatt.

It is the measured power referenced to one milliwatt (mW).

Its value is 10 * log[ P(W) / 1mW ]

The Rx level is the strength of the signal that our mobile receives from a BTS (mobile tower). Here, the Rx level stands for Receiver Level.

The mathematical formula to calculate the Rx level is:

RxLev (dBm) = EIRP (dBm) - Path Loss (dB)

EIRP - Equivalent/Effective Isotropically Radiated Power is the amount of power an antenna evenly distributes in all directions that would be emitted to produce the peak power density observed in the direction of maximum antenna gain.

EIRP (dBm) = Pt (dBm) + Ga (dBi)

i - antenna gain in reference to isotropic antenna

t - output power transmitted

Path Loss - For a given antenna, the received power is inversely proportional to the distance between the transmit and receive antennas and also to the square of frequency.

Ls ~ d^2 f^2

Path loss - Ls(dB) = 32.4(dB) + 20*log [ f (MHz) ] + 20*log [ d (km)], where 32.4 is a constant of proportionality.

The value of Path loss is always greater than EIRP, hence the Rx level is negative.

Thanks!