Acknowledgements

The editors would like acknowledge and appreciate all the collaborators that have contributed to the compilation and completion of this book with recent discoveries in different fields of telecommunication systems. Furthermore, we would like to acknowledge the members of the Optical Communications group at the Instituto de Telecomunicações, Aveiro, Portugal, who have vastly contributed with valuable ideas, comments, recommendations and fruitful discussions. In addition, the editors would like to acknowledge support of the European Regional Development Fund (FEDER), through the Regional Operational Programme of Lisbon (POR LISBOA 2020) and the Competitiveness and Internationalization Operational Programme (COMPETE 2020) of the Portugal 2020 (P2020) framework, under Project 5G (POCI-01-0247-FEDER-024539). Also, we acknowledge support of the FEDER through COMPETE 2020 of the P2020, under the Project Virtual Fiber Box with Nr. 033910 (POCI-01-0247-FEDER-033910)]. The projects have contributed immensely both technically and financially towards Chapters 7 and 8. Likewise, we deeply appreciate the technical support being offered under the project DSPMetroNet (POCI-01- 0145-FEDER-029405). Without the project's support, it would have been challenging for this book to come to fruition.

**IV**

discussed.

protection.

It is remarkable that wireless and optical network convergence is an attractive solution for leveraging the optical network's inherent bandwidth as well as the mobility benefit of wireless connectivity. Apart from being a good approach for realizing high-network penetration with the anticipated ubiquitous feature, it can facilitate achievement of the 5G network-envisioned EE and capacity. In Part III, enabling technologies for effective convergence of wireless-optical networks are presented. In addition, means of exploiting network convergence in cloud/fog computing are

Part IV focuses on advanced relay and antenna systems for smart networks. In this part, high-gain and miniaturized antennas capable of operating at microwave and millimeter wave bands are presented. The antennas offer good features such as low-cost, simplified structure, low footprint and ease of installation. Part IV also covers high-speed directional relay based on wireless sensor network for smart grid

In general, this book presents not only the fundamental features, concepts and the associated evolutions of telecommunication, but also explains the underlying technical principles of state-of-the-art systems with good perceptions into the expectation of the next-generation telecommunication systems. The information presented in the book is clear, easy to follow, concise and comprehensible. It covers both theoretical and practical aspects of system implementation in such a way that makes it suitable for students, researchers and professional engineers. It is a good reference for all prospective readers to keep abreast of the current trends in tele-

communication systems and to motivate them towards innovative ideas.

**Isiaka A. Alimi, Paulo P. Monteiro and António L. Teixeira**

Universidade de Aveiro, Instituto de Telecomunicações,

Aveiro, Portugal

**Isiaka A. Alimi, Paulo P. Monteiro and António L. Teixeira** Universidade de Aveiro, Instituto de Telecomunicações, Aveiro, Portugal

Section 1

Telecommunication Protocol,

Optimization, and Security

Frameworks

1

Section 1
