ABSTRACT
Cellular networks have been investigated for several decades (Mac Donald 1979). Quite naturally, the advances of wireless communications have made necessary the consideration of several aspects linked to reliability. How can one ensure that communications are indeed made possible, and are not untimely terminated ? Failure protection and Quality of Service are very important issues for network operators, which are constrained by a few factors. For instance, the range of each base station is limited, so that the radius of each “cell” does not extend infinitely. When a user moves to another cell, he/she expects the call to proceed seamlessly. Resources for such a continuation of the call are required, which are also used to process new calls. Cell switching (and the associated handover procedures) also consume some of the resources. A proper optimization of resources is therefore crucial, to say nothing of financial aspects.
