On the Performance of MultiPath TCP in Multihomed Vehicular Networks

Vehicular networks face critical connectivity challenges due to the high mobility of their mobile nodes. Multihomed configurations, supported by multiple radio access networks, such as IEEE 802.11p and 4G/5G, are used to complement the different communication ranges, eliminating situations with no connectivity between the vehicles and the infrastructure. On top of this path diversity, higher layer protocols, such as MultiPath Transmission Control Protocol (MPTCP), can be used not only to increase the overall channel capacity, but also to eliminate the effects of horizontal and/or vertical handovers, with the latest one being more critical than the first one.This work proposes and evaluates a solution to dynamically manage MPTCP subflows in multihomed and multiple technology vehicular networks. According to the wireless link conditions, MPTCP subflows are created and removed over the different logical connections between the vehicle and the IEEE 802.11p Roadside Units or the 5G gNodeB. Performance results, obtained through real-world experiments in a city-scale vehicular network, using vehicular network stacks and communication hardware, show that MPTCP can successfully transmit data simultaneously over multiple paths, even when the vehicle is constantly changing its point-of-attachment with the infrastructure. This way, the solution ensures continuous, stable and efficient communication, as well as it improves network performance by combining the different radio access networks.