  Cloud-Radio Access Networks (Cloud-RANs) are separating the mobile networks
base station functions into three units, the connection between the two of them
is referred to as the fronthaul network. This work demonstrates the
transmission of user data transport blocks between the distributed Medium
Access Control (MAC) layer and local Physical (PHY) layer in the radiounit over
a Passive Optical Network (PON). PON networks provide benefits in terms of
economy and flexibility when used for Cloud-RAN fronthaul transport. However,
the PON upstream scheduling can introduce additional latency that might not
satisfy the requirements imposed by Cloud-RAN functional split. In this work we
demonstrate how our virtual Dynamic Bandwidth Allocation(DBA) concept can be
used to effectively communicate with the mobile Long Term Evolution (LTE)
scheduler, adopting the well known cooperative DBA mechanism, to reduce the PON
latency to satisfactory values. Thus, our results show the feasibility ofusing
PON technology as transport medium of the fronthaul for the MAC/PHY functional
split, in a fully virtualised environment.Further background traffic is added,
so that measurements show a more realistic scenario. The obtained round trip
times indicates that using PON at fronthaul might be limited to the distance of
11km for a synchronised scenario, or no compliance for a non-synchronised
scenario.
