10-05-2013, 02:18 PM
i need the source code in NS2 for safety Message broadcasting protocol for Vanet, please help me as soon as possible.[/font]
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ns2 source code for safety message broadcast protocol in vanet
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i need the source code in NS2 for safety Message broadcasting protocol for Vanet, please help me as soon as possible.[/font]
09-03-2016, 04:36 PM
i want to ns2 code for hidden terminal problem in vanet,so please help me.
10-03-2016, 03:16 PM
ns2 source code for safety message broadcast protocol in vanet
Abstract
Most safety-related applications targeting at Vehicular Ad-hoc Networks (VANETs) use Vehicle-to-Vehicle (V2V) broadcast method to disseminate safety-related information to all surrounding vehicles. However, the conventional broadcast schemes have the broadcast storm problem which can lead to unbearable transmission delay and packet loss. In this paper, we present an efficient broadcast scheme referred as Vehicular Multi-hop broadcasting Protocol (VMP) for fast dissemination of safety message within the critical area. The core of the VMP is that it designates multiple reliable forwarders with differentiated forwarding delay, and exploits cooperative forwarding mechanism to help the forwarding when the specified forwarders fail to transmit the alert message. With the realistic simulation studies, the VMP demonstrates better performance than previous contention-based schemes by reducing end-to-end delay and message rebroadcasting ratio while keeping high message reception rate.In vehicular ad hoc networks (VANETs), the medium access control (MAC) protocol is of great importance to provide time-critical safety applications. Contemporary multihop broadcast protocols in VANETs usually choose the farthest node in broadcast range as the forwarder to reduce the number of forwarding hops. However, in this paper, we demonstrate that the farthest forwarder may experience large contention delay in case of high vehicle density. We propose an IEEE 802.11-based multihop broadcast protocol VDF to address the issue of emergency message dissemination. To achieve the tradeoff between contention delay and forwarding hops, VDF adaptably chooses the forwarder according to the vehicle density. Simulation results show that, due to its ability to decrease the transmission collisions, the proposed protocol can provide significantly lower broadcast delay.
Introduction
During the last decade, the intelligent transportation systems (ITSs) have used advanced wireless communication technologies to enhance current road transportation systems. Most of ITS applications utilize vehicular ad hoc networks (VANETs) to provide the communications between vehicle-to-infrastructure (V2I) and vehicle-to-vehicle (V2V) [1]. As a kind of self-organizing wireless networks, VANET chooses the suitable candidate vehicle as the forwarder to accomplish the multihop data delivery.
The accident detection and avoidance by disseminating safety messages are considered as one of the most important services of VANETs. When accident happens, the safety message should be broadcasted through the following vehicles (namely, a platoon) covering a specific area of few kilometers [2–4]. Lowering the dissemination delay between the time of an accident event and the time at which all vehicles of the following platoon receive the emergency message, the probability of chain collisions can be reduced. Since the wireless transmission range is limited (about 250 m), the vehicles have to relay the safety messages by multihop broadcasting. In the case of accident, there exist two issues. The first is how to accomplish the multihop broadcasting in very tight message delivery time, typically few hundreds of milliseconds [5]. The second one is that the messages should be delivered to all vehicles with very high delivery reliability.
Due to the high mobility and restricted mobility patterns of vehicles, it is challenging work to design emergency message dissemination scheme with low delay and high reliability. Because the wireless channel is shared by all vehicles, the flooding broadcasting will lead to transmission contention and collision among neighboring vehicles, which degrades reliability and efficiency [6–8]. Many researchers have widely investigated the problem of disseminating safety messages in IEEE 802.11p protocol, which is MAC-layer standard in VANET [9]. Most of the proposed multihop broadcast protocols use the geographical information to avoid the broadcast storm problem. In these protocols, each vehicle is aware of its own position by the GPS devices. To reduce the number of forwarding hops in multihop broadcast, the farthest node in broadcast range is chosen as the forwarder. Consequently, the end-to-end broadcast delay is decreased.
In this paper, we use mathematical analysis and simulation results to demonstrate that, when the vehicle density is large, the farthest forwarder may experience large number of collisions, which bring about the high contention delay. Thus, we propose an efficient vehicle density based forwarding (VDF) protocol for safety message dissemination in multihop VANETs. The protocol adaptably chooses the forwarder according to the vehicle density to obtain the good tradeoff between contention delay and forwarding hops.
The remainder of this paper is organized as follows. In Section 2, we present a brief overview of the related broadcast protocols. To investigate the problem of current protocols in detail, the mathematical analysis and simulation results are given in Section 3. The proposed protocol is described in Section 4. Section 5 compares and analyzes the protocol performances by the NS2 simulations. Finally, we draw conclusions in Section 6.
Abstract
Most safety-related applications targeting at Vehicular Ad-hoc Networks (VANETs) use Vehicle-to-Vehicle (V2V) broadcast method to disseminate safety-related information to all surrounding vehicles. However, the conventional broadcast schemes have the broadcast storm problem which can lead to unbearable transmission delay and packet loss. In this paper, we present an efficient broadcast scheme referred as Vehicular Multi-hop broadcasting Protocol (VMP) for fast dissemination of safety message within the critical area. The core of the VMP is that it designates multiple reliable forwarders with differentiated forwarding delay, and exploits cooperative forwarding mechanism to help the forwarding when the specified forwarders fail to transmit the alert message. With the realistic simulation studies, the VMP demonstrates better performance than previous contention-based schemes by reducing end-to-end delay and message rebroadcasting ratio while keeping high message reception rate.In vehicular ad hoc networks (VANETs), the medium access control (MAC) protocol is of great importance to provide time-critical safety applications. Contemporary multihop broadcast protocols in VANETs usually choose the farthest node in broadcast range as the forwarder to reduce the number of forwarding hops. However, in this paper, we demonstrate that the farthest forwarder may experience large contention delay in case of high vehicle density. We propose an IEEE 802.11-based multihop broadcast protocol VDF to address the issue of emergency message dissemination. To achieve the tradeoff between contention delay and forwarding hops, VDF adaptably chooses the forwarder according to the vehicle density. Simulation results show that, due to its ability to decrease the transmission collisions, the proposed protocol can provide significantly lower broadcast delay.
Introduction
During the last decade, the intelligent transportation systems (ITSs) have used advanced wireless communication technologies to enhance current road transportation systems. Most of ITS applications utilize vehicular ad hoc networks (VANETs) to provide the communications between vehicle-to-infrastructure (V2I) and vehicle-to-vehicle (V2V) [1]. As a kind of self-organizing wireless networks, VANET chooses the suitable candidate vehicle as the forwarder to accomplish the multihop data delivery.
The accident detection and avoidance by disseminating safety messages are considered as one of the most important services of VANETs. When accident happens, the safety message should be broadcasted through the following vehicles (namely, a platoon) covering a specific area of few kilometers [2–4]. Lowering the dissemination delay between the time of an accident event and the time at which all vehicles of the following platoon receive the emergency message, the probability of chain collisions can be reduced. Since the wireless transmission range is limited (about 250 m), the vehicles have to relay the safety messages by multihop broadcasting. In the case of accident, there exist two issues. The first is how to accomplish the multihop broadcasting in very tight message delivery time, typically few hundreds of milliseconds [5]. The second one is that the messages should be delivered to all vehicles with very high delivery reliability.
Due to the high mobility and restricted mobility patterns of vehicles, it is challenging work to design emergency message dissemination scheme with low delay and high reliability. Because the wireless channel is shared by all vehicles, the flooding broadcasting will lead to transmission contention and collision among neighboring vehicles, which degrades reliability and efficiency [6–8]. Many researchers have widely investigated the problem of disseminating safety messages in IEEE 802.11p protocol, which is MAC-layer standard in VANET [9]. Most of the proposed multihop broadcast protocols use the geographical information to avoid the broadcast storm problem. In these protocols, each vehicle is aware of its own position by the GPS devices. To reduce the number of forwarding hops in multihop broadcast, the farthest node in broadcast range is chosen as the forwarder. Consequently, the end-to-end broadcast delay is decreased.
In this paper, we use mathematical analysis and simulation results to demonstrate that, when the vehicle density is large, the farthest forwarder may experience large number of collisions, which bring about the high contention delay. Thus, we propose an efficient vehicle density based forwarding (VDF) protocol for safety message dissemination in multihop VANETs. The protocol adaptably chooses the forwarder according to the vehicle density to obtain the good tradeoff between contention delay and forwarding hops.
The remainder of this paper is organized as follows. In Section 2, we present a brief overview of the related broadcast protocols. To investigate the problem of current protocols in detail, the mathematical analysis and simulation results are given in Section 3. The proposed protocol is described in Section 4. Section 5 compares and analyzes the protocol performances by the NS2 simulations. Finally, we draw conclusions in Section 6.
10-04-2016, 01:14 AM
can i get the source code of this. My email id is gupta.akash2107[at]gmail.com
I shall be highly obliged
I shall be highly obliged
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