The growth in self-provided backhaul has largely been achieved with microwave. Going forward, and for the purposes of this review period there is considerable uncertainty that the throughput capability of microwave-based backhaul will be sufficient to meet the capacity requirements of mobile networks. Based on the typical topology of Vodafone’s networks, we already know that fibre will be required at aggregation sites which represent 20% of Vodafone’s base station footprint. In addition, once 2Gbps throughput requirements at sites are commonplace, fibre will be required on suburban and rural sites which require >2km transmission lengths. As the diagram below shows, the current limits of microwave at 0.8 Gbps (excluding MIMO) will be reached at feeder sites by 2017/18 based on the current view of traffic growth.