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Major applications of Vehicular Ad Hoc Networks (VANETs) are strongly related with safety applications like emergency warning, rescue operations, information about road conditions and accident alert. However, little attention has been given to the design of comfort applications with social approach, such as the connecting of people with common interests (like twitter or SMS services). Most of the...
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...
Emerging applications rely on wireless broadcast to disseminate time-critical information. For example, vehicular networks may exchange vehicle position and velocity information to enable safety applications. The number of nodes in one-hop communication range in such networks can be very large, leading to congestion and undesirable levels of packet collisions. Earlier work has examined such broadcasting...
Abstract-Simultaneous usage of multiple channels in vehicular ad-hoc networks (VANETS) has strong impacts on the communication range of the adjacent channel caused by adjacent channel interference (ACI). This is a big issue in dual radio environments where the distance between the interfering and receiving radio is low. To enhance the communication range on the service channel 2 (SCH2) while using...
In this paper a novel Medium Access Control (MAC) protocol for vehicular ad-hoc networks (VANETs) that uses the Dedicated Short Range Communication (DSRC) standards, is proposed. This protocol is a new Self-organized TDMA (STDMA) based MAC protocol with the ability of providing both reliable and real-time inter-vehicle communications, simultaneously. The proposed protocol takes advantage of both CSMA...
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...
Position messages will be the foundation for many emerging traffic safety applications based on wireless communications. These messages contain information about the vehicle's position, speed, direction, etc. and are broadcasted periodically by each vehicle. The upcoming IEEE 802.11p standard, intended for vehicle ad hoc networks (VANETs) has flaws caused by the unpredictable behavior of its medium...
In VANET, the researches based on the wireless LAN are conducting and the method based on 802.11a is being adapted in IEEE 802.11p WAVE (wireless access in vehicular environments). However, wireless LAN which uses a single channel in a competition can cause transmission delays because of a frequent collision and a use of CSMA/CA(carrier sense multiple access/collision avoidance) VANET(vehicle ad hoc...
The majority of vehicle-to-vehicle (V2V) protocols presented in the literature utilize a combination of controlled access techniques (e.g., TDMA, FDMA, CDMA) to provide prioritized access to the communication medium. While these protocols split the capacity of the communication link to support a maximum number of users with different priority levels, our work utilizes a combination of CDMA and TDMA...
Recently, in order to avoid traffic accidents, several studies using inter-vehicle communication have been proposed. This paper proposes a slot allocation protocol which allocates TDM slots based on location information of running vehicles. The proposed protocol allocates a slot for each coordinate in advance. To improve efficiency of slot utilization, each vehicle collects the location information...
In this paper, we investigate inter-vehicle networks offering an application of safety driving support. For appropriately evaluating the efficiency of inter-vehicle communication systems to support such an application, it is of paramount importance to make extensive evaluations under realistic accident model. In this paper, assuming realistic intersection collisions scenarios, we provide simulation...
Although the near-far effect has been considered to be the major issue preventing CDMA from being used in ad-hoc networks, in this paper, we show that the near-far effect is not a severe issue in inter-vehicle networks for safety driving support, where packet transmissions are performed in the broadcast manner. Indeed, the near-far effect provides extremely reliable transmissions between near nodes,...
In opportunistic routing the next relay is selected at each hop of each packet depending on the local pattern of simultaneous transmitters. The protocol considered in this paper assumes that at each hop, the optimal relay is chosen in a greedy way such that the packet receiver minimizes the remaining distance to the destination. The selection between potential relays is done using a logarithmic scale...
In this paper, improving DS/SS inter-vehicle communication using p-persistent CSMA MAC protocol is studied. It is possible for p-persistent CSMA to adapt optimally to current packet traffic situation by setting p to an appropriate value. Therefore, improvement of IVC performance is expected if optimal p value can be set according to the traffic of vehicles. In order to perform this, the scheme where...
In this paper the medium access control (MAC) method of the upcoming vehicular communication standard IEEE 802.11p has been simulated in a highway scenario with periodic broadcast of time-critical packets (so-called heartbeat messages) in a vehicle-to-vehicle situation. The 802.11p MAC method is based on carrier sense multiple access (CSMA) where nodes listen to the wireless channel before sending...
This paper describes how we can use existing mobile technology to track the vehicle. Here the embedded system along with the mobile is used to prevent the vehicle from being stolen and also if the vehicle is stolen then its location can be tracked. Mobile technology is the fastest growing communication mode. In todaypsilas mobile technology we all are acquainted with short message service (SMS). In...
Many real-time communication protocols have been studied to guarantee the communication requirements of distributed real-time systems. But, current techniques lack all or most of these requirements specially bounded message delivery time. In this paper we have proposed a Mac layer protocol called RDM+ with concepts similar to Round Data Mailer multi layer protocol. Our simulation results show that...
Video-streaming can now be offered on third-generation (3G) mobile networks. Most research efforts have focused on video download. This paper presents a detailed study of challenges faced for successfully deploying applications requiring life video upload. Both subjective and objective qualities as well as the effects of mobility are analyzed on real 3G networks. Consequently, video profiles are identified...
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