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Wyszukujesz frazę "Gierlowski, K." wg kryterium: Autor


Wyświetlanie 1-5 z 5
Tytuł:
Ubiquity of Client Access in Heterogeneous Access Environment
Autorzy:
Gierłowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/308576.pdf
Data publikacji:
2014
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
handover
mesh networks
mobility
technological networks
ubiquitous access
wireless networks
Opis:
With popularization of mobile computing and diverse offer of mobile devices providing functionality comparable to personal computers, the necessity of providing network access for such users cannot be disputed. The requirement is further reinforced by emergence of general purpose mobile operating systems which provide their full functionality only with network connectivity available and popular XaaS (Everything as a Service) approach. In this situation and combined with the fact that most Internet-based services are able to function efficiently even in best effort environment, requirement of ubiquity of network access becomes one of the most important elements of today’s computing environment. This paper presents a general overview of the the vast group of mechanisms and technologies utilized in modern attempts to efficiently provide ubiquity on network access in heterogeneous environment of today’s access systems. It starts with division of users interested in ubiquitous network access into broad groups of common interest, complete with their basic requirements and access characteristics, followed by a survey of both already popular and new wireless technologies suitable to provide such access. Then a general discussion of most important challenges which must be addressed while attempting to fulfill the above goal is provided, addressing topics such as handover control and mobility management.
Źródło:
Journal of Telecommunications and Information Technology; 2014, 3; 3-16
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interworking and cross-layer service discovery extensions for IEEE 802.11s wireless mesh standard
Autorzy:
Gierłowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/307686.pdf
Data publikacji:
2013
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
802.11
cross-layer
interworking
mesh
wireless networks
Opis:
With the rapid popularization of mobile end-user electronic devices, wireless network technologies begin to play a crucial role as networks access technologies. While classic point-to-multipoint wireless access systems, based on fixed infrastructure of base stations providing access to clients, remain the main most popular solution, an increasing attention is devoted to wireless mesh systems, where each connecting client can extend overall resources of the network by becoming a network node capable of forwarding transit traffic. This ability results in severe reduction of the necessary network infrastructure, provides through coverage (thereby offering significant step towards ubiquity of network access) and offers massive redundancy. One of the most promising wireless mesh solutions currently being developed is an IEEE 802.11s standard, based on popular Wi-Fi technology. It combines low deployment costs with comprehensive suite of mechanisms able to operate a self-forming, autoconfigurable, dynamically extending, and secure mesh solution. However, despite its advantages, the standard lacks sufficient support for a number of functionalities, which can lead to significant inefficiency and degradation of service quality in real-world IEEE 802.11s network deployments. In the paper we propose a number of extensions of IEEE 802.11s mechanisms, designed to provide better service quality in case of real-world deployment scenarios, especially in case of large systems. Both propositions introduce modifications to mesh path discovery and interworking procedures, while retaining compatibility with standard solution. Their basic functionality and efficiency have been verified by means of simulation model in large-scale, self-organizing mesh structure. Subsequently they have been implemented and tested in real-world, access network testbed deployment. The results clearly indicate their utility, particularly in case of larger deployments of this network system type.
Źródło:
Journal of Telecommunications and Information Technology; 2013, 3; 97-105
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A hybrid-mesh solution for coverage issues in WiMAX metropolitan area networks
Autorzy:
Gierłowski, K.
Wodniak, J.
Nowicki, K.
