What is SerDes? The High-Speed Bridge Connecting Cameras and Processors

The way robotics and vehicles accurately observe the surrounding environment depends not only on their sensors but on the invisible pathways that carry vision data to the processor. As robots move outdoors and autonomous systems rely on increasingly complex perception, traditional links have struggled to keep up with the demands of speed, distance, and reliability. This shift has quietly reshaped how cameras connect to computing units. In this blog, we’ll explore how the industry evolved from analog to digital and now to SerDes, why GMSL is becoming essential for mobility applications, and how it defines the future of robotic and autonomous vision.

What is SerDes?

SerDes, short for Serializer/Deserializer, is a pair of high-speed interface chips that enable reliable long-distance transmission of camera data. Each side of the link uses its own IC, a Serializer chip inside the camera and a Deserializer chip near the processor.

How does SerDes work?

At a practical level, SerDes converts the wide MIPI data from an image sensor into a fast serial stream that travels over a single cable, then reconstructs the original data at the receiver. This allows high-resolution video, control signals, and even power to be carried through one cable, which simplifies system design and reduces wiring complexity.

A typical SerDes camera chain looks like this:

• Serializer chip (inside the camera module): Takes MIPI sensor data and converts it into a multi-gigabit serial stream.
• Cable (coax or shielded twisted pair): Transports the high-speed serial data, control channels, and sometimes power (Power-over-Coax).
• Deserializer chip (near the SoC): Rebuilds the original MIPI data format so the processor can use the video stream.

From Analog to Digital to SerDes: The Evolution of Camera Connectivity

1. The Analog Era: Simple but Limited

Analog formats such as CVBS, AHD, and TVI once dominated camera transmission because they were inexpensive, well understood, and easy to deploy. They worked adequately for basic rear-view monitoring or surveillance streams where image quality and latency were secondary concerns.

But as mobility robots and autonomous systems emerged, the shortcomings became impossible to ignore:

• Bandwidth capped at low resolutions
• Susceptibility to noise and interference
• No deterministic latency or advanced control channels
• Limited scalability for multi-camera synchronization architecture

Analog could no longer keep pace with the complexity of perception-driven machines.

2. Digital Interfaces: A Step Forward, but Not the Final Answer

Common digital interfaces like MIPI CSI-2, USB, and Ethernet brought higher resolutions and more reliable signal transmission. Some of them allowed for plug-and-play connectivity and better integration with processors, making them standard in mobile devices, industrial cameras, and embedded systems. Yet, digital interfaces still face several challenges:

• Cable length limits (especially MIPI)
• EMI exposure in harsh environments
• Higher and less predictable latency
• The need for synchronized multi-camera setups
• Automotive-grade reliability over years of operation

These limitations make digital interfaces less suitable for complex, high-performance robotics or autonomous vehicle systems.

3. The Rise of SerDes: Built for Distance, Speed, and Tough Environments

Serializer-Deserializer (SerDes) technology arrived as the answer to the industry’s accumulated frustrations. Instead of transmitting wide, MIPI data lines, SerDes compresses data into a high-speed serial stream, sends it over a robust differential pair coaxial cable, and reconstructs it on the other end.

For robotics and autonomous systems, SerDes unlocked capabilities that neither analog nor general-purpose digital interfaces could meet:

• Long-reach connections up to 15 meters with minimal loss
• Low latency, essential for real-time perception
• High bandwidth supporting multiple Full HD or even multi-gigapixel streams
• Automotive-grade EMI tolerance
• Power-over-coax reducing cable complexity
• Scalability to multi-camera synchronization required for SLAM, 360-degree awareness, and well-known 3D occupancy prediction particularly in autonomous driving and robotics

The Shift from Proprietary to Open SerDes Standards

The table above effectively highlights that while SerDes interfaces like FPD-Link (TI) and the GMSL (Analog Devices) solved the high-resolution, low-latency demands of ADAS/AV/Robotics, their proprietary nature created vendor dependency. However, the camera interface ecosystem is rapidly evolving toward standardization. This transition is marked by the emergence of new, vendor-neutral alternatives like A-PHY (MIPI Alliance) and ASA, which are positioned as Open standards to foster multi-vendor interoperability and reduce supply chain risk.

This move toward openness is gaining significant traction, exemplified by Mobileye's adoption and mass-production use of Valens' A-PHY technology, and further affirmed by announcements from dominant players like ADI to open up their GMSL protocol. This shift suggests that while proprietary solutions were mainstream in the past, open standards are poised to become the indispensable backbone for future highly scalable and reliable autonomous driving systems.
 

Beyond the Protocol: The Role of Camera Developers in Building Reliable Systems

From a camera developer’s perspective, SerDes technologies like GMSL, FPD-Link, and A-PHY are critical, but they are just one piece of the puzzle. Having a good interface ensures high-speed data transfer, low latency, and multi-camera capability, but it alone cannot guarantee a robust, reliable camera product especially in the challenging conditions encountered by robotics and autonomous vehicles.

That’s where the expertise of manufacturers like oToBrite comes into play. Beyond selecting the right SerDes technology, a high-quality camera must undergo rigorous testing, including temperature extremes, shock and vibration, EMI resilience, and long-term durability. Camera developers also focus on sensor calibration, lens quality, firmware optimization, and power management to ensure the system performs consistently in real-world conditions. In other words, while protocols like GMSL enable technical foundation, it’s the holistic design, manufacturing, and validation process that turns a camera into a reliable key element for demanding robotics and mobility applications.
 

Conclusion

As mobility and robotics continue to advance, SerDes has evolved beyond a simple data link, it’s the bridge enabling real-time perception between the physical world and computational intelligence. From analog signals to today’s multi-gigabit links, camera connectivity has always pursued faster, longer, and more reliable data transfer.

With technologies like GMSL, FPD-Link, and open standards such as A-PHY, high-speed vision data can now move seamlessly across platforms. For camera developers, this means more flexibility and scalability paving the way for safer and smarter autonomous systems.

In the end, the future of smart mobility and robotics will not be defined by any single protocol, but by how well the industry integrates advanced interfaces like SerDes with robust design, testing, and system-level expertise to bring dependable vision to life.

Explore oToBrite’s GMSL camera solutions to see how we’re enabling reliable, high-performance vision systems for next-generation mobility and robotics: https://www.otobrite.com/product/robotics-camera-for-amrs-and-ugvs/category