What is EP NO

For acquiring an AT signal on reverse link (during connection setup), RN needs to know the approximate distance from the antenna. RN uses this distance and a BTS wide search window configurable value to search the signal from AT. This distance is known as Earliest PN Offset (EPNO).

What is Ec/I0

In CDMA refers to the portion of the RF signal which is usable. It's the difference between the signal strength and the noise floor.

Ec/Io (pronounced "ee-see over eye-not") is basically a measure of how well your phone can hear the tower over all the other traffic on the channel.

A reading near 0.0 is very good. You can find low readings late at night on weekdays when traffic is low. When the reading is high (-12.0 to -15.0), quality will drop and you may even lose the call.