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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>MOSS: Mobile Social Spaces</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Anna V. Zhdanova</string-name>
          <xref ref-type="aff" rid="aff4">4</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Marcin Davies</string-name>
          <xref ref-type="aff" rid="aff4">4</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Oliver Jorns</string-name>
          <email>jorns@ftw.at</email>
          <xref ref-type="aff" rid="aff4">4</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Vera Stavroulaki</string-name>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Panagiotis Demestichas</string-name>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Marta Gonzalez</string-name>
          <email>marta@robotiker.es</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Klaus Moessner</string-name>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Francois Carrez</string-name>
          <email>f.carrez@surrey.ac.uk</email>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Hariharan Rajasekaran</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Luigi Lo Iacono</string-name>
          <email>lo_iacono@it.neclab.eu</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>NEC Laboratories Europe</institution>
          ,
          <addr-line>Germany &lt;rajasekaran</addr-line>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Robotiker-Tecnalia</institution>
          ,
          <country country="ES">Spain</country>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>University of Piraeus Research Center (UPRC)</institution>
          ,
          <addr-line>Greece &lt;veras</addr-line>
        </aff>
        <aff id="aff3">
          <label>3</label>
          <institution>University of Surrey</institution>
          ,
          <country>UK &lt;k.moessner</country>
        </aff>
        <aff id="aff4">
          <label>4</label>
          <institution>ftw. Telecommunications Research Center Vienna</institution>
          ,
          <addr-line>Austria &lt;zhdanova, davies</addr-line>
        </aff>
      </contrib-group>
      <abstract>
        <p>We present an emerging approach of Mobile Social Spaces (MOSS) that intends to improve the ways in which people communicate in the modern world. Pervasive content and service creation and provisioning, in particular for dynamically changing social groups, is a complex task and subject to varying locations of individuals, of the complete group and its context. MOSS tries to remove some of the obstacles in this area and defines a range of functionalities that will support dynamic ubiquitous creation and instantiation of community content and services.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1 Introduction</title>
      <p>
        With the introduction of smartphones, advances in mobile and sensor technologies,
ubiquitous computing as it was envisioned by Mark Weiser [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ] gets closer to
realization. In tandem with the Internet and the Web, it enables a kaleidoscopic view
on information reflecting the anywhere-anytime paradigm which influences not only
communication but also the way people are working and socializing. Today’s cheap
wireless access facilitates production, provisioning and usage of more complex and
powerful mobile services and enables implementation of complex interaction patterns.
Chips and RFID technologies become ubiquitously spread, allowing devices to
communicate with each other with minimum human involvement. Humans, in their
turn, have more time to focus on what is more important for them, i.e., managing their
social spaces instead of software on their mobile devices.
      </p>
      <p>In this paper we present the requirements and design for an infrastructure called
Mobile Social Spaces (MOSS) which aims to enhance the user experience when
communicating in highly dynamic social spaces. More specifically, MOSS targets
integration of various mobile and social network services, simplification of
configuring and sharing social information in a mobile space, efficient utilisation of
the available network infrastructure, dynamic personalisation of services, anytime,
anywhere, through any mobile device, and is thus envisaged to significantly increase
the satisfaction of a user. One important prerequisite is that the components of a
user’s mobile social space are self-managed and configure themselves not only in a
reactive but also proactive manner, taking into account various different aspects such
as the users’ preferences, communities, policies, the current context the user is
situated in, and also the device and network capabilities that inherently influence the
communication capabilities. The realization of such self-management capabilities
calls for mechanisms for modelling, accessing, learning and updating user and context
information in a transparent manner.</p>
      <p>The proposed approach for such realization is the subject of this paper, which is
structured as follows. Section 2 delivers two exemplifying scenarios for typical
MOSS infrastructure usage, and the main derived requirements to the MOSS
infrastructure are listed in Section 3. In Section 4, an overview and technical approach
towards creation of MOSS infrastructure are provided. The main areas targeted by
MOSS and the related progress beyond the state of the art are described in Section 5.
