What is a Distributed Antenna System (DAS)?

A distributed antenna system (DAS) is a network of antennas placed throughout a facility to boost a wireless signal and expand its coverage and capacity. DAS systems are commonly utilized in large commercial buildings such as hospitals, hotels, stadiums, airports, and educational campuses. The goal of a DAS system is to improve cellular connectivity to users within those buildings which will help to reduce dropped calls and slow speeds.

Imagine being in a large sports stadium with thousands of other fans on game day. Most fans are eager to share their photos on social media while also staying connected to friends and family, whether to coordinate locations, or just to check in. In a high-density environment such as this, the stadium's network may struggle to meet demand leading to dropped calls and slow data speeds.

By deploying a DAS, the stadium could offer a reliable cellular connection to all fans in attendance without interruption. This network of antennas would be strategically placed in a way that provides coverage throughout the facility, minimizing dead spots, and providing adequate signal strength. The DAS antennas would be connected to a central hub that is commonly located in a secure room which would interface with the wider cellular network.

When a user makes a call or uses data on their mobile phone, their device would communicate with the nearest antenna which would then relay that signal to the central hub through a network of fiber optic cables. The hub would then route the signal to the appropriate carrier network. This scenario plays out at sporting events throughout the world every day.

There are three different types of distributed antenna systems: active, passive, and hybrid. Each DAS type has its own unique characteristics that will need to be considered when designing a network that meets the needs of a given space.

An active DAS is a network where each antenna node is equipped with its own signal amplification equipment which allows for more flexibility while providing the most reliable signal distribution.

A passive DAS relies on coaxial cables that distribute the signal from a central hub to more remote antennas on the network as needed but must rely on the incoming signal from cell towers.

A hybrid DAS combines the elements of both an active and passive system to offer more versatility. A hybrid network may utilize active DAS components in areas known for higher capacity demands and passive DAS components in areas that already have strong signal reception.

Aside from the obvious benefit to end users of a stronger wireless signal, a DAS offers flexibility and scalability as a facility grows, allowing a structure to add marginal components to meet needs. This makes a DAS network a cost-effective solution that can mitigate up-front costs. A DAS also brings the network closer to the end user as they move about throughout a facility.