## 1 Introduction  
Cloud-radio access network (RAN) is one of the architecture enablers of the fifth generation of mobile communication networks (5G) paradigm, providing an innovative platform that can enhance flexibility and adaptability to mobile communication networks. 5G Cloud-RAN consists of three component elements, namely: a Central Unit (CU), a Distributed Unit (DU) and a Radio Unit (RU). The two components, CU and DU, are connected through a transport interface called midhaul, while the interface connecting DU and RU is called fronthaul [1]. 5G Cloud-RAN offers different radio network deployment scenarios each with different requirements. Recent developments in the softwarization and virtualization of mobile networks [2] provide the platform for the deployment of Cloud-RAN solutions through a flexible functional split. A flexible functional split is a promising approach that aims to provide greater flexibility to sufficiently fulfill the diversified service requirements of 5G. Different functional splits impose different requirements on fronthaul, which have created new challenges in terms of optimizing the allocation of radio processing and transmission resources [3]. Consequently, the optimal split choice depends on a variety of factors, such as deployment scenario, availability of RAN resources and user traffic. For example, the work in [4] demonstrated how different use cases can impact the selection of RAN functional split. In our previous work, we also demonstrated the impact of user traffic, in particular 5G classes of traffic, on the choice of RAN functional split through an experimental evaluation of three different functional splits [5]. Different solutions exist for fronthaul in 5G new radio. While the fiber has clear benefits compared to other wired solutions in terms of bandwidth and speed [6], the potential for Ethernet has also been explored [7]. Ethernet is a promising solution for the transport network, given its wide availability and low cost. Therefore, several standardization bodies defined Ethernet fronthaul as a possible solution. In particular, Open RAN, which is an evolution of the Next Generation RAN architecture, considered Ethernet as a selected transport [8]. The Enhanced Common Public Radio Interface also defined a packetized interface employing an Ethernet or Internet Protocol, as a possible interface for the fronthaul [9]. Nevertheless, any fronthaul solution adopted needs to support diverse Cloud-RAN deployment scenarios and efficiently meet the key performance indicators of 5G. Within the context of 5G, there is a growing interest in the need to provide high reliability while maintaining low latency to support the delivery of Ultra-Reliable Low Latency Communications (URLLC). One approach considered in the research on supporting URLLC is diversity, in which the same data are transmitted independently over multiple links. The authors of [10] show that, with multi-user diversity, an improvement in reliability and spectral efficiency can be achieved. Another approach considered to achieve the stringent latency-reliability requirement of URLLC is to use a combination of channel coding techniques and diversity. In this context, the authors of [11] showed, through simulation, the effectiveness of combining data duplication and network coding approaches. The combined approach achieved the highest reliability compared to network coding. While high reliability is foreseen for users' data, in Cloud-RAN architecture such reliability should also be considered for the fronthaul link. To this end, and focusing on Cloud-RAN, there is a need for the fronthaul to maintain stringent key performance indicators of URLLC. The work in [12] proposed a multiple description coding approach to improve the quality of the signal received at the cloud in the uplink, assuming a multiple paths packet-based fronthaul. They validated the effectiveness of the approach through numerical results.