Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "cellular systems" wg kryterium: Wszystkie pola


Wyświetlanie 1-2 z 2
Tytuł:
A Hybrid Extension for IP Multicasting in Push-to-talk over Cellular Systems
Autorzy:
Gębarowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/226638.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Push To Talk (PTT)
PoC
OMA PoC
PTT
IMS
SIP
RTP
IP Multicasting
VoIP
Opis:
OMA Push-to-talk over Cellular (abbr. PoC or PTT) as an IP-based service can be considered the first Voice-over-IP technology delivered in a broad manner in cellular networks world wide. Two key differences between PoC and regular voice communication systems are its half-duplex nature, which converts it into 'walkie-talkie' style of service and ability to establish group sessions between large groups of participants. As a matter of fact, majority of available PoC solutions are inefficient in handling groups of large size because they rely on IP unicasting for delivering media streams. This introduces not only redundancy and greater packet loss, but also increases computational and transmission effort. This paper proposes a hybrid IP multicasting extension for Push-to-talk technology allowing to reduce group size limitation significantly and increase the performance of large scale Push-to-talk systems. The proposed enhancement is elaborated and verified basing on an automatic testing framework feedback and some statistical measurements.
Źródło:
International Journal of Electronics and Telecommunications; 2012, 58, 1; 77-83
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the Impact of Transient Disturbances on Railway Signaling Systems Using an Adapted Time-Frequency Analysis Method
Autorzy:
Kousri, M. R.
Deniau, V.
Heddebaut, M.
Baranowski, S.
Powiązania:
https://bibliotekanauki.pl/articles/226198.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
EMC
railways
signaling
transient disturbances
transient detection
cellular radio
bit error rate
Opis:
As many other industrial environments, the railway electromagnetic environment is characterized by a large number of electromagnetic signals and disturbances. Among these, transient signals, with high energy level and wide frequency spectrum, represent an important threat to different signaling subsystems. In this paper, a new methodology dedicated to the detection and the characterization of the transient disturbances is presented. Based on a flexible and adjustable time-frequency analysis, this methodology is used to evaluate the impact of transient disturbances on a ground-to-train radio communication. A test bench was developed in order to validate the results of this evaluation.
Źródło:
International Journal of Electronics and Telecommunications; 2017, 63, 4; 347-354
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies