Look, Ma, My homepage is Mobile!

Much of the ongoing research in ubiquitous computing has concentrated on providing context information, e.g. location information, to the level of services and applications. Typically, mobile clients obtain location information from their environment which is used to provide “locally optimal” services. In contrast, it may be of interest to obtain information about the current context a mobile user or device is in, from a client somewhere on the Web, i.e. to use the mobile device as an information provider for Internet clients. As an instance of such services we propose the metaphor of a “location-aware” Web homepage of mobile users providing information about, e.g. the current location a mobile user is at. Requesting this homepage can be as easy as typing a URL containing the mobile user's phone number such ashttp://mhp.net/+49123456789 in an off-the-shelf browser. The homepage is dynamically constructed as Web users access it and it can be configured in various ways that are controlled by the mobile user. We present the architecture and implementation and discuss issues around this example of “inverse” ubiquitous computing.     

Context Awareness and Mobile Phones

This paper investigates some aspects of how context-awareness can support users of mobile phones, in particular the calling party. The use of mobile and stationary phones is discussed in relation to situational properties of a phone conversation, especially with regards to who might benefit from context-awareness in this context. An initial hypothesis is that mobile phone users communicate context information to each other (verbally) to a much higher degree than do stationary phone users. Mobile phone users could benefit much from context awareness technology, in particular when about to make a call, if they can receive context information regarding the person they are trying to reach prior to establishing the call. We argue that such technology should require low amounts of explicit user interaction, and could lead to less disrupting calls in inappropriate moments, as well as less frustration for the calling party when a call is not answered.     

Mobile map interactions during a rendezvous: exploring the implications of automation

Location awareness can help facilitate a rendezvous of two or more persons. To further enhance the rendezvous experience, we conducted two complementary field studies to identify what information in a location-aware map application is important to rendezvous individuals (study 1) and to explore the use of autofocus, our automation technique to reduce user interactions with the rendezvous application while still providing relevant information to assist users with their navigation task (study 2). Overall, our results highlight the importance of maintaining the visibility of the user’s location in relation to that of their partner(s) and rendezvous location. Additionally, we show that automation is useful in the context of a rendezvous application, but that the considerations are significantly more nuanced than originally conceived. We discuss unique instances when and why the automation process broke-down or did not perform as required by users. The results of this work demonstrate the potential for automation in a location-aware rendezvous application and identify important design considerations for future work in this area.     

Supporting Ubiquitous IMS-based Teleconferencing Through Discovery and Composition of IMS and Web Components

Natural communication among people happens in flexible ways and is strongly affected by the users’ situation (such as communication tools available, user’s location, and user’s preferences). This situation or context information is seldom used to initiate communication sessions among users. Current communication systems are indifferent about users’ context, often require time consuming manual configurations and often result in conferencing tools not being easily accessible when needed. This leads to lower adoption of innovative communications services. IMS SIP (IP Multimedia Subsystem, Session Initiation Protocol) sessions allow users to access the session from different points of contact (home, office, etc.), however, IMS still requires a prior knowledge of all SIP components that might be used in a SIP session. Furthermore, IMS makes limited use of context information (mainly user-defined availability). To address these issues our research approach combines techniques from pervasive computing with IMS networking principles to facilitate compositions of communication sessions based on users’ context. We propose a platform and APIs for pervasive application development support to allow greater intelligence in IMS applications. We additionally provide mechanisms for IMS applications to apply their intelligence to the configuration of physical devices and web resources used to set up a conference. The innovations proposed in this paper are: (1) A new standard for intelligent IMS-based conferencing applications. (2) Application Development Interfaces (APIs) for a platform for pervasive computing. (3) An architecture for a pervasive IMS platform.

An Ontology-Based Approach to Personalized Situation-Aware Mobile Service Supply

Mobile devices such as personal digital assistants (PDAs) and mobile phones are in widespread use already today and converging to mobile smart phones. They enable users to access a wide range of services and information without guidance through their actual demands. Especially during mass events like the Olympic Games 2008 in Beijing—which was initially the context of our work—a large service space is expected to support all mobile visitors, being athletes, journalists, or spectators. Current approaches tackling such problems are location based, meaning that a user's location is central to service provision, and even context-aware, meaning that, beyond location, characteristics of a user's environment are taken into account. Such information obviously helps to deliver relevant information at the right time to the mobile users. Going one step further, a situation-aware system abstracts from the context dimensions by translating specific contexts into logical situations. Knowing the situation end users are in allows the system to better identify the information to be delivered to them and to choose the appropriate services with regard to their scope, which is referred to as service roaming. Even though many context frameworks have been introduced in the past few years, what is usually missing is the notion of characteristic features of contexts that are invariant during certain time intervals. This paper presents these concepts in the context of a platform development, namely FLAME2008, which is able to support its mobile users with personalized situation-aware services in push and pull mode.     

