It seems that you are not really up to speed in this area as ELINT is gathering data from sensors etc. What you probably mean is COMINT. COMmunications INTelligence is information gathered from the communications of individuals, including telephone conversations, text messages and various types of online interactions. Time and duration of communication. Frequencies and other technical details of note in the transmission.
ELINT and COMINT are both part of SIGnal INTelligence (SIGINT).