5G requires significantly more cell towers and antennas than 4G. Deploying hardware in so many places is prohibitively expensive for traditional wireless companies. DeWi is the solution to the challenges raised by 5G.
I’ve seen versions of the argument above a dozen times. It’s mostly wrong. Several bits of information are getting combined and confused by folks hoping to shine a positive light on DeWi.
Most 5G coverage relies on signals with frequencies between 600MHz and 6GHz. That’s the same frequency range used for 4G. Holding other factors constant, a 5G signal at a given frequency will travel similarly to a 4G signal using that same frequency.
One of the innovations coming with 5G is the possibility of using high frequency spectrum that 4G didn’t work with. So-called “millimeter wave 5G” uses spectrum around 30GHz.1 Millimeter wave 5G signals don’t travel far and are easily blocked by buildings and other obstacles. However, millimeter wave can offer incredible speeds. If you’ve seen 5G tests showing speeds of multiple gigabits per second, the tests probably relied on millimeter wave 5G.
Close to 0% of land in the U.S. is covered by millimeter wave. While networks may roll out more millimeter wave 5G over time, it’ll be supplemental to lower frequency service. Thanks to its poor propagation characteristics, millimeter wave 5G will never be the backbone of a nationwide network.
DeWi projects use small cells (radio nodes) that operate in the CBRS Band (around 3.5GHz). These CBRS small cells have limited coverage potential largely because they’re low power. “5G” isn’t to blame. No DeWi projects are even using 5G smalls cells. They’re all 4G LTE. While 5G small cells will become part of DeWi eventually, they’ll continue to have limited range unless power limits for CBRS hardware are changed.
But, But, But…
DeWi projects aren’t using millimeter wave 5G today, but could they eventually? I won’t rule out that happening, but a lot would have to change about the world before it’s a possibility. I’m not aware of any DeWi project that legitimately has millimeter wave service on its roadmap.
If we drop the focus on 5G, we might be able to rescue a bit of the argument I’m objecting to. In many places, cell networks are congested. There’s a case for “densifying” networks—i.e., adding capacity in areas that already have coverage but are short on bandwidth. Densification is possible with 4G or 5G technology. Short-range small cells might be helpful for networks looking to densify. Maybe DeWi projects can roll out that hardware in a uniquely cost-effective way.