The Gigabit Multimedia Serial Link (GMSL) interface, specifically GMSL2, is renowned for its ability to transmit video data over long distances. It does so with minimal latency, as well as high reliability. Initially developed for automotive video applications, including infotainment systems and Advanced Driver Assistance Systems (ADAS), GMSL cameras are now finding applications in a variety of other fields, such as robotics