Antenna (Antenna System)
Transmitting Antenna: Converts the electrical signals output by the base station equipment into electromagnetic waves, broadcasting them to the coverage area (such as mobile phone signals and 5G millimeter waves).
Receiving Antenna: Captures electromagnetic waves sent by terminal devices (such as mobile phones), converts them into electrical signals, and transmits them to the base station for processing.
Antennas are typically directional (for example, directional antennas cover a specific area, while omnidirectional antennas cover 360°). Their coverage range is controlled by adjusting their angle and gain.
Base Station (Signal Processing Center)
Base station equipment (such as BBU and RRU), installed in the equipment room below or on the tower, is the core of signal processing:
Receive Signal Processing: Filters, amplifies, and demodulates the electrical signals transmitted by the antenna to extract the information sent by the terminal (such as voice and data).
Transmit Signal Processing: Encodes, modulates, and amplifies the information to be transmitted to the terminal (such as data from other mobile phones or the internet), converts it into electromagnetic waves, and transmits it through the antenna. Base stations also handle management functions such as access control (such as verifying mobile phone identities) and channel allocation (avoiding signal interference).
Transmission Link (Connecting to the Core Network)
Communication towers are connected to the communications core network via wired (fiber optic, cable) or wireless (microwave) links.
Communications between terminals (e.g., a call from phone A to phone B) require a path from terminal to base station to core network to another base station to another terminal. The transmission link of a communication tower serves as the "bridge" connecting the base station and the core network.
