62,396 research outputs found
Mobility Management in beyond 3G-Environments
Beyond 3G-environments are typically defined as environments that integrate different wireless and fixed access network technologies. In this paper, we address IP based Mobility Management (MM) in beyond 3G-environments with a focus on wireless access networks, motivated by the current trend of WiFi, GPRS, and UMTS networks. The GPRS and UMTS networks provide countrywide network access, while the WiFi networks provide network access in local areas such as city centres and airports. As a result, mobile end-users can be always on-line and connected to their preferred network(s), these network preferences are typically stored in a user profile. For example, an end-user who wishes to be connected with highest bandwidth could be connected to a WiFi network when available and fall back to GPRS when moving outside the hotspot area.\ud
In this paper, we consider a combination of MM for legacy services (like web browsing, telnet, etc.) using Mobile IP and multimedia services using SIP. We assume that the end-user makes use of multi-interface terminals with the capability of selecting one or more types of access networks\ud
based on preferences. For multimedia sessions, like VoIP or streaming video, we distinguish between changes in network access when the end-user is in a session or not in a session. If the end-user is not in a session, he or she needs to be able to start new sessions and receive invitations for new sessions. If the end-user is in a session, the session needs to be handed over to the new access network as seamless as possible from the perspective of the end-user. We propose an integrated but flexible solution to these problems that facilitates MM with a customizable transparency to applications and end-users
Cast together: inclusive and unobtrusive mobile interactions with a situated display
We describe our Cast Together prototype that demonstrates inclusive and unobtrusive mobile interactions with a situated display. The prototype consists of a mobile and web application, and a Google Chromecast connected to a situated display. An inclusive and unobtrusive experience is encouraged for co-located persons by sharing notifications on the display, allowing users to decide at a glance if an alert requires further attention, and sharing app launches provides others with insight into private smartphone interactions. Music and photo collections generated from social media profiles can project personalities without active engagement with a personal device. Profiles can be linked to physical objects with NFC tags, and the act of exploring collections can become a visible performance by explicitly scanning objects with the smartphone. Shared information can also be managed implicitly by hiding details when a user steps out of the room, or by reacting to a change of place. A user study with two colleagues in an office setting leads to initial insights with our Cast Together probe
Social Sensing of Floods in the UK
"Social sensing" is a form of crowd-sourcing that involves systematic
analysis of digital communications to detect real-world events. Here we
consider the use of social sensing for observing natural hazards. In
particular, we present a case study that uses data from a popular social media
platform (Twitter) to detect and locate flood events in the UK. In order to
improve data quality we apply a number of filters (timezone, simple text
filters and a naive Bayes `relevance' filter) to the data. We then use place
names in the user profile and message text to infer the location of the tweets.
These two steps remove most of the irrelevant tweets and yield orders of
magnitude more located tweets than we have by relying on geo-tagged data. We
demonstrate that high resolution social sensing of floods is feasible and we
can produce high-quality historical and real-time maps of floods using Twitter.Comment: 24 pages, 6 figure
Realising context-sensitive mobile messaging
Mobile technologies aim to assist people as they move from place to place going about their daily work and social routines. Established and very popular mobile technologies include short-text messages and multimedia messages with newer growing technologies including Bluetooth mobile data transfer protocols and mobile web access.Here we present new work which combines all of the above technologies to fulfil some of the predictions for future context aware messaging. We present a context sensitive mobile messaging system which derives context in the form of physical locations through location sensing and the co-location of people through Bluetooth familiarity
Sybil attacks against mobile users: friends and foes to the rescue
Collaborative applications for co-located mobile
users can be severely disrupted by a sybil attack to the point of
being unusable. Existing decentralized defences have largely been
designed for peer-to-peer networks but not for mobile networks.
That is why we propose a new decentralized defence for portable
devices and call it MobID. The idea is that a device manages two
small networks in which it stores information about the devices
it meets: its network of friends contains honest devices, and its
network of foes contains suspicious devices. By reasoning on these
two networks, the device is then able to determine whether
an unknown individual is carrying out a sybil attack or not.
We evaluate the extent to which MobID reduces the number
of interactions with sybil attackers and consequently enables
collaborative applications.We do so using real mobility and social
network data. We also assess computational and communication
costs of MobID on mobile phones
Third Party Tracking in the Mobile Ecosystem
Third party tracking allows companies to identify users and track their
behaviour across multiple digital services. This paper presents an empirical
study of the prevalence of third-party trackers on 959,000 apps from the US and
UK Google Play stores. We find that most apps contain third party tracking, and
the distribution of trackers is long-tailed with several highly dominant
trackers accounting for a large portion of the coverage. The extent of tracking
also differs between categories of apps; in particular, news apps and apps
targeted at children appear to be amongst the worst in terms of the number of
third party trackers associated with them. Third party tracking is also
revealed to be a highly trans-national phenomenon, with many trackers operating
in jurisdictions outside the EU. Based on these findings, we draw out some
significant legal compliance challenges facing the tracking industry.Comment: Corrected missing company info (Linkedin owned by Microsoft). Figures
for Microsoft and Linkedin re-calculated and added to Table
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