A distributed antenna system (DAS) is a network of antennas that provides wireless cellular service for a small area, such as a building. In order to function, DAS solutions require participation from at least one mobile network carrier. DAS technology was developed when mobile connectivity issues began to arise due to increasing data usage.

How a DAS Works

DAS diagram

DAS solutions provide cellular service via a combination of coaxial, fiber and Ethernet cabling. The antennas connect to a base station, which collects a signal from a carrier network and creates a dedicated cellular network for the building.

Types of DAS Solutions

At a high level, there are two broad categories of DAS solutions. Outdoor DAS (oDAS) solutions are used for tunnels, campus environments, hilly terrain, busy metro areas and remote locations. Indoor DAS (iDAS) solutions are used for buildings, stadiums and other facilities. WIN specializes in iDAS solutions, of which there are four types:

Passive DAS

Passive DAS solutions boost cell coverage by distributing radio frequency (RF) signals from one or more carriers throughout a building without amplification. The signals travel from a base transceiver station (BTS) through a system of coaxial cabling and antennas, and get weaker the farther they go. For this reason, passive DAS solutions cost less and only work well for small coverage areas.

Active DAS

Active DAS solutions boost cell coverage by amplifying RF signals from carriers and distributing them throughout a building. The signals are first converted back to their original frequency and then transmitted through antennas connected to remote units and / or hubs. Active DAS solutions cost more than passive systems and work well for large coverage areas in Class A buildings.

Enterprise Small Cell Technologies

Small cell technologies are a newer type of DAS that use radio access nodes to boost cell coverage at specific points within a building. Small cells provide reliable indoor coverage for Class B and Class C buildings, as well as smaller buildings. They're ideal for small- to mid-size businesses, as well as companies that might need to expand or are in the process of getting a more robust DAS solution.

Hybrid DAS

Hybrid DAS systems use a combination of passive and active DAS systems and / or small cell technologies. RF signals travel between floors through active DAS technologies, and across floors through passive DAS technologies. Some signal loss may occur on individual floors, but not as much as with fully passive systems.