How I finally got cell service in my metal building

[strantor]

The theory behind that is the Shannon channel capacity theorem. This basically says if you have a stronger signal (better signal to noise ratio), you can get more data through end-to-end.

Both cell signals and wifi use adaptive coding. That is, they measure the signal strength and adjust the transmission rate to get the best throughput. If the signal strength changes, they adjust on the fly. Since the adjustment is made at the tower and the cell phone (or router and wifi device), it really doesn't matter how the signal strength was improved.

This helps tremendously with serving more customers over a larger area. The closer (stronger signal) customers get better service, but they also take up less overall time on the cell tower or wifi hub, so the tower/hub can serve more customers. Distant and weak signals take a larger time slice, but still get service at a reduced data rate. The exact details are very complicated and quite sophisticated, and change between cell versions (3G/4G/5G) or wifi versions (802.11 a/b/g/n) ....

The wiki article went from 0 to over my head in record time but your "for dummies" explanation is all I really needed. Who knew I would be learning about such things on a machinist forum? That's why I love this place. Thanks for broadening my knowledge. Even if I don't understand the finer details, I understand enough now to give yesterday's version of me a pass for being so mystified by it.

 

[rwdenney]

I have been curious how well this thing would work for actually boosting a weak signal. Out at my dad's place it's a cellular black hole, you might get one bar if the planets are aligned right, but if you plan on actually making a call from a cell phone, plan on walking or driving a half mile to the top of the nearest hill. I thought about recommending this thing to him but wasn't sure it would work, and after reading your post I think I won't mention it to him. I would hate for him to spend $400 on something that won't work.

That sucks! I don't know how well the one I got would work outside of a 30x30 metal box but I am pretty sure it would be better than that. Maybe you need a better indoor antenna?

There are three third-party apps mentioned in the manual which can tell you where the towers are. They are OpenSignal, Cell Mapper, and Network Cell Info Light. I just picked the first one and it worked fine.

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I pointed the antenna exactly along that line the app suggested and got strong signal from the tower that I can't even see. Maybe using one of these apps could help you better align your outdoor antenna and get better results.


That's odd. Does Apple have its own app for wifi calling? On my android I just turn on wifi calling (it's a setting, not an app, on my phone) and then I can call or text anyone I want.

Apple uses a separate texting protocol between iPhones. Instead of SMS, it uses iMessage. Voice over IP still requires your network provider to cross the Internet/Phone System boundary at some point, even if you use Internet from your end. That setting is just permission to your cell service provider to do that.

The towers in our area are owned by service companies and the cellular providers that hang their antennas on them are not publicly disclosed. I can find towers but I don’t know who they serve. I have Open Signal already.

My indoor antenna would work better in a big open space. It’s a commercial-grade pizza-box antenna on the inside—it’s directional and doesn’t penetrate heavy walls and floors very well. Part of what limits its effectiveness is the marginal coverage we have outdoors. The outdoor antenna is a directional YAGI in a plastic cover and it has to be aimed correctly. But signal strength measurements on the connected phones are so damped and laggy that getting good aim by sweeping the horizon is not going to be very precise.

We are supposed to get fiber “next year”. Been hearing that since 2014.

Rick “an extra-class ham” Denney