We use a weboost cellbooster that "repeats" the cell signal from the outside to an inside antenna and boosts it at the same time. It can boost up to 4 devices and I saw the signal on my verizon S7 ( as hotspot ) improve from - 110 to -84 dbm. ( 2 bars to 4 bars ) $500 and well work the money.. easy to install to.
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