Femtocells: Opportunities and Challenges for Business and Technology

10

Femtocell Implementation Considerations

Simon Saunders

10.1 Introduction

The design and implementation of femtocells is non-trivial. There is a wide range of engineering and commercial issues, involving many engineering disciplines, which have to be addressed to meet the requirements described in previous chapters. This involves a considerable focus on the underlying hardware and software architecture and cost. The major factors are discussed in this chapter. Overriding all of these is the need to deliver the full set of desired features and the levels of performance required by standards and operators, while ensuring that the cost is sufficiently low to support a strong business case. In all cases this will be supported by a high volume market with significant levels of commonality of parts and functionality, at least as far as the major components and undifferentiated software elements are concerned.

The main challenges we address here are as follows:

• signal processing;
• location;
• frequency and timing control;
• protocol implementation;
• RF implementation.

We also examine the femtocell hardware architecture and the associated cost challenges. Finally the opportunities and challenges for optimising mobile devices for enhanced femtocell operation are highlighted.

10.2 Signal Processing

The emergence of sufficiently cheap signal processing to deliver femtocells is one of the critical factors for their implementation, as discussed in Section 2.5.7. A 3G femtocell needs several hundred ...