Digital Home Networking E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 607

Veröffentlichungsjahr: 2013

Beschreibung

In an era of ubiquity, nomadism and ecological challenge, the maturity of wireless technologies, the readiness of broadband Internet access and the popularity of smart terminals should contribute to emancipating IT services in connection with the home and home-based resources. This book, in light of several years of applied research and technological surveys, aims at describing the digital home networking environment, its techniques, and the challenges around its service architecture. Digital Home Networking aims to provide a broad introduction to state-of-the-art digital home standards and protocols, as well as an in-depth description of service architectures for entertainment and domotic services involving digital home resources. The book covers aspects such as networking, remote access, security, interoperability, scalability and Quality of Service. Notably, it describes the generic architecture, which was proposed and developed in the context of the EUREKA/Celtic research project "Feel@Home".

Leseprobe

Table of Contents

Chapter 1. Introduction

1.1. Cultural context around a definition

1.2. A brief history of home automation

1.3. Coming to a definition of the digital home

1.4. Plan of this book

1.5. Bibliography

Chapter 2. Actors in Digital Home Networking

2.1. Scope

2.2. Categories of actors

2.3. User roles

2.4. Bibliography

Chapter 3. Network Technologies

3.1. Local connectivity and networks

3.2. Connectivity to main networks

3.3. Bibliography

Chapter 4. Standards

4.1. Introduction

4.2. Standards used in the home

4.3. Remote access to homes

4.4. Bibliography

Chapter 5. Personalization and Home Context

5.1. Introduction

5.2. Personalization

5.3. Context management and sharing

5.4. Protégé — an ontology editor

5.5. Bibliography

Chapter 6. Security

6.1. Importance of security and privacy

6.2. Security requirements of the extended digital home

6.3. A conceptual security architecture

6.4. Relevant security mechanisms

6.5. Applying the security architecture

6.6. Bibliography

Chapter 7. Quality of Experience and Quality of Service

7.1. Introduction

7.2. QoS concepts and standards

7.3. IETF multimedia protocols

7.4. Semantic approach for QoS management in home networks

7.5. Conclusion

7.6. Bibliography

Chapter 8. Service Management

8.1. Introduction

8.2. Service management basis

8.3. Basic protocols

8.4. Network architecture and service management

8.5. Conclusion

8.6. Bibliography

Chapter 9. The Feel@Home System

9.1. The Feel@Home architecture

9.2. Local and remote content distribution through VPN

9.3. Local and remote content distribution through IMS

9.4. Conclusion

9.5. Bibliography

Chapter 10. Home Interconnection through the Internet

10.1. Introduction

10.2. Interoperability scenarios

10.3. Internet-based content sharing between remote homes

10.4. Conclusion

10.5. Bibliography

Chapter 11. Conclusion

11.1. Bibliography

List of Authors

Index

First published 2011 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.

Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:

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Wiley & Sons, Inc.111 River StreetHoboken, NJ 07030USA

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© ISTE Ltd 2011

The rights of Author’s nameto be identified as the author of this work have been asserted by them /her/him in accordance with the Copyright, Designs and Patents Act 1988.

Library of Congress Cataloging-in-Publication Data

Digital home networking / edited by Romain Carbou … [et al.].

p. cm.

Includes bibliographical references and index.

  ISBN 978-1-84821-321-0

1. Home computer networks. 2. Home automation. I. Carbou, Romain.

  TK5105.75.D54 2011

  643′.6--dc23

2011034775

British Library Cataloguing-in-Publication Data

A CIP record for this book is available from the British Library

ISBN: 978-1-84821-321-0

Chapter 1Introduction1

1.1. Cultural context around a definition

The transformation of our lives, thanks to the “digital revolution” over recent decades, is something challenging to talk about in general terms, without sounding irremediably naive.