Existing related work is outlined in Section 6. Finally, the potential exploitation and
evaluation principles of the approach are discussed in Section 7.</p>
    </sec>
    <sec id="sec-2">
      <title>2 Sample scenes and use cases</title>
      <p>In this section we describe possible scenarios highlighting features of service
provisioning in mobile social spaces when various factors (such as the user profile,
context and policies) are taken into account in a dynamic fashion. The aim is to
present a vision of how the MOSS system could operate and provides a starting point
for the derivation of technical requirements for the MOSS services/functionalities.</p>
      <sec id="sec-2-1">
        <title>2.1 Busy working mum</title>
        <p>Patricia is mother of three children and she is working at the office and at home. She
has to organize all the supplies acquisition, appointments and immediate actions for
the wellbeing of the whole family. Patricia uses her mobile phone to set up a service
to draw up the list for the ”supplies” (e.g. food) and ”suppliers” (shops she usually
goes to) as new necessities arise at home (e.g. no sugar at home), she uses another
service to manage the different appointments she has (labor and personal), another for
periodic events (e.g., children’s private classes) and the last one for immediate
actions. People in Patricia’s social space, e.g. her husband, her mother, a sister and
her domestic help, share some of the services according to different policies indicated
by Patricia. Also these people can in turn share their own services with her.
Triggering an immediate action implies that a person goes to a certain place. The
service created to manage immediate actions will choose the person that belongs to
Patricia’s social space and that is nearest to the destination place. That person receives
a notification indicating the task to be carried out (e.g., to pick some clothes up at a
concrete dry-cleaner’s establishment, to buy a product at a particular shop). This
person can refuse the task; then the service will again select the most appropriate
person to fulfill the task until the task is performed or postponed by Patricia.</p>
        <p>In two days, Patricia has to make a business travel and therefore wants to organize
the home. So during her absence all the supplies have been bought and the different
menus scheduled. As she shares the periodic events service with her husband, in her
absence, he will take care of children to attend private classes. The service for
supplies purchase is shared by her domestic help, as medical appointments service is
shared by Patricia’s mother. For her peace of mind, she can monitor and re-schedule
all the activity at home while she is traveling. The different services will notice the
appropriate people according to Patricia’s scheduling or she can delegate that
responsibility to her husband.</p>
        <p>During her business trip, Patricia has to share her social space with partners of the
project consortium, because she is attending a Consortium Plenary Meeting, but the
services will be different (presentations interchange, flights scheduling, etc.).</p>
      </sec>
      <sec id="sec-2-2">
        <title>2.2 Living and working in Greece</title>
        <p>Ann is a Key Account Manager at a large beer producing company. The clients she
deals with are mainly managers of hotels or big restaurant chains. Part of her work is
to organize promotion events such as parties at various client premises. With the help
of MOSS, Ann builds a professional social network. All she has to do is to provide
her business profile and the initial criteria that people should meet to fit to her
professional interests. Every time a new subscriber fits these criteria, and if policies
allow it, MOSS automatically adds her/him to a suggested members list. If and when
Ann wants to, she can check the information on new suggested members and accept
or decline a new member.</p>
        <p>Ann has an appointment with the manager of a large hotel which is located at the
coast of Athens. She is organizing a beach party to promote the latest beer brand at
the hotel’s new beach bar. After the meeting, Ann steps into her car to drive to the
next client. On the way she uses a voice-dictation service in her mobile device to
update her professional calendar with the details of her event. A notification message
with the details of the event is send to all the subscribed members of Ann’s
professional network. Between her last two appointments for the day, Ann has some
spare time. MOSS has information regarding the time and location of these two
appointments. Based on the available traffic information, calculations indicate that
there is not enough time to drive back to the office in between. MOSS also detects
that one of Ann’s favorite cafe is on the route from the location of the first meeting to
the second. Since Ann is driving, MOSS plays an audio message asking her whether
she would like to try to arrange a meeting with one of her friends for a quick coffee.
