In-Building Coverage - 3G / 4G / 5G

Distributed Antenna Systems (DAS)

R-Spectrum specialise in the design of mid-sized distributed antenna systems using what is known as an OTA Repeater. DAS are a cost effective way to provide strong mobile coverage throughout larger facilities such as hotels, underground car parks, hospitals, commercial buildings, multistorey office buildings, universities, mine sites, and more.

DAS can be built for any of the three Australian Mobile Network Operators, and depending on budget any combination of networks can be provided throughout the building. Our systems operate independently of the Network Operator, meaning our team can fit out your building without lengthy approval times.

R-Spectrum OTA Repeater systems provide high quality 3G and 4G coverage throughout buildings of any shape and size. Builds can be completed in a matter of weeks.

Each build is conducted under strict document and project management framework, providing performance assurance and whole of lifecycle management.

DAS distributed antenna system for mobile coverage, Queensland

What is a DAS?

For those who are unfamiliar with mobile technology, a Distributed Antenna System (DAS) is a series of small antennas located throughout your building which all connect by cables to a centralised repeater unit.

The key piece of technology in a DAS is called a Repeater. This is a complex electronics unit which regulates the amplification of a signal that it will output. A Repeater can often add as much as a 100 dB boost between its input and output antennas.

A rooftop antenna, called a Donor Antenna, feeds the repeater unit with a strong signal that it receives from the Mobile Network. This provides a high quality input to the Repeater that it can now amplify for distribution throughout the building. As the old saying goes - "Garbage In, Garbage Out" - the better the input signal quality means the better the output quality will be.

The Repeater is connected to a chain of antennas located at strategic positions throughout the building. These are called Server Antennas and their purpose is to rebroadcast the strong signal from the Repeater into each room.


Telstra Optus DAS System Diagram

While the three components - Donor, Repeater, and Server, form the key elements of a distributed antenna system, the reality is of course more complex.

Distributing mobile coverage throughout the building requires careful management of power levels to ensure an equitable rebroadcast. Incorrect power levels are not only highly inefficient but can result in user devices exhibiting irregular behaviour.

Off-Air Passive DAS, like the systems R-Spectrum builds, use a selection of Passive Distribution Components. These components are used to provide the necessary inter-port isolation between active hardware, and control power levels between building floors.

DAS must also conform to strict operator requirements who, through the MCF, mandate minimum hardware standards and system design characteristics to prevent an adverse impact to each operator's macro network. Designs are required to follow a project management approach in order to provide the necessary documentation to the MNO on request.

How do I get a DAS Installed?

The very first step is to contact our team. We will then ask a number of questions relating to the building's occupancy and request a floor-plan of the building. This floor plan is used by our design technicians to identify key installation elements, distribution methods, and estimate the number of Server Antennas required.

We will also look at the building's location with respect to the macro network. Using RF modelling software our team will look at the available network technologies, as well as location and strength of nearby cell towers to determine the required Donor Antenna and Repeater configuration.

It typically takes less than a week to develop a preliminary design. Once completed, through our national partnerships R-Spectrum can arrange a technician to attend the site to confirm the proposed system diagram and estimate cable routes and lengths. At this point a quote can be generated for the installation.

R-Spectrum are partnered with Powertec to provide DAS installation nationally.

What Causes Weak Signal in Buildings?

Despite mobile networks getting better each day, mobile coverage still has difficulty reaching inside large buildings.

In Australia the focus on energy efficiency has seen a push to using energy efficient window tinting. This type of metallic tinting is designed to prevent the penetration of solar radiation, which is a form of electromagnetic energy similar to those used to carry mobile signals.

R-Spectrum's field observations have shown this type of tinting can result in a 20 to 30 dB reduction in signal strengths - enough to turn a five-bar connection outside into a one-bar of signal inside.

DAS installed in an office building (server antenna)

Modern building materials and their construction methodology also pay little regard to their effect on mobile services.

Many modern buildings use tilt-slab construction or incorporate metal framing and insulation. Unlike wood and plaster these heavy duty materials are too dense for signal to penetrate.

Your building may also sit in a blackspot, such as a localised terrain depression or behind a small hill which blocks transmission from the nearby tower. Regardless of any and all reasons for weak mobile signal, R-Spectrum can design a solution.

Typical Costs

If you've investigated the costs of having a network DAS installed previously, an OTA Repeater system can be dramatically cheaper.

Systems start from as little as $4,000 to around $150,000 for large building sizes. Modern office buildings with dedicated communications risers and simple tiled ceilings are the simplest and therefore lowest cost. Complex architectural designs however require far more planning and are generally more challenging from a physical perspective.

It's very easy to get started. Fill out the form below, or send an email to [email protected] to begin a no-obligation conversation with one of our team.