The migration to 5G is critical for carriers who are also moving towards cloud RANs and wanting, where possible, to move to open solutions. 5G will bring higher bandwidths, lower latencies, new radio technologies and a new wireless core. RAN disaggregation enabled by cloud RANs and open interfaces gives carriers the opportunity to benefit from a wider ecosystem but may also create new challenges as they migrate to 5G. The decisions made by carriers, and their suppliers, on cloud RAN architectures will have big implications on the connection bandwidths needed in the 5G RAN and the systems required.