Ann agrees. MOSS retrieves information that indicates that Alice’s friend Ellie will
be near the cafe at a suitable time. Ann dictates a message that is send to Ellie. Ellie
agrees and they meet at the cafe. Ann arrives at the location of her final meeting for
the day.
3</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>MOSS technical requirements</title>
      <p>In order to be able to successfully meet the technical requirements, stemming from
the sample use cases presented in the previous, MOSS should facilitate the creation of
a mobile social network infrastructure that includes the following innovative aspects:
• Acquiring and managing information on user profiles, preferences, behaviour
and constraints, as well as data related to the capabilities of the current user device.
This includes collecting user feedback so as to appropriately update.
• Gathering and maintaining updated user context as he/she changes the
localization and activity.
• Acquiring and managing location and presence data as well as this
information sharing with the members of the networks a certain user belongs to,
taking into account specific privacy constraints defined by the user.
• Defining and imposing privacy policies indicated by user: what to share with
whom.
• Ability to create services, in an easy and friendly way, to be shared with the
rest of the members of a user’s networks.
• Access to sensors data or other data sources for services functionality, e.g.
RFID for goods at shops, airport services for flights scheduling, etc.
• Reasoning capabilities for rendering personalised content and services to
users, such as tasks scheduling inside a user’s networks.
• Knowledge management functionality so as to create and exploit experience
related to user preferences and requirements, as well as contextual situations.
• Searching mobile social spaces content and forming mobile social spaces
based on user preferences and goals.
• User Rating of MOSS services so as to obtain feedback from the user side
and refine aspects of service provisioning if necessary.</p>
    </sec>
    <sec id="sec-4">
      <title>4 Overview of Mobile Social Spaces</title>
      <p>The infrastructure for MOSS comprises a solution enabling end users to be
accompanied and to take benefit from their social knowledge-based spaces, adapting
to their location, policies, available devices, services and modalities. Core parts of
such spaces include different localization technologies, policy management,
dynamicity and interoperability. Furthermore, this altogether overcomes existing
search and access barriers.</p>
      <p>In Figure 1, the generic MOSS infrastructure is shown. In order to dynamically
create and publish community services, issues like business models, location and
context as well as user-obtained or generated content need to be provided to the
knowledge base. There, a range of functions such as policy based
inference, semantic search engines, etc. are used to predict user behaviour and to
generate customised services for a particular community. Basic mechanisms for
achieving this goal include community driven ontology management, reasoning and
the linking of the service data/content to protocols and data formats that are
understood by the devices used to interface with the actual user.</p>
      <p>MOSS enables user generated community services facilitating “mobile social
spaces”. The four main concepts within the MOSS architecture are “create”,
“publish”, “interoperate” and “access”. Many of the mechanisms to instantiate these
concepts are available but are restricted to applications in fixed spaces − MOSS
exploits these mechanisms by adapting them, where possible, or extending them
(where necessary) to support mobile social spaces.
• “create”: create content on the go enriched or driven by sensor / context
information, decide the rules to share this content, decide what the users’ “mobile
social space” consists of;
• “access”: ubiquitous access not only to the user’s social space and its related
available content, but also access/retrieve context information relating to the user;
• “publish”: rule and context based publishing of content/knowledge, using tags
and underlying community-evolved ontologies;
• “interoperate”: Community-driven ontology building, matching, management,
recommendations, social networking as techniques maximizing the discovery
process and guaranteeing the appropriate result.</p>
      <p>Figure 2 goes further and provides an architectural view of MOSS highlighting the
main building blocks, which are distributed between the users’ terminals and a knowledge
warehouse in the network supporting ontologies, a knowledge base (excluding the user’s
knowledge/content), community building, and management.</p>
      <p>The user terminal requires only few functions like profile/preferences, user rules and
policies that dictate the way Mobile Social Space should be built, taking into account
people met or surrounding the user as she moves. Context information that is gathered by
the user’s terminal/devices sensors enrich the whole set of information used during the
building of the social space. In addition, two very important blocks, namely
publishing/discovery and content management, are responsible for the handling of
content/knowledge at the user side. It is worth noting that no piece of user’s content or
knowledge is stored or handled at the central server. Only tools (counterpart of the
publishing/discovery blocks) for discovering and accessing this knowledge are provided in
there. The knowledge warehouse (KWH) is the central place where users’ policies and
rules are applied, taking into account context information like people presence and
profiles, events, places, etc. While the social space is clearly created and proposed to the
user at the KWH side, it is nevertheless rendered and managed at the user terminal side.
