  In modern implementations of Cloud Radio Access Network (C-RAN), the
fronthaul transport network will often be packet-based and it will have a
multi-hop architecture built with general-purpose switches using network
function virtualization (NFV) and software-defined networking (SDN). This paper
studies the joint design of uplink radio and fronthaul transmission strategies
for a C-RAN with a packet-based fronthaul network. To make an efficient use of
multiple routes that carry fronthaul packets from remote radio heads (RRHs) to
cloud, as an alternative to more conventional packet-based multiroute reception
or coding, a multiple description coding (MDC) strategy is introduced that
operates directly at the level of baseband signals. MDC ensures an improved
quality of the signal received at the cloud in conditions of low network
congestion, i.e., when more fronthaul packets are received within a tolerated
deadline. The advantages of the proposed MDC approach as compared to the
traditional path diversity scheme are validated via extensive numerical
results.
