Introduction

What Is Mobility Data Mining?

The trajectories of a moving object are a powerful summary of its activity related to mobility. As seen in Chapters 3 and 4, such information can be queried in order to retrieve those trajectories (and the objects that own them) that respond to some given search criteria, for instance following a predefined interesting behavior. However, when massive amounts of information are available, we might be able to move a step further and ask that such “interesting behaviors” automatically emerge from the data. That is precisely the domain explored by mobility data mining.

Moving from queries to data mining essentially consists of adding degrees of freedom to the search process that the algorithms perform. For instance, a query might consist of searching those trajectories that at some point perform the following sequence of maneuvers: abrupt slow down, U-turn, and, finally, accelerate. One possible corresponding data mining task, instead, might require one to discover which sequences of maneuvers are performed frequently in the database of trajectories. Then, the output sequences obtained might also contain the slow down → U-turn → accelerate example just mentioned. To perform this data mining process the user needs to specify the general structure of the behaviors he or she searches (sequences), what kind of elements they can contain (the set of maneuvers to consider, as well as a precise way to locate a given maneuver within a trajectory), and a criterion to select “interesting” behaviors – in our example, the user wants only behaviors that appear frequently in the data.

Introduction

In this chapter, we consider the problem of modeling and representing trajectories in the context of database systems. Since about 1995 there has been research on moving objects databases (MODs), also termed spatio-temporal databases. The general goal has been to allow one to represent moving entities in databases and to enable a user to ask all kinds of questions about such movements. This requires extensions of the DBMS data model and query language. Further, DBMS implementation needs to be extended at all levels, for example, by providing data structures for representation of moving objects, efficient algorithms for query operations, indexing and join techniques, extensions of the query optimizer, and extensions of the user interface to visualize and animate moving objects.

Moving objects databases come in two types. The first represents a set of currently moving objects. One is interested in maintaining the current locations and asking queries about current and expected near future locations. The second type maintains complete histories of movement. These are sometimes called trajectory databases and are the topic of this chapter.

Whereas spatio-temporal databases had been around for a much longer time, they supported only discrete changes of geometries over time. The emphasis in the new field of moving objects databases is to consider continuously changing geometries. Neither the position of a car on a road nor the shape and location of a hurricane changes in discrete steps; these are clearly continuous phenomena.

Near Field Communications (NFC) is an intuitive technology that provides an instinctive experience when it interacts with other products that are NFC-enabled. If you like, it's the magic wand of wireless technologies: a simple swish of your NFC-enabled device can gain you access to buildings, cinemas, and subways, and another swish or two can allow you to make a payment and even to simplify connectivity with other wireless technologies. We'll be discussing these very real user scenarios and much more later, in Section 12.2, “NFC's Market,” and Section 12.3, “NFC's Application Portfolio.”

NFC is an open standards-based, short-range technology that has its origins firmly based in Radio Frequency Identification (RFID) technology; in this chapter, we discuss NFC's inception and evolution. You may recall from Chapter 1, “It's a Small Wireless World,” that we discussed the nineteenth-century wireless secret and revealed how RFID technology was used during World War II as a means of identifying aircraft; we illustrate in Figure 12.1 how pilots would roll their planes to enable the ground forces to identify them as friend or foe. In this chapter, we'll also explore the NFC Forum, its membership benefits, and its structure. The chapter discusses the market scope, whereby initial NFC-enabled products have started to emerge in greater numbers due to the uptake of the technology in smart or cellular phones. We will, of course, look at how NFC fares against other technologies within the same market sector and how the technology has been misunderstood as a competitor to more mainstream wireless technologies such as Bluetooth. Finally, the chapter delves inside NFC and takes a first-hand look at its software architecture and protocol.

In Chapter 2, “What is a Personal Area Network?,” we started to reveal how, with the diversification of pervasive Wide Area Networking (WAN) communications, coupled with a breadth and diverse collection of wireless-enabled products with their associated applications, and with the consumer's ability to remain permanently connected to the one-network, a new generation of technologies and products has inadvertently spawned an era of disruptive topologies through technology convergence. In short, a plethora of connectivity opportunities have become openly available and widely encouraged – consumers have every reason and every opportunity to sustain that all-important IP-fix, irrespective of location. We discuss in Chapter 4, “Introducing the Lawnmower Man Effect,” how the Lawnmower Man Effect (LME) characterizes our ubiquitous ability to traverse digital systems across the globe, the one-network, as we illustrate in Figure 3.1.

