With the advancement of automotive intelligence and connectivity, in-vehicle infotainment (IVI) systems have evolved from simple radios and CD players into comprehensive information platforms integrating navigation, audio-visual entertainment, vehicle information, remote control, and internet services. In this evolution, stable, high-speed, and reliable wireless connectivity has become a core requirement. Ebyte, with its extensive WiFi module product line, provides diversified wireless connectivity solutions for in-vehicle IVI systems. This article will analyze WiFi module application cases and application guidelines in the automotive sector, using the E103 series WiFi module product solution as an example.

I. Wireless Connectivity Requirements and Challenges of In-Vehicle Infotainment System

Modern in-vehicle IVI systems place stringent requirements on wireless modules:

1. High Reliability

Vehicle operating environments are complex, requiring them to cope with challenges such as drastic temperature changes (industrial-grade standards of -40℃ to +85℃ are basic), electromagnetic interference, and continuous vibration. For example, in northern winters, the temperature at vehicle startup may drop as low as -30℃, while in southern summers, the interior temperature may reach over 70℃. This necessitates that the WiFi module maintain stable operation under extreme temperatures.

2. Fast Connection and Low Latency

Functions such as screen mirroring (e.g., CarPlay, Android Auto), online video streaming, and OTA upgrades require fast connection establishment and low-latency transmission. For example, CarPlay screen mirroring needs to transmit the phone screen content to the in-vehicle display in real time; a latency exceeding 100ms will significantly impact the user experience.

3. Multiple Protocols and High Integration

In addition to basic Wi-Fi connectivity, Bluetooth (BLE) is usually integrated for phone pairing, audio transmission, or low-power sensing. Some high-end models also require dual-band Wi-Fi to provide better bandwidth. For example, an in-vehicle IVI system may need to simultaneously connect to the phone via Bluetooth for audio playback and connect via Wi-Fi for online navigation and video playback.

4. Low Power Consumption and Security Management

Even in functions where the vehicle is off (e.g., remote status query, anti-theft), the module needs to maintain extremely low power consumption; at the same time, connection security (WPA2/WPA3 encryption) is crucial. For example, the remote status query function requires the module to remain in standby mode after the vehicle is off, with power consumption below 1mA to avoid draining the vehicle's battery.

5. Easy Development and Integration

The development cycle of in-vehicle systems is long, requiring modules to provide mature AT command sets, pass-through functions, or SDKs to lower the development threshold and accelerate product launch. For example, AT command sets allow developers to configure WiFi modules through simple serial port commands without needing in-depth knowledge of complex network protocols.

Ebyte's WiFi module product matrix precisely meets these needs at different levels.

II. Application Cases of E103 Series WiFi Modules in In-Vehicle Systems

Based on the technical characteristics of multiple models in the document, we can summarize the following typical application scenarios:

1. Low-Cost Basic Networking and Data Pass-Through (T-Box/Telematics Unit)

① Scenario Description: Used in in-vehicle T-Boxes or low-to-mid-range IVI hosts to upload vehicle status data (such as GPS location, fault codes, sensor data) to a cloud server via in-vehicle WiFi hotspots or external mobile hotspots, or to receive commands issued from the cloud.

② Core Requirements: High cost-effectiveness, industrial-grade temperature range, stable and reliable TCP/UDP/MQTT connections, and low power consumption.

③ Recommended Models and Basis

E103-W01 / E103-W05 Series: The document clearly states that they are based on the ESP8266EX or W600 chip, support STA/AP mode, and have a built-in complete TCP/IP protocol stack and AT command set, enabling rapid transparent transmission of serial port data to the WiFi network. Their high cost-performance ratio and mature ecosystem make them ideal for cost-sensitive, functionally demanding basic networking applications.

E103-W12 Series: Based on the Dialog DA16200 chip, designed specifically for ultra-low power consumption. The document emphasizes its "ultra-low power consumption" characteristic, which has significant advantages in scenarios where network connectivity must be maintained even after the vehicle is turned off to support functions such as remote wake-up and status reporting.

