Embodiments of a User Equipment (UE) to operate in accordance with a physical random access channel (PRACH) are disclosed herein. The UE may comprise hardware processing circuitry to determine a coverage enhancement category for the UE based on downlink channel statistics related to reception of downlink signals at the UE from an Evolved Node-B (eNB) and an uplink-downlink imbalance parameter related to uplink reception at the eNB. The hardware processing circuitry may be further to select, for use in a coverage enhancement mode, a PRACH preamble from a set of candidate PRACH preambles based on the determined coverage enhancement category for the UE. In some embodiments, at least some of the candidate PRACH preambles may span a different number of sub-frames.