Powiązania:
https://bibliotekanauki.pl/articles/308513.pdf
Data publikacji:
2008
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
IEEE 802.16
WiMAX
coverage
mesh
measurements
Opis:
The new WiMAX technology offers several advantages over the currently available (GSMor UMTS-based) solutions. It is a cost effective, evolving, and robust technology providing quality of service guarantees, high reliability, wide cov- erage and non-line-of-sight (NLOS) transmission capabilities. All these features make it particularly suitable for densely populated urban environments. In this paper we discuss the design and implementation difficulties concerning network coverage discovered in a test-bed implementation of WiMAX. We point out the presence of unexpected "white spots" in the coverage, which are not inherently characteristic of the WiMAX concept. As a possible remedy to this significant drawback of the otherwise very promising technology, we consider reconfigurable mesh organization of WiMAX base stations. We also suggest directions for further development of this kind of network operation, partly based on our practical experience. Despite the clear advantages of the mesh mode in WiMAX networks, its development is currently at an early stage, due to the high complexity of the necessary mechanisms. In this situation, we propose an original, much simpler solution: the so-called support-mesh mode.
Źródło:
Journal of Telecommunications and Information Technology; 2008, 1; 20-28
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
NetBaltic system – heterogeneous wireless network for maritime communications
Autorzy:
Hoeft, M.
Gierłowski, K.
Rak, J.
Woźniak, J.
Powiązania:
https://bibliotekanauki.pl/articles/260004.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
maritime communication systems
heterogeneous maritime network
mobility management
maritime mesh networks
delaytolerant networks
Opis:
In case of maritime communications, we observe a growing interest in deployment of multitask satellite-based solutions and development of new maritime-specific systems intended for improvements in safety of e-navigation. Analysis of different types of currently used maritime communication systems leads, however, to a conclusion that neither global and still very expensive satellite systems nor cheaper, but short-ranged transmission technologies can, on their own, fully meet the today’s expectations and quality requirements formulated for broadband maritime systems. This lack of reliable solutions, offering high throughput and ubiquitous availability of coverage to a wide audience at a relatively low price is one of the main barriers in a widespread implementation of e-navigation initiatives. This issue is addressed in the netBaltic project with the objective to design, deploy and validate in a real maritime environment a non-satellite wireless communication system enabling ship-to-ship and ship-to-shore information exchange via a multi-hop network composed of onshore base stations, maritime vessels and other transit elements such as buoys. In this paper, the idea of a heterogeneous wireless maritime system is presented. Details of the proposed netBaltic node architecture are described highlighting the solutions introduced in the project as a response to specific maritime communication requirements. Numerical results of communication area coverage are presented for four different scenarios utilizing different wireless transmission technologies. In particular, they indicate that when using appropriate wireless communication solutions, the number of vessels being able to connect to Internet is significantly increased as compared to traditional wireless systems (capable of one-hop communication) from 14% for short-range transmission technologies up to as high as 127% in case when relatively long-range transmission technologies are employed within the system.
Źródło:
Polish Maritime Research; 2018, 2; 14-26
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurements of QoS/QoE parameters for media streaming in a PMIPv6 testbed with 802.11 b/g/n WLANs
Autorzy:
Hoeft, M.
Gierlowski, K.
Gierszewski, T.
Konorski, J.
Nowicki, K.
Wozniak, J.
Powiązania:
https://bibliotekanauki.pl/articles/220593.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
media streaming
mobility
Proxy Mobile IPv6
IEEE 801.11
QoS/QoE
Opis:
The growing number of mobile devices and the increasing popularity of multimedia services result in a new challenge of providing mobility in access networks. The paper describes experimental research on media (audio and video) streaming in a mobile IEEE 802.11 b/g/n environment realizing network-based mobility. It is an approach to mobility that requires little or no modification of the mobile terminal. Assessment of relevant parameters has been conducted in an IPv6 testbed. During the tests, both Quality of Service (QoS) and Quality of Experience (QoE) parameters have been considered. Against the background of standard L3 and L2 handovers, an emerging mobility solution named Proxy Mobile IPv6 (PMIPv6) has been examined. Its advantages (L3 connectivity maintenance) and disadvantages (packet loss during handover) are emphasized based on the obtained results. Moreover, a new solution for handover optimization has been proposed. A handoff influence upon audio/video generation and transfer imperfections has been studied and found to be an interesting direction of future work.
Źródło:
Metrology and Measurement Systems; 2012, 19, 2; 283-294
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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