Traffic information, road works, dynamic speed adjustments, dangerous situations on the road are a state of the art of geo-referenced alert services in urban areas but often alerts information is not up-to-date or accurate and it does not strictly concern the part of road we are traveling on. Thanks to the fog/edge computing it is possible to distribute such traffic information in a targeted way to vehicles only if involved and relevant.
In the “Urban geo-referenced scenario” traffic information are typically provided by city traffic centers and distributed at the fog/edge of the network using brokers. Vehicles send its information (position, direction, current lane …) to brokers at fog/edge and, only if appropriate, vehicles receives traffic alerts in advance in order to avoid accidents or allow it to carry out the lane change maneuver in safety and comfort.
Geo-referenced warning messages can be provided to the vehicle ahead of the critical situations on the road and data exchange between broker and vehicles is typically based on C-V2X standard defined by 3GPP. C-V2X provides a messaging layer (CAM, DENM, IVIM) which relies on a PC5 or 802.11p communication layers, the message delivery through the mobile network is called V2N (Vehicle to Network) and can be supported using publish&subscribe protocols like the Advanced Message Queuing Protocol (AMQP). The AMQP protocol also guarantees full functional interoperability between vehicle, messaging middleware server and event producers. In the Fog scenarios those kinds of messages can be also sent in V2I (Vehicle to Infrastructure) mode by Road Side Units using a PC5 or 802.11p standards.
For V2X functionalities vehicles use 5G connectivity modules which sends a subscription request to the edge broker specifying the topics of interest and its location and receives alerts from the remote server generated for the area of interest. If the vehicle moves by changing its area of interest, it will send out another subscription request updating the topic with the new location. Specifically, the vehicle sends the broker not only a single position but a geographical format that identifies a rectangle of the earth’s surface calculated as a function of latitude, longitude and desired precision. When the local authority generates alerts that fall within this “detection area”, the vehicle receives a push message. Messages received by the communication module are processed and displayed in vehicles through the on-board user interface when the information relates to the vehicle’s trajectory.
Future connected vehicles pave the way for the development of numerous services in which the automotive industry and mobile networks play a vital role. Among these services, applications that manage information in real time by improving traffic safety and efficiency have a significant social and economic impact. This type of service shows how the 5G architecture is shifting the paradigm from the cloud to fog/edge computing and paving the way with its distributed solutions for the design of new, more performing services. The main advantages of maintaining data traffic and computing at the fog/edge are:
• Optimization of traffic data
• Reduction of latency in the exchange of messages
• Improvement of the scalability of connected services
In the future, such use cases can be implemented at city level enabling the distribution of dynamic and real-time information on board the vehicle to report all relevant traffic events in the vehicle’s trajectory horizon. Consequently, the expected benefits for citizens and the municipal administration are:
• The reduction of the risk of accidents caused by maneuvers carried out in critical situations.
• A new concept of dynamic traffic management for city events of any nature.
• The prevention of road congestion (for example in adverse weather conditions).
In this complex fog distributed scenario RAINBOW provides important enablers to manage, deploy and scale services with security and trust.