Wyniki wyszukiwania - Biblioteka Nauki

Ten serwis zostanie wyłączony 2025-02-11.

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

netBaltic System - heterogeneous wireless network for maritime communications

100%

Hoeft M. , Gierlowski K. , Rak J. , Wozniak J.

Polish Maritime Research

2018

tom 25

nr 2

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

Measurements of QoS/QoE parameters for media streaming in a PMIPv6 testbed with 802.11 b/g/n WLANs

75%

Hoeft M. , Gierlowski K. , Gierszewski T. , Konorski J. , Nowicki K. , Wozniak J.

Metrology and Measurement Systems

2012

tom Vol. 19, nr 2

283-294

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.