Serwis Infona wykorzystuje pliki cookies (ciasteczka). Są to wartości tekstowe, zapamiętywane przez przeglądarkę na urządzeniu użytkownika. Nasz serwis ma dostęp do tych wartości oraz wykorzystuje je do zapamiętania danych dotyczących użytkownika, takich jak np. ustawienia (typu widok ekranu, wybór języka interfejsu), zapamiętanie zalogowania. Korzystanie z serwisu Infona oznacza zgodę na zapis informacji i ich wykorzystanie dla celów korzytania z serwisu. Więcej informacji można znaleźć w Polityce prywatności oraz Regulaminie serwisu. Zamknięcie tego okienka potwierdza zapoznanie się z informacją o plikach cookies, akceptację polityki prywatności i regulaminu oraz sposobu wykorzystywania plików cookies w serwisie. Możesz zmienić ustawienia obsługi cookies w swojej przeglądarce.
The IEEE 802.11p is an emerging wireless protocol dedicated for Wireless Access in the Vehicular Environment (WAVE). It employs the Enhanced Distributed Channel Access (EDCA) mechanism to access the channel. Its objective is to provide differentiated services to vehicular networks which are delay-sensitive and requires high communication throughput. In this paper, we carry out comprehensive performance...
An analytical model for the reliability of a dedicated short-range communication (DSRC) control channel (CCH) to handle safety applications in vehicular ad hoc networks (VANETs) is proposed. Specifically, the model enables the determination of the probability of receiving status and safety messages from all vehicles within a transmitter's range and vehicles up to a certain distance, respectively....
In this paper, we propose a cooperative media access control (CMAC) protocol to improve the packet reception ratio and to reduce the average delay for multi-hop transmission. The proposed protocol shows better packet delivery ratio and less delay than the IEEE 802.11p MAC protocol for multi-hop transmission.
In this paper, we address the beacon congestion issue in Vehicular Ad Hoc Networks (VANETs) due to its devastating impact on the performance of ITS applications. The periodic beacon broadcast may consume a large part of the available bandwidth leading to an increasing number of collisions among MAC frames, especially in case of high vehicular density. This will severely affect the performance of the...
This paper presents a study of the Dedicated Short Range Communication (DSRC) Physical Layer in order to determine its reliability for Vehicle-2-Vehicle (V2V) communication under varying Signal-to-Noise Ratio (SNR), vehicle speed, delay spread, and packet lengths. In particular, we focus on computing the expected delay when packets with errors are retransmitted until received correctly. IEEE 802.11a...
Recently, IEEE 802.11p based vehicular communication has been widely studied in different area of vehicular applications. In this paper, we mainly focus on the automated guided vehicle (AGV) applications which have a strict communication requirement for very low transmission delay and very high reliability. However, CSMA-based 802.11p standard has problems with unbounded channel access delay and multiple...
Data dissemination is a key component of Infotainment and safety services in Vehicular Ad Hoc Networks. For infotainment services data dissemination starts from a Road Side Unit (RSU) and propagates to a multiplicity of On Board Units (OBU). A RSU typically can reach with a single hop only a fraction of the interested vehicles. Multi-hop, inter-vehicle communications is necessary to reach vehicles...
In recent years, Vehicle Ad Hoc Networks (VANETs) have become very popular. A typical VANET defines an intelligent way of using vehicular networking by integrating vehicular connections via a number of short-distance ad-hoc networking links, such as the IEEE802.11p. This type of system could provide effective communication between moving vehicles and fixed Road Side Units (RSUs), which are usually...
Since IEEE 802.11p has been adopted as Vehicular Ad hoc Networks (VANET) main technology, the research and development of vehicular safety applications has gained momentum. Because broadcasting is the predominant traffic type in VANETs, their safety applications will face a challenge in managing the channel capacity to insure good performance in terms of throughput, delay, fairness and broadcast coverage...
This paper proposes an implementation of systematic Raptor code in an ad hoc V2V (vehicular-to-vehicular) environment for post-crash safety broadcast. This is to address the latency problem caused by use of repetition code in a high speed vehicular environment for time-sensitive safety applications. The highly dynamic topology and challenging RF behavior of vehicular networks necessitate the use of...
We study the problem of multihop routing in vehicular ad hoc networks (VANET). IEEE 802.11p and other vehicular network standards advocate vehicles to issue periodic broadcast messages at regular intervals called beacons. Beacons include among other information geographic coordinates of the vehicle, heading, speed, etc. Thus, most VANET routing solutions in the literature use those beacons to know...
Cooperative active safety applications in WAVE employ periodic beacon broadcasting for status advertisement. High beacon rate enables each vehicle sense the traffic situation from its vicinity promptly. This timely information may assist the driver for safer driving experience. However, high beacon rate will congest the wireless medium due to the contention-based IEEE 802.11p MAC. In this paper, an...
Intelligent Transportation Systems (ITS) have been under development since the 80's as part of a global strategy for solving many of our modern life transportation problems. These systems enable people to reach their destinations in a safe, efficient, and comfortable way. In order to reach that goal, several radio access technologies (RAT) such as UMTS, WiFi, WiMAX and 5.9 GHz have been proposed for...
Road accidents and traffic jams are the most important problems on the roads. Wireless Access in Vehicular Environments (WAVE) can be used as preemptive and informational measure. WAVE builds multi-path communication between vehicles and infrastructure nodes, where nodes share emergency and other information. In this paper we analyze the delay of emergency message transmission in multi-hop link, based...
This paper proposes new MAC layer based back-off and retransmission strategies for throughput enhancement, in broadcast transmissions of inter vehicular communication. We present adaptive back off strategy which is based on the concept that there exists an optimum contention window (CW) period in a broadcast CSMA/CA system, given the fixed number of users. We also propose a simple probabilistic approach...
In recent years the research on Vehicular Ad Hoc Network (VANET) has been paid much attention due to the development of wireless network becoming mature, people think highly of traffic safety issue, the popularity of Global Positioning System (GPS), promising applications of VANET being exploited. However, VANET has the essential property of rapid change of large scale network topology. Besides, the...
In this paper, the effective channel usage is investigated in IEEE 802.11p WAVE (wireless access in vehicular environments) communication protocol. IEEE PI609 family is the standard for wireless access in vehicular environments based on IEEE 802.11p, and the WAVE architecture with multi-channel operation over CCH (control channel) and SCH (service channel) are defined in the MAC layer. However, there...
IEEE 802.11p is an emerging standard intended to support wireless access in the vehicular environment and to deliver both safety and non-safety applications to vehicles on the roads. Despite the numerous research works related to the design of reliable and timely dissemination of safety messages among vehicles, only a few works have investigated on-the-road delivery of non-safety data traffic, such...
The FCC has set apart a frequency band with the specific goal of improving safety and efficiency of the transportation system. Its purpose is to provide wireless communications between stations on the roadside and mobile radio units located on board of vehicles. The resulting technology is known as WAVE and is currently under development as draft standard IEEE 802.1 lp. The most time- critical messages,...
IEEE 802.11p is currently being developed international standard, which specifies physical (PHY) and medium access control (MAC) protocols for car-to-car and car-to-infrastructure communication and should become a basis for safety-related and infotainment applications in future vehicular ad-hoc networks (VANETs). In VANETs beaconing is one of the most important communication modes, which is used to...
Podaj zakres dat dla filtrowania wyświetlonych wyników. Możesz podać datę początkową, końcową lub obie daty. Daty możesz wpisać ręcznie lub wybrać za pomocą kalendarza.