While Long Term Evolution (LTE) is part of the GSM path, it will be the only cellular technology going forward. It has been introduced in data form by most carriers and in widespread use by Verizon. Voice over LTE (VoLTE) will eventually handle your voice calls as well.
Full Definition of CONDUCTIVITY. : the quality or power of conducting or transmitting: as a: the reciprocal of electrical resistivity b: the quality of living matter responsible for the transmission of and progressive reaction to stimuli.
Resistivity - The resistance that a unit volume of a material offers to the passage of electricity, the electric current being perpendicular to two parallel faces. More generally, the volume resistivity is the ratio of the potential gradient parallel with the current in the material to the current density.