The progress from initial 3G networks to mobile broadband technology has transformed industry and society by enabling an unprecedented level of innovation. If 5G becomes a true generational shift in network technology, we can expect an even greater level of transformation. There are varying implications of providing an increased level of connectivity or developing a new radio access network (RAN) to deliver a step change in per connection performance, or a combination of the two. This means that the final design of a 5G network could be any one of a range of options with differing radio interfaces, network topologies and business capabilities. While a shift to 5G would be hugely impactful, the industry will need to overcome a series of challenges if these benefits are to be realised, particularly in terms of spectrum and network topology.