This paper gives results from Vehicle-to-Vehicle (V2V) communication field tests in a platoon consisting of four trucks. During these tests it was assumed that large vehicles such as trucks need multiple antennas to overcome shadowing and obstruction caused by the vehicle itself, trailers and other trucks in the platoon. Therefore, in the experiments the vehicles had one antenna in each side-view mirror, and each antenna was connected to an IEEE 802.11p radio transmitting at 5.9 GHz according to the ETSI ITS-G5 standard. The purpose of the tests was to estimate the V2V channel for trucks participating in a platoon and to investigate the potential of diversity for such cooperative application. Three communication schemes for diversity were evaluated: receive diversity, transmit diversity, and transmit in combination with receive diversity. Studies were performed for two different antenna configurations in three different environments (rural, highway and tunnel). © 2016 IEEE

In the coming years V2V communications will probably be mandated and vehicle OEMs strive to find business opportunities to finance its investments in V2V communications technology. For heavy vehicles, platooning can be this business opportunity, with the motivation for the fleet owners that platooning can decrease the fuel consumption by up to 15 % when driving in platoons. However, challenges still exists with respect to the quality and reliability of the V2V communications, which is essential in order to enable platooning in a safe way.

In this thesis, two proposals of improving the quality and reliability of V2V communications in a platooning scenario are presented. The first proposal is the Curvature Based Antenna Selection Method that utilize the curvature of the road in order to estimate which antenna have the highest probability of having line of sight conditions, hence highest probability of successful communication. The method assumes a platoon of heavy vehicles with one antenna mounted in each rear view mirror. It also assumes that the leading vehicle can estimate the yaw rate of the platoon in order to determine if it is turning or not. The second proposal include two message forwarding algorithms, the Reachability Matrix forwarding algorithm and the Data Age Dependent forwarding algorithm. Both algorithms utilize information on the preceding communication capability in order to estimate which node to choose as forwarding candidate. The Reachability Matrix Algorithm puts its focus on keeping the overhead low, while at the same time improve the information up-to-dateness. The Data Age Dependent algorithm instead puts its main focus on performance with respect to improving the information up-to-dateness, with the cost of higher overhead compared to the Reachability Matrix algorithm.

Both proposals show potential of improving the quality of the V2V communication in a platooning scenario. The first proposal, the antenna selection method, is able to maintain a Data Age deadline of 150 ms approximately twice as often as when selecting transmission antenna in a round robin fashion. For the second proposal, the Reachability Matrix Algorithm reduces the miss of a 0.2 s Data Age deadline in the communication between the first and the fourth vehicle in a platoon from 18 % to 11 %, while only increasing the number of sent messages from 40 to 48.5 per second compared to when only broadcast is used. The Data Age Dependent algorithm shows even better performance with respect to reducing the missing of the 0.2 s Data Age deadline, i.e., with a reduction from 18 % to 5 %.

In this paper, we compare a method for selecting transmission antenna based on road curvature to a method based on periodically alternating between left and right hand side transmission antennas. Both methods aim to improve the success rate for communication between participants in a platoon of vehicles. Moreover, we propose the data age metric for online use as input to the algorithm controlling the inter-vehicle distance in platooning, e.g. to decide appropriate gap between the vehicles depending on the V2V communication quality. The methods have been evaluated through V2V communication measurements performed using heavy duty vehicles on public highway. We show that, when using the curvature-based method, a 150 ms data age deadline is only missed approximately half as often compared to when periodically alternating between left and right hand side transmission antennas. The methods have also been compared for different antenna combinations. © 2015 IEEE

We propose a broadcast message forwarding algorithm for V2V communication in a platooning scenario for heavy duty trucks. The algorithm utilizes link information, which is piggybacked on the original data packet, to estimate which nodes are best suited to forward the packet. The aim is to reach all nodes in the platoon with as few forward messages as possible in order to avoid channel congestion. The algorithm is evaluated by simulation using real world V2V measurement data as input. We show that the algorithm performs almost as good as two ETSI standardized forwarding algorithms with respect to keeping the data age for the entire platoon at a low level. But when it comes to keeping the message intensity low, our algorithm outperforms the better of the ETSI algorithms by 35%.

In this paper we present a novel message forwarding algorithm, the reachability matrix algorithm, for V2V communication in a platooning scenario. The algorithm uses a communication quality estimate to determine appropriate forwarding candidates. We show that the algorithm achieve a higher reliability in the communication compared to only using broadcast but still keeping the message intensity at a low level. The reachability matrix algorithm can decrease the ratio of missing a data age limit of 0.2 seconds from 18% to 11%, a decrease of 40%, while increasing the message intensity by only 21% compared to only using broadcast. The evaluation has been performed through simulation using input from real-life V2V measurements on heavy duty trucks in a platooning scenario. © 2015 by IEEE