xviii Preface
This book is organized as follows:
In Chapter 1 (Introduction), a n introduction to femtocell concepts and the book is
given. The advantages and disadvantages of using femtocells, the standardization and
business models are also briefly touched on.
In Chapter 2 (Indoor Coverage Techniques), an overview of the different indoor
coverage techniques is given. As femtocell is mainly used for indoors, we think a brief
introduction to other indoor coverage techniques might be useful for readers. In this
chapter, the evolution from macrocell to femtocell is presented and the different methods
are compared. Advantages and drawbacks of the different techniques, like Distributed
Antenna System (DAS), repeaters, and picocells are also given and the main challenges
related to femtocells are introduced. It needs to be pointed out that femtocells can also
be used outdoors, provided that backhaul connections are available or can be easily
established.
In Chapter 3 (Access Network Architecture) , the evolution of femtocell architecture
from 3GPP Release 8 and different options to ensure the connectivity of the femtocell
to the core network are described. Functional split between HNB and HNB-GW, new
interfaces such as Iuh are also described. Security aspects are also touched on.
In Chapter 4 (Air Interface Technologies), different air interface technologies for
femtocells are presented. In particular, femtocell specific features in the discussed air
interfaces are described. The technologies covered in this chapter include Global Sys-
tem for Mobile communication (GSM), Universal Mobile Telecommunication System
(UMTS), High Speed Packet Access (HSPA), Wireless Interoperability for Microwave
Access (WiMAX) and Long Term Evolution (LTE).
In Chapter 5 (System-Level Simulation for Femtocell Scenarios), the methodology
of how to simulate femtocells is detailed. The development of a femtocell simulation
tool is presented, from the radio coverage level, to the system level. Simulation meth-
ods, including both static and dynamic approaches, are illustrated with some femtocell
deployment examples. Coverage and capacity analysis is given for the given scenarios of
a hybrid femtocell/macrocell WiMAX network.
In Chapter 6 (Interference in the Presence of Femtocells), interference between fem-
tocell and macrocell (so-called cross-layer interference), as well as between neighbouring
femtocells (so-called co-layer interference) are analysed for both CDMA and OFDMA
based femto/macro networks. The performance of a UMTS macrocell network in the pres-
ence of femtocells is also given. Moreover, some interference cancellation and avoidance
techniques are also presented in this chapter.
In Chapter 7 (Mobility Management), issues related to mobility management such
as cell selection/reselection and handovers in two-tier femto/macro networks for various
access methods (CSG, open access and hybrid access) are discussed in detail. Mobility
management is a major issue and presents a big challenge for hybrid femto/macro network.
In Chapter 8 (Self-Organization), issues related to femtocell self-organization are
presented. Self-organization includes self-configuration, self-optimisation and self-healing.
With self-conguration, the initial femtocell parameters are automatically selected (such as
PCI, neighbouring list, channel and power). Self-optimization kicks in when FAPs are
operational and optimize the FAP parameters taking into account the fluctuations of the
channel and resources available. In order to achieve self-organisation, FAPs should know
their radio environments; hence, radio channel sensing techniques such as those using