A method for estimating the quality of experience of a service provided over a communication network from activities performed by a user in the fruition of said service through a user device connected to said communication network , the method comprising, at a processing unit connected to said communication network : a1) detecting a data traffic within said communication network comprising events indicative of said activities performed by the user in the fruition of said service during a user session; a) subdividing said user session of the service into a number of time intervals; b) determining a number of said events indicative of said activities performed by the user during a time interval, T x , of said number of time intervals; and c) on the basis of said events, calculating an index, BT x , indicative of the quality of experience of said service in said time interval, wherein the method further comprises, at step b): b1) subdividing said time interval, T x , into a number of time sub-intervals; b2) gathering a number of elementary events, each elementary event being indicative of a respective activity performed by the user during a time sub-interval, t i,x , of said number of time sub-intervals; and b3) combining said elementary events into a complex event and comparing said complex event with a set of patterns, each pattern being associated with a respective predefined combination of elementary events and with a predefined index, B i,x , indicative of the quality of experience associated with said predefined combination of elementary events. a1) detecting a data traffic within said communication network comprising events indicative of said activities performed by the user in the fruition of said service during a user session; a) subdividing said user session of the service into a number of time intervals; b) determining a number of said events indicative of said activities performed by the user during a time interval, T x , of said number of time intervals; and c) on the basis of said events, calculating an index, BT x , indicative of the quality of experience of said service in said time interval, a) subdividing said user session of the service into a number of time intervals; b) determining a number of said events indicative of said activities performed by the user during a time interval, T x , of said number of time intervals; and c) on the basis of said events, calculating an index, BT x , indicative of the quality of experience of said service in said time interval, wherein the method further comprises, at step b): b1) subdividing said time interval, T x , into a number of time sub-intervals; b2) gathering a number of elementary events, each elementary event being indicative of a respective activity performed by the user during a time sub-interval, t i,x , of said number of time sub-intervals; and b3) combining said elementary events into a complex event and comparing said complex event with a set of patterns, each pattern being associated with a respective predefined combination of elementary events and with a predefined index, B i,x , indicative of the quality of experience associated with said predefined combination of elementary events. b1) subdividing said time interval, T x , into a number of time sub-intervals; b2) gathering a number of elementary events, each elementary event being indicative of a respective activity performed by the user during a time sub-interval, t i,x , of said number of time sub-intervals; and b3) combining said elementary events into a complex event and comparing said complex event with a set of patterns, each pattern being associated with a respective predefined combination of elementary events and with a predefined index, B i,x , indicative of the quality of experience associated with said predefined combination of elementary events. <EOS>