Building low-latency and high-capacity optical networks is vital for new high-speed cellular technologies. Coherent wavelength division multiplexing passive optical networks (WDM-PONs) are expected to play a key role in these applications. In this article, an overview of PON technologies for the 5th generation (5G) transport systems has been given. Moreover, a modified scheme based on coherent WDM-PON has been investigated using a dual polarization quadrature phase shift keying (DP-QPSK) transceiver. The aim of the scheme is to build a 1 600 Gbit/s network that will be used in the construction of the transport architecture of 5G and beyond cellular networks either in mobile front haul (MFH) or mobile back haul (MBH). The results indicate that the proposed scheme offers a promising solution for future 5G transport systems.