There are several contributing factors which lead to consumers craving an IP-fix. One such obvious factor may simply be a trend to have immediate access to anything, anytime, anywhere. Another significant factor, which we discuss in Chapter 4, is social media. Social media platforms, such as Twitter, Facebook, Pinterest, LinkedIn, Foursquare, and so on, indirectly encourage consumers to maintain their online status and presence in the hope that they never miss a tweet or Facebook message from their virtual community, or perhaps to triumph through the adornment of a new badge awarded to them by Foursquare, as they oust their colleague to become Mayor of a popular business venue or restaurant.

The personal area networking space may nowadays encompass a personal computer and may include a diverse collection of other peripherals or gadgets, where each serves a unique purpose within the personal topology. Let's not forget that, first and foremost, a Personal Area Network (PAN) is a term used to describe a particular networking topology (we include in Table 2.1 further examples of networking topologies). The Wireless Personal Area Network (WPAN) has offered us a diverse collection of short-range radio technologies, which have had an influence on the dynamics of the personal area network, and we will explore this later. The PAN is a relatively new term to the computing industry, probably appearing about two decades ago or so. This chapter aims to provide a conclusive and modern definition of the PAN, by drawing on several attributes and technologies that have already influenced the network space, as well as potentially dissolving its boundaries. In fact, in Chapter 3, “Disruptive Topologies through Technology Convergence,” and Chapter 4, “Introducing the Lawnmower Man Effect,” we look at the diversification of the PAN domain, where social (media) networking has extended what was once a private space into several virtual communities that have supported technology-enabled socializing. Furthermore, Section 2.3, “Ever-decreasing Circles,” looks at the increasingly blurred PAN topology and how the boundaries that separate one topology from another are rapidly dissolving. But first we look at the origin of the area network and other networking topologies that have characterized the way we perceive network interconnection and uniquely how we have come to understand them.

A number of books have often dedicated their first chapter to a narrative covering the historical aspects of wireless technology. It's a process that seemingly brings the reader up to date; a snapshot, if you like, of where we are and how far wireless technology has evolved. Nonetheless, whilst we acknowledge that wireless technology has reached a level of maturity with venture capitalists, product developers, engineers, and consumers alike, this chapter will instead focus on the changing perception of wireless technology and consider how it is fundamentally perceived by consumers. A comprehensive historical introduction to wireless technology would have certainly been relevant 20 years or so, maybe even as little as a decade, ago, but many consumers have now abandoned their cables for the transparency, simplicity, and ease of use that is often purported by advocates of the technology, making such lengthy historical introductions unnecessary.

Anyhow, wireless technology is still a relative newcomer in enabling a wealth of consumer electronic products, although its penetration isn't as pervasive as some would like. In short, we no longer need to dedicate a lengthy introduction and discussion surrounding wireless technology to explain the historical perspective of its conceptualization and ultimately its formation; nor do we need to discuss the ingenuity of the pioneers who were instrumental in paving the way for today's voice and data communication capabilities. Undoubtedly, these pioneers will never be forgotten, and will most certainly be remembered in other various guises and texts. Instead, in this chapter, we may use historical references merely to reinforce models of perception and primarily to illustrate how consumers have adopted wireless technology so comfortably. Likewise, we analyze consumers’ perceptions of the small wireless world, offering perspectives from both the consumers themselves and the consumer electronics industry. This will provide you with an insight that will enable you to form a better understanding of consumers and their ability to adapt to the new technologies that are becoming increasingly inherent in today's innovative products.

In this penultimate chapter, we discuss future and emerging technologies that didn't make the relevant sections in this book – the technologies were either too immature or sufficient information could not be obtained at the time of writing. Perhaps we can include these technologies in a future edition if they have matured sufficiently and have been widely adopted. Nonetheless, this chapter introduces a number of technologies that are definitely worth watching, as they will ultimately redefine and enhance our user experiences with wireless connectivity. The wireless industry is notorious for advancing at a modest pace, but manufacturers are always eager to launch the latest wireless-enabled gadget, a difficult dichotomy for both industries. In this chapter, we review a number of high profile technologies that have received significant press coverage, and in Figure 16.1 we take a timeline snapshot of these technologies to demonstrate their maturity level.

802.11ac

We discussed in Chapter 13, “The 802.11 Generation and Wi-Fi,” that a number of products have emerged touting .11ac “draft” capability – very much reminiscent of the 802.11n draft standard furor. 802.11n is only several years’ old and provides backwards compatibility with .11a, .11b, and .11g legacy products. Likewise, .11ac also provides backwards compatibility with the same legacy products – this is primarily due to the incumbent base of products that still very much perform, even today, the function that they were originally designed to do. If you recall from Chapter 13, 802.11b was introduced as far back as 1999, and undoubtedly it may take another decade or so for consumers to exchange their access points for newer products.