When a mobile device is connected to the car’s infotainment system over Bluetooth, an initial pairing process is initiated via the vehicle’s HMI (Human-Machine Interface). Once pairing is completed, the HFP (Hands-Free Profile), PBAP (Phone Book Access Profile), and MAP (Message Access Profile) are activated as a protocol bundle to enable call handling and contact management functionality. If the same device is selected as a music source, an additional protocol bundle is established: A2DP (Advanced Audio Distribution Profile) (vehicle as the A2DP sink) and AVRCP (Audio/Video Remote Control Profile) for non-iOS devices, or iAP2 (iPod Accessory Protocol 2) and AVRCP for iOS devices.

All protocol interactions are managed by the Bluetooth stack within the IVI, coordinating communication between the HMI, the TCU’s Bluetooth chip, and the connected device, enabling a seamless and integrated user experience for call handling, contact access, messaging, and media playback.

When a headset is connected to the infotainment system as an audio sink, the A2DP (Advanced Audio Distribution Profile) and AVRCP (Audio/Video Remote Control Profile) protocol bundle is established. In this use case, audio is streamed from the IVI to the headset via A2DP, while AVRCP enables playback and volume control directly from the headset. This functionality enhances in-car connectivity by allowing the co-driver to listen to media privately without distracting the driver, improving safety and convenience.

In addition to standard Bluetooth profiles, brand-specific protocols such as Apple CarPlay and Android Auto enable the infotainment system to act as an extension of the user’s smartphone. These systems use Bluetooth for initial handshake and USB or Wi-Fi (typically 5 GHz) for high-speed data transfer, allowing the smartphone’s interface to be mirrored on the IVI’s HMI. For wireless operation, the TCU (Telematics Control Unit) provides a 5 GHz hotspot to facilitate the connection.

Device management within the IVI layer oversees the full lifecycle of connected devices, enforcing system and user-defined policies, tracking active connections, and providing mechanisms to disconnect or remove paired devices. This ensures seamless, secure, and user-friendly management of in-car connectivity.

The Wi-Fi chip on the vehicle’s TCU can operate in both station mode and as an access point (AP), enabling a range of connected services. In AP mode, the TCU provides a Wi-Fi hotspot that allows devices inside the vehicle to access the internet. This APs also enable applications and services within the car to connect to external networks for navigation, streaming, software updates, and more.

All data traffic is routed through the TCU layer, which handles communication with the mobile network, ensuring reliable connectivity even while on the move. This architecture supports seamless integration of online services, enhancing the overall connected car experience

Given a vehicle’s multi-year lifetime, over-the-air (OTA) software updates are essential for maintaining functionality, security, and feature improvements. OTA updates are delivered as a specialized use case of the vehicle’s Wi-Fi capabilities. The update process is typically triggered by a backend server connection, after which update services running on the IVI or TCU manage the download and installation of new software versions. This ensures a seamless transition to updated system versions without user intervention, keeping the vehicle’s software up to date throughout its lifecycle.

Gaming controllers are increasingly popular in vehicles equipped with multiple displays, including co-passenger and rear seat entertainment screens. These controllers connect to the IVI over the HID (Human Interface Device) Bluetooth protocol, enabling direct interaction with gaming applications. Once paired, users can control games using handheld controllers, providing an enhanced and intuitive in-car gaming experience that complements the broader connected entertainment ecosystem.

Passenger safety is another critical area where connectivity plays a key role. Standards such as EU eCall, ERA-GLONASS, and other private SOS certifications require the vehicle’s TCU to support a range of safety features, the most important being the transmission of a Minimum Set of Data (MSD) containing essential information for emergency response. In an emergency, the vehicle’s status—consolidated by the TCU—is sent to the eCall center over the mobile network, either through an in-band channel embedded in a voice call or via a dedicated IMS (IP Multimedia Subsystem) service, ensuring timely assistance and improving occupant safety.

Another key function of in-vehicle connectivity is providing accurate position updates for navigation services. The GPS chip and GNSS receiver in the TCU connect to GNSS satellites to obtain precise positioning data. This data is used by the IVI for applications such as turn-by-turn navigation, enabling real-time route guidance and location-based services throughout the journey.