If you have the cell signal blues, you're probably looking at cell signal boosters for your home or vehicle. For any application, weBoost is the place to start looking. From their excellent out-of-the-box experience to their high performance, weBoost boosters set the bar – or bars, in this case. The update Drive Reach is their strongest booster for cars and SUVS with a max gain of 50dB.
As usual with cell boosters, first thing to do is register your device with the FCC. It's free and just takes a minute. Installation is essentially the same with all weBoost boosters: place one antenna inside, one outside, connect both to the booster and the booster to power and you're done. Optimizing the placement to squeeze out every dB of signal boost is a bit more involved but pretty simple and worth the effort. Just move the antenna around and test your signal strength each time. The following sequence will get you there; don't be intimidated by all the codes, just go step-by-step and it will all make sense.
Cell signal is measured from -50dB (perfect signal) to -120dB (dead zone). After installing put your phone in field test mode to see your signal strength in dB, because the bars that supposedly show signal strength really don’t mean jack. On iOS open phone app > dial pad > type in *3001#12345#* > hit send to open a hidden menu. Go to LTE > Serving Cell Meas > look at the rsrp0 number to see the strength of the closest cell tower in dB. On an iPhone this mode used to replace the useless bars with a useful numerical decibel reading where -50dB is a perfect signal and -120dB is a dead zone. However since iOS 11 you now get this funky menu setup that has a lot more information but is difficult to read, not least because the list of data that includes the critical rsrp0 number keeps automatically resorting every second or so. If you’re specifically interested in data up/download speeds get the Speedtest app by Ookla to test your speeds before and after boosting.
Signal strength generally depends on the location and power of the nearest cell tower, which you can find at least roughly with a number of apps and websites. Performance of the booster depends on signal strength: the higher the signal strength, the more you'll gain, it's just the nature of the thing, and weBoost recommends a base signal strength of -100dB to operate.
We rely on weBoost boosters in both our vehicles, and since they both have cigarette lighter adapters in the cargo area it was simple to locate the amplifier in the cargo area and route the interior antenna cable under the rear seat to the back of the center console where we stuck it using the included adhesive pads. The exterior antenna we routed through the hatch to the roof, where it has remained without moving. Signal definitely improves, including in some remote Alaska campgrounds where we need to leave the vehicle accessory power on to use the booster for a usable cell signal. Done and done.