Indeed, the successive appearance on the mass market of such technologies as the personal computer (PC) in the late 1970s, mobile telecommunication networks in the 1980s, and, as the most prominent aspect of the public Internet, the World Wide Web in the early 1990s has drastically changed our relationship with space, time, and access to information. As is well known, this addition of technological revolutions simply built a new paradigm in the way we behave and live together in the global village. Very few areas of human activity could be considered not to have been impacted by the possibilities offered by the digital era: retrieving information, communicating with friends, and purchasing goods on a marketplace are some of the most trivial examples of the extent to which our daily life has been drastically modified within one human generation.

Such means of communication also have unexpected consequences in the area of sociology. Blogs, forums, “walls” of social networks – these various forms of the Web 2.0 – have led people to become gradually the “online script-writers” of their own existence, thereby giving to private events of their existence an exposure hitherto unseen with such spontaneity.

In line with this, the multiple existing communication channels yielding opportunities to meet new people and to develop social networks have produced a semantic “new deal” around several key aspects of human relations, among which friendship appears undoubtedly as the most spectacular example. Indeed, if [HEL 09] “Friendship […] is a distinctively personal relationship that is grounded in a concern on the part of each friend for the welfare of the other, for the other’s sake, and that involves some degree of intimacy”, one could hardly admit that such – classical – a definition reflects the characteristics of friendship as practiced on Facebook or any other social network. Anyone having some online exposure on social networks has experienced the situation of becoming the “digital friend” of a colleague, the person on the table next to them at the restaurant during their last holiday, a vague “friend of a friend”, an occasional tennis partner, and so on.

However, this semantic shift, if admitted in these common, day-to-day interactions with people, can still refer back to a more conservative social norm regarding our willingness to open the home to this cloud of loose friendly connections. Just assess which percentage of friends belonging to your favourite social network would you invite home for real – either for the genuine pleasure of having them enjoy your authentic scallops in a mushroom julienne, or, conversely, to ask them for a little help next Sunday to remove a ton of rubble from the cellar.

Nonetheless, one should not underestimate how the day-to-day immersion of the individual in the digital ecosystem can bolster interactions among people in the physical world – either in evident, natural formats of social links (seeking an affective relationship or attending a job interview) or throughout totally new and spontaneous sociological phenomena, illustrated by flash mobs, freeze parties, or monster T.G.I.F1. But these latter examples, noticeably enough, happen in public places.

And precisely, by contrast, they raise the following question: Are the social criteria to get invited in the very sanctuary of one’s home, significantly different from what they were in the last century, in each given culture? An extensive answer, which would call for both a segmented analysis and a continuous observation over time, is far beyond the objective of the present book. However, once an acceptable definition of the “digital home” itself has been proposed hereafter in the chapter, we will see how it is equally, if not more, affected by new societal paradigms, in terms of trust and privacy.

Just as the notion of a friend has been irreversibly shaken by the growing popularity of online social networks, similarly, on geographic and professional grounds, the home and the office are gradually becoming more and more entwined in some “yin-yang” pattern. The modern worker, proverbially, always keeps a bit of the office with him when back home – and vice versa. In this regard, defining the formal borders of the “digital home” ecosystem will be a question, subject to spatial and systemic conventions, which is not that obvious.

To sketch an intuitive definition, the “digital home” suggests an addition of digital equipment, hardware, computers, sensors, devices, with a capacity to communicate and to interact, either with users or through machine-to-machine interfaces, aimed at delivering services and, above all, bound to the physical place, called home, where a family, or an individual, or a group of people lives. Now, would a smartphone used to remotely access home resources still be considered part of the “digital home” ecosystem? Is the car part of the digital home? And so on, for my professional laptop, used occasionally to store temporarily a set of pictures from my last holiday? Not only ubiquity, but also nomadism, as structuring patterns of contemporary life, and the overlapping of private/professional usages in a single device, strongly hinders a spontaneous and objective delimitation of the boundaries of a digital home.

1.2. A brief history of home automation

1.2.1. Stay naive and humble

Technological predictions often meet with contrasting levels of acceptance by communities. Evoking the practical, physical feasibility of a particular innovation always yields as many cautious reactions as enthusiastic ones among experts, yet referring to a common epistemological background and state-of-the-art references. One noticeably fierce modern debate illustrating this syndrome, in the late 1970s, concerned nothing but the very possibility of cellular telecommunications networks, at a merely theoretical level! In that period, a claim, announced during a famous scientific popularization program (“Temps X”, France, 1979–1989), about the likelihood of the appearance in the very near future of a mass market mobile service, had led the head of a public telecommunications research agency to call the TV producer and demand public apologies for broadcasting such nonsense!

