How Low Can You Go?

How Low Can You Go?

Initial Thoughts on 5G NR Operating in FR1 and FDD Mode

01/30/2020 | 28 pages

In this Signals Flash! we focus exclusively on 5G NR coverage, how it compares between the two operators’ networks as well as with their advertised coverage map.  We also cover why our results (and the published coverage maps) almost certainly overstate the probability of using 5G NR.  In our two forthcoming Signals Ahead reports we will delve into the actual performance of 5G NR, how it compares with LTE, and how it impacts the user experience, including its contribution to popular user applications and its effect on total current consumption.

We have a Winner! 5G NR has arrived to SRG HQ, thanks to T-Mobile.  We confirmed the availability of 5G NR on January 23rd at 8:30 PM.  No one came close to guessing the date and the measured 5G NR throughput was substantially different than any guesses.  No one takes home the prize.  We share the details.

Our Thanks! A special thanks to our T&M partner companies (Accuver Americas, Rohde & Schwarz and Spirent Communications) who supported us in this campaign and in our forthcoming Signals Ahead

5G Coverage Maps are Optimistic. Using the R&S scanner, we mapped out potential 5G NR coverage areas in San Diego and Indianapolis.  Although coverage is quite good and 5G NR is available in some very unlikely places, the maps overstate where the 5G NR signal is strong enough to support a good data connection.

 Mid-band LTE is the Weakest Link. Although low-band 5G NR signals may propagate for miles and miles, they still need LTE for an anchor with NSA.  This requirement means 5G NR coverage is limited by the propagation of LTE @ 2000 MHz.  Moving to a Standalone (SA) architecture is one way to address the issue.

5G Icon Woes. If you believe the 5G indicator icon and strength bars, the smartphone is almost always using 5G NR on the T-Mobile network.  If you examine chipset log files and scanner results, the story is completely different.

Stuck in Low Band. Today’s 5G smartphones can’t simultaneously support two low bands channels, be they based on LTE or 5G NR.  This situation means a phone can’t use LTE Band 12 and 5G NR Band n71 or Band n5, for example.  We also observed a strong tendency for the smartphones to favor LTE Band 12 (and Band 14) in some of the networks we tested, meaning a typical consumer’s smartphone may not use 5G NR, even if the 5G NR signal is present.