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zap_p25 t1_ixr794m wrote

Reply to comment by _WhoisMrBilly_ in Bye-bye airplane mode: EU allows smartphones during flights by Zhukov-74

The primary limitation to the frequencies used by cell phones is that they are line of sight, power isn’t really as relevant. A 25,000+ foot elevation difference between phones and towers allows for some pretty awesome line of sight.

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FriendlyDespot t1_ixs4kjz wrote

Sure, but antennas on cell towers don't point up, they point towards the horizon, sometimes with a slight downward angle depending on the height of the tower relative to the subscribers. The part of the beam pattern that points above the horizon is typically pretty weak.

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MickeyElephant t1_ixt8g6h wrote

In LTE, the antennas have a fairly significant downward angle since every cell uses the same set of channels as every other cell. Before LTE, there would be a frequency reuse pattern, so another cell a few miles away would be using the same spectrum. So even then they are aimed somewhat down rather than at the horizon, as you said. But with LTE it's much more significant.

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zap_p25 t1_ixscjm1 wrote

Yes but the higher you are, the further the distance to horizon. And like you stated depending on the tower’s location and the engineered coverage it needs to provide, it could be configured for mechanical down tilt, no tilt, or up tilt.

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