  Passive optical network (PON) technology offers an attractive cost-efficient
alternative to support 5G and Beyond 5G mobile network fronthauling (MFH).
However, MFH for such networks is challenging given its high bandwidth and
strict latency requirements. To reduce these requirements, radio access network
(RAN) functional splitting has been introduced in 5G networks; this provides
more flexibility in resource allocation since the protocol stack is distributed
between the centralized and the distributed units. In contrast to the
conventional MFH requirement of the RF-PHY splitting, the MFH traffic produced
by higher-layer splittings becomes more dependent on the actual user traffic
load. By capitalizing on the new characteristics of the MFH traffic with RAN
functional splitting, this article introduces a resource allocation mechanism
to improve the performance of PONs serving MFH.
