Random events Arrival process Packets arrive according to a random process Typically the arrival process is modeled as Poisson The Poisson process Arrival rate of n packets per second Over a small interval s P(exactly one arrival)=78 P(O arrivals)=1-78 P(more than one arrival)=0 It can be shown that P(narrivalsinintervalT) (T'eEytan Modiano Slide 4 Random events • Arrival process – Packets arrive according to a random process – Typically the arrival process is modeled as Poisson • The Poisson process – Arrival rate of λ packets per second – Over a small interval δ, P(exactly one arrival) = λδ P(0 arrivals) = 1 - λδ P(more than one arrival) = 0 – It can be shown that: P(narrivalsinintervalT)= − ( ) ! λ λ T e n n T