Erlang capacity degradation in multi-access/multi-service wireless networks due to terminal/coverage restrictions

Abstract

The benefits of jointly managing the combined radio resources offered by heterogeneous networks consisting of several Radio Access Technologies (RATs) have been profusely studied and assessed in recent years. Nevertheless, most of the existing work assumes scenarios where all RATs are accessible (provided the RAT is not at full capacity) to all users demanding service. If this is so, the obtained benefits become rather optimistic given that we neglect the fact that the deployed RATs may have different coverage overlapping conditions among them and that users may not have terminals that support all RATs (i.e. multimode terminals). In this paper we extend a previously developed Markov framework in order to capture the effect of having different coverage overlapping conditions along with the capability of certain terminals to support all or a subset of available RATs. As a result, we assess the degradation, in terms of Erlang capacity, that a heterogeneous network undergoes in scenarios with limited terminal and coverage conditions and compare it to the ideal case of full coverage and full terminal availability.