rized into two primary categories, non-orthogonal shar- ing and orthogonal sharing. In the formal, all FH resources are shared among the services. In the case of orthogonal sharing, a dedicated amount of resources are allocated to ser- vices. For instance, a percentage of the bandwidth or a percentage of the available path is allocated to a service to guarantee the required QoS. This type of orthogonality enables ser- vice slicing in the coexistence of heterogeneous service to offer the requirement according to the specific service. Traffic is steered to the appropriate slice using, for example, the concept of identification. The packets, hence, are enqueued into the specific FH path associated to a slice identity. Each slice offers a set of reserved KPIs such as delay and packet loss. 11.3 Experimentation Results Evaluation of Flexible Functional Split for RAN Slicing 11.3.1 Experimental Setup In this section, we study the flexibility in RAN configuration in terms of splitting the base- band functionalities between CU and DU entities, and the impact of this flexibility on communication latency and jitter is examined. Higher layer and lower layer splits have been implemented, i.e. PDCP-RLC, MAC-PHY, and intra-PHY, using the real-time platform Open Air Interface (OAI). The experimental setup for the evaluation of the FH functional split is depicted in Figure 11.3 [6]. The overall experimental testbed consists of an end-to-end LTE system from eNodeB to user equipment (UE), with full implementation of functionalities of the protocol stack of the eNodeB and the UE. The OAI UE is based on LTE UE developed by the OAI community [16]. The software runs on Intel Core i5-650 @ 3.20 GHz with 2 cores and it is connected via Universal Serial Bus 3 to a USRP (Universal Software Radio Peripheral) used to transmit and receive data. 11.3 Experimentation Results Evaluation of Flexible Functional Split for RAN Slicing 1-Gigabit Ethernet OAI UE Figure 11.3 Setup of the testbed platform. Source: © 2017, IEEE Reprinted, with permissio