5G Will Use Lots of New Spectrum for the First Time

To an unprecedented degree, the future fifth generation mobile network likely will use extraordinary amounts of new spectrum, never commercially deployed before. 

To be sure, virtually all next generation mobile networks have used new spectrum, for the simple reason that doing so minimally disrupts existing users served by the older blocks of spectrum. 

But 5G will feature breath-taking performance, both in terms of peak bandwidth and latency performance. While 5G networks also will be designed so that a device can use any available network, 5G also will feature mobile network bandwidths of perhaps a gigabit per user, or 10 Gbps total bandwidth.

That literally is a few orders of magnitude greater capacity than provided by present-generation Long Term Evolution 4G networks in most markets, though a few LTE networks already have shifted to 300 Mbps air interfaces.

A number of technology innovations, all related directly to Moore's Law improvements in signal processing, with new network architectures, will enable the stunning advances.

Small cells are helpful, but the truly big advances are the ability to commercially deploy millimeter wave frequencies (3 GHZ to 300 GHz). In the past, such frequencies could not be commercially used to support communications apps. 

One major shift in context--namely user reliance on Internet apps and access from stationary locations--also will enable the shift. That means very high amounts of bandwidth can be usefully deployed using small cells, since users primarily will be stationary when using the networks, not in transit, as has been the case for prior mobile networks organized around voice usage. 

At the same time, observers expect 5G networks will support seamless use of any available access network. That might, or might not, result in service providers offering reciprocal access (federating mobile access) to their mobile networks, something that has not happened before. 

Decisions of that sort will be driven by business considerations, not technology. 

One key implication is that, for the first time ever, it might actually make sense to argue that mobile networks are full substitutes for fixed network access.