All aspects relating to ontology management are handled at the KWH side as well.</p>
    </sec>
    <sec id="sec-5">
      <title>Main areas and progress beyond the state-of-the-art</title>
      <p>In this section we conceptualize main research and development areas of MOSS and
accordingly indicate the plausible progress beyond the state-of-the-art.</p>
      <sec id="sec-5-1">
        <title>5.1 Location-based social services</title>
        <p>
          The notion of Location-Based Services (LBS) is in fact difficult to capture and there
are various definitions such as the one proposed by Junglas et al. [
          <xref ref-type="bibr" rid="ref4">4</xref>
          ]:
“LocationBased Services are services that take into account the geographic location of a user”.
In contrast to that very brief definition Adusei et al. [
          <xref ref-type="bibr" rid="ref1">1</xref>
          ] are more specific: “Location
Based Services are business and customer services that give users a set of services
starting from the geographic location of the client”. Both definitions are valid, but it is
not that easy as it seems to be at first glance. As Küpper [
          <xref ref-type="bibr" rid="ref5">5</xref>
          ] alludes there is no
common definition or terminology for the term “Location-Based Service”.
Confusingly, the term itself is often used interchangeably with Location-Aware
Service, Location-Related Service or Location Service.
        </p>
        <p>
          However, it is obvious that location is − amongst others such as time − perhaps the
most important context information. From this follows another possible explanation
of LBS that subsumes all services where information about the location of the user is
needed [
          <xref ref-type="bibr" rid="ref4">4</xref>
          ] and as such represents the combined use of wireless communication,
location determination, geo-information systems and mobile devices for creation of
services such as traffic information, shopping services and location-based gaming.
Most mobile services and traditional LBS services do not take into account the users
social context and the social network, forgetting that the mobile phone is a social tool
that can be used to connect people with each other [
          <xref ref-type="bibr" rid="ref2">2</xref>
          ]. LBS must take the next step
and avoid being solely based on a pair of geographical coordinates. Users position is
indicative of an activity, intention, or goal, but it can be further refined by using the
rest of context information about the user, especially their social network: “Are my
friends near here?”, “Are all these people also attending the event?”, “Can anyone
around inform me about traffic conditions?”. By integrating localization with context,
MOSS allows LBS to achieve a higher level of intelligence as it is perceived by users.
        </p>
        <p>
          Location-Based Social Services (LBSS) enrich traditional LBS by adding the
interaction inside a personal and social context. In LBS users act rather passively,
mostly as consumers and mobile terminals as download-only devices whereas LBSS
are user-centric, that is, the user is contributing to the community, being cared for by
the community. No matter if reactive or proactive LBS functions are used, with LBSS
the users are in the role of content creators and providers from a mobile device [
          <xref ref-type="bibr" rid="ref6">6</xref>
          ].
        </p>
        <p>The traditional business model of LBS is based on a closed model where only the
network operator provides services to its subscribers. During the last years it turned
out that this model does not meet the expectations, nor does it cope with the
requirements of new emerging technologies and the subsequent implications. With
LBSS, which is fundamentally user-centric, it is possible to integrate location as a
kind of user-generated content. This can be published and integrated with any other
information or content. Thus, next generation LBS complement with the Web 2.0
paradigm and allow MOSS to move towards an open model, where the operator acts
as an open link between the subscriber and third-party content providers, expanding
the range of services users have access to.</p>
      </sec>
      <sec id="sec-5-2">
        <title>5.2 Semantic, pervasive, user-oriented policies</title>
        <p>The concept of social networks is currently booming on the internet with applications
such as Facebook, MySpace, Orkut, etc. Such applications and platforms are currently
attracting millions of users. In addition to these social networking applications,
professional networking sites such as LinkedIn and Xing provide a platform for
professionals to publish and share professional information to help in industry
networking. However, most of the current social networking applications on the
internet are currently “static”, in the sense that content and user details are updated by
the user only when they explicitly visit these applications either through their mobile
device or PC. In contrast, mobile social networks are more ”dynamic” as they have
access to more information about the user such as location, surrounding environment,
context, etc. that can be continuously updated. Therefore it is imperative that access to
and especially dissemination of such information is granted only to authorized
contacts to ensure that the privacy of the user is still preserved. In MOSS privacy
issues will be operated via user-generated, machine-processable and sharable policies.
