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Oulasvirta A.,Aalto University | Lehtonen E.,Aalto University | Kurvinen E.,Elisa Corporation | Raento M.,Google
Personal and Ubiquitous Computing | Year: 2010

Microblogging is a "Mobile Web 2.0" service category that enables brief blog-like postings from mobile terminals and PCs to the World Wide Web. To shed light on microblogging as a communication genre, we report on multiple analyses of data from the first 10 months of a service called Jaiku. The main finding is that microblogging centers on selective, I-centered disclosure of current activities and experiences, making daily experiences visible for others. The high frequency of brief and mundane status updates, like "working," may be a second-order effect resulting from posting becoming a routine executed to keep the audience interested. The results highlight the importance of reciprocal activity and feedback in users' motivation to invest in this activity. © 2009 Springer-Verlag London Limited. Source


Silvola R.,Elisa Corporation | Jaaskelainen O.,University of Oulu | Kropsu-Vehkapera H.,University of Oulu | Haapasalo H.,University of Oulu
Industrial Management and Data Systems | Year: 2011

Purpose - This paper aims to provide a framework of the multidimensional concept of one master data. Preconditions required for successful one master data implementation and usage in large high-tech companies are presented and related current challenges companies have today are identified. Design/methodology/approach - This paper is qualitative in nature. First, literature was studied to find out the elements of one master data. Second, an interview study was carried out in eight high-tech companies and in three expert companies. Findings - One master data management framework is the composition of data, processes and information systems. Accordingly, the key challenges related to the data are that the definitions of master data are unclear and overall data quality is poor. Challenges on processes related to managing master data are inadequately defined data ownership, incoherent data management practices and lack of continuous data quality practices. Integrations between applications are fundamental challenge to tackle when constructing an holistic one master data. Research limitations/implications - Studied companies are vanguards in the area of master data management (MDM), providing good views on topical issues in large companies. This study offers a general view of the topic but not describes special company situations as companies need to adapt the presented concepts for their specific case. Significant implication for future research is that MDM can no more be classified and discussed as only an IT problem but it is a managerial challenge which requires structural changes on mindset how issues are handled. Practical implications - This paper provides a better understanding over the issues which are impacting on the implementation of one master data. The preconditions of implementing and executing one master data are: an organization wide and defined data model; clear data ownership definitions; pro-active data quality surveillance; data friendly company culture; the clear definitions of roles and responsibilities; organizational structure that supports data processes; clear data process definitions; support from the managerial level; and information systems that utilize the unified data model. The list of preconditions is wide and it also describes the incoherence of current understanding about MDM. This list helps business managers to understand the extent of the concept and to see that master data management is not only an IT issue. Originality/value - The existing practical research on master data management is limited and, for example, the general challenges have not been reported earlier. This paper offers practical research on one master data. The obtained results illustrates the extent of the topic and the fact that business relevant data management is not only an IT (application) issue but requires understanding of the data, its utilization in organization and supporting practices such as data ownership. Copyright © 2011 Emerald Group Publishing Limited. All rights reserved. Source


Yunas S.,Tampere University of Technology | Valkama M.,Tampere University of Technology | Niemela J.,Elisa Corporation
IEEE Communications Magazine | Year: 2015

To tackle the 1000× mobile data challenge, the research towards the 5th generation of mobile cellular networks is currently ongoing. One clear enabler toward substantially improved network area capacities is the increasing level of network densification at different layers of the overall heterogeneous radio access system. Ultra-dense deployments, or DenseNets, seek to take network densification to a whole new level, where extreme spatial reuse is deployed. This article looks into DenseNets from the perspectives of different deployment strategies, covering the densification of the classical macro layer, extremely dense indoor femto layer, as well as outdoor distributed antenna system (DAS), which can be dynamically configured as a single microcell or multiple independent microcells. Also, the potential of a new indoor-to-outdoor service provisioning paradigm is examined. The different deployment solutions are analyzed from the network area spectral and network energy efficiency perspectives, with extreme densification levels, including both indoor and outdoor use scenarios. The obtained results indicate that dedicated indoor solutions with densely deployed femtocells are much more spectrumand energy-efficient approaches to address the enormous indoor capacity demands compared to densifying the outdoor macro layer, when the systems are pushed to their capacity limits. Furthermore, the dynamic outdoor DAS concept offers an efficient and capacity-adaptive solution to provide outdoor capacity, on demand, in urban areas. © 2015 IEEE. Source


Yunas S.F.,Tampere University of Technology | Valkama M.,Tampere University of Technology | Niemela J.,Elisa Corporation
International Journal of Wireless Information Networks | Year: 2015

In order to support anywhere and anytime services of Beyond 4G networks, new deployment solutions will be required that can cost-effectively address the capacity demand of the future and also offer consistently high bit rates and decent quality of service throughout the network coverage area. In this article we look into an advanced outdoor distributed antenna system (DAS) concept, dynamic DAS, that offers on-demand outdoor capacity in urban areas by dynamically configuring the remote antenna units to either act as individual small cells or distributed nodes of a common central cell. The performance of the investigated DAS solution is evaluated and compared with legacy macrocellular deployment in a dense urban environment. Furthermore, the analysis covers the performance evaluation, mainly from an outdoor perspective. The obtained results indicate superior performance of dynamic DAS concept in terms of coverage and SINR, network capacity and cost-efficiency as compared to legacy macrocellular network deployments. © 2015, Springer Science+Business Media New York. Source


Yunas S.F.,Tampere University of Technology | Niemela J.,Tampere University of Technology | Niemela J.,Elisa Corporation | Valkama M.,Tampere University of Technology | Isotalo T.,Tampere University of Technology
Proceedings - Conference on Local Computer Networks, LCN | Year: 2014

Network densification has been identified as one key enabling technology to address the 1000x mobile data challenge. This article analyzes network densification from the different deployment options perspective by looking into three mainstream technologies; Macrocells, Microcells, and Femtocells. The technologies are evaluated in a suburban neighborhood with modern residential houses. As majority of the data traffic in the network is believed to be generated by indoor users, we make a techno-economic analysis and comparison of the different deployment strategies from the indoor local area service provisioning viewpoint. Results show superior performance of low power indoor femtocell based deployment solutions in terms of coverage, capacity, energy and cost efficiency as compared to the outdoor solutions. Densifying the traditional pure Macro or Micro layers does provide improvement in the indoor coverage levels, however, due to the closer proximity of the co-channel interfering sites, the achievable capacity in the indoor environment deteriorates, which in turn also affects the energy and cost efficiency. These findings strongly motivate towards ultra dense deployments, based on indoor femtocell solutions, for addressing the local area capacity needs of the emerging future 5G networks. © 2014 IEEE. Source

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