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Diverse virtual social networks: Implications for remote software testing teams
This paper evaluates offshore outsourcing in the IT testing industry and determines what conditions determine its success. There is particular focus on the influence of diversity in teams on group relationships. Two studies are described: the first, investigated the perceptions of professional software testers on the critical factors of offshore outsourcing; and the second study looked at the ability for diverse teams to form close working relationships through virtual networks. We find that overt diversity factors inhibit interaction across nationality boundaries. The limitations of virtual networks for fostering personal communications is apparent in preventing group members from overcoming the initial aversion to mix with out-group members, which could be achieved with closer and more personal communications between members with different diversity factors in normal face to face communications. Where software testing teams are outsourced globaly, and must rely on virtual communications, there seems potential for significant difficulties in developing close working relationships, which on the one hand, can be negative for group cohesion, but one the other hand, can be positive for encouraging imparitality
On the Experimental Evaluation of Vehicular Networks: Issues, Requirements and Methodology Applied to a Real Use Case
One of the most challenging fields in vehicular communications has been the
experimental assessment of protocols and novel technologies. Researchers
usually tend to simulate vehicular scenarios and/or partially validate new
contributions in the area by using constrained testbeds and carrying out minor
tests. In this line, the present work reviews the issues that pioneers in the
area of vehicular communications and, in general, in telematics, have to deal
with if they want to perform a good evaluation campaign by real testing. The
key needs for a good experimental evaluation is the use of proper software
tools for gathering testing data, post-processing and generating relevant
figures of merit and, finally, properly showing the most important results. For
this reason, a key contribution of this paper is the presentation of an
evaluation environment called AnaVANET, which covers the previous needs. By
using this tool and presenting a reference case of study, a generic testing
methodology is described and applied. This way, the usage of the IPv6 protocol
over a vehicle-to-vehicle routing protocol, and supporting IETF-based network
mobility, is tested at the same time the main features of the AnaVANET system
are presented. This work contributes in laying the foundations for a proper
experimental evaluation of vehicular networks and will be useful for many
researchers in the area.Comment: in EAI Endorsed Transactions on Industrial Networks and Intelligent
Systems, 201
Usage of Network Simulators in Machine-Learning-Assisted 5G/6G Networks
Without any doubt, Machine Learning (ML) will be an important driver of
future communications due to its foreseen performance when applied to complex
problems. However, the application of ML to networking systems raises concerns
among network operators and other stakeholders, especially regarding
trustworthiness and reliability. In this paper, we devise the role of network
simulators for bridging the gap between ML and communications systems. In
particular, we present an architectural integration of simulators in ML-aware
networks for training, testing, and validating ML models before being applied
to the operative network. Moreover, we provide insights on the main challenges
resulting from this integration, and then give hints discussing how they can be
overcome. Finally, we illustrate the integration of network simulators into
ML-assisted communications through a proof-of-concept testbed implementation of
a residential Wi-Fi network
Cores of Cooperative Games in Information Theory
Cores of cooperative games are ubiquitous in information theory, and arise
most frequently in the characterization of fundamental limits in various
scenarios involving multiple users. Examples include classical settings in
network information theory such as Slepian-Wolf source coding and multiple
access channels, classical settings in statistics such as robust hypothesis
testing, and new settings at the intersection of networking and statistics such
as distributed estimation problems for sensor networks. Cooperative game theory
allows one to understand aspects of all of these problems from a fresh and
unifying perspective that treats users as players in a game, sometimes leading
to new insights. At the heart of these analyses are fundamental dualities that
have been long studied in the context of cooperative games; for information
theoretic purposes, these are dualities between information inequalities on the
one hand and properties of rate, capacity or other resource allocation regions
on the other.Comment: 12 pages, published at
http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/318704 in EURASIP
Journal on Wireless Communications and Networking, Special Issue on "Theory
and Applications in Multiuser/Multiterminal Communications", April 200
Interactive Real-Time Embedded Systems Education Infused with Applied Internet Telephony
The transition from traditional circuit-switched phone systems to modern packet-based Internet telephony networks demands tools to support Voice over Internet Protocol (VoIP) development. In this paper, we introduce the XinuPhone, an integrated hardware/software approach for educating users about VoIP technology on a real-time embedded platform. We propose modular course topics for design-oriented, hands-on laboratory exercises: filter design, timing, serial communications, interrupts and resource budgeting, network transmission, and system benchmarking. Our open-source software platform encourages development and testing of new CODECs alongside existing standards, unlike similar commercial solutions. Furthermore, the supporting hardware features inexpensive, readily available components designed specifically for educational and research users on a limited budget. The XinuPhone is especially good for experimenting with design trade-offs as well as interactions between real-time software and hardware components
An experiment in remote manufacturing using the advanced communications technology satellite
The goal of the completed project was to develop an experiment in remote manufacturing that would use the capabilities of the ACTS satellite. A set of possible experiments that could be performed using the Advanced Communications Technology Satellite (ACTS), and which would perform remote manufacturing using a laser cutter and an integrated circuit testing machine are described in detail. The proposed design is shown to be a feasible solution to the offered problem and it takes into consideration the constraints that were placed on the experiment. In addition, we have developed two more experiments that are included in this report: backup of rural telecommunication networks, and remote use of Synthetic Aperture Radar (SAR) data analysis for on-site collection of glacier scattering data in the Antarctic
A comparative investigation on the application and performance of Femtocell against Wi-Fi networks in an indoor environment
Due to the strenuous demands on the available spectrum and bandwidth, alongside the ever increasing rate at which data traffic is growing and the poor quality of experience QoE) faced with indoor communications, in order for cellular networks to remain dominant in areas pertaining to voice and data services, cellular service providers have to reform their marketing and service delivery strategies together with their overall network rchitecture. To accomplish this leap forward in performance, cellular service operators need to employ a network topology, which makes use of a mix of macrocells and small cells, effectively evolving the network, bringing it closer to the end-‐user. This investigation explores the use of small cell technology, specifically Femtocell technology in comparison to the already employed Wi-‐Fi technology as a viable solution to poor indoor communications.The performance evolution is done by comparing key areas in the
every day use of Internet communications. These include HTTP testing, RTP testing and VoIP testing. Results are explained and the modes of operation of both technologies are compared
LIS: Localization based on an intelligent distributed fuzzy system applied to a WSN
The localization of the sensor nodes is a fundamental problem in wireless sensor networks.
There are a lot of different kinds of solutions in the literature. Some of them use external
devices like GPS, while others use special hardware or implicit parameters in wireless
communications.
In applications like wildlife localization in a natural environment, where the power available
and the weight are big restrictions, the use of hungry energy devices like GPS or hardware
that add extra weight like mobile directional antenna is not a good solution.
Due to these reasons it would be better to use the localization’s implicit characteristics in
communications, such as connectivity, number of hops or RSSI. The measurement related
to these parameters are currently integrated in most radio devices. These measurement
techniques are based on the beacons’ transmissions between the devices.
In the current study, a novel tracking distributed method, called LIS, for localization of
the sensor nodes using moving devices in a network of static nodes, which have no additional
hardware requirements is proposed.
The position is obtained with the combination of two algorithms; one based on a local
node using a fuzzy system to obtain a partial solution and the other based on a centralized
method which merges all the partial solutions. The centralized algorithm is based on the
calculation of the centroid of the partial solutions.
Advantages of using fuzzy system versus the classical Centroid Localization (CL)
algorithm without fuzzy preprocessing are compared with an ad hoc simulator made for
testing localization algorithms.
With this simulator, it is demonstrated that the proposed method obtains less localization
errors and better accuracy than the centroid algorithm.Junta de Andalucía P07-TIC-0247
Simulation of Lunar Surface Communications Network Exploration Scenarios
Simulations and modeling of surface-based communications networks provides a rapid and cost effective means of requirement analysis, protocol assessments, and tradeoff studies. Robust testing in especially important for exploration systems, where the cost of deployment is high and systems cannot be easily replaced or repaired. However, simulation of the envisioned exploration networks cannot be achieved using commercial off the shelf network simulation software. Models for the nonstandard, non-COTS protocols used aboard space systems are not readily available. This paper will address the simulation of realistic scenarios representative of the activities which will take place on the surface of the Moon, including selection of candidate network architectures, and the development of an integrated simulation tool using OPNET modeler capable of faithfully modeling those communications scenarios in the variable delay, dynamic surface environments. Scenarios for exploration missions, OPNET development, limitations, and simulations results will be provided and discussed
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