Spatial cloaking for anonymous location-based services in mobile peer-to-peer environments

This paper tackles a privacy breach in current location-based services (LBS) where mobile users have to report their exact location information to an LBS provider in order to obtain their desired services. For example, a user who wants to issue a query asking about her nearest gas station has to report her exact location to an LBS provider. However, many recent research efforts have indicated that revealing private location information to potentially untrusted LBS providers may lead to major privacy breaches. To preserve user location privacy, spatial cloaking is the most commonly used privacy-enhancing technique in LBS. The basic idea of the spatial cloaking technique is to blur a user’s exact location into a cloaked area that satisfies the user specified privacy requirements. Unfortunately, existing spatial cloaking algorithms designed for LBS rely on fixed communication infrastructure, e.g., base stations, and centralized/distributed servers. Thus, these algorithms cannot be applied to a mobile peer-to-peer (P2P) environment where mobile users can only communicate with other peers through P2P multi-hop routing without any support of fixed communication infrastructure or servers. In this paper, we propose a spatial cloaking algorithm for mobile P2P environments. As mobile P2P environments have many unique limitations, e.g., user mobility, limited transmission range, multi-hop communication, scarce communication resources, and network partitions, we propose three key features to enhance our algorithm: (1) An information sharing scheme enables mobile users to share their gathered peer location information to reduce communication overhead; (2) A historical location scheme allows mobile users to utilize stale peer location information to overcome the network partition problem; and (3) A cloaked area adjustment scheme guarantees that our spatial cloaking algorithm is free from a “center-of-cloaked-area” privacy attack. Experimental results show that our P2P spatial cloaking algorithm is scalable while guaranteeing the user’s location privacy protection.     

M2S maps: supporting real-world navigation with mobile VR

Mobile devices are becoming increasingly integrated into our society. In addition to entertaining people with applications like pervasive games, mobile devices can also help to address cognitive challenges people face in the real world. This paper, by drawing on research findings from cognitive psychology and geography, explores a design to use mobile VR to help people overcome one cognitive barrier in navigation, which is to establish the correspondence between 2D spatial information found in maps and 3D entities they perceive from the real world. The design offers users multi-format, multi-scale, and semantic (M²S) maps, ranging from 2D maps to 3D immersive environments, and helps users to connect 2D maps to the real world through 3D environments which are equipped with semantic representation and animation techniques. Consequently, users can apply various kinds of spatial knowledge, 2D or 3D, in understanding the real world as well as assisting in navigation. This research enhances the design repertoire of mobile VR, and suggests a way to integrate virtual environments into people’s real-world life by examining the cognitive implications of 3D models on users’ activities.     

Using ubiquitous computing in interactive mobile marketing

Unique features of handheld devices, including their mobility, personalization and location-awareness engender new types of applications for mobile commerce, such as mobile advertising. Mobile marketing and advertising applications deliver promotional information to consumers based on their preferences and location. In this paper, we present SMMART, a context-aware, adaptive and personalized m-commerce application designed to deliver targeted promotions to the users of mobile devices about the products they like while guarding the users’ identity and protecting them from any unsolicited messages. Promotions distributed by SMMART are personalized by performing intelligent matching of the user’s shopping interests to current promotions available at a retail site. SMMART can adapt to changing preferences of its user by inconspicuously monitoring his or her shopping habits. We describe a fully functional prototype of SMMART built for Pocket PCs running Windows CE with .NET Compact Framework. This paper also presents a study demonstrating end-user usability and economic viability of SMMART.     

Cloning SIM Cards Usability Reduction in Mobile Networks

This paper studies the probability of using cloning subscriber identity module (SIM) cards in Universal Mobile Telecommunications Systems. It also explores how the mobile system can discover the cloning SIM cards as soon as possible and how to reduce the probability of using cloning SIM cards in mobile networks. The illegal mobile station attached to mobile networks can be detected by a Normal Location Area Update, a periodic area location update, and by outgoing calls that are issued from genuine mobiles. An analytical model is developed to investigate the effects of a location area update and outgoing calls issued by genuine mobiles on the use of illegal mobiles. Mobility management, such as registration, cancellation, and outgoing and incoming procedures for legal and illegal users are investigated and analysed. An analytical model to investigate the effect of outgoing call arrival rates, and location area residence time on the detected illegal user has been presented. This paper seeks to increase the security of communication by avoiding fraud of cloned mobile phones by proposing a solution to speed up the detection of cloning SIM cards.     

