A bidirectional 60-GHz/30-GHz/15-GHz wireless-over-fiber (WoF) transmission system based on an optical Interleaver (IL) and a phase modulator to deliver intensity-modulated 60-GHz millimeter-wave (MMW), 30-GHz microwave (MW), and phase-remodulated 15-GHz MW data signals is proposed and demonstrated. A broadband light source (BLS), comprising a distributed feedback laser diode (DFB LD), a phase modulator, a Mach-Zehnder modulator (MZM), and an optical signal-to-noise ratio (OSNR) enhancement scheme, is employed in such bidirectional 60-GHz/30-GHz/15-GHz WoF transmission systems. For down-link transmission, light is optically promoted from 5Gbps/15GHz RF data signal to 5Gbps/60GHz MMW and 5Gbps/30GHz MW data signals in fiber-wireless convergence. Moreover, the downstream light is successfully phase-remodulated with 5Gbps/15GHz MW data signal for up-link transmission. Based on an in-depth investigation in such bidirectional 60-GHz/30-GHz/15-GHz WoF transmission systems, bit error rate (BER) is observed to perform impressively over a 40-km SMF and a 4-m RF wireless transmission. This bidirectional 60-GHz/30-GHz/15-GHz WoF transmission system reveals a prominent alternative, not only due to its advancement in the integration of optical fiber and in-house networks, but also given the fact that it offers the advantages of communication channels for higher bandwidth and data rates.