Quite similarly, in the economic sphere, business model forecasting has always had a complex relationship with the history of underlying technologies, alternating between the utmost narrow-mindedness and the sharpest intuition.

In the first category, let us remember that Gutenberg’s printing revolution was primarily, in fact rather exclusively, considered by spiritual powers (and, vicariously, by most governments) as a means of improving the dissemination of the Holy Writ. The innovation rapidly got out of control at an unpredictable level, so far as to bolster the Renaissance movement, a scientific revolution and a knowledge-based economy2. In more recent times, we can also remember how skeptical about the Internet the – then – most influential software company was, until the mid-1990s. On the contrary, in the latter category, futurologists of the early 1970s had remarkably predicted e-commerce usages on home terminals looking exactly like a TV with a keyboard, at a time when neither the PC nor the Videotex standard had been invented.

Precisely, the concept of “digital home” is a peculiar historical subject, both in technological and economic terms. On the one hand, it never encountered a major argumentation or a theoretical hindrance against its practical feasibility, like, for instance, cellular networks did. On the contrary, enabling technologies have been around for several decades. The X10 protocol designed for device/appliance control, using a power line as a communication channel, was designed in 1975 and was soon adopted by such device manufacturers and industry players as BSR, Sears and General Electric. On the other hand, it was steadily and enthusiastically announced as the very next revolution of personal services, though it consistently failed to raise hitherto a mass-market-wide demand.

Are we today in a conjunction with conditions that would eventually help the digital home to become a reality as widely deployed and massively adopted as, say…, telephony services? Can the ongoing convergence of telecom networks bolster this scenario? Just as with printing, flying, or wireless communications, the digital home, understood as a universally accepted service will probably arise from societal, ecologic, demographic, cultural leapfrogs calling for a pervasive, ubiquitous necessity to monitor, control, and share home resources in any situation. In other words, will the digital home, a mature-enough technical reality (if one omits the noticeably large number of legacy devices, up to today, with no native controlling interface), find its own path of appropriation. The present book will try to show some possible factors that may – at last? – influence the emancipation of the digital home era.

1.2.2. Terminology around domotics

The term “domotics” (an entry surprisingly absent from referential English dictionaries) is considered as a synonym for “home automation”. The latter is defined [TFD 10a] in the following way: “[…] a field within building automation, specializing in the specific automation requirements of private homes and in the application of automation techniques for the comfort and security of its residents. Although many techniques used in building automation (such as light and climate control, control of doors and window shutters, security and surveillance systems, etc.) are also used in home automation, additional functions in home automation can include the control of multimedia home entertainment systems, automatic plant watering and pet feeding, automatic scenes for dinners and parties, and a more user-friendly control interface”.

In the same source [TFD 10b], “domotics”, derived from the Latin “domus” (home) and standing for “DOMus infOrmaTICS” is itself defined in a pretty equivalent way: “Information technology in the home […]. Although remote lighting and appliance control have been used for years […], domotics is another term for the digital home, including the networks and devices that add comfort and convenience as well as security. Controlling heating, air conditioning, food preparation, TVs, stereos, lights, appliances, entrance gates and security systems all fall under the domotics umbrella”. This alternative definition suggests that the “digital home” would actually be nothing but another synonym for “domotics”. In the next section we will propose a slight distinction between, on the one hand, the field of activity/engineering and the development of techniques (home automation/ domotics) and, on the other hand, its particular embodiment in devices, software, sensors, appliances, network entities, constituting the digital home ecosystem, per se.

