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Active vs. Passive DAS: What’s The Difference?

Distributed antenna systems (DAS) are installed to deliver expanded cellular and wireless coverage in buildings and facilities that face signal challenges. They may be installed indoors or outdoors, with the majority being in-building DAS. These systems are either active or passive DAS. Telamon Wireless explains the differences between both options.

Components of DAS

All in-building DAS solutions utilize three main components:

  • Signal source
  • Central amplification unit
  • In-building distribution

 

Active vs. passive DAS both have the same goal – improving indoor cellular and wireless coverage. However, each system type has differences in how they operate, which creates advantages and disadvantages for users.

Active DAS

In an active DAS solution, the signal source is received from carrier networks. The signals are converted to digital signals from analog radio frequencies, which allows signal strength to be maintained despite the coverage area or cable run. Essentially, with an active DAS, it’s as if there is a small cell tower within the facility.

Digital signals are converted back to radio frequency for the areas in need of coverage. Active DAS uses powered components and consists of remote notes connected by fiber optic cable. Base stations can be used to expand network capacity through generating signal strength and direct communication with the carrier. 

Active DAS is usually specific to one carrier, though it is possible to operate with multiple carriers if additional base stations are installed. However, connection requires special permission from the carrier, which involves an extensive process of paperwork and time delays. For every carrier you want the system to connect with, a separate permission process is necessary.

Installation of active DAS can be costly and take several months to complete. Active systems are more expensive and take longer to deploy. However, when it comes to power and coverage, active systems definitely win.

Passive DAS

A passive DAS solution gains signal source by boosting off-air signals, rather than a direct connection with a carrier. Therefore, they need plenty of outside signal to operate properly, which is typically readily available in urban areas. However, stronger amplifiers and antennas are required to achieve adequate signal boost when passive DAS solutions are installed in rural areas.

When it comes to cost between active and passive DAS, passive solutions are far less expensive. They can be deployed in a matter of weeks, which is a much shorter period than that of an active system. When active DAS is used to provide total coverage, passive DAS is more suitable for spot coverage in main areas of a facility.

Active vs. Passive DAS? Ask Telamon

Active or passive DAS are viable solutions depending on the needs and attributes of your facility. Our experts work to design DAS around the needs of your building as well as budgetary restrictions in order to deliver to signal coverage you require. Learn more about DAS solutions from Telamon Wireless – contact us today.