Handoff phenomena have a considerable effect on the efficiency of any communication network. Probability of failures occurring because of handoff must be determined. This paper presents the parameters affecting handoff problem of communications networks and optimizing and controlling such parameters to get minimum handoff of the mobiles networks mathematically. The parameters controlling handoff phenomenon are studied and optimized using mathematical and analytical methods. It is found that handoff has bad effects on the mobiles calls, the probability of handoff failures depends strongly on the arrival rate of handoff calls such that as this rate increased the probability of handoff is decreased but this rate has a critical value.