1.2.3. A bit of history

The myth of an automated home, featured with “intelligent” appliances, is hard to date objectively. Jacques Tati’s satirical movie, Mon Oncle, shot between 1956 and 1957, used as its main set the famous “Villa Arpel”, a “modern” building with a remote control to switch on/off the garden fountain and, not less unforgettable, a futuristic kitchen, stuffed with monitoring LED and alarms surrounding the cooker, suggesting the kind of “interactivity” that digital home facilities may propose. Home automation really became a field for applied research in the 1970s, with the concomitant development of data network technologies capable of proposing a (unidirectional) programming interface for appliances (X10) and the earliest forms of PCs (Altair 8080, TRS-80, and much later the Apple II, and all their successors).

The 1980s, thanks to the progressive deployment of reliable digital networking technologies (e.g. ISDN) and to the introduction of electronic components in household electrical appliances, were a determining decade for durably installing the interest towards a better management of home resources. Embedding intelligence, autonomy, and capacity of interaction with the neighborhood in the device was already a pivotal concept, decades before the “machine-to-machine” paradigm or the “Internet of Things”. Another focus was around the convergence of controls through unified interfaces, for any service – from energy consumption monitoring to human communication.

There was, however, no spontaneous craze toward domotics in society.

If an equal sluggishness prevailed in the home automation mass market during the 1990s, it was a transitional decade of utmost importance for the future rise of the digital home era. First, the dramatic emancipation of mobile communications created progressively and irreversibly the addiction to “reachability”, anywhere, anytime. The second evidence of this period is the massive rise in Internet Service Providers and the election of the Web as both a universal data access service and an enabler of a worldwide form of conscience. Technically speaking, the kind of Internet access during this period not only had slow capacity (provided by analog modems or ISDN technology) but was also linked most often to a single computer in the home.

The early years of the new millennium will be possibly seen, one day, as the swing that really ignited the conditions for the rise of the digital home, thanks to the conjunction of the following two factors.

The first one is the naturally growing connectivity inside the home, coming from the popularization of LAN technologies3, allowing several home users, from several terminals, to enjoy the same high-speed Internet connection for various purposes (most requests are still outgoing, in a classical client–server usage, but peer-to-peer file exchange has also become increasingly popular, thereby slowly but surely contributing to change in the rules of the game in the multimedia sector).

The second factor is nothing other than the collapse of the “Internet bubble”. Within a few years, several telecommunication/media giants, who have an unreal level of debt, cannot dissimulate feet of clay. The internal pressure from the stakeholders and the aggressivity of pure Internet players require the search of new revenues and new territories to conquer. As a result of which, it may be safely claimed that the very idea of a wholly new battlefield for the “meters beyond the home router” (i.e. within the home network) is a child of Y2K’s economic downturn.

Figure 1.1.A general chronology of domotics

As a temporary conclusion, that decade ended just at the dawn of three new factors bolstering, in their turn, the strategic interest toward the digital home. Another economic crisis refreshed the need of new revenues among all the actors involved in the sector (Internet players, telco’s, and third-party services). The emergence of “smart phones” on the market of mobile terminals now allows the convergence of networks to be a truly user-friendly experience (thereby achieving the ambition of unified interfaces lingering from the 1980s). But in the end, the very crystallization of the digital home era may be a pragmatic sequel of the ecologic challenge, personified in recent years by Green labels.

1.3. Coming to a definition of the digital home

The attempt to define the digital home hereafter aims at delimitating a satisfactory scope in terms of functional logics and in light of the related services falling in the field of home automation. Among numerous possibilities of taxonomy, the first element of categorization in this book will distinguish inner home user experiences (the user is physically at home and enjoys a service involving resources located at home) from outer home user experiences (the user is not at home and remotely accesses, modifies, manages, and monitors resources located at home).

Remote access to the home network, because of specific network connectivity issues and security challenges, will be extensively discussed in the following chapters. It reflects the de facto observation that, even if not yet a mass market reality, the digital home must commit to the constraints yielded by the era of mobility and nomadism.

1.3.1. What is in the digital home?

The present book will refer to the “digital home” as a set of software and hardware components aiming at delivering a set of home-related services involving and interacting with at least one home-based resource.

