Chapter 10 highlights the evolution of the circuit-switched telephone network to the all-digital cellular network. The details of the world's most popular switching network during the growth phase of the wireless industry, System Switching number 7 (SS7) is described in detail, and the introduction and use of asychronous packet switching and the X.25 protocol in the wireless network are demonstrated.The networking architectures for the first, second, and third generations of global cellular networks (e.g., 1G, 2G, and 3G) are presented. Examples of early paging and mobile network architectures are also presented, to clearly illustrate the evolutionary nature of digital packet data within the global cellular network architecture.

In this chapter, differences between magnetic communication and electromagnetic wave-based communication are summarized and major advantages of magnetic communication are discussed, which provides a big picture of the applicable scenarios of magnetic communication. In addition, the physical circuit for magnetic communications is introduced. The fundamental performance metrics, such as path loss, bandwidth, capacity, and connectivity are discussed.

This chapter initially explains how dependencies are established when at least a part of an infrastructure system requires the provision of the service to function. Although the focus is on functional dependencies, this chapter also explores physical and conditional dependencies. Resilience metrics presented in previous chapters are broadened in order to represent the effect of dependencies on resilience levels. Dependencies established within an infrastructure system are also explained. The concept of buffer as a local storage of the resources related to the depending service is defined as part of these expanded metrics, and then it is exemplified by examining a practical application of such buffers: power plants for information and communication network (ICN) sites. After introducing the main concepts and ideas related to dependencies, this chapter takes a broader view by discussing interdependencies when those are established both directly and indirectly. The study of interdependencies for electric power grids and ICN also explores the relationship with other infrastructures, such as transportation networks and water distribution systems, and with community social systems.

The increased interest that the topic of critical infrastructure resilience is attracting in academia, government, commerce, services, and industry is creating an alternative engineering field that could be called resilience engineering. However, the views of the meaning of resilience have varied, and even in some very relevant world languages, an exact translation of the word “resilience” has only recently been introduced – for example, the word “resiliencia” was added to the dictionary of the Royal Academy of Spanish Language in 2014 – or it still does not exist, as happens in Japanese. Thus, this chapter introduces the main concepts associated with the study of resilience engineering applicable to critical infrastructure systems with a focus on electric power grids and information and communication networks (ICNs) because these are the infrastructures that are identified as “uniquely critical” in US Presidential Policy Directive 21, which is the source for the definition of resilience that is used in this book.

Although today’s power grids have their own sensing and control communications infrastructure in dedicated networks operating separate from the publicly used information and communication networks (ICNs), technological advances may lead to more integrated electric power and ICN infrastructures. Some of the motivating technological changes that may act as catalysts for such increased integration of both infrastructures include the need for much higher power supply resilience for ICN sites, development of an “Internet of Things,” and the increased communication needs for electric power devices at users’ homes or at the power distribution level of the grid as part of power systems’ evolution into “smarter” grids. Hence, this chapter explores the implications in terms of resilience of integrated electric power and ICN infrastructures. In particular, the use of integrated power management to facilitate the use of renewable energy sources is discussed. Fundamental concepts about cybersecurity are also presented.

Magnetic communication is a novel physical communication technology. To connect a large number of magnetic communication devices, traditional networking protocols can be employed, but we need to make significant modifications on the physical layer to accommodate the special features of magnetic communication. For example, to access the communication medium, traditional carrier-sense multiple access or Zigbee can be adopted, but the magnetic communication has a short communication range, and the antennas of different devices may have substantial coupling, which can affect the communication performance. To address this issue, we need dedicated scheduling algorithms to reduce mutual couplings among coils and increase the network throughput. In this chapter, we first introduce a complete magnetic communication network stack. Then, we show the unique features of magnetic communication at the network level. After that, we introduce the scheduling algorithms for magnetic communication networks.

We study the connectivity of a large-scale ad hoc MI networks, whose nodes are randomly located with randomly deployed MI antennas. The pathloss model we use here considers the effect of MI noise via a signal-to-noise ratio threshold instead of magnetic signal strength. In addition, the effects of carrier frequency and eddy current both are considered for the determination of signal coverage. To study the MI coverage and connectivity under such assumptions, we develop a Lambert W-function-based integral method to evaluate the effective coverage space and the expected node degree of an MI node. The probability of having no isolated node in the network is further derived to estimate the required parameters for an almost surely connected network. Passive MI waveguide is not considered in this chapter. We also performed carrier frequency optimizations.

As was introduced in Chapter 1, adaptation is a fundamental attribute of resilient systems. Adaptation could occur by identifying changes in the physical and social environment with the potential to affect a community system operation or by reacting after a disruptive event happens. Part of a positive reaction in the latter of these adaptation mechanisms involves learning about which factors contributed to improving resilience and which factors caused a lower resilience. This chapter focuses on an important tool that is part of such a learning process for improved resilience: disaster forensics. Disaster forensics are based on a postdisaster investigation, in which field investigations and postevent data collection are important components. Hence, the first part of this chapter will focus on explaining the steps and procedures involved with a disaster forensic investigation, including a description of how to perform field investigations. This chapter then describes power grids’ and information and communication networks’ performance in recent natural disasters based on lessons obtained during past forensic investigations.

The so-called magnetic communication makes use of the time-varying magnetic field produced by the transmitting antenna, so that the receiving antenna receives the energy signal by mutual inductance. Research studies show that the penetrability of a magnetic communication system depends on the magnetic permeability of the medium. Because the magnetic permeability of the layer, rock, ice, soil, and ore bed is close to that of the air, channel conditions have less effects on magnetic transmission than electric transmission. Therefore, the communication network based on deep-penetrating MI can expand the perception ability and sensing range of information technology effectively, which can be applied to complex environments such as underground, underwater, tunnel, mountain, rock, ice, and forest. We conclude that the network construction of IoT based on magnetic communication is of great value and can be regarded as one of the reliable technologies to improve the connectivity of a wireless network.

One of the important peculiarities of MI communications is the use of magnetic antennas that can deliver information by using inductive coupling instead of radiation. The magnetic coupling is constrained in the near field, which is more secure since it is not easy to be detected. Moreover, magnetic fields have better penetration efficiency than electric fields. A magnetic antenna is more robust to environment changes than its electric counterpart. In this chapter, we first introduce the fundamentals of antennas to show the difference between magnetic antennas and the widely used electric antennas to gradually narrow our discussion from a big picture. We present the advantages of magnetic antennas and their applicable conditions. Also, we introduce the signal transmission techniques and channel characteristics for the single-input-single-output (SISO) system. Finally, we discuss the multiple-antenna MI system with different antenna placement strategies, which is more reliable and efficient than the SISO system.

In this chapter, several kinds of MI-based applications are introduced. Specifically, the MI-based localization system is one of the most widely used and mature applications of the MI-based techniques. Thus, this chapter first describes several typical MI localization applications, such as the motion capture system, pipeline position systems, and fusion localization with other techniques (such as inertial measurement correction). Second, we summarize some MI-based communication applications for IoT, such as radio frequency identification, through-the-earth communication and underwater communication.