The function of radio frequency is just like the dispatcher's modulation of radio frequency. On the one hand, as mentioned above, baseband signals are not conducive to long-distance transmission.
On the other hand, wireless spectrum resources are scarce, and low frequency bands are generally occupied by other uses. However, high frequency band resources are relatively rich, and it is easier to realize large bandwidth.
Electromagnetic radiation exists in radio remote unit, but most of it is within the safe range, so residents need not worry. Natural magnetic fields and the sun will emit electromagnetic radiation of different intensities.
In fact, in people's daily life, electronic products such as mobile phones and home appliances radiate except base stations. The current data show that the common electrical appliances that people come into contact with have little or no harm to health.
Base station radiation, like mobile phone radiation, belongs to non-ionizing radiation, that is, electromagnetic waves with a frequency of 0-300 GHz, which will not cause ionization of substances and generally will not destroy the molecular structure. In addition to these two, there are routers, televisions, induction cookers and so on. What we use in our daily life will also produce non-ionizing radiation.
In other words, base station radiation belongs to non-ionizing radiation, which will not actually cause harm to human health.
Extended data:
The advantage of remote RF system is that it uses optical fiber to transmit data between RRH and base station. In the traditional system, the distance between the base station and the antenna should not exceed 100 meters (due to analog signal loss), so it is necessary to rent expensive communication space near the antenna or install expensive containers on flat roofs or outdoors.
Ethernet with optical fiber as transmission medium will not cause any signal loss when transmitting digital data between the base station and RRH, and the maximum distance allowed can reach 20 kilometers, so the base station can be concentrated in the communication room with lower cost, and the network planning will become more flexible and modular.
The link uses the existing or newly installed optical fiber infrastructure to transmit data, which is simpler and cheaper than using corrugated cable to transmit data. Various reports also show that the use of optical fiber can reduce the installation time of remote RF system, which is very important when implementing base station replacement.
References:
Baidu encyclopedia-radio remote control unit