DAS Flower: an interesting way to understand DAS platform

If you are new to DAS, here is an easy way to understand DAS platforms by solving a very simple puzzle. Based on 3 simple rules below you will have to figure out what will be the connection type in picture 1 between the blue ball (Antenna) and the square box (media converter)?

3 simple rules:

1. RF travels on coaxial cable. Antenna can only receive RF signal.
2. Loss of signal is high in a coaxial cable (signal loss is 50% every 100 ft for a typical ½” cable)
3. Signal loss in fiber is minimal even on a long run (such as over 1000 ft) 

As you have figured out, answer is simple, since antenna can only take RF via coaxial cable, connections between the antenna and the media converter will be coaxial cable. Connections between 2 media converters will be fiber due to long length and to keep the signal loss minimum.  Now using this principle, you will be able to easily figure out the overall architecture of majority of DAS platform.

I have shown 3 basic platforms in the pictures below. Interestingly, they are very similar - see pictures 2, 3, and 4. For the actual DAS, these square boxes are much more complex than just plain media converter, I just wanted to keep it simple; you get the idea...

Here is another tip, if you have Single Mode Fiber with SC/APC connectors, you will be able to work with majority of the DAS platform.