New Call Blocking versus Hando

In cellular networks, blocking occurs when a base station has no free channel to allocate to a mobile user. One distinguishes between two kinds of blocking , the rst is called new call blocking and refers to blocking of new calls, the second is called handoo blocking and refers to blocking of ongoing calls due to the mobility of the users. In this paper, we rst provide explicit analytic expressions for the two kinds of blocking probabilities in two asymptotic regimes, i.e., for very slow mobile users and for very fast mobile users, and show the fundamental diierences between these blocking probabilities. Next, an approximation is introduced in order to capture the system behavior for moderate mobility. The approximation is based on the idea of isolating a set of cells and having a simplifying assumption regarding the handoo traac into this set of cells, while keeping the exact behavior of the traac between cells in the set. It is shown that a group of 3 cells is enough to capture the diierence between the blocking probabilities of handoo call attempts and new call attempts.