Outdoor GSM antenna : Oriented towards the nearest operator antenna and attached at a height, on the roof or on a facade, the latter picks up the upward and downward signal.
Different types of external antenna exist, depending on your environment and the distance to the operator antennas: Omnidirectional, monodirectional, omnidirectional plate with tubes. The omnidirectional antenna is ideal in urban areas since the signal is high and comes from multiple directions. In rural areas, it is recommended to turn to a directional antenna capable of picking up a distant signal, provided that it is well oriented.
GSM amplifier (repeater) : This electronic box improves the signal. First of all, it receives a quality signal from the outdoor antenna.
Then, this signal is recalibrated and transmitted to the smartphone by the antenna placed inside. The gain of an amplifier can be variable, depending on the quality of the signal received by the external antenna.
The latter is selected according to the frequencies of the operator. Some operators use the 900, 1800 and 210 Mhz, others do not. The mono, bi or tri-band GSM amplifier must be chosen carefully to match the frequencies of the mobile operators within signal range.
In the amplifier market, the main difference is in the supported frequency bands (3G, 4G, both ...) and in the number of internal antennas included or possible to add later.
Indoor GSM antenna : The indoor antenna should be placed close to where you are calling. Captured by the outdoor antenna, the signal is then amplified by the repeater and then the indoor antenna broadcasts the improved signal. It can be used in various and varied places (home, warehouse, office, car, boat).