Joint Task Offloading and Flexible Functional Split in 5G Radio Access Network

Task offloading is a cost-effective way to allow users to obtain better service by offloading the computation intensive tasks to the fog or cloud computing nodes. Many previous work have been done and many of them focus on where to offload the task and how to split the task for cooperative execution. However, few of them consider task offloading in 5G flexible radio access network(F-RAN) and split the task according to the flexible functional split between the central unit(CU) and distributed unit(DU). In this paper, we study the task offloading in 5G F-RAN and combine the task split with flexible functional split. We firstly formulate a multiuser offloading decision problem as a energy consumption minimization problem which results in a trade-off between energy consumption and delay tolerance. In view of the characteristics of 5G F-RAN, the fronthaul and backhaul network are taken into consideration when calculating the energy consumption and delay. We split the task according to the flexible functional split between CU and DU for cooperative execution when the task is offloaded. Numerical simulations show that our proposed model can reduce the energy consumption and execution delay.