Optical Camera Communication (OCC): Advantages and Disadvantages

This article explores the pros and cons of Optical Camera Communication (OCC), providing a comprehensive overview of its technology and applications.

What is Optical Camera Communication (OCC)?

Optical Camera Communication (OCC) is a technology that utilizes devices equipped with a flash and a camera as a transceiver pair. Most modern devices come with front and/or rear cameras along with LED flashes, making them suitable for OCC implementation.

OCC systems function through the use of LEDs, displays, or other light sources as transmitters, and a camera (or Image Sensor - IS) as the receiving module.

Key features of OCC include:

• Frequency Usage: Employs both infrared (IR) and Visual Light (VL) frequencies.
• Transmitter Flexibility: Can utilize only LEDs, unlike VLC systems which use both LEDs and Laser Diodes.
• Receiver Type: Uses a camera (or IS) as the receiver.

Image showing the Optical Camera Communication setup

How OCC Works

As illustrated in the image above, data transmitted from multiple LED transmitters can be easily captured and differentiated simultaneously by the Image Sensor (IS).

Background noise sources like sunlight, ambient light, and digital signage can be filtered out by isolating the pixels associated with these noise sources. This allows the IS to provide secure, interference-free, and reliable communication, even in outdoor environments.

Applications of OCC

OCC has a wide range of potential applications, including:

• V2X (Vehicle-to-Everything) communication
• Indoor positioning
• Digital Signage
• Drone-to-drone communication
• Augmented Reality/Virtual Reality
• Motion detection and recognition
• Data sharing

Benefits (Advantages) of OCC

Here are some of the key advantages of using Optical Camera Communication:

• Non-Interference: OCC provides a non-interference-based communication link because it uses an Image Sensor. The sensor utilizes a large number of pixels, allowing for almost perfect separation of light from different sources. Optical signals are derived separately from each pixel, preventing signal mixing and enabling communication even in the presence of strong ambient light sources.
• High Signal-to-Noise Ratio (SNR): OCC offers a higher SNR compared to some other communication methods.
• Simplified Signal Processing: LEDs not required by receivers are omitted, reducing the need for complex signal processing to filter out unnecessary information.
• Distance Stability: Provides stable communication against changing distances, as long as the imaged LED size is not smaller than the size of a pixel.
• Frequency Flexibility: By utilizing both infrared and visual light frequencies, OCC can leverage the benefits of both.

Drawbacks (Disadvantages) of OCC

Despite its advantages, OCC also has some limitations:

• Line of Sight (LOS) Requirement: Optical communication relies on a direct line of sight. Any object blocking light penetration (e.g., buildings, walls, thick fog, or gas) will disrupt the communication link.
• Limited Data Rate: Traditional cameras support relatively low frame rates (around 30 fps), which limits the data rate achievable with OCC.
• Cost of High-Speed Cameras: To overcome the data rate limitation, high-speed cameras with advanced Image Sensors are needed, which increases the overall cost of the OCC system.
• Flickering Perception: At lower transmission frequencies, the human eye can detect light flickering when using visual light sources, particularly with low frame rate commercial cameras.