aul is very different from the backhaul or from the high layer fronthaul, due to requirements for low latency and high capacity. IEEE 802.1CM [20] has defined TSN for fronthaul applications. Non-TSN flows and TSN flows can be supported by the same network. Profile A mostly relies on IEEE802.1Q while an optional Profile B introduces additional capabilities, frame pre- emption, and interspersing express traffic [21]. The standard also specifies requirements for synchronization. 9.4.1.1 Network Solutions The physical distance from the RUs to the baseband is capped to some tens of kilometers due to the propagation delay: 25 km on fiber alone means 250 us RTT, which may be, depending on a number of factors, already excessive. On top of this, some allowance needs to be given for the network nodes for processing. One of the targets for remote RU deployment is simplification of the network by locat- ing baseband computing at a central site. The RUs should be simple appliances with minimal manual operation and no - or rare - site visits. This target drives also the split point to include more of the baseband computing in the baseband unit, provided that the resulting transport rates remain reasonable, SO it is a compromise between these two goals. The simplest transmission configuration is with point-to-point fiber: each RU is directly attached to the respective baseband unit using dedicated fiber. The only facility in between is the fiber cabling. For fiber count savings, traffic flows from the RU sites may be optically (passively or actively) multiplexed into a single fiber. The additional element involved now is the opti- cal device. In the digital domain, an alternative includes introducing a device to first perform the multiplexing at the digital level (Ethernet frames or IP packets) before con- verting the signal to an optical signal for transmission. This adds the switch element and the digital layer for the operations. While deployments are expected to be very fiber dominated, wireless media need not be ruled out,