Packet forwarding for heterogeneous technologies for integrated fronthaul/backhaul

To meet the future mobile user demand at a reduced cost, operators are looking at solutions such as C-RAN and different functional splits to decrease the cost of deploying and maintaining cell sites. The use of these technologies forces operators to manage two physically separated networks, one for backhaul and one for fronthaul. To solve this issue, transport networks for 5G will carry both fronthaul and backhaul traffic operating over heterogeneous data plane technologies. Such an integrated fronthaul/backhaul (denoted as 5G-Crosshaul) transport network will be software-controlled to adapt to the fluctuating capacity demand of the new generation air interfaces. Based on a proposed data- and control-plane architecture for 5G-Crosshaul, we propose a frame format common to both fronthaul and backhaul traffic as well as a corresponding abstraction of the forwarding behavior of the network elements. The common frame format and the forwarding abstraction define the information to be exchanged at the southbound interface (SBI) of the 5G-Crosshaul Control Infrastructure (XCI). This paper derives requirements for the SBI from 5G use cases.