④ Operating Mode
The WiFi module acts as a STA, connecting to the hotspot created by the in-vehicle 4G/5G C-V2X module or the passenger's mobile hotspot, and then connects to the vehicle manufacturer's backend server in TCP Client mode to achieve data transparent transmission. For example, the T-Box can upload real-time data such as vehicle GPS location, speed, and fuel consumption to the cloud via its WiFi module, while simultaneously receiving remote control commands from the cloud, such as remotely starting the engine and turning on the air conditioning.

2. Dual-Band High-Speed Connectivity and Hotspot Sharing (High-End IVI Head Unit)

① Scenario Description: Used in high-end vehicle IVI head units, it acts as an in-vehicle WiFi hotspot (AP) to provide high-speed internet access for passengers' mobile phones, tablets, and other devices; simultaneously, it functions as a STA (Stationary Targeting Unit), connecting to external high-quality networks for high-definition map updates, online entertainment, etc.

② Core Requirements: Supports 2.4GHz & 5GHz dual-band, high throughput (supports 802.11ac and even ax), and the ability to handle multiple device connections simultaneously.

③ Recommended Models and Basis

E103-RTL8811CU / E103-RTL8812CU Series: The documentation clearly states that they support the IEEE 802.11b/g/n/ac protocol, operate in dual-band 2.4GHz and 5GHz, with a maximum speed of 433Mbps (RTL8812CU). Their USB 2.0 interface facilitates high-speed communication with the vehicle's main control chip, making them ideal as high-speed in-vehicle wireless network cards or hotspot modules.

E101-C5WN8 Series: Based on the ESP32-C5 chip, the documentation states that it supports the latest IEEE 802.11ax (WiFi 6) standard, also operating in dual-band. It supports OFDMA, MU-MIMO, and other technologies, better handling high-concurrency scenarios with multiple devices in the vehicle, providing a more efficient and stable network experience.

④ Operating Mode
The module operates in STA+AP mode. The STA side connects to an external network (such as a 5G CPE or high-quality home WiFi), while the AP side creates a WiFi network for use by in-vehicle passenger devices. For example, during long journeys, passengers can connect to the internet via the in-vehicle Wi-Fi hotspot to watch online videos, play games, etc., while the in-vehicle IVI head unit can connect to external networks via STA mode to update high-definition maps in real time and download online music.

3. Intelligent Bluetooth Network Configuration and Dual-Mode Interconnection

① Scenario Description: Simplifies the process of connecting the in-vehicle head unit to a new Wi-Fi network (such as connecting to home Wi-Fi after arriving home). Users no longer need to tediously enter passwords on the in-vehicle screen; instead, they can send the Wi-Fi password to the in-vehicle module via Bluetooth through a mobile app.

② Core Requirements: Integrates Wi-Fi and Bluetooth (BLE) dual-mode, supporting secure and convenient network configuration via BLE (SmartConfig or similar technology).

③ Recommended Models and Basis: E103-W14 Series: The documentation clearly states that this module supports the Bluetooth BLE 5.2 protocol, supporting simultaneous operation of the module as a STA and BLE slave. This means that the in-vehicle head unit can continuously broadcast via BLE. After the user's mobile app scans and connects, it can securely transmit the home Wi-Fi SSID and password to the module via the BLE channel, and the module then automatically connects to the Wi-Fi, greatly improving the user experience.

E103-W11: The document mentions that it is a Bluetooth Low Energy (BLE) 5.1 and Wi-Fi 6 module, also possessing dual-mode capability, suitable for vehicle models with requirements for power consumption and the latest protocols.

④ Workflow: After module initialization, BLE is in broadcast mode. The user's mobile app connects to the vehicle's BLE and sends network configuration information. Upon receiving this information, the module automatically switches to STA mode to connect to the designated Wi-Fi. For example, after arriving home, the user opens the mobile app, which automatically searches for the vehicle's BLE device. After the user clicks to connect, the app sends the home Wi-Fi's SSID and password to the vehicle module. The vehicle module automatically connects to the home Wi-Fi, achieving seamless integration between the vehicle and home networks.

