What is GMSL technology and why is it critical for embedded vision systems?

🚀 What is GMSL technology and why is it critical for embedded vision systems?

In this episode of Vision Vitals, we break down GMSL (Gigabit Multimedia Serial Link) — a high-speed camera interface used in automotive vision systems, industrial cameras, robotics, and AI-powered embedded vision applications.

Learn how GMSL works using SerDes (Serializer/Deserializer) technology to transmit high-resolution, low-latency video over long distances using coaxial or twisted-pair cables.

🎯 What you’ll learn in this video:

• What is GMSL (Gigabit Multimedia Serial Link)?
• How GMSL works (Serializer & Deserializer explained)
• GMSL1 vs GMSL2 vs GMSL3 comparison
• Data rates, latency, and cable performance
• Why GMSL is critical for automotive, robotics & industrial vision
• How to choose the right GMSL interface for your application

🔍 Key Applications:

• ADAS & automotive surround view systems
• Industrial inspection & machine vision
• Robotics & AMRs
• Medical and smart agriculture vision systems

🔗 Explore GMSL camera here

👉 Subscribe to Vision Vitals for more embedded vision insights every week.

Transcript

Host:

Welcome back to Vision Vitals – e-con Systems’ podcast about the wonderful world of embedded vision. 

Today, we’re looking to unravel the mysteries of an interface that’s behind a lot of modern embedded vision systems, especially in automotive, broadcasting, and industrial applications. 

It’s called GMSL, or Gigabit Multimedia Serial Link. If you’ve ever wondered how high-resolution, low-latency video travels reliably over long cables, this episode is for you.

Joining us again is our embedded vision expert. 

Welcome!

Speaker:

Thanks, glad to be here. Yeah, GMSL is an absolutely critical camera interface for making high-performance vision systems work in the real world.

Host:

To kick things off, what exactly is GMSL technology? Let’s talk about it!

Speaker:

So, GMSL stands for Gigabit Multimedia Serial Link. It’s a camera interface built to manage high-speed and high-resolution video output. The way it works is, umm, it uses a serializer on the transmitter side to convert parallel data into a high-speed serial stream. 

That reduces the complexity of data lines and minimizes the risk of signal interference. Then, on the receiving end, a deserializer converts the serial data back into its original parallel form, so it’s ready for processing.

Host:

So it’s all about converting data to travel more cleanly over longer distances. What kind of performance are we talking about?

Speaker:

Right. The GMSL interface can handle video transfer speeds of up to 6 gigabytes per second. That makes it capable of transmitting uncompressed, high-resolution video streams with really minimal latency. And you know, that kind of speed is crucial for applications that need real-time data processing.

Host:

Interesting. So, what are the core principles that make GMSL work so well?

Speaker:

Well, the core of it is the Serializer/Deserializer technique, known as SerDes. The serializer takes incoming parallel data from the camera sensor and converts it into a sequential serial stream. That helps simplify cable design and reduces potential signal interference. 

Then, the deserializer on the other end reverts the serial data back into parallel form so the system can process it correctly.

Another key principle is the cabling. GMSL typically uses coaxial cables, which are known for excellent shielding and the ability to carry high-frequency signals over long distances without major loss. Umm, it can also work over twisted pair cables, which are more cost-effective but still support high-speed data transmission.

Host:

And what about data rates and compatibility?

Speaker:

GMSL supports high data rates, up to 6 GB per second, which enables the transmission of uncompressed video and high-resolution images. It’s also compatible with various data formats like HDMI, CSI 2, DSI, and eDP, so it can meet the specific requirements of different applications. 

Oh, and another important thing: it supports bidirectional communication. That means cameras can send and receive control signals over the same cable used for video. That’s crucial for real-time feedback and control, and it simplifies system design a lot.

Host:

As we already know, there are different versions like GMSL1, GMSL2, and GMSL3. What distinguishes them?

Speaker:

Yeah, that’s right. GMSL1 provides high-speed data transmission suitable for various applications, including automotive video streaming. It uses coaxial cabling and offers data rates up to 3.125 Gbps. It can transmit 1080p60 uncompressed video with a typical latency of less than 1 microsecond.

Compared to earlier versions, GMSL2 provides even higher bandwidth, supporting data rates up to 6 Gbps over a 15-meter cable. It also features higher resolutions, like 4K, increased cable length support, and enhanced data integrity checks. So, it’s perfect for demanding environments where data quality and higher bandwidth are critical.

Then there’s GMSL3. That supports data rates up to 12 Gbps in the forward channel and 187 Mbps in the reverse channel. It enables uncompressed 4K resolution at 90 fps for really smooth video streams. Umm, it also enables the integration of three 4K streams over a single PoC cable, which is great for real-time 3D imaging and surround view capabilities.

Host:

Walk us through how GMSL actually works in a real system, from capture to processing.

Speaker:

Sure. So, first, the camera sensor captures an image. The raw pixel data, which is typically in parallel format, goes to the serializer. The serializer converts this parallel data into a high-speed serial stream, which reduces the number of data lines needed and minimizes interference. 

That serialized data is then transmitted over a cable, like coaxial or shielded twisted pair, chosen for its resistance to noise. 

Once it reaches the destination, say, a display or a processing unit, the data goes through deserialization. The deserializer converts the serial data back into its original parallel form, making it ready for processing. And throughout all this, the GMSL protocol integrates error correction techniques to maintain data integrity.

Host:

So it’s a full loop: parallel to serial, travel over a robust cable, then back to parallel at the other end, right?

Speaker:

Yep. It’s a streamlined way to move high-fidelity video data reliably, especially when you need both distance and speed. The use of coaxial or twisted-pair cables helps maintain signal integrity over those longer runs, up to 15 meters in many cases. 

And because the GMSL interface supports high data rates, it ensures that even data-intensive applications can run smoothly without compromising on performance. That’s what makes it such a go-to choice for embedded vision systems.

Host:

Now, if someone is looking to integrate GMSL into their project, what should they keep in mind?

Speaker:

Well, they should think about the required data rate, resolution, cable length, and whether they need features like bidirectional control. And, you know, they should consider which version, whether GMSL1, GMSL2, or GMSL3, fits their bandwidth and application needs. 

For example, automotive surround-view might need GMSL3, while a standard industrial inspection system might do great with GMSL2.

Host:

Thank you for so clearly explaining this technology. It’s been quite an eye-opening episode!

Speaker:

It’s been an absolute pleasure. GMSL is truly a crucial interface for high-performance vision, especially where distance and reliability matter. Understanding it can really help engineers design more robust and efficient systems.

For our listeners interested in GMSL technology, e-con Systems offers several GMSL, GMSL2, and GMSL3 cameras for various use cases, from industrial and agriculture to medical. 

These cameras come with features like HDR, IP66/67/69K rated enclosures, global shutter or rolling shutter, and LED flicker mitigation. They’re also compatible with platforms like the NVIDIA Jetson development kit.

If you need help integrating GMSL cameras into your embedded vision applications, you can write to camerasolutions@e-consystems.com. 

You can also browse the full portfolio on the Camera Selector page on e-con Systems' site.

As always, thanks for tuning in to Vision Vitals. 

We'll look forward to seeing you next time.