Mirce
The PDF distribution is a collection of data, for example from drive test or statistics from OSS, you make a plot with this data and you will see the distribution for example of RxLev agains times of each value, x coordinate RxLev, y coordinate quatity or times of particular value, then you will see the distribution of the signal in for example a particular place or the distribution in an area, then next time the probability that you find the same values in the same points are high if not changes happened there, like new buildings, antenna movements, power changing, etc., that is PDF, you can save in order to compare changes in time for example. The CDF is the version of the same data but you can see the general distribution of signal, for example if you have that in the entire area you have very strong signal you will see that the points in CDF will be shows a big step to right and few values at left then you can conclude that you are very near to antenna all the time or there area a lot of antenas an the signal strenght in that place isn’t an issue. By the way, recently I made a PPT showing some conclusions using that graphs give me your e-mail and I will send to you. Best regards,