Friday, January 11, 2019

5G Coverage Meets the Laws of Physics

5G Wireless has been identified as the catalyst for everything from driverless cars to finding life on Mars.  What 5G needs to accomplish these miracles is lots of bandwidth.  The easiest way to get more bandwidth is to move up in frequency.  Unfortunately, the higher the frequency, the shorter the range, and the less the coverage. It's the law of physics, a law we can't break.  Coverage for the "low" cellular frequencies (600MHz, 700MHz, 800MHz) is measured in miles.  Coverage for the "high" cellular frequencies (24GHz, 28GHz, 32GHz) is measured in feet.

A well-located cell site could cover a radius of 5 to 30 miles with the lower and maybe mid-band (1 to 5GHz) frequencies.  But a site at, say, 28 GHz (2,800 MHz), would not cover even one mile from the cell site.  The tradeoff is that more bandwidth is available on the higher channels.


How do we overcome this frequency disadvantage?  The answer is getting more signal at the user's location, and that is most easily provided by an outdoor antenna, which limits us to getting the most from 5G at a fixed location.  There's nothing wrong with getting faster Internet access wirelessly at home, but of course, most of us would rather have it in our pocket wherever we travel.

T-Mobile plans to provide 5G Wireless on their new, low-band assignments at 600 Mhz.  Yes, there are bandwidth limitations there, so T-Mobile plans to let your wireless device access other, higher wireless channels where there is more bandwidth, if you're within the more restricted coverage area of those channels.  You see, you can't break the "law".

The other method of getting more 5G signal to more users is more cell sites...spaced about a mile or two apart.  Just look at all the fun in that!