The effectiveness of methods for pre-selection, search and sharing of mobile content
and components, their advertisement and personalized delivery will be evaluated by
user tests. Aspects of service controlling and personalization should be achieved in an
unobtrusive manner as required in the scope of pervasive systems.</p>
        <p>Policy-based and fine-grained access control. With such a vast amount of
information about a user presently online, privacy is a huge concern followed by the
need to sort through this information overload and find content that is relevant for a
particular user. MOSS addresses the privacy issue by developing a content access
framework that deals with fine-grained access control to content controlled by user
specified policies. Today’s web-based social networks feature access control models
that are too coarse and not suited for very fine-grained access control to a user’s
content. Some of the options available today are:
• Private / Public model – Photo sharing sites such as Flickr use such a model for
controlling access to user’s pictures. Private pictures can be viewed by “invited”
friends while “public” tagged pictures can be viewed by all.
• “Friends” model – Most social networking sites use this model where it is
possible to restrict content to users who are classified as friends. Though this
makes the access control enforcement easier, it is not entirely efficient from a
privacy point of view, since the “degree of intimacy” varies among friends. Some
social applications offer the choice of creating sub-groups among friends, but
even this is not enough to apply fine-grained access control on user’s content.</p>
        <p>
          Some of the methods currently investigated in the research community to
implement such access control solutions include ReBAC (Relationship Based Access
Control) [
          <xref ref-type="bibr" rid="ref8">8</xref>
          ], where a user’s relationship with another user determines the access to
content, social attestations from social networks confirming a user’s relationship to
another user, and social access control lists [
          <xref ref-type="bibr" rid="ref9">9</xref>
          ].
        </p>
        <p>MOSS will investigate existing methods and adapt them to the mobile social
networking context with enhancements to enable fine grained access control to user’s
content. In MOSS privacy issues will be operated via user-generated,
machineprocessable and sharable policies. Effectiveness of methods for pre-selection, search
and sharing of mobile content and components, their advertisement and personalized
delivery will be evaluated by user tests.</p>
        <p>Reasoning with Policies. The type of reasoning solution operated on
usergenerated policies in MOSS will manage situations not typically considered in the
reasoning field so far, but still representative for communications in various
ubiquitous settings where communities may be found: appearing and disappearing
people and resources in the vicinity, limited availability, strong context dependency
and social/communication context.</p>
        <p>
          Usability Mechanisms for Security. Even the most comprehensive security
infrastructure will fail if users of the system are not provided with effective tools to
configure and test their security settings. The need for such tools is highly desirable in
social networks where the majority of the users are young adults who are unaware of
the privacy implications that might arise out of faulty access control policies set by
themselves. The options available in current social networks are coarse grained
options that hardly fit the privacy needs of a highly mobile social space. MOSS’
policy management environment (PME) [
          <xref ref-type="bibr" rid="ref3">3</xref>
          ] addresses this problem by providing an
easy to use tool for end users to compose, manage and enforce machine readable and
fine grained access control policies.
