21 | 05 | 2019

Infrastructure: Distributed Antenna System

What is DAS

DAS (distributed antenna system) is a RF (radio frequency) signal distributing system. It broadcast RF signal from at least one common source along the path via transport medium (usuall coaxial cable or we call it leaky cable) to antennas. By distributing the RF signal, wireless service is enabled around the antennas.

DAS is commonly used by mobile network network, commonly like Smartone, CSL for their mobile service coverage (2G, 3G) inside building facilities, example: hotel, business centers, government facility and shopping mall. DAS is modified to fit to use for Wi-Fi network while Wi-Fi is running at high frequency (2.4GHz and even 5.8GHz) and Wi-Fi client is lower receive sentitivity and transmit power then mobile phone.

The unit of energy measure in radio frequency is dB. When a AccessPoint generate electronic impulse along the cabling and to the antenna, RF signal is created and “jump out” the equipments by the antenna. A LOS (line of sight) transmission can be put into equations for calculating the single strength along the path. Once the RF signal strength is enough for a receiver to analyze and translate to data, the connection is successful, so all the implementations, follow this rule and turns out to be possible for implementation and usage.

Advantages of Wi-Fi over DAS

- Dramatically decrease number of access point and controller scale (license) by 60%
- Increase and enhance coverage
- Benefit to roaming less required applications, eg. VoIP, Remote Desktop
- Lowest maintenance cost


Ritz Carlton HK guest wi-fi@2009-2010
Crown Motors Wi-Fi@2008
Capitol Wi-Fi Hotspot
Case Study : Weikeng B2B distributor Wi-Fi