Search results for "Computer network"
showing 10 items of 1634 documents
The influence of dataset size on the performance of cell outage detection approach in LTE-A networks
2015
The configuration and maintenance of constantly evolving mobile cellular networks are getting more and more complex and hence expensive. Self-Organizing Networks (SON) concept is an umbrella term for the set of automated solutions for network operations proposed by 3rd Generation Partnership Project (3GPP) group. Automated cell outage detection is one of the components of SON functionality. In early studies our research group developed data-driven approach for the detection of malfunctioning cells. In this paper we investigate the performance of the proposed solution as a function of the density of active users and the size of observation interval. The evaluation is conducted in Long Term E…
Towards proactive context-aware self-healing for 5G networks
2017
In this paper, we suggest a new research direction and a future vision for Self-Healing (SH) in Self-Organizing Networks (SONs). The problem we wish to solve is that traditional SH solutions may not be sufficient for the future needs of cellular network management because of their reactive nature, i.e., they start recovering after detecting already occurred faults instead of preparing for possible future faults in a pre-emptive manner. The detection delays are especially problematic with regard to the zero latency requirements of 5G networks. To address this problem, existing SONs need to be upgraded from reactive to proactive response. One of the dimensions in SH research is to employ more…
Multi-hop D2D Communications with Network Coding : From A Performance Perspective
2019
Multi-hop device-to-device (D2D) communications play an important role in expanding D2D coverage. In this paper, we study a relay-based and network-coding-assisted (in particular, XOR coding) multi-hop D2D communication system. In the system, toward jointly considering the impact of interference and network traffic conditions on the quality of D2D communications, various channel fading models and traffic models are investigated, and the packet loss probability of D2D links is meticulously computed using these models. With the packet loss probability of D2D links, the general closed-form expressions of end-to-end packet loss probability (E2EPLP) of the system with the presence (or absence) o…
Performance of an asymmetric and asynchronous decode-and-forward FBMC relay system
2014
End-to-end link performance of an asymmetric and asynchronous dual-hop decode-and-forward (DF) relay system built up using a causal multirate filter bank multicarrier (FBMC) technique operated under Rayleigh fading is presented. Three main performance measures namely bit error rate (BER), outage probability and channel capacity are used for this evaluation and approximate closed-form expressions for them are also made available. FBMC setup is modeled in exact form without any approximations while customizing to one of the most efficient subcarrier filter. Simulations are carried out in quasi-static multipath fading channels under symmetric, asymmetric, synchronous and asynchronous condition…
Performance of Lead-Acid Batteries with Nanostructured Electrodes at Different Temperature
2018
In this work we present innovative lead-acid batteries with nanostructured electrodes, which are cycled in a wide range of temperatures typically of lead-acid commercial batteries (EN 61427-1: 2013). In comparison to parameters usually used to commercial batteries, much more stressful conditions in terms of cut-off, charge/discharge rate and discharge were imposed.
On Temporal Aspects in Cross-Cultural e-Collaboration Between Finland and Japan Research Teams
2018
Time is an essential dimension in cross-cultural e-collaboration among research project teams. Understanding temporal aspects and project dynamics in cross-cultural research e-collaboration and related processes can improve team members' skills in cross-cultural communication and increase their cultural competence. The present case cultures are Finnish and Japanese, and the case universities are the University of Jyväskylä (Finland) and Keio University (Japan). Three issues are addressed in this article. First, cultural dimensions and time models in the cross-cultural e-collaboration context are discussed. Second, temporal aspects related to e-collaboration activities are introduced. Third,…
Interactive Tools for the Preservation, Dissemination and Study of Silk Heritage—An Introduction to the SILKNOW Project
2018
Silk was a major factor for progress in Europe, mostly along the Western Silk Road’s network of production and market centers. The silk trade also allowed for the exchange of ideas and innovations, having impacts at economic, technical, functional, cultural and symbolic levels. However, silk has today become a seriously endangered heritage. Although many European specialized museums are devoted to its preservation, they usually lack the size and resources to take advantage of state-of-the-art digital technologies. The aim of this paper is twofold; firstly, we introduce SILKNOW, an interdisciplinary project that has been recently funded by the H2020 Programme of the European Union in order t…
Smart Wireless Sensor Networks and Biometric Authentication for Real Time Traffic Light Junctions Management
2013
The main challenge of intelligent transportation systems (ITS) is to deal with ‘real-time’ information to improve vehicular traffic management. Road data can be processed and used for dynamic traffic light management in order to reduce waiting times in queues. This paper proposes an innovative distributed architecture based on a wireless sensor network (WSN) with a network coordinator providing remote and ubiquitous authentication module for managing unexpected events. The architecture is completed by a dynamic module for street priority management depending on traffic rate. Many experimental trials have been carried out considering three different levels of traffic intensity to prove the e…
On the effects of transmit power control on the energy consumption of WiFi network cards
2009
Transmit power control has been largely proposed as a solution to improve the performance of packet radio systems in terms of increased throughput, spatial reuse and battery lifetime for mobile terminals. However, the benefits of transmit power control schemes on these different performance figures may strongly depend on the employed PHY technology and channel access mechanism. In this paper, we focus on the effects of power control on the energy consumption of WiFi network cards. By means of several experimental tests carried out under different operation conditions and modulation schemes, we try to justify why the reduction of the transmission power has a marginal effect on the overall en…
Dealing with viewers’ complaints: Role, visibility and transparency of PSB Ombudsmen in ten European countries
2017
The article shows the results of a comparative analysis of the complaints management mechanisms offered by ten European Public Service Broadcasting (PSB) systems on their corporate websites. Using a qualitative methodology, it maps the procedures and evaluates the visibility, transparency and dissemination of results. The findings show, firstly, great diversity in terms of responsible election and management, despite the converging media governance. Also noteworthy is the margin of substantial improvement in the transparency and dissemination possibilities, specially relating to the interaction offered by the digital environment. Among the ten public corporations analysed, the BBC is the be…