Question

Difficulty: HardMobile Device Ports and Accessories

A field service technician is setting up smartphones for remote site inspectors who need to capture data using a specialized external USB Type-A digital sensor. The technician plugs the sensor into the smartphone's USB Type-C port using a passive USB Type-C to USB Type-A adapter. Although the adapter works correctly when connecting storage drives to a laptop, the smartphone fails to detect or power the sensor probe. Which of the following capabilities must be supported by the mobile device for this peripheral to function correctly?

  1. USB On-The-Go (USB OTG) capability to allow the mobile device to act as a USB host and supply bus power to connected peripherals.Answer
  2. B
    Thunderbolt 4 protocol controller support on the mobile device to establish PCIe tunnel communication with the external sensor.
  3. C
    Exchange ActiveSync background service enrollment to authorize hardware data streaming over the mobile physical interface.
  4. D
    Mobile Application Management (MAM) container enforcement to unlock physical USB connector data pins for unverified accessories.

Answer

The mobile device must support USB On-The-Go (USB OTG) to operate as a host and provide power to the external USB Type-A sensor.
Mobile devices typically operate as peripheral client devices when plugged into PCs. For a smartphone to communicate with and supply power to external accessories (such as keyboards, mice, flash drives, or specialized USB sensors), the mobile device must support USB On-The-Go (USB OTG). This feature enables the mobile device's port controller to function in host mode.

Step-by-Step Solution

1
Analyze the technical scenario and connection failure
The external sensor is a USB peripheral requiring a USB host controller and bus power to function, but smartphones operate by default as client peripherals when connected to computers.
Standard mobile USB controller behavior defaults to client mode for charging and file transfer unless host mode functionality is supported.
2
Evaluate the required mobile hardware/OS specification for hosting peripherals
USB On-The-Go (USB OTG) allows mobile ports to dynamically switch roles from client to host.
Without USB OTG support, the smartphone cannot initiate communication or supply power over the USB Type-C port to connected USB Type-A accessories.

Key Concept

USB On-The-Go (USB OTG) Host Mode Requirements
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