Hi, anyone here more knowledgeable about IBS? Can I ask some queries to solve my problem?
I plan to have a design with common DAS with multiple frequency band.
How can I combine 1 operator with GSM 900 frequency, 2 operators with dcs 1800 frequency and 3operators with umts 2100 frequncy in one system? thank you
well, it is always possible to combine 900 1800 and 2100 onto one antenna system (using a triplexer 3 -> 1 and a triband antenna)
The main problem is going to be combining the operators using the same band. That requires using a combiner (-4dB loss for 2 inputs (=2 operators 1800 in your case), -5dB loss for 3 inputs (= 3 operators 2100 in your case) )
depending on how many floors you must cover, the biggest choice is to use “analog” transmissions, or “optical” transmissions (or digital).
If analog : you’l probably need some amplifiers on the way, because feeder losses are gonna take their toll !)
If optical : you’ll need A/D and D/A convertors. It is the most expensive solution, obviously.
Visit RFS website, they can give you some good ideas, i suppose.