Transitioning from CPRI to eCPRI
Upgrading from 4G to 5G means tackling the challenge of transitioning from CPRI (Common Public Radio Interface) to eCPRI (Enhanced Common Public Radio Interface).
eCPRI offers the advantage of using standard “off-the-shelf” Ethernet components, which are considerably cheaper than the proprietary equipment used in 4G. It also creates a more flexible and scalable architecture that supports virtualization options like SDN and NFV. The eCPRI initiative is supported by the O‐RAN alliance, which is supported by most of the biggest NEMs, network operators and telecom companies.
However, unlike CPRI, eCPRI does not provide end-to-end synchronization or guarantee zero loss.
Testing the timing of data traffic as it flows from the Central Units on the backhaul Ethernet to the 5G fronthaul part of the network is therefore critical.
Fronthaul networks consist of the Distributed Units (DU), the Radio Units (RUs) and all the antennas. They can vary in size from just a few kilometers to over 50kms. What’s more, the DUs are responsible for controlling multiple antennas – each with dedicated transmission windows – and these need to be coordinated with adjacent antennas to avoid interference.