These software and hardware components may include, not exhaustively, local network technologies used at home (Ethernet, Wi-Fi, CPL, etc.), routers/gateways, firewalls, bridges, PCs, physical sensors/monitoring devices, media players, media renderers, set-top boxes, DLNA TV, UPnP radios, alarms, domestic machines with communication capabilities, and telephones. They also include the means of communication (access network technologies, proxies, authentication servers, mobile terminals, laptops, and their applications/user interfaces) used to communicate remotely with the home resources.

1.3.2. What is not in the digital home?

At this time, a hardware or software entity that would not be involved in a call flow with at least one home-based resource is not considered part of the digital home per se.

As a second limitation, unless considering the whole World Wide Web as a part of the digital home, public web servers joined from an HTTP client (PC, Wi-Fi-capable smartphone and tablet) in the home are not considered part of the digital home. More generally, public servers requested by a human user from a home-based host over standard client–server protocols such as HTTP/HTTPS, Telnet, FTP, etc. are also not considered part of the digital home.

Consequently, consider your favorite online backup system for sets of personal pictures, allowing you to store and share on the Internet the pictures taken during your previous holiday. If their location is in a remote data center provider, this web server on which you upload picture files from your home PC, and from which your friends enjoy them as an online slideshow, is not part of the “digital home” (uploading is just standard web browsing, and, likewise, displaying this content from the web server does not involve any of your home resources). On the contrary, if the pictures are uploaded to a server located at home and are accessible by using your home network, they are part of the digital home.

Figure 1.2.Systemic boundaries for the digital home

Furthermore, if your latest fashionable camera allows you to upload pictures over a telecommunication network (3G, Wi-Fi, etc.) directly onto a network attached storage (NAS) located on your home network (and let us even imagine, with the possibility of awakening this device remotely), the whole chain of network entities from the camera to the NAS (noticeably involving your Internet router) will be definitely considered as an extended but valid illustration of the digital home, from the systemic point of view proposed above.

1.4. Plan of this book

Chapter 1 proposes a panoramic introduction to digital home concepts with short historical, sociological, and technical references. Chapter 2 gives a categorization of the digital home actors. Chapter 3 will focus on existing or emerging technologies, while Chapter 4 will aim at presenting the digital home standards, relating either to the home network itself or to the home gateway (Internet router). Accessing home resources is a natural ground for the field of ambient intelligence and digital home services call for large possibilities of user preferences. Chapter 5 will, accordingly, deal with the specific aspects of context management and personalization. The digital home is a de facto sanctuary of data. Chapter 6 will address the security and privacy challenges and solutions for digital home-related services. Chapter 7 deals with the quality of service (QoS) and the quality of experience (QoE) pertaining to those services (e.g. how may I hope to stream remotely a high-definition home-stored video) and QoS/QoE frameworks. Chapter 8 specifically focuses on the service management aspects in the scope of the digital home. Chapters 9 and 10, respectively, describe the particular digital home architecture achieved in the EUREKA/CELTIC Research Project “Feel@Home” and the service interoperability concerns between heterogeneous solutions.

Finally, the concluding Chapter 11 will speculate about the future of the digital home in light of technological and more general issues.

AUTHOR’S NOTE: For further information on the subject of Digital Home Networking and the “Feel@Home” project, see http://projects.laas.fr/feelathomebook.

1.5. Bibliography

[BRU 09] DE LA TOUR B., http://domotique-news.com/2009/05/21/historique/, Connecticut-Com, 2009.

[EDW 02] EDWARD B.D. JR., http://www.eddriscoll.com/timeline.html, Yablok & Associates, 2002.

[HEL 09] HELM B., Stanford Encyclopedia of Philosophy, http://plato.stanford.edu/entries/friendship/, 2009.

[MOR 09] MORÉTEAU S., Le b.a.-ba de l’habitat écologique, Rustica Editions, 2009.

[TAN 03] TANENBAUM A., Réseaux, Pearson, 4th edition, 2003.

[TFD 10a] The Free Dictionary, http://encyclopedia.thefreedictionary.com/domotics, Farlex, 2010.

[TFD 10b] The Free Dictionary, http://encyclopedia2.thefreedictionary.com/domotics, Farlex, 2010.

