DAS or Distributed Antenna System is a connection of spatially separated antenna nodes that is connected to a common network source. It provides wireless services within a range of areas. DAS is installed below the clutter level, and its node installations are compact.
There are many companies in different places that provide DAS installation services. Now let us learn about DAS in detail.
Active DAS is the Distributed Antenna System which requires a power source to be operated. These active systems apply fiber optic cables to connect with remote nodes.
- Signal Sources: A powerful active DAS cannot withstand signal alone. So signal sources are needed. These sources lie in the head-end equipment room.
- POI Tray: The POI Tray connects RF signals from diverse sources before giving it to head-end equipment.
- Head-end Unit: The head-end equipment room has head-end units. On one side, RF modules connect with head-end units corresponding to uplink and downlink port-pairs on the POI through coaxial cables. On the other hand, similar uplink and downlink ports are present to distribute signals.
- Radio Units: Radio units of active DAS receive signals from head-end units, segregate and amplify them according to their frequency, then transmit them to regional places via an antenna.
- Fiber Optic Cables: These fibers are thin, flexible and light-weight cables that are perfect for active DAS. It allows the radio unit to be installed at a considerable distance from the head-end unit without any signal loss or interruptions.
- It can be used over multi-mode (MMF) or single-mode fiber (SMF).
- It is highly scalable and can be easily upgraded without additional modules.
- It’s one primary hub that distributes eight secondary hubs and each secondary hub to 8 remote hubs.
- It supports the same systems: FDD and TDD.
Passive DAS are those DAS that amplify signals on the roof of a building and retransmit it inside the building.
- Signal sources: Its signal sources are nothing but cell towers, donor sites, and exterior antenna. They are the main component of passive DAS.
- RF Bi-Directional Amplifier: Bi-directional amplifiers (BDA) amplify the signal received from signal sources.
- RF Combiners: They combine the main and diverse receive paths while it sends uplinks from DAS to base stations or cell towers. They also combine signals to transmit them to various zones.
- Interior Antenna: Antennas are used to distribute signals, and here the interior antennas do that all over the building.
- Coaxial Cables: These cables are used to connect the exterior antenna with amplifiers and interior antenna.
- Splitters, Couplers, and Taps: These are attached to coaxial cables so that uniform distribution of the desired signal levels is ensured.
- It distributes RF signals through cables to more than one antenna.
- It also uses RF amplifiers to help the signals from not losing path.
- RF source of 43 dBm power carrier is used in passive DAS.
- It uses RF coaxial cables with a 7/8” measure for a low cost per ft.
Hybrid DAS is a new type of DAS that uses active repeater amplifiers with integrated antennas connected over CAT5e Ethernet cables.
Components: Cel-Fi or Hybrid DAS have the same configurations as active DAS. But these DAS are improved versions of active DAS. Some extra components are
- Network unit.
- Small cell interface.
- Multiple coverage units.
- It is a carrier-approved active DAS.
- It can solve any coverage issues for 3G/4G/LTE.
- It helps in increasing the capacity of cellular towers.
- Can manage the increasing demand for bandwidth.
- Improve internet connectivity by multiple carriers.
- It helps to improve the speed of communication.
So DAS is a wireless setup providing uniformly distributed network. One can install it for their internet uses and can choose any one of the above-mentioned types according to their convenience.