Techniques for random access channel signaling on a shared communication medium are disclosed. A broadcast message including information associated with a Physical Random Access Channel (PRACH) may be transmitted and received on one or more subframes in a portion configured for downlink signaling. The broadcast message may comprise a contention type indicator, a timing advance indicator, or a combination thereof. The contention type indicator may indicate whether contention is in effect for transmission on the PRACH. The timing advance indicator may indicate whether an uplink transmission offset is in effect for transmission on the PRACH. Signaling over the PRACH may be transmitted and received on one or more subframes in a portion configured for uplink signaling.