Preface

Telecommunication is the act of transmitting information at a considerable distance with the aid of transmission media. Typical telecommunication equipment comprises a set of well-assembled hardware with embedded software to facilitate reliable and efficient communications. For compatibility purposes, telecommunication equipment performance and design should conform to international standards. Globally, telecommunications have been contributing immensely to economic growth on an unprecedented scale. However, with the ever-increasing deployment of innovative wireless technologies and exponential traffic growth, communication systems have been subjected to significant pressures. To address the challenges, modern telecommunication systems have evolved from being economical and efficient homogeneous systems to converged heterogeneous networks, capable of supporting reliable and quality voice, data, video and other information transmission services. This can be attributed to the advancements in microelectronics and cloud computing-based technologies as well as other fields of telecommunication systems as expatiated in this book.

This book is grouped into four parts: "Telecommunication Protocol, Optimization, and Security Frameworks"; "Next-Generation Optical Access Technologies"; "Convergence of Wireless-Optical Networks"; "Advanced Relay and Antenna Systems for Smart Networks."

Part I presents telecommunication protocol, optimization, and security frameworks. It is noteworthy that there are a number of well-defined protocols in telecommunication systems. These protocols help in achieving efficient communication through collections of distinct rules and regulations. Since telecommunication systems entail several areas, multiple protocols can be employed in different communication fields to accomplish a specified goal. A number of the field-related protocols, such as cellular communication protocols, public switched telephone network communication protocols, data networking protocols, and hybrid communication protocols, are well established. So, well-defined protocols can help in preventing signal loss and in optimizing communication system efficiency. Another important factor in telecommunication systems is system security. All these aspects are comprehensively described in Part I.

The exponential growth in bandwidth demand calls for viable means of meeting system requirements. The advancements in optical communication have been notable solutions to the current and future networks. With optical devices, both short and long transmission can be effectively achieved. Part II provides detailed information on the next-generation optical access technologies. It focuses on different passive optical network variants and advanced optical modulation formats that are vital to telecommunication systems for enhanced spectral efficiency and energy efficiency (EE). Apart from the presented optical fiber-based schemes, free-space optical (FSO) is also considered as a cost-effective, flexible and comparatively easier network deployment. Part II also covers a number of spatial light modulator technologies, which are viable for different applications such as FSO, multicore fiber and spatial division multiplexing.

**II**

**Chapter 7 115**

Convergence of Wireless-Optical Networks **135**

**Chapter 8 137**

**Chapter 9 169**

Advanced Relay and Antenna Systems for Smart Networks **183**

**Chapter 10 185**

**Chapter 11 203**

New High-Speed Directional Relay Based on Wireless Sensor Network for

*by Cátia Pinho, Isiaka Alimi, Mário Lima, Paulo Monteiro and António Teixeira*

Spatial Light Modulation as a Flexible Platform for Optical Systems

Enabling Optical Wired and Wireless Technologies for 5G and Beyond

*by Isiaka A. Alimi, Ana Tavares, Cátia Pinho, Abdelgader M. Abdalla,* 

*Paulo P. Monteiro and António L. Teixeira*

Radial Line Slot Array (RLSA) Antennas

Role of Optical Network in Cloud/Fog Computing

**Section 3**

Networks

**Section 4**

*by Kiran Deep Singh*

*by Teddy Purnamirza*

Smart Grid Protection *by Ali Hadi Abdulwahid* 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 discussed.

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.

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

Universidade de Aveiro, Instituto de Telecomunicações,

Aveiro, Portugal

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 protection.

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 telecommunication 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