[TOU 11] TOUTAIN L., Local Networks and the Internet, ISTE, London, John Wiley & Sons, New York, 2011.

1Chapter written by Romain CARBOU.

1 Thank God It’s Friday!

2 Gutenberg is regarded as the most influential person of the millennium and beyond (http://rhsweb.org/library/1000PeopleMillennium.htm).

3 Even the early release of Ethernet came from the PARC team at Xerox in 1973!

Chapter 2Actors in Digital Home Networking1

2.1. Scope

Whether your way of life resembles more that of the Great Gatsby, or, on the contrary, that of St. Anthony of the Desert, your home is certainly known, used, monitored, or visited by some people. Your friends, your family, perhaps your colleagues visit you at home. Public services and commercial services (the water provider, estate agencies, the postal service, a catering service, etc.) may visit your home for different purposes (technical control, meter reading, financial evaluation, etc.), occasionally or regularly.

In the same manner, your digital home is likely to interact with a large diversity of agents – individuals or corporate bodies – either in the real world or through their digital identity. Friends coming for dinner in the evening may be detected by a motion sensor in the alley that switches on the outside lighting. The electricity provider may, through a secure communication channel, perform a remote meter reading. Digital home use cases are just countless.

These digital home actors, depending on their very nature (adults, children, animals, moral persons), may certainly have specific abilities or privileges. Your 10-year old may wash the Aston Martin but does not drive it. And, likewise, while your kitten is able to go in and out through the cat flap, you have no such capability. In other words, categories of actors may encompass different properties, which may have, furthermore, a permanent character or may change over time. Those properties, in turn, will tailor the logics of digital home services according to the peculiarities of each given actor, thanks to context management functionalities, ambient intelligence, or personalization – a field extensively discussed in Chapter 5.

Finally, actors can be characterized in terms of the role they play in a certain scenario of usage. The same person, with given privileges and abilities, will enjoy different uses of a digital home system depending on his/her current location (in the home, outside the home), the relationship with respect to this home (owner, visitor) or other parameters. So, in the same manner as for context management, the roles resulting from the combination of those dynamic or permanent hypotheses determine requirements and constraints in various aspects of user experience, such as authentication/authorization, privacy, and, above all, Quality of Service (e.g. for streaming a home-located high-definition video file, being at home, or outside, has an evident impact on the QoS, because of the potential distinct end-to-end bandwidth limitations). Chapter 7 will be devoted to Quality of Service and Chapter 10 to Interoperability.

Precisely because of the pervasive influence of the user location on the global distributed system architecture in the context of the digital home, this chapter will propose a simple model of user roles embracing both local and remote access situations.

2.2. Categories of actors

2.2.1. Persons

The most natural digital home actors are private individuals. They consist of the homeowners and the household members, and basically everyone – friends, families, colleagues, or occasional visitors participating in a digital home service.

Depending on their nature, digital home services may work in an anonymous way (users are not identified), or may, on the contrary, require some authentication, or may propose both the modes. For instance, a motion sensor in a home alarm system would definitely work in an anonymous mode since “users” are not likely to register spontaneously. Conversely, a system allowing us to access home-located digital files remotely or to take the control over the PC desktop would for sure require a strong user authentication.

For these reasons, individuals may be bound to zero or one (or several) digital identities when interacting with a digital home service. As a matter of fact, identity is at the heart of the architecture and security chapters of this book. Indeed, a person is bound to several identities when interacting with the digital ecosystem (credentials on his/her favorite social network, mobile phone number, etc.).

Authenticating on a digital home service then brings up the question of the choice of user authentication methods at stake – with the traditional compromise to decide between privacy concerns and ergonomy.

2.2.2. Other home actors

Domestic pets and more generally any animal can have a great diversity of interactions with the digital home. An intrusion detection system may launch specific actions, when it detects a human being or a pet. The aquarium may be controlled remotely to feed the goldfish during vacations.

Distinction among living beings (human/animal), in the home, yields its specific challenges of image/sound/video analysis and advanced context management capacities.

