A Dynamic Replication Scheme of User Plane Data over Lossy Backhaul Links

5G networks are characterized by strict latency, jitter and reliability requirements. On the other hand, a lossy backhaul scenario where high packet losses over the backhaul transmission medium can render backhaul links unavailable for service consumption. This necessities a multi-transmission scheme over backhaul using the existing resources of the operators such as base stations and core networks. This can enhance reliability for 5G backhaul networks to meet the requirements of new 5G services that have strict end-to-end latency requirements.
In this paper, we propose a GPRS Tunnelling Protocol User Plane (GTP-U) Protocol Data Unit (PDU) multitransmission scheme that achieves improved Transmission Control Protocol (TCP) latency and packet loss probability at the expense of higher resource (bandwidth) utilization compared to existing traditional systems. The scheme can use several measuring mechanisms such as continuous Two-Way Active Measurement Protocol (TWAMP) testing between core network and base stations, GTP-U user plane echo requests/replies or backhaul quality testing during evolved Packet System Radio
Access Bearer (eRAB) establishment phase. This mechanism can also be applied to X2 interface between base stations to reduce the service latency and improve the backhaul link performance.
Our simulation results using ns-3 indicate that by applying the proposed strategy in backhaul systems, the application level packet loss and TCP delay can be improved at the expense of the bandwidth improvement at certain drop or loss levels.