4. In-vehicle Device Interconnection and Local Services (e.g., USB Dongle)

① Scenario Description: Used to connect wireless projection adapters, game controllers, or as a network hub for aftermarket entertainment systems to achieve high-speed local wireless interconnection between screens, speakers, and gaming devices.

② Core Requirements: Small size, plug-and-play USB interface, high bandwidth, low latency.

③ Recommended Models and Basis

E103-RTL8812CU (USB Interface Type): Its USB 2.0 interface is ideal for creating plug-and-play USB dongles, and dual-band AC support ensures low-latency transmission of high-definition video streaming and game control commands.

E103-W06 (Based on TI CC3235S): The documentation states that it supports both 2.4GHz and 5GHz dual-band, offering powerful functionality and suitability for integration into in-vehicle devices with high wireless connectivity requirements.

④ Application Examples
For example, users can plug a wireless projection adapter into the vehicle's USB port and wirelessly project their phone screen onto the vehicle's display via a WiFi module, achieving large-screen display of mobile phone content; game controllers can wirelessly connect to the in-vehicle IVI host via a WiFi module for wireless game control.

III. WiFi Module Selection Guide and Key Considerations

When selecting a WiFi module for an in-vehicle IVI system, the following approach can be followed:

1. Define Core Functions and Interfaces

For pure data upload (T-Box): Prioritize E103-W01/W05 (cost) or E103-W12 (power consumption).

For in-vehicle hotspot and high-speed internet access: Dual-band modules are essential, such as E103-RTL8811CU/RTL8812CU (mature AC solution) or E101-C5WN8 (cutting-edge AX solution).

For convenient network configuration and dual-mode applications: Choose a WiFi module with integrated BLE, such as E103-W14.

1. Main Control Integration and Development: If the automotive main control unit is a high-performance processor (such as the ARM Cortex-A series), it needs to connect to the WiFi chip via an SDIO/USB interface. Refer to models such as E103-RTL8189FTV (SDIO interface) in the documentation, or use modules like E101-C5WN8 that allow for secondary development for deep customization.

2. Strict Environmental Adaptability:

All automotive applications must select models with an operating temperature range of -40℃ ~ +85℃ or -20℃ ~ +70℃ (wide-temperature industrial grade) as specified in the documentation.

Note the power supply requirements (usually 3.3V), ensuring the automotive power supply design can meet its peak current (the documentation often recommends an external LDO power supply capacity greater than 500mA).

3. Protocols and Security:

Ensure the module supports WPA2/WPA3 encryption to meet automotive network security requirements.

According to the vehicle manufacturer's protocol requirements, confirm whether the module supports the required network protocols, such as TCP/UDP/MQTT/HTTP, etc.

4. Development Support

For projects requiring rapid mass production, transparent transmission modules using AT command control (such as the E103 series) can significantly shorten the development cycle.

For projects requiring deep customization of network protocols and deep integration with in-vehicle systems, modules that can be further developed (such as the E101 series based on ESP32-C3/C5/S3) offer greater flexibility.

IV. Summary and Outlook

The Ebyte E103 series WiFi modules offer a complete layout, ranging from high cost-effectiveness to high performance, from single-band to dual-band, from pure WiFi to WiFi+BLE dual-mode and WiFi MESH networking, providing a solid and diversified hardware foundation for the wireless and intelligent transformation of in-vehicle infotainment systems. Whether it's achieving basic vehicle networking, building a high-speed in-vehicle information hub, or creating a convenient and seamless intelligent interactive experience, corresponding solutions can be found.

As the intelligent cockpit evolves into a "third living space," the requirements for wireless connection bandwidth, real-time performance, reliability, and security will continue to increase. E-BIT's continuously iterating modules supporting WiFi 6/6E and even more advanced standards will help the next generation of in-vehicle IVI systems achieve more immersive audio-visual entertainment, smoother multi-screen interaction, and more reliable remote services, ultimately bringing users an excellent intelligent travel experience.