2.2.3. Services and third parties

Service providers, such as fixed telephony operators, Internet Service Providers, electricity/gas companies, constitute de facto actors already interacting today with the digital home, and will steadily develop their roles in the future.

For example, a cornerstone player enabling the connectivity between the digital home and public networks, the telecom operator, now proposes digital home-related services, such as home monitoring and remote access to home equipment. Moreover, remote meter reading services are starting to be proposed by energy companies, thereby, participating to cost reductions (no need for a technician sent on site) and improving the user experience.

In addition to those pivotal, historic actors, many newcomers may arise soon if a successful emancipation of the digital home appears. Indeed, technical conditions are almost gathered today to propose an “application store” of digital home services, similar to the online marketplaces popularized by smartphones. Today, home networks are equipped with a reliable execution environment (e.g. set-top boxes or even the latest generations of Internet routers) that could run applications purchased on a portal interface, accessible through the PC or the TV sets.

Just in the same manner as you call a babysitting service at home for your next holiday, you could imagine contacting an “online home-sitting” performing home monitoring, smart energy management, or simulating a presence during your vacation. For this, you would download an application, running typically on your home gateway, and allowing the home-sitting operator to perform the tasks remotely.

As a result, all existing home-related services may become in this context the new actors of the digital home economy.

2.2.4. Legal bodies and public services

Firemen, policemen, or the postal service extend the set of actors that can participate in the digital home ecosystem, either through a “digital home application store” as described earlier, or through legacy solutions available today.

The example that immediately comes to mind is provided by all intrusion detection systems connected to the police station. Another example is illustrated by the “postman use case”, which describes the possibility of a postman ringing at the door when the house owner is not at home, to establish a video connection between the (video-capable) entry phone and the owner’s mobile terminal (the owner can then agree with the postman whether to leave the parcel with a trusted neighbor or at the post office, etc.).

Because of its potential threats over the house security (a false postman may use the system to check that nobody is at home), this kind of application raises the challenges of smart ambient intelligence, so as to prevent its misuse. This will be the subject of in-depth discussion in the context management chapter.

Also, because the digital home constitutes both the default Internet access point for private usage and, at the same time, a sanctuary of private data, it inspires a peculiar interest from public authorities in charge of copyright law enforcement. This concern was in some countries the basis for laws authorizing public authorities to analyze the private Internet traffic and apply a punitive legislation in case of copyright infringement (with the noticeable example of the “HADOPI” law in France1).

In the likelihood of a middle-term perspective with citizens’ growing willingness to open the digital home to friends, social networks, or third-party services, it can be expected that public authorities will aim at increasing their legal capacity of observation observing over any private data flow involving the home network – not only outgoing as today, but also incoming.

In some way, reliable evidence confirming the emancipation of digital home services will be the legislative activity over their regulatory aspects, especially in light of copyright enforcement issues and fraud tracking.

2.3. User roles

This section pretends in no way to deliver an objective model of categorization for digital home roles, simply because such effort of ontology definition is context-specific, and depends heavily on the perimeter of home services addressed. This said, some general paradigms (share a right over a resource) and evident dichotomies (owner, not owner), suggest patterns of categorization that can, in a sketchy stage, be a basis for early system architecture analysis (see section 5.2 on ETSI standards).

Whatever the domain of the digital home service (pure domotics addressing the management of physical equipments, sensors, etc., or multimedia applications for content sharing), almost everything can be seen as a home resource (an electric window, an audio file) that the owner can access, and optionally share with trusted contacts or with anybody, for a given purpose. This basically calls for a dichotomy between an owner and a leaser.

Because the digital home primarily provides us with powerful perspectives of remote access and because of the pivotal security aspects, the user location is another key element. In its most basic expression, location can be a Boolean value, expressing the state “at home”/“not at home”.

Finally, this latter dichotomy, if sufficient for certain applications, fails to reflect many practical situations where the service, primarily when the user is not at home, is partially delivered, in a best-effort way.

Among various factors, a degraded or unavailable service may occur because of limited network connectivity/bandwidth constraints, end-to-end, between the remote user and the home network.

