ZTE Macro's RF remote unit is because the frequency of the signal sent by the baseband is very low. What the RF needs to do is to continue to modulate the signal, from the low frequency to the designated high frequency frequency band. For example, the GSM band of 900MHz, the 4GLTE band of 1.9GHz, and the 5G band of 3.5GHz.
The role of radio frequency is just like the reason why the dispatcher does such modulation of RF radio frequency. On the one hand, as mentioned above, the baseband signal is not conducive to long-distance transmission.
On the other hand, wireless spectrum resources are scarce, and low-frequency frequency bands are generally occupied by other uses. The high-frequency band resources are relatively abundant, and it is easier to achieve large bandwidth.
The electromagnetic radiation of the radio frequency remote unit exists, but it is mostly within the safe range, and residents do not need to worry about it. Both the natural magnetic field and the sun emit electromagnetic radiation of different intensities.
In fact, in people's daily life, in addition to base stations, electronic products, such as mobile phones and home appliances, have radiation. The current data shows that the commonly used electrical appliances that people come into contact with have little or no damage to the body.
The base station radiation is the same as the mobile phone radiation. It belongs to the non-ionizing radiation in the radiation, that is, the electromagnetic wave with the frequency of 0-300GHz. It does not cause ionization of matter, and generally does not destroy the molecular structure. In addition to these two, the routers, TVs, induction cookers, etc. we use in our daily lives also generate non-ionizing radiation.
That is to say, the base station radiation, which is non-ionizing radiation, does not actually cause harm to human health.
The advantage of the remote radio system is to use optical fiber to transmit data between the RRH and the base station. In traditional systems, the distance between the base station and the antenna must not exceed 100 meters (due to analog signal loss), so expensive communication space must be rented near the antenna, or an expensive container must be installed on a flat roof or outdoors.
Ethernet using optical fiber as the transmission medium will not cause any signal loss when transmitting digital data between the base station and the RRH, and the maximum allowable distance can reach 20 kilometers, so the base station can be concentrated in a lower-cost communication room, and Network planning will also become more flexible and modular.
The link uses existing or newly installed fiber optic infrastructure to transmit data, which is much simpler and cheaper than using corrugated cables. Various reports have also shown that using fiber optics can reduce the installation time of remote RF systems, which is important when implementing base station replacements.