Indoor Radio Planning: A Practical Guide for GSM, DCS, UMTS, HSPA and LTE, Second Edition

12.1 The Challenges of Reaching Indoor Users From the Macro Network

The main focus of this book is to provide knowledge on how to design and implement coverage solutions deployed inside buildings so as to overcome this challenge.

It would be nice if we at some point could have indoor coverage solutions inside each and every building, and we do envisage a solution that addresses even small buildings, such as the femtocell deployed in residential buildings and houses (see Section 4.11 for more detail about femtocells). For shopping and commercial buildings dedicated indoor DAS would often be the best choice from a technical point of view. Even though it would be a theoretical possibility to deploy a dedicated indoor DAS inside all medium to large buildings the challenge remains to make it an economically viable and attractive solution.

We know for a fact that the macro network will struggle to achieve deep indoor penetration of the RF service a few kilometers from the site – so we will have to consider other options. As we see in Figure 12.1 the macro site deployed above the clutter (height of the buildings) will struggle to reach indoor users. Most signal paths will have to rely on reflections, and this gives rise to the challenge of multi path and high link losses between the serving base station and the mobile. The high losses will cause the base station to use high DL transmit power, potentially causing unwanted DL interference in the surrounding network, degrading service and ...