*6.1. Wireless-Enabled Technology for AEVs*

While embedding the highly autonomous features in a car to turn it into an autonomous vehicle, there must be a method of communication to interact with surrounding vehicles, and this communication is commonly known as vehicle-to-vehicle communication (V2V), whereas the communication in between vehicles and any infrastructure is known as vehicle-to-infrastructure (V2I). Moreover, there is vehicle-to-home (V2H) as well as V2P, which stands for vehicle-to-people communication. V2N is an acronym for vehicle-to-network. All of these protocols are illustrated in Figure 11.

**Figure 11.** Vehicle-to-everything (V2E) protocol illustration.

There are numerous ways to establish this contact, each having benefits and downsides of their own. Bluetooth, 5G, and Wi-Fi are well-known wireless communication technologies. Although these radio wave technologies may occasionally offer enough bandwidth for V2V and V2I communication, it is important to take into account circumstances where this is not possible. Examples include rural areas, urban areas with poor coverage, areas with high electromagnetic interference, indoor and underground spaces such as parking lots and tunnels, etc. Light Fidelity (Li-Fi), which uses visible and infrared light for data flow, is an alternative to radio wave communication. Professor Harald Haas coined the term "Li-Fi" for the first time in 2011 [123]. Using the light from a straightforward LED desk lamp, he demonstrated how data may be delivered in the direction of a photoreceiver. By adjusting the light radiation from currently installed lighting infrastructure, such as streetlights, automobile headlights, etc., this can be accomplished. A unidirectional or bidirectional communication link with a bandwidth that can produce a data rate up to 100 times greater than Wi-Fi can be established with the use of suitable photoreceivers [123].

Figure 12 shows the technical implementation of Li-Fi. By turning the current on and off, an electrical driver controls the brightness of the light generated by the transmitter of solid-state light sources such as an LED or a laser diode. Implementing Li-Fi is rather simple because solid-state lighting is becoming more and more common in infrastructure (road lighting, traffic signals, and vehicle head- and taillights). A completely new infrastructure must be constructed in comparison to similar systems employing traditional RF-based communication (such as dedicated short-range communications, or DSRC). Since a Li-Fi transmitter can be as basic as an LED light, current lighting systems could be converted to Li-Fi transmitters. Following that, it can serve as a hub for accessing information for both automobiles and other road users (pedestrians, bikes, etc.). This results in a low implementation cost and a large number of accessible access points. With minimal effort, the current "dumb" lighting infrastructure for roads may transform into a "smart" lighting infrastructure. However, as was previously mentioned, its implementation is still difficult. However, compared to alternatives, the expenses of implementation are cheaper.

**Figure 12.** Implementation of a Li-Fi downlink channel on a technological level.