Accordingly, a third perspective is to distinguish whether or not the “Quality of Service” (service-dependent definition) is ensured end-to-end, so as to appreciate what acceptable service degradation can be still delivered by the system.

The terminology in Figures 2.1 and 2.2 is in no way standardized, merely subjective, and could be modified at the taste of the software architect or service designer or student reading this book. Nevertheless, no matter what activity you may have around the design, the development, or the exploitation of digital home services, early adoption of a common vocabulary designing clearly the different user roles will probably save unbelievable amounts of time and energy in your digital home project.

Figure 2.1.A sketchy terminology of user roles

Figure 2.2.A sketchy terminology of user roles introducing Quality of Service for remote access

Once we have explained the different actors that can interact with a digital home environment and their possible roles, let us now consider in the next chapter the present network technologies and the digital home standards.

2.4. Bibliography

[BEL 09a] BEL M., CORDÓN D., CARBOU R., BARS R., DUGEON O., EXPOSITO E., FASSON J., PAILLASSA B., ROMÁN R., CASADO A, MAESTRO G., Specification of the Feel@Homeservices (Deliverable 3.1), https://rd-projet-feelathome.rd.francetelecom.com/public/deliverables/D3.1%20Specification%20of%20services.pdf, 2009.

[BEL 09b] BELIMPASAKIS P., Seamless User-Generated Content Sharing in the Extended Home, Tampere University of Technology, 2009.

[ZAH 03] ZAHARIADIS T.B., Home Networking Technologies and Standards, Artech House Telecommunications Library, 2003.

1Chapter written by Romain CARBOU.

1 “HADOPI” stands for “Haute autorité pour la diffusion des œuvres et la protection des droits sur Internet” [Authority for the broadcast of works and protection of rights on the Internet].

Chapter 3Network Technologies1

3.1. Local connectivity and networks

Local connectivity means that two or more devices communicate with one another within a geographically limited area. Networks comprising such entities are known as local area networks (LANs). LANs have been increasing in complexity over the past decade. Initially, a LAN was only composed of computers in a controlled environment, such as an office or a home, with the aim to share resources (i.e. printers, disk space) and to enable communication between them. Today, however, the equipment or nodes that can participate in a LAN have varied substantially, from personal computers (PCs) to personal digital assistants (PDA), mobile phones, various types of sensors, even radiofrequency identification (RFID) chipsets. As a consequence, numerous LAN technologies have appeared so as to connect such heterogeneous devices in a local environment, involving hardware and software components.

Subsequent sections will be focused on the different LAN technologies that have been developed to cover home user requirements, with the aim to illustrate the principal alternatives that can be deployed in a home environment. We will start the analysis with a brief description of the relationship between the existing technologies.

3.1.1. Background of LAN technologies

Ethernet is the most widely deployed technology for high performance in LAN environments. Although its origins date back to 1972, it was ratified by the Institute of Electrical and Electronics Engineers (IEEE) in 1983 only, under the name of “IEEE 802.3 10BASE5”, shortened to 802.3. The first specification of the standard achieves data rates up to 10 Mbps, supporting a variety of physical implementations (i.e. coaxial cable, unshielded twisted pair (UTP), and optical fiber). Several evolutions of the technology are mainly designed to increase the peak data rate, with results of over 100 Mbps and 1 Gbps for fast Ethernet and Gigabit Ethernet, respectively. With the aim to increase the initial data rate of 10 Mbps of Ethernet, an alternate technology based on optical fiber emerged. The American National Standards Institute (ANSI) Committee X3-T9 standardizes the fiber distributed data interface (FDDI), a technology for data transmission over fiber optic lines in a LAN, with a range up to 200 km. FDDI (also known as ISO 9384) uses two fiber rings, one of them for data transmission and another for backup, thereby achieving a maximum data rate of 100 Mbps over the first, although it is possible to extend this value up to 200 Mbps if the backup ring is used to carry data. However, Ethernet achieves the same data rates as that of the FDDI at lower cost, thereby making it a more popular option than the FDDI.