4G and 5G Roles in the Ecosystem

Long Term Evolution 4G networks will continue to boost internet access speeds even as 5G begins to appear on a commercial basis, with a target of gigabit speeds. 

That suggests an obvious set of roles for 4G and 5G. At gigabit levels, 4G will handle virtually any application a human using a smartphone cares about. 

And though 5G obviously also will be available to a growing number of devices, what 5G will be optimized for are applications used by machines and sensors, requiring only modest bandwidth (kilobits per second, not megabits), as well as for some apps that are latency dependent (autonomous vehicles) or require very-high bandwidth (remote surgery). 

In addition, 5G will represent a clear alternative to traditional fixed network internet access, as well, using both mobile and fixed 5G modes. 

EE, the largest U.K. mobile service provider, has begun to activate higher-speed 4G service with download speeds of 429 Mbps. The expectation is that speeds in excess of 50 Mbps will be routine, per device.

The sites that are capable of delivering these maximum speeds use 30 MHz of 1800-MHz spectrum, or 35-MHz of 2.6 GHz spectrum. Such spectrum aggregation is the  way

4G bandwidth is boosted enough to support the higher speeds, in part. Use of smaller cells, unlicensed spectrum and better radios are other tools that also help boost 4G network speeds.  

source: IHS

Up to this point, mobile service providers have refarmed existing 2G and 3G spectrum for use in LTE-Advanced deployments that boost speeds into the hundreds of megabits per second ranges.

Such moves can double or triple capacity, and therefore speeds.

An order of magnitude increase requires additional steps. Currently, vast majority of global wireless carriers have about 20 MHz to 30 MHz of licensed LTE spectrum. A few  have upwards of 50 MHz  to 60 MHz to work with.

Gigabit speeds will require additional steps, such as using LTE in conjunction with unlicensed spectrum.

Globally, two blocks of unlicensed spectrum can enable gigabit LTE access, including the 5-GHz region and, in the United States and Europe, the 3.5-GHz or 3.2-GHz regions, respectively.

In the United States, the 3.5-GHz Citizens Broadband Radio Service (CBRS) will release about 150 MHz of shared spectrum, either for licensed or unlicensed use.

That provides one example of how 4G and 5G networks will operate, in terms of business model. Basically, 4G will, for quite some time, be a network supporting most end user applications.

Where 5G will come in is at the high and low ends of the user cases, where ultra-low or ultra-high bandwidths have particular relevance. Think pressure sensors on the low end, or remote surgery on the high end.