With any radio system deployment you need to consider the "Link Budget".  With Distributed Antenna Systems a "Link Budget" Calculation needs to be done to ensure the signal levels are adequate.  Whether cellular requirements at -85dBm or voice over WLAN at -65dBm it is just a part of the system design. This the official NIST Link Budget Calculator.

Download NIST_LinkBudgetCalc_2_4.xls