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Components of Passive DAS Cell / Public Safety Signal Booster Install

Mar 14, 2018

Components of Passive DAS Cell / Public Safety Signal Booster Install

When it comes to installing signal enhancing solutions for 3G, 4G, LTE cell service & public safety, Passive DAS is an indisputable choice by signal booster installers for most of the enterprise structures and public infrastructures out there.

Faster deployment time and relatively cheaper installation costs make passive DAS (Distributed Antenna System) both reliable and economically viable signal boosting solution for architectures to increase coverage and capacity in small to medium-sized buildings. Both these factors make the majority of market sway towards Passive DAS. Beyond the RF sources, a Passive DAS does not contain any active gain components. Passive DAS (Distributed Antenna Systems) typically use passive components like coax cables, splitters, diplexers to distribute signal. Unlike active DAS, Passive DAS sytems use bi-directional amplifiers or boosters to rebroadcast signal from the macro cellular network using a donor signal acquired through exterior antenna on the roof of respective building.

What are the fully configured components that drive a Passive DAS without the presence of any active component between the signal source and antennas? Without much ado, let us configure hypothetically by taking a look at the six major components of a Passive DAS for cellular / public safety signal booster installations.

Typical Passive DAS Configuration Includes:

  1. Signal Sources (Cell Tower AKA. Donor Site & Exterior Antenna).

    Signal sources are at the heart of a Passive DAS. This is because unlike other DAS solutions, Passive DAS does not contain any other active components or signal producers other than the RF signal sources. Exterior antenna(s) are the main source of signal into the building. They catch signals from cell towers aka. donor sites within nearest proximity.

  2. RF Bi-Directional Amplifier (BDA).

    Bi-directional amplifiers (BDAs) amplify the signal received from signal sources (Cell Tower and Exterior Antenna). Multiple signal amplifiers can be used for larger buildings requiring larger cellular & public safety bands coverage areas.

  3. RF Combiners (Signal Consolidators).

    RF combiners play a vital role in equipment room of a passive DAS. Primarily, they are used to combine the main and diverse receive paths while sending uplink signals from the DAS to the base station, donor site, or cell tower to prevent the diversity imbalance alarm from tripping off. Additionally, combiners are also used to combine signals from varied signal sources so that the signal can be transmitted to the zones that they serve.

    Various types of combiners such as wideband hybrid combiners or low loss cavity filters are deployed depending on the exact requirements of the purpose to be served. Usually, a set of hybrid combiners are used to unite different signal sources on a single floor. This structure is then combined using filter combiners across the various floors in the building.

    Consequently, the more complex the structure, the number of combiners are required. For example, in certain instances when exterior signal is strong, a single exterior antenna may suffice. However, in other instances, multiple exterior antennae would be required and the signal combined for input into bi-directional amplifier.

  4. Interior Antennas.

    A multi-band network of antennae distributes the signals across the building. Two types of antennas come into play. Within interior spaces, a wide-band, omnidirectional antenna scatters the signal all across large spaces. However, things get a little bit tricky near windows and doors. There're high chances that outside signals may interfere with the signals emitted by antenna, and that majority of it actually ends up being transmitted outside the space to be covered.

    Hence, panel, directional antennas are installed near the building openings to gain the maximum coverage and capacity thanks to its directional abilities. To do this, directional antennas near edges are particularly installed with their emitters pointing inwards. This ensures that all useful signal is delivered within the building and any signal loss is minimized.

    Additionally, metal equipment within the building can create significant interference due to passive intermodulation. Due care should be taken to ensure that all antennas are placed at proper locations to maximize the signal output from them.

  5. Coaxial Cables.

    Passive DAS installations typically use two types of coax cables to connect exterior antenna with signal amplifier and interior antennas. They basically distribute signal throughout the building. On the first level, large diameter cables are used within and between amplifier or bi-directional amplifier equipment room and the zones to be served. Then, between and on each of the floors, rugged fire & heat resistant plenum coated cables are used through plenum spaces to connect the larger network to the antennas.

    During their installation, maneuvering coaxial cables in-and-out of the building throughout its length can be a daunting task and it requires highly skilled labor to get it done right while keeping its proximity to other objects. Otherwise, the cables can always run a risk of wear and tear after a short period of time.

  6. Splitters, Couplers, and Taps.

    A set of splitters, couplers, and tappers are used at various points across the running length of the coaxial cable. This is done to ensure a proper distribution of the desired signal levels at each interior antenna.

Now you know what goes into an installation of a Passive DAS system or signal booster system for cellular networks on 3G, 4G, LTE and Public Safety Bands. And that if your building requires budget-signal boosting, you know the answer to your poor coverage woes is Passive DAS installation that we provide. Our turnkey solution will save you time, effort, and money. Guaranteed.

Expert LTE and Public Safety Signal Booster Installers Ready To Help.

Struggling to find public service signal booster installers to install your system professionally? Our cellular LTE & public safety signal booster installation service costs less! Furthermore, we provide total satisfaction guarantee second to none. Expect an industry leading maintenance service level agreement (SLA) from SignalBooster.com that will ensure constant wireless connectivity into the future. Call 1(855)846-2654 for a FREE consultation or submit questionnaire for public safety wireless signal booster install service. Installation will meet federal requirements for first responders. It will be approved by ALL cellular service carriers. We will ensure total compliance with all certifications in place per local state & county fire department.


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  • Stan, there is a lot of confusion, but I hope this answers your question about what are devices available for a mobile signal booster for at home. There are a number of cell phone boosters for the home. You’ll want to make sure you get the right one for the right sized home. There are boosters built for 1000-1200 square feet (estimates) and ones for larger homes up to mansions. You can also get multipurpose devices that act as a cell phone booster, wifi booster, and help with HDTV. This site has a lot of great blogs on home boosters and how they can help you whether you have a home office, or are just somewhere remote where the signal is weak.

    John Thomas Plymouth on
  • I am confused. There are these DAS things. There are cell phone boosters too. So with that in mind, what’s a device available for a mobile signal booster for home? What is it called and how is it different than this thing (DAS).

    Stanley Mazurek on
  • There are many write-ups on cell signal boosters here, but I didn’t know how many there are for cellular das systems too. The distributed antenna system design does wonders in certain types of buildings. Buildings like shopping malls and sports facilities can benefit from consistently strong signals as can places like airports. All those places need better cell phone coverage, both for safety and allowing people a chance to make calls while shopping or waiting. It must be helpful that there are cell phone booster installation services because I imagine a distributed antenna system architecture is complicated

    Harold Byrd on

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