The study undertaken with the consulting firm RTT reviewed the evolution of global cellular frequency bands and multi-band handset support and considered the design challenges associated with supporting new frequency bands and the associated costs and benefits of such support.  The likely relationship between the number of frequency bands supported and the RF cost and performance of a user device over the next ten to fifteen years was investigated.  The final report is available on the Ofcom web site at https://stakeholders.ofcom.org.uk/binaries/research/technology-research/2013/RF/Future_Mobile_Handset.pdf.