Ambient Communication and Context-Aware ...

Ambient Communication and Context-Aware Presence Management* Stanislaw Borkowski, Thibaud Flury, Anne Gerodolle, and Gilles Privat Orange Labs/France Telecom R&D {stan.borkowski,thibaud.flury,anne.gerodolle, gilles.privat}@orange-ftgroup.com

Abstract. Ambient communication adapts interpersonal remote communication to the activities of users and supports interactions that come as close as possible to face to face communication. Elements of both user, physical environment and system context are taken into account to support adaptation of the communication setup and to offer implicit and intuitive interaction with the system. User presence and availability are two of the key elements of context information used by ambient communication systems. In this paper, we discuss our approach to context-aware user presence management, and describe an implementation of a presence management service. This software leverages middleware and services developed by the Amigo project to estimate user presence and availability with respect to communication applications. We also show an example of a visual communication application using interfaces distributed in the user's environment to support spatial interaction functionalities. Keywords: Ambient Intelligence, Smart Spaces, Communication, Presence, Context-awareness, Activity detection.

1 Introduction Ambient communication draws upon converging technology evolutions that offer both ubiquitous broadband network access and enriched interaction between the physical environment and the information world. Departing radically from such trends as virtual reality or immersive telepresence, ambient communication propounds a vision of communication that leaves priority to user activities in their familiar environment and lets communication recede in the background, adapting unobtrusively to their time, space and attention [1]. This adaptiveness calls for a new role of context in communication, on a par with and inseparable from content proper. In this view, context is anchored in the physical environment of communicating parties, and brings remote communication as transparently close as possible to face to face communication. Presence is such a key element of context that opens up new modes of communication. Beyond its primary use in instant messaging, it may now be seen as an enabler for new presence-aware modes of communication, but has still mostly been dealt with *

This work was partly funded by the IST-004182 Amigo project.

M. Mühlhäuser et al. (Eds.): AmI 2007 Workshops, CCIS 11, pp. 391–396, 2008. © Springer-Verlag Berlin Heidelberg 2008

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as resulting from explicit user interaction and directly related to network connectivity. Building upon the context management framework of the Amigo project [3] and distributed presence management protocols, we propose here to integrate seamlessly in ambient communication an enlarged notion of presence based on physical context that makes it possible for communication to move back and forth smoothly between context and content, between phatic1 and focused communication.

2 Related Work Presence management was first introduced in Instant Messaging (IM) applications. It is now common for all communication systems (VoIP, CSCW, etc.), but it also becomes integrated into "presence-enabled" applications, such as MS Office suite, which in principle were not designed for communication purposes [4]. In these applications presence is typically associated with a state of technical connectivity with respect to the target system or application. The presence is estimated based only on data entered explicitly by the user or on data that can be directly acquired by the application, e.g. an editor can detect user presence thanks to keyboard activity. Some research projects [6] have tried to integrate context data (potentially obtained from implicit interaction) related to user's activity detected through sensors deployed in the environment or through re-use of information obtained by other systems. However, in these approaches, presence remains limited to a few discrete states, which is rather inadequate given the multidimensional and continuous nature of presence. Typically the notion of presence is limited to practical availability, even when context data is taken into account. Non-objective dimensions of presence such as intentness or willingness to communicate are much more difficult to estimate. Mapping these to predefined (and culturally biased) ontologies as attempted by a few standards (e.g. the notions of "moods" in XMPP /XEP and SIMPLE/RPID), is a heavy-handed and ultimately pointless approach, as no user will bother to enter these manually, and no automatic detection system could ever match to such categories. In this article, we propose a presence management service based on a presence model that is richer than present-day IM presence systems, and more open-ended than proposed "rich presence" standards.

3 Presence Management Service A number of application demonstrators in the Amigo project are designed to support remotely distributed parties in sharing ambience or activities. In collocated situation, the time for starting an activity is chosen based on the observation of activity protagonists' context. Typically, one would propose a friend to 1

Phatic communication is communication without content proper, or with content that should not be taken literally, as conveyed by such ritual phrases as "how do you do", handshakes, salutes, etc. Much like signalling or control packets in network protocols, it opens up or keeps active a communication "channel" between persons.

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play a game or to watch a movie only when the two parties would not be engaged in other activities, i.e. they would be available for playing a game. Sharing an ambience or mood is natural and transparent when sharing the same physical space, but in remote situations it becomes difficult and potentially intrusive. Direct audio-visual communication offers much smaller bandwidth for interaction and may intrude on people's private sphere. Communicating context information such as user presence or availability or activity, together with content proper is precious for ambience and activity sharing. In this section, we present a Presence Management Service (PMS) designed to support ambience and activity sharing applications in conveying information about user presence. 3.1 Presence Model Presence for ambient communication is considered as a multidimensional piece of context information characterizing to what extent the user is ready to communicate. Willingness to communicate, user attention, availability, intentness with respect to the communication, availability of communication and interaction resources, can all be considered as components of this multidimensional notion of user presence. We restrict it here to a two-dimensional presence model that combines two parameters; user ability to communicate and user "awareness". The ability to communicate depends on the existence of interaction resources needed for communication. It is defined over four states corresponding to the following situations: 1. 2. 3. 4.

The user is unable to communicate if there are no interaction resources that could support the communication. The user can receive messages or notifications, but there are no resources allowing her/him to respond immediately. The user can send messages or notifications, but no resources can support the interlocutor's response. The user is in proximity of sufficient resources to both send and receive communications.

User awareness is defined on a linear scale from 0 to 1. It is meant to capture the user's willingness to communicate, i.e. awareness of 0 means that the user does not want to communicate, 1 corresponds to an urgent need to communicate. As a "state of mind" of the user, this willingness to communicate is of course impossible to reflect accurately on the basis of a purely automatic detection. It may however be partially inferred or modulated on the basis of such objective clues as the user being engaged in other activities than communication, or getting closer to devices that afford communication resources. 3.2 Implementation The implementation of the PMS follows Service Oriented Architecture principles, and is based on the Amigo OSGi programming and deployment framework [5]. It uses standard XMPP protocol to exchange user status data between distributed instances of

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the PMS. It also leverages the Amigo Context Management System (CMS) [3] to acquire, aggregate and interpret user and system context. In the following sections, we present principal features of our presence management service. Per-application presence model User presence can be potentially important for various applications. However, to cover all four communication ability levels defined above, each application might have different needs in terms of interaction resources. It is therefore natural that each application defines a presence model of its own. This allows for flexible perapplication presence management. Each application using the PMS must define its own presence model, as an XML document listing services required for each level of user's communication ability (i.e. emitting, receiving and both way dialog). An application registers to the PMS to receive user status changes by submitting its presence model. Presence estimation The PMS can estimate user presence status based on user and services location, service availability and user preferences. User ability to communicate is evaluated each time the user moves to a different area, e.g. to a room. On such event, the PMS performs a location-aware service discovery to obtain a list of services available in the area. This list is then compared with the list of services required by each application and ability level is set accordingly. While the availability can be estimated automatically based on user and services location, the awareness is meant to be explicitly input by the user, being in most cases impossible to infer automatically from context data. Nevertheless, the PMS will modulate the awareness level when the user approaches or moves away from a device hosting services required by an application. This variation must be still validated by the user. Presence visualization service While the PMS is a web-service that can be used by other applications, it can also be considered as an application when combined with a visualization service. The composition of the PMS and a visualization service may allow the user to monitor presence status of remote buddies and to control her/his own status. We have developed a presence visualization service that we call PMS-GUI. Awareness and communication abilities are computed by the PMS according to context information and are sent to all registered GUIs. The GUI shows presence of buddies as a patchwork of pictures. The more "aware" a buddy, the bigger his/her picture. Buddy's communication abilities are reflected by the color intensity of their pictures (see Figure 1). The user may also control the awareness/ability information the PMS exposes to his/her buddies by opening a feed-back panel. The panel shows the current presence status of the user as computed by the PMS, the status exposed to buddies can be modified explicitly by dragging corresponding sliders. The GUI allows the user to notify a buddy that he/she wants to communicate with him/her. To do so, the user first selects an application, by selecting it from the menu

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on the right, and then clicks on the buddy’s picture. On the buddy’s PMS-GUI, the image of the caller vibrates to indicate the call and the PMS notifies the selected application of the user’s intention. Therefore, the presence management application, i.e. the composition of a PMS with a PMS-GUI service, can be used as a universal interface for triggering other communication applications.

Fig. 1. Snapshot of the GUI, while the user is controlling her awareness

4 Using the PMS in Ambience Sharing We illustrate how the PMS can be used by applications supporting remote communication with the example of the Ambience Sharing application. The Ambience Sharing application is a context-adaptive extension of traditional person to person visual communication services such as videoconference. It offers a quasi-permanent communication channel supporting smooth switching between different communication modes, covering a continuous spectrum between non-communication and full communication. For further details on interactions supported by Ambience Sharing please refer to [2]. Ambience sharing integrates the PMS to help users initiating the communication. The application registers to the PMS a presence model specifying that it requires an audio and a video streaming service for outgoing communication and an audio and a video decoder service for reception. When the user is close to devices offering these services the PMS-GUI shows high level of presence. If the user touches a picture of a buddy, the selected person's PMS is alerted. Also the Ambience Sharing clients of the two parties are notified. This notification is a trigger to start the audio-visual communication. The PMS is thus used as a loosely coupled session initialization interface.

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5 Conclusions Ambient communication does not enforce any single particular mode of interaction or modality of communication: it opens up a new repertoire of interactions and communications modes for user to experiment with. We present a new approach to user presence management that is based on a two dimensional presence model that represents user ability and willingness to communicate as two independent features. An implementation of a presence management service supporting this model is also presented, and the use of the PMS is illustrated with an ambient communication application called Ambience Sharing. Expanding the ongoing drift from synchronous to asynchronous communication, the evolution towards ambient communication may be endorsed by a new generation of users unencumbered by the mindset of present-day communication: it will be up to them to invent collectively, using the tools that we have modestly attempted to propose, new forms of communication for tomorrow.

References [1] Privat, G.: Ambient Communication: when devices disappear. In: 7th Workshop on ManMachine Interfaces, Berlin (October 2007) [2] Borkowski, S., Privat, G.: Spatial interaction in ambient communication. In: Enactive 2007, 4th International Conference on Enactive interfaces, Grenoble (November 2007) [3] Ramparany, F., Poortinga, R., Stikic, M., Schmalenströer, J., Prante, T.: An open Context Information Management Infrastructure. In: Proceedings 3rd IET International Conference on Intelligent Environments, Ulm (September 2007) [4] Vaughan-Nicols, S.: Presence Technology, more than just instant messaging, IEEE Computer (October 2003) [5] Georgantas, N., et al.: The Amigo Service Architecture for the Open Networked Home Environment. In: WICSA 2005 (2005) [6] Kranz, M., Holleis, P., Schmidt, A.: Ubiquitous presence systems. In: Proceedings 2006 ACM symposium on Applied computing, Dijon, France (2006)