What is the purpose of cell specific reference signal and where is it present?

Question

What are all factors are considered while calculating the range of RSRP ?

Answer 1

Reference signal are use for the channel estimation, it's presence is depend on no. Of transmission antenna.
For 1 or 2 transmission antenna these will be at 0, 4,7,11 ofdm simbol .for more information you can refer 3gpp spec 36.211