The Difference Between 5G and 5G

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Are you confused about the difference between 5G (for WiFi) and 5G (for cellular)? They have the same name, and share some of the same technology, so it’s perfectly understandable.

WiFi was originally on the 2.4 GHz frequency—the very same frequency as your microwave oven, by the way. But with 802.11ac it also could use the 5 Ghz frequency. This “5G” WiFi offered dramatically faster speeds but a much shorter range. Most WiFi can travel about 50~75 feet in a home or about 150 feet in open air. But 5G WiFi is 10~20 times faster but can only travel about 25~50 feet indoors. Faster-but-closer.

Cellular labels its generations with “G” numbers. The US is largely on 4G although some of the LTE is really 4G-minus and some 4G is really “Advanced” 4G or what I call 4G plus. The next cellular generation will be called 5G, which is not to be confused with AT&T’s not-5G called 5Ge or with WiFi 5G.

Now here’s where it gets really confusing. Cellular 5G can be implemented on the 5GHz spectrum, similar to WiFi 5G 802.11ac. And, just like WiFi 5G, Cellular 5G is much much faster but also has a very short range. So WiFi 5GHz and cellular 5GHz both share the “Faster-but-closer” rule.

But the technology and compatibility between WiFi 5GHz and cellular 5G or 5GHz are 100% different. They cannot intercommunicate. They don’t use the same radios or chipsets and they aren’t interoperable at any level or in any way. It’s confusing and unfortunate that they happen to both use the “5G” name and (coincidentally) can both operate in the 5 GHz frequency.

There is a wonderful chart which shows this one commonality “Faster Worse Coverage”. You can see that as the frequency increases, coverage gets WORSE. (Higher in this graph is worse.) The pink area shows Cellular 3G/4G frequencies and the blue shows frequencies most typically thought of as “5G”. Note that WiFi 5 GHz is where I have drawn the red line:

Now, look at the blue arrow. This shows the REDUCTION of in-building coverage at the 5GHz frequency. The diagram is non-linear so you are looking at something like an 80%~90% reduction in in-building coverage.

The author of the chart correctly points out that cellular 5G coverage is 100x worse on 95% of typical Cellular 5G frequencies than today’s 3G/4G frequencies.

The other thing to pick out is that 600 MHz in-building coverage is vastly superior to the more common 1~2 GHz frequencies most 3G and 4G networks are built on. T-Mobile has been buying and deploying 600 MHz left and right because they know it is the best way to have “coverage everywhere” (Both inside buildings and throughout vast swaths of open land.)

Where cellular 5G naming gets so confusing is that it is widely associated with frequencies above 2.1 GHz and it is being billed as faster with promos touting GB speeds. The public is being advertised into thinking that cellular 5G is all about speed. This is true in that cellular 5G unlocks higher frequencies which can yield high speeds at very close distances.

But cellular 5G is much more about managing spectrum efficiently. One of the most important cellular 5G features is the ability to have overlapping cells. A carrier would have a 600 MHz cell that provides far and everywhere coverage in a large area, up to a 30 mile radius. Then, they would deploy 850 MHz, 950 MHz, and 2100 MHz to offload the 600 MHz cell. Finally, higher frequencies such as 5 GHz would be deployed in stadiums and concert venues where there are a lot of people very close to the tower. Users would be routed to the highest frequency that provides acceptable service. Thus, 600 MHz can be used to “fill in the gaps” and 5 GHz can be used to “fill in the gasps” with higher speed and bandwidth.

So here are the takeaway points:

  • Cellular 5G is completely different from WiFi 5G
  • Both of them can operate on the 5 GHz frequency, but they are not compatible.
  • Both of them have exceedingly short range, but are very very fast if you can get the signal.
  • Both of them have troubles penetrating walls. Most cellular “5G frequencies” (higher frequencies) cannot even penetrate a piece of glass.
  • 95% of cellular 5G frequencies are up to 100x worse at penetrating walls, glass, and buildings.

BUT

  • Cellular 5G also allows use of the 600 MHz frequency, which is not widely publicized and which will provide “coverage everywhere” service. But without the 5G protocol it doesn’t effectively work with today’s frequencies, so it must be deployed as “islands” of extended coverage.
  • Let me repeat: cellular 5G’s hidden gem is that it allows the 600 MHz frequency to be used as an “overlay” cell on top of 3G and 4G frequencies.

The 5Gs:

  • WiFi 5G is 5 Ghz
  • Cellular 5G is a protocol that unlocks more frequencies a carrier may own.
  • Cellular 5 GHz (and any frequency above 2100 MHz) provides faster speeds but has very short range.

Colin Berkshire