November 1, 2021

Indoor DAS

When demand for traffic is concentrated 80% indoor. Specifically when the trend of developing high buildings for example residential, commercial centers, apartments, basements…


Telecommunications service providers began to create solutions for coverage with distributed antennas called DAS.

The DAS system will divide the signal from the operator BTS to the designed locations through passive and active elements.

However, with a large number of subscribers for different carriers, it is necessary for operator to sit together and find a way to share infrastructure.

Soon this solution has been deployed very early in North America, Europe, developed countries, and after that gradually spread to Asian countries.

Indoor DAS
Figure. Omni Celling antenna indoor

The system above consists of the main equipment’s

Base Station : Service providers / telecom operator

Passive elements: Connector, feeder, antenna, coupler, splitter, combiner and terminator load ( another cable antenna, connector not include of TMEV)

Active elements: MU/HU, RU/RRH

Depending on the characteristics of each country and coverage area, the number and standard of equipment will be different

Divided into 2 main types of Passive DAS and Active DAS. In Active DAS including eDAS, oDAS, iDAS

Passive DAS
Active DAS
Figure. Passive DAS
Figure. Active DAS

Tamagawa would like to introduce some passive products produced by TAMAGAWA, that are applied in the IBS system including

Power Splitter
Directional Coupler
Hybrid coupler
Figure. Power Splitter
Figure. Directional Coupler
Figure. Hybrid coupler
POI/Combiner
Terminator Load
Attenuator
Figure. POI/Combiner
Figure. Terminator Load
Figure. Attenuator

These components will contribute to the signal transmission, and also division according to the designer’s purpose. It helps to equalize E.I.R.P at the output of the antennas.

Finally Tamagawa Passive devices with high reliability, low loss, and Low PIM. will help IBS system have better quality. Reduce drop call, interference and power loss

Especially Support frequency 600-4500Mhz, for both FDD and TDD, 2G.3G.4G and 5G