Centralised RAN
The C-RAN, which is sometimes also labelled Cloud RAN, is an architecture that pools the baseband processing capacity of base stations in a central site – effectively extending the connection from the radio head, or active antenna, to the BBU over several hundred meters instead of from the bottom of a building or tower, for example.
These baseband pools, also known as “baseband hotels”, are connected to the remote radio heads on an interface known as Common Public Radio Interface (CPRI) over fibre or perhaps a high capacity wireless link. This link is known as fronthaul.
An active antenna integrates the radio element of a remote radio head into the antenna itself.
The BBU units will be required to support future standards implementations such as CoMP, to enable greater co-ordination between sites.
A Cloud-RAN vision, rather than Centralised RAN, proposes virtualised baseband clusters that can dedicate resources across the radio network where and when required.
