Distributed antenna systems (DAS) were the original small cells. First used more than 30 years ago, DAS began as a solution to provide wireless coverage in areas where there was none.
Today’s DAS networks help fill in holes where wireless coverage is weak and boost the capacity of traditional networks in high-traffic areas.
Ideal settings for DAS include:
- Large indoor areas like high-rise office buildings or airports
- Contiguous outdoor areas such as stadiums or open courtyards
- A combination of indoor and outdoor environments, such as a college campus
Instead of building a new tower, operators install a network of connected DAS nodes that are linked, often by fiber, to a central communications hub. These low-powered antennas are the size of a fire alarm or smoke detector, and cover a short range of less than a half-mile.
DAS and Joint Use Assets
By the end of 2018, sixteen million DAS nodes will be deployed. One of the most significant concerns with relying on utility poles for DAS installations is the increasing crowding on poles and the lack of available space as this and other technologies – like the newer small cell attachments – continue to grow in response to increased wireless demands.
The Difference Between DAS and Small Cells
DAS are carrier-neutral, meaning multiple carriers can use a single node, and nodes can handle many frequencies (including 2G, 3G and 4G commercial frequencies, public safety, UHF and VHF bands). They were designed to scale to meet the needs of a growing network, and aren’t ideal for low-density applications.
Small cells are primarily single-carrier and single-frequency technologies, although this is changing with ongoing advancements. They are designed to deliver coverage and capacity over a relatively small area (like a Wi-Fi access point) and are better suited for a single carrier.
While the best technology choice will vary from one situation to the next, the best solution may be a combination of DAS and small cells.