        </p>
      </sec>
      <sec id="sec-5-3">
        <title>5.3 Management of location and presence information</title>
        <p>Another goal is to implement a concept for policy-based sharing of location and
presence information between end users. Users are able to define the ways the
location and presence information is shared with the others and to retrieve
information about other users employing the presence and location service in
conjunction with other context-aware systems. In particular, such a system may locate
the user’s buddy-list contacts on an interactive map. Social software and social
networking websites providing users’ location and presence information have gained
high usage over the last several years. Spread of applications like Google Maps and
Virtual Earth increasingly facilitate awareness about the surrounding objects, streets
and directions. As an increasing number of users have mobile devices, mobility
aspects become more relevant. Policies on sharing user data are also gaining more
importance as the data becomes to appear in structured or semantic formats that are
easy to process and combine. Therefore MOSS aims to integrate aspects of semantic
policies, location and presence services, mobility and visualization.</p>
      </sec>
    </sec>
    <sec id="sec-6">
      <title>6 Selected related work</title>
      <p>
        MOSS is to advance the developments of the following projects’ efforts as well as
typical state-of-the-art commercial initiatives:
- eSense (http://www.ist-esense.org): this project provides an extensive study on
different types of sensors, in particular, delivering detailed characteristics of the
information that can be collected with state-of-the-art sensor technology. However,
the domain has not been modeled semantically (i.e., with an ontology or via semantic
services) which makes reuse of the project interfaces very difficult.
- m:Ciudad (www.mciudad-fp7.org): the goal of this ongoing project is to enable
users to create micro services using mobile devices. One of the outcomes of the
project is an ontology for defining such mobile micro-services. In MOSS, this
ontology work is to be adapted together with the semantic policy technology to enable
the users to make and employ micro-services at their social spaces.
- SPICE (http://www.ist-spice.org): introduces a service platform for the next
generation mobile services. One part of the platform provides the mobile ontology
[
        <xref ref-type="bibr" rid="ref10">10</xref>
        ] which is a higher-level comprehensive ontology designed for the mobile
communications domain. Furthermore, it is a machine readable schema intended for
sharing knowledge and exchanging information both across people and across
services/applications in mobile ubiquitous environments. However, the ontology
framework would be applicable to MOSS when accompanied by a management
environment and thus being subject to an easy update on the fly as well as to
plugging-in new mobile sub-ontologies arising from the changing context.
- Commercial mobile services for social networking (such as Dodgeball, Loopt,
Kaliloc, Jaiku, Aka-Aki) comprise functionality addressing specific user’s needs for
sharing information (e.g., photos, activities, locations) in mobile settings. Services are
not interconnected, and no common knowledge-based infrastructure to develop,
deploy and use such services in a unified manner is available. Knowledge
management facilities for such services are at the moment highly restricted:
information processed and transferred by them is typically created by the users for
each individual service from scratch and is not reusable in different contexts and
applications.
7
      </p>
    </sec>
    <sec id="sec-7">
      <title>Potential exploitation and evaluation</title>
      <p>Any company which has to do with communication within distributed (groups of)
people and accessing and managing data coming from heterogeneous
platforms/sources can be a potential MOSS user. Furthermore, the presented
infrastructure is of interest for advertisement enterprises who can employ MOSS
social characteristics to deliver products and services directly to communities and via
”word-of-mouth” marketing supported by modern technology. Examples of direct
industrial end users include companies producing robots, intelligent TV and radio,
web-based systems supporting communication of people who want to extend to the
mobile world, physical ubiquitous environment (e.g., for fitness centers, ski resorts,
nightclubs, lecture rooms, hospitals), providers who want their users to have enhanced
social experience, collaborative work environment producers addressing needs of
nomadic working groups, environments for finding experts/specialists/objects, and
integrators of existing social networking or communities data.</p>
      <p>The evaluation of the MOSS success is deemed as primarily user-oriented, in
particular, decreased costs for the mobile social services and increase in quality of
experience (overall user satisfaction, larger choice, easiness of usage, etc.). For the
industries, acquisition and maintenance of permanent customer user communities as
well as new more competitive and facilitating infrastructures and models of service
provisioning will be the adding value aspects.</p>
      <p>Acknowledgments. The Telecommunications Research Center Vienna (ftw.) is
supported by the Austrian Government and the City of Vienna within the competence
center program COMET.</p>
    </sec>
  </body>
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