• tal@lemmy.today
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    6 months ago

    Walmarts are big windowless boxes. A cell signal has to go through masonry walls to get out.

    5G Ultra Wideband, which is what OP’s map is showing to be in the area, and what he’s upset about not getting, uses millimeter-wave frequencies, which are fast if they have a clear line to the tower…but don’t penetrate material well.

    https://www.5gamericas.org/here-comes-millimeter-wave/

    On the challenging side of the equation, millimeter waves don’t propagate as far as low-band or mid-band signals, so there is a much smaller target area used to receive a signal, compared with sub-6 GHz signals. In addition, millimeter wave signals are subject to more diffused scattering when in contact with large objects, and they receive higher signal loss from foliage, object penetration, and from the atmosphere. This means you have to put a lot more millimeter wave signal repeaters around, so you get good mmWave coverage.

    I suspect that if WalMart wants, they could maybe pay to run femtocells inside the store or something to get more coverage, but if (a) they already have 4G coverage in the store and (b) they’re also providing WiFi access, they probably aren’t gonna be putting even more network infrastructure in.