Understanding Situated Social Interactions: A Case Study of Public Places in the City

Ubiquitous and mobile computer technologies are increasingly being appropriated to facilitate people’s social life outside the work domain. Designing such social and collaborative technologies requires an understanding of peoples’ physical and social context, and the interplay between these and their situated interactions. In response, this paper addresses the challenge of informing design of mobile services for fostering social connections by using the concept of place for studying and understanding peoples’ social activities in a public built environment. We present a case study of social experience of a physical place providing an understanding of peoples’ situated social interactions in public places of the city derived through a grounded analysis of small groups of friends socialising out on the town. Informed by this, we describe the design and evaluation of a mobile prototype system facilitating sociality in the city by (1) allowing people to share places, (2) indexing to places, and (3) augmenting places.     

Tactful calling: investigating asymmetric social dilemmas in mobile communications

Recipients of phone calls face a constant dilemma between ignoring calls at the possible expense of offending the caller, missing business opportunities or neglecting family members on one hand; and answering them at the expense of interrupting their train of thought or appearing rude and impolite towards others with whom they share a social activity on the other hand. We studied people's attitudes regarding these dilemmas, with emphasis on their social aspects. In a cross-cultural study, conducted in Israel and in Germany, we surveyed both caller and recipient attitudes towards answering mobile phone calls in various circumstances. The study also assessed the aspects of providing contextual information about a call prior to it being answered, including types of information deemed most valuable. The results emphasise the importance of social norms in affecting respondents’ attitudes towards making or accepting phone calls regardless of role (caller or recipient), gender or culture. We also found that the norms in the physical context (e.g. being in a meeting) prevailed over norms in the virtual context (e.g. the phone call). Cultural and gender differences did not affect the degree to which people were frustrated by insufficient information regarding the other party's context. However, these factors did affect the suggested design solutions to this problem. The research provides insight into the social aspects of the problem of interruptive mobile phone calls and towards designing applications that help users maintain politeness while handling the caller–recipient dilemma.     

Knowledge Management in Locating the Patient in an Emergency Medical Service in Italy

This study examines an Emergency Medical Service in order to analyze the composite set of activities and instruments directed at locating the patient. The good management of information about the location of the emergency is highly relevant for a reliable rescue service, but this information depends on knowledge of the territory that is socially distributed between EMS operators and callers. Accordingly, the decision-making process often has to go beyond the emergency service protocols, engaging the operator in undertaking an open negotiation in order to transform the caller’s role from layman to “co-worker”. The patient’s location turns out to be an emerging phenomenon, collaborative work based on knowledge management involving two communities—the callers and the EMS operators—that overlap partially. Drawing examples from emergency calls, the study analyzes the practice of locating a patient as a complex and multi-layered process, highlighting the role played by new and old technologies (the information system and the paper maps) in this activity. We argue that CSCW technologies enable the blended use of different kinds of instruments and support an original interconnection between the professional localization systems and the public’s way of defining a position.     

位置隐私研究综述

近年来随着传感器和无线移动设备的飞速发展,随时随地获得个人位置成为可能。一方面,促进了基于位置服务的飞速发展,另一方面,个人位置隐私泄露的问题引起人们的广泛关注。由于移动环境中位置信息的特殊性,造成无法直接利用现有的关系数据库隐私保护技术。文章分析了位置隐私保护中存在的挑战问题,从系统结构、位置匿名技术和查询处理技术三方面归纳总结了现有的研究工作,并指出了未来的研究方向。     

A lightweight and distributed middleware to provide presence awareness in mobile ubiquitous systems

Several researchers have identified the need to count on presence awareness in ubiquitous systems that support mobile activities, particularly when these systems are used to perform loosely-coupled mobile work. In such a work style, mobile users conduct face-to-face on-demand interactions, therefore counting on awareness information about the position and availability of potential collaborators becomes mandatory for these applications. Most proposed solutions that provide user presence awareness involve centralized components, have reusability limitations, or simply address a part of that service. This article presents a lightweight and fully distributed middleware named Moware, which allows developers to embed presence awareness services in mobile ubiquitous systems in a simple way. The article also describes the Moware architecture, its main components and strategies used to deal with several aspects of the presence awareness support. These design strategies can be reused by software designers to provide presence awareness capabilities into middleware and specific software applications. Moware services were embedded in a mobile ubiquitous system that supports inspectors during the construction inspection process. The preliminary results indicate that the middleware was easy to use for developers, and its services were useful for the end-users.     

There is more to context than location

Context is a key issue in interaction between human and computer, describing the surrounding facts that add meaning. In mobile computing location is usually used to approximate context and to implement context-aware applications. We propose that ultra-mobile computing, characterized by devices that are operational and operated while on the move (e.g. PDAs, mobile phones, wearable computers), can significantly benefit from a wider notion of context. To structure the field we introduce a working model for context, discuss mechanisms to acquire context beyond location, and application of context-awareness in ultra-mobile computing. We investigate the utility of sensors for context-awareness and present two prototypical implementations — a light-sensitive display and an orientation-aware PDA interface. The concept is then extended to a model for sensor fusion to enable more sophisticated context recognition. Based on an implementation of the model an experiment is described and the feasibility of the approach is demonstrated. Further, we explore fusion of sensors for acquisition of information on more sophisticated contexts.     

Support for real-time decision making in mobile financial applications

Mobile users making real-time decisions based on current information need confidence that their context has been taken into consideration in producing the system’s recommendations. This chapter reviews current use of mobile technologies for context-aware real-time decision support. Specifically, it describes a framework for assessing the impact of mobility in decision making. The framework uses dynamic context model of data quality to represent uncertainties in the mobile decision-making environment. This framework can be used for developing visual interactive displays for communicating to the user relevant changes in data quality when working in mobile environments. As an illustration, this chapter proposes a real-time decision support procedure for on-the-spot assistance to the mobile consumer when choosing the best payment option to efficiently manage their budget. The proposed procedure is based on multi-attribute decision analysis, scenario reasoning, and a quality of data framework. The feasibility of the approach is demonstrated with a mobile decision-support system prototype implementation. This article is part of the “Handbook on Decision Support Systems” edited by Frada Burstein and Clyde W. Holsapple (2008) Springer.     

A Protocol for a Private Set-Operation

A new private set-operation problem is proposed. Suppose there are n parties with each owning a secret set. Let one of them, say P, be the leader, S be P＇s secret set, and t （less than n - 1） be a threshold value. For each element w of S, if w appears more than t times in the rest parties＇ sets, then P learns which parties＇ sets include w, otherwise P cannot know whether w appears in any party＇s set. For this problem, a secure protocol is proposed in the semi-honest model based on semantically secure homomorphic encryption scheme, secure sharing scheme, and the polynomial representation of sets. The protocol only needs constant rounds of communication.     

User needs for location-aware mobile services

Mobile contexts of use vary a lot, and may even be continuously changing during use. The context is much more than location, but its other elements are still difficult to identify or measure. Location information is becoming an integral part of different mobile devices. Current mobile services can be enhanced with location-aware features, thus providing the user with a smooth transition towards context-aware services. Potential application fields can be found in areas such as travel information, shopping, entertainment, event information and different mobile professions. This paper studies location-aware mobile services from the user's point of view. The paper draws conclusions about key issues related to user needs, based on user interviews, laboratory and field evaluations with users, and expert evaluations of location-aware services. The user needs are presented under five main themes: topical and comprehensive contents, smooth user interaction, personal and user-generated contents, seamless service entities and privacy issues.     

CoWSAMI: Interface-aware context gathering in ambient intelligence environments

In this paper we present CoWSAMI, a middleware infrastructure that enables context awareness in open ambient intelligence environments, consisting of mobile users and context sources that become dynamically available as the users move from one location to another. A central requirement in such dynamic scenarios is to be able to integrate new context sources and users at run-time. CoWSAMI exploits a novel approach towards this goal. The proposed approach is based on utilizing Web services as interfaces to context sources and dynamically updatable relational views for storing, aggregating and interpreting context. Context rules are employed to provide mappings that specify how to populate context relations, with respect to the different context sources that become dynamically available. An underlying context sources discovery mechanism is utilized to maintain context information up to date as context sources, and users get dynamically involved.     

The strategy of reducing the location update traffic using forwarding pointers in virtual layer architecture

The strategy of location updating is a critical issue for tracking the current locations of users in wireless networks. Especially when the mobile user is located near the boundaries of networks, the signaling traffic of the location updating will be excessively excited. In this paper, we shall propose a newly developed scheme for reducing both the location updating rate and location updating cost. The new scheme employs forwarding pointers in the virtual layer architecture. The forwarding pointer is a useful tool to get rid of the registrations at the HLR, and thus the location updating cost can be reduced. The virtual layer architecture is efficient in lowering the high updating rate of the current location when a user moves around the boundaries of the Location Area (LA). Our scheme can significantly reduce the location updating traffic.