The 2012 ACMA Communications Report shows that at June 2012 3.129 million people over 18 years of age (18%) don’t use a fixed line. This number has doubled in the last three years. The USA Wireless Association CTIA in the USA reports that at December 2011 34% of American households were mobile only.
So while this trend continues it will reach a limit imposed by the need for fixed access to carry the ever increasing volumes of internet data. Mobile networks could carry all of the voice calls, SMS and MMS. With the current technology, number of base stations and mobile spectrum the volume of data carried on the fixed network could not be carried on mobile networks. In Australia according to the ACMA report there were 421 PB (One Peta Byte is 1015 Bytes) downloaded in the three months to June 2012 – who says the Government isn’t watching what you are doing! Of this only 32PB (7.6%) was downloaded to mobile phones and devices. There were 6 million fixed internet access services and 22 million mobiles and dongles used to access the internet. Thus the 21% of internet connections which are fixed carried over 92% of data. Mobile networks would need to have their capacity increased by a factor of 13 and then be able to continue to grow capacity to match the annual over 50% yearly increase in internet data.
Of course it is technically possible for a mobile network to be designed to carry all the internet data as NBN is proving. It would be technically possible to scale this sort of network up to serve everyone and not just the 4% NBN is targeting. It would require a base station for approximately every 250 premises (tripling the number of base stations to circa 60,000), perhaps a doubling of the mobile spectrum, and some serious fibre for backhaul (like that needed for fibre to the node FTN). Food for thought!