DAS Antennas Indoor Or Outdoor

　　1. DAS Antennas Definition

　　Distributed antenna system (DAS) achieves wide-area uniform coverage or high-capacity access by distributing RF signals from base stations to multiple small antenna nodes. Its antennas can be divided into indoor and outdoor types, and the core difference lies in the installation environment, design requirements and coverage scenarios.

　　2. Indoor DAS Antennas

　　2.1 Design Features

　　Installation location: inside the building (ceiling, wall, column).

　　Coverage goal: solve indoor signal blind spots (such as corridors, compartments, basements).

　　Antenna types:

　　Omni-Directional Antennas: Cover the horizontal plane (±360°).

　　Directional Antennas: Focus on specific areas (such as conference rooms, exhibition halls).

　　Patch Antennas: Integrated in the ceiling or wall, beautiful and low profile.

　　Typical parameters:

　　Gain: 0–15 dBi

　　Frequency band: 700 MHz–6 GHz (supports 4G/5G/LTE/Wi-Fi 6)

　　Power: low power (≤20 W)

　　2.2 Typical application scenarios

　　Commercial buildings: shopping malls, office buildings, hotels.

　　Medical facilities: wireless device support in hospital wards and operating rooms.

　　Educational institutions: classroom and laboratory signal enhancement.

　　Transportation hubs: subway platforms, airport terminals.

　　2.3 Advantages and challenges

　　Advantages:

　　Refined coverage and reduced signal interference.

　　Support high-density user access (such as 5G NR).

　　Challenges:

　　Complicated wiring and high construction costs.

　　Mutually shielding antennas must be avoided.

　　3. Outdoor DAS Antennas

　　3.1 Design features

　　Installation location: outside the building (roof, pole, mast).

　　Coverage goal: Expand outdoor coverage or connect multiple indoor DAS nodes.

　　Antenna types:

　　Sector Antennas: Horizontal coverage of 120°–240°, suitable for roads and squares.

　　Parabolic Reflectors: Long-distance directional coverage (such as stadiums and parks).

　　Yagi-Uda Antennas: Medium- and short-range point-to-point communication.

　　Typical parameters:

　　Gain: 15–30 dBi

　　Frequency band: 300 MHz–5 GHz (supports microwave backhaul, satellite communication)

　　Power: High power (≥50 W)

　　3.2 Typical application scenarios

　　Large venues: stadiums, exhibition centers, open-air concerts.

　　Urban backbone network: connects multiple buildings or regional DAS.

　　Rural/remote areas: low-cost solutions covering wide areas.

　　Emergency communications: temporary deployment at disaster sites.

　　3.3 Advantages and challenges

　　Advantages:

　　Wide coverage, support for long-distance signal transmission.

　　Strong anti-interference ability (pure signal in open environment).

　　Challenges:

　　Need to withstand harsh weather conditions (IP67/IP68 protection).

　　May need to coordinate spectrum resources (avoid conflicts with satellite/microwave communications).