Overview

The issue of management and allocation of resources in multilayered cellular structures has been investigated in this book. Several CASs were proposed and/or modified and applied to single-layered systems first (microcellular systems) and then to two-layered HCSs. The topic of spectrum partitioning has also been addressed in this book when trying to optimize the division of resources in a two-layered HCS.

Throughout this book, several teletraffic analyses were performed either to model or to validate a proposed CAS. They were also a tool to develop new methods to partition the spectrum.

In view of the complexity involved, a set of assumptions in system functions (such as handovers and coverage) was made to facilitate the derivation of the formulas that describe the system in question. As expected, the complexity of the analysis was alleviated considerably with the simplifications, but many important parameters with great impact on the implementation of real cellular systems were not considered (i.e., irregular areas of coverage, imperfect power control, and imperfect user classification based on their speed).

As in the case of analysis, computer simulations were performed based on idealized systems. Simplifications are necessary and helpful but also contribute to create biased results, in some cases optimistic, and in some others pessimistic; thart would not match a real system. Examples of these simplifications are environments formed by regular cell patterns (both microcells and macrocells), perfect hierarchical cellular structure scenarios, and simplified mobility and traffic models.

8.1 Further Research Required

The idealization of the simulation platforms and...