 Fig. 1.37 illustrates a deployment scenario where both new and legacy radio technologies coexist in the same cell site. In essence, the same transport infrastructure has to serve legacy backhaul, legacy non- packet CPRI fronthaul, and the highly versatile 5G fronthaul incorporating multiple func- tional split options with varying traffic profiles. It is also possible to deploy multi-level functional splits between an RRH and a BBU pool, resulting in multiple fronthaul transport domains in the network. However, practical limitations limit the number of splits that can be supported. For instance, an RRH to the aggregating DU node connection may implement 3GPP functional split option 7, and the DU to the CU connection may subsequently imple- ment 3GPP functional split option 2. Fig. 1.37 illustrates an example deployment with two functional splits between the RRH and the CU. Typically, the DU would be an aggregation node close to the radio access network edge, and possibly in charge of time- and latency- sensitive coordinated scheduling and MAC-level retransmission functions. IEEE 1914.1 standard specifies a number of service classes corresponding to the charac- teristics of traffic being transported over the backhaul/fronthaul links in a C-RAN, which includes control information or user traffic. In particular, it defines dedicated sub- classes providing requirements for maximum tolerable latency for mobile control, trans- port control, and synchronization signals. The data-plane (or user traffic) class is further divided into five different subclasses, each addressing a specific network application (e.g., 5G service transport or functional split options implemented between RRH, DU, and CU). More specifically, the very low-latency subclass addresses network segment supporting URLLC service; the low-latency subclass addresses network segment where 3GPP split options 6, 7, 8 are implemented, the medium-latency subclass addresses net- work segment where 3GPP split options 2, 3, 4, 5 are implemented, the high-latency s