An Altruistic Prediction-Based Congestion Control for Strict Beaconing Requirements in Urban VANETs

Abstract

Periodic Beacon Messages are one of the building blocks that enable the operation of VANET applications. In vehicular networks environments, congestion and awareness control mechanisms are key for a reliable and efficient functioning of vehicular applications. In order to control the channel load, a reliable mechanism allowing real time measurements of parameters like the local density of vehicles is a must. These measurements can then serve as an input to perform a fast adaptation of the transmit parameters. In this context, considerable efforts have been directed in the recent years towards designing flexible yet robust protocols solving this problem; yet, very few have considered a proactive adaptation of the transmit parameters as a preventive measure from channel load peaks. To this end, we take the opportunity to introduce P&A-A, a new congestion control protocol that performs a joint adaptation of the transmit rate and power, relying on an altruistic short-term prediction algorithm that estimates the vehicular density around a given vehicle within the next short while. Additionally, P&A-A adapts the transmit parameters in a way that guarantees the strict beaconing requirements and satisfies the level of awareness required for the operation of most critical VANET applications. The results of the simulations performed in a realistic scenario justify our theoretical considerations and confirm the efficiency and the effectiveness of our protocol by showing significant improvements in terms of network performance (up to 8% and 14% improvement in collision rate; and up to 10% and 20% increase in busy ratio compared to our previous scheme and the ETSI schemes respectively) as well as the achieved level of awareness (higher coverage with higher transmission rate and power in dense scenarios, and up to 8% and 55% improvement in density perception accuracy compared to our previous scheme and the ETSI schemes respectively).

Toward a Standard-Compliant Implementation for Consensus Algorithms in Vehicular Networks

“…Since the performance of a consensus-based application is expected to increase when the vehicles density grows [8] the idea to use a consensus approach is particularly attractive in C-ITSs. However, the intensive rate of information exchange over the shared DSRC control channel naturally introduces significant communication overhead into the vehicular network [9]. In this section, our simulation study will show that frequent range information exchange has a significant impact not only on the reliability of communications but on the consensus algorithm performance as well.…”

Fair and stable joint beacon frequency and power control for connected vehicles

“…In [18] beacon adaptation mechanism is relied on three parameters, the local density of vehicles, the CBR and the collision rate that are computed by vehicles. The local density of vehicles is predicted for short horizon of 100 ms. Then, if any of the above parameters is not in a predefined range, the beaconing adaption is triggered.…”

“…To address the problem of channel congestion, several solutions based on adaption of beacon transmission parameters such as transmission frequency, power and bit rate have been proposed [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Many of these approaches just adapt one of the beacon transmission parameters, however, it is very likely that approaches that adapt more than one parameter are used in the future VANETs.…”

A Context-Aware Edge-Based VANET Communication Scheme for ITS

“…Since vehicles could be deployed in a high-density manner for some hours or some road segments, the number of concurrent sender nodes is expected to be large. IEEE 802.11p, the standard for wireless access in vehicular environments, has the performance degradation problem when the number of sender nodes increases due to the MAC layer contention scheme based on the exponential backoff [ 12 , 13 ]. However, this problem is not sufficiently considered in the design of routing protocols.…”

“…There have been many studies discussing the routing problem in VANETs [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. However, the unicast routing problem and broadcast problem have been discussed separately.…”