Vehicular CrowdSensing (VCS) is an emerging solution designed to remotely collect data from smart vehicles. It enables a dynamic and large-scale phenomena monitoring just by exploring the variety of technologies which have been embedded in modern cars. However, VCS applications might generate a huge amount of data traffic between vehicles and the remote monitoring center, which tends to overload the LTE networks. In this paper, we describe and analyze a gEo-clUstering approaCh for Lte vehIcular crowDsEnsing dAta offloadiNg (EUCLIDEAN). It takes advantage of opportunistic vehicle-to-vehicle (V2V) communications to support the VCS data upload process, preserving, as much as possible, the cellular network resources. In general, it is shown from the presented results that our proposal is a feasible and an effective scheme to reduce up to 92.98% of the global demand for LTE transmissions while performing vehicle-based sensing tasks in urban areas. The most encouraging results were perceived mainly under high-density conditions (i.e., above 125 vehicles/km2), where our solution provides the best benefits in terms of cellular network data offloading.

Several existing IP mobility solutions use invasive approaches, when adjustments in legacy protocols from the TCP/IP stack are necessary, or rely on specific network infrastructures. We devised an architecture to handle mobility using a Session-based Mobile Socket Layer (SMSL). With no need for software adaptation in the core of the network or adjustment on the TCP/IP stack, SMSL operates only at the end systems involved in the communication, being fully transparent to neighboring Transport and Application layers. The session scheme allows mobility awareness for TCP-based applications that require resilience to failures, delays, or disconnection. A general-purpose API extended from the Socket and implemented in GNU/Linux provides session services, such as tracking mobile peers, detecting disruptions, and suspending and resuming sessions with efficiency, security, and reliability. In this paper, we present the entire session support system as a mature work of research achieved with advances made in our previous study. The results of experiments in real and emulated test environments demonstrate efficiency. SMSL introduces little overhead, with a mean goodput degradation of 6.9% compared to an application implemented on top of the standard TCP/IP stack. Disruptions are detected in microseconds and suspended sessions resume in milliseconds for single-homed mobile nodes.

Current ubiquitous computing technologies provide access to customized, contextual, and location-based services. Device mobility, however, is frequently associated with communication delays, link disruptions due to signal loss, and changes in IP address. As a result, connection-oriented applications may fail and node location strategies should not rely on node addresses. In this paper, we propose the use of communication sessions to create mobility-aware applications that do not break with transmission delays or disruptions. The concept of these communication sessions is embedded in the basic network socket API functions and operates transparently with the applications. Sessions provide application level support to keep track of the location of peer nodes, to detect connection disruptions, and to suspend and resume transmissions. Experiments show our approach offers superior performance of the general IP layer mobility solution, with no need to implement or adapt software at the core network infrastructure.

This paper address the challenge of design a feasible social-based mechanism to manage wireless mobile connectivity. In a previous work, we proposed a methodology to share connectivity experiences among mobile users inside on-line social networks [11]. The aim was explore peoples social circles to enhance their wireless connectivity experiences e.g., QoS metrics such as: throughput, latency and signal quality. In this paper, details of the mashups, between wireless connectivity context data and location-based social media, are provided. We report how this data is handled using complex networks metrics e.g., vertex's strength and centrality degree, to identify high density handover areas, define the mobile users' reputation and to reveal the networks' coverage. Real experiments showed that collaboration can improve QoS metrics from ∼18 to ∼30% if compared to just use a mobility predictor or a modern operational system, respectively. The discussion unfolds with focus on the collaboration's efficiency as function of time, number of users, discovered area size and mobility patterns.

Wireless connectivity context data is composed by date, time, geographical localization, and QoS metrics, to cite the most common. These data are employed, in a particular way, by fundamental techniques for context-aware connectivity management, e.g. mobility predictors, handoff mechanisms and mobility management. For instance, mobility and QoS predictors use, as input, previous georeferenced network context data. Normally, context data are available in hardly updated databases with considerable size. In this paper, we propose a social-based methodology to allow mobile users collaborate to discover wireless connectivity islands. The methodology is composed by methods to gather, combine, summarize and share context data inside the users' social circles. We, also, designed a schema to mashup context data with location-based social media. It is result of a prototyping effort and we focus the discussion on its feasibility and limitations in terms of storage size, power consumption and QoS metrics.

The SOHand (Service Oriented Handover) architecture supports ubiquitous systems handovers, allowing the user to take control of the session and to migrate, transparently, between wireless technologies and providers (access and content ones). To ensure that the handovers will be done with no problems while users are using services, such architecture uses a set of ontologies called DOHand (Domain Ontology for Handovers). The ontologies will help the negotiation process between the different agents involved. Additionally, as users migrate in their daily duties and activities, they will eventually want to communicate with each other, in an ad-hoc way, to exchange information or to share device/network resources, such as memory, processing, email and bandwidth, in opportunistic ways in a strategy named PSN (Pocket Switched Network). Be it in an infra-structured or ad-hoc way, during the interactions the users need to have a good notion of risk and trust to their partners. They need to define privacy policies that must be negotiated between the parts during the inter-providers handovers; and they need to assess the potential of danger during an opportunistic exchange. In this paper, we describe PrOHand (Privacy Ontology for Handovers), which is an extension of DOHand privacy concept. PrOHand supports privacy policies management, handling information and services used by the SOHand users during infrastructured and PSN interactions. A case study is described in which PrOHand is instantiated for the haggle architecture.

Purpose This paper aims to show the difficulties involved in dealing with the quantity, diversity and the lack of semantics security information. It seeks to propose the use of ontologies to tackle the problem. Design/methodology/approach The paper describes the general methodology to create security ontologies and illustrates the case with the design and validation of two ontologies: system vulnerabilities and security incidents. Findings Two examples of ontologies, one related to systems vulnerability and the other related to security incidents (designed to illustrate this proposal) are described. The portability/reusability propriety is demonstrated, inferring that the information structured at lower levels (by security management tools and people) can be successfully used and understood at higher levels (by security governance tools and people). Research limitations/implications Work in the area of managing privacy policies, risk assessment and mitigation management, as well as CRM, business alignment and business intelligence, could be greatly eased by using an ontology to properly define the concepts involved in the area. Practical implications Ontologies can facilitate the interoperability among different security tools, creating a unique way to represent security data and allow the security data from any security tool (for instance, Snort) to be mapped into an ontology, such as the security incident one described in the paper. An example showing how the two ontologies could be plugged into a high level decision‐making system is described at the end. Originality/value Although several previous papers examined the value of using ontologies to represent security information, this one looks at their properties for a possible integrated use of management and governance tools.

Interactive video technology is meant to support user-interaction with video in scene objects associated with navigation in video segments and access to text-based metadata. Interactive TV is one of the most important applications of this area, which has required the development of standards, techniques and tools, such as MPEG-4 and MPEG-7, to create, to describe, to deliver and to present interactive content.In this scenario, the structure and organization of documents containing multimedia metadata play an important role. However, the Interactive TV documents structuring and organization has not been properly explored during the development of advanced Interactive TV services.This work presents a model to structure and to organize documents describing Interactive TV programs and its related media objects, as well as the links between them. This model gives support to represent contextual information, and makes possible to use relevant metadata information in order to implement advanced services like object-based searches, in- movie (scenes, frames, in-frame regions) navigation, and personalization. To demonstrate the functionalities of our model, we have developed an application which uses an Interactive TV program's documents descriptions to present information about in-frame video objects.

The paper examines the experience of Brazilian small and medium enterprises (SMEs) in relation to electronic commerce looking at the perceived barriers and catalysts to its adoption with focus on the socio-economic implications. The study combined quantitative and qualitative methods with the aim to gain detailed and in-depth knowledge of the experience of adopting e-commerce over time and to accompany the SMEs developments in the use and implementation of ICT. According to the participant SMEs, e-commerce is a reality that is here to stay and while the main drive behind its adoption was stated as being economic, it was pointed out that the social implications, mainly internal, were quicker to arise and be felt. The study also highlights the finding that the adoption of e-commerce at this early stage does not imply abandoning more traditional communications technologies such as the phone and the fax in favor of more modern ones such as the email. Instead, different functions seem to be attributed to the respective communication mediums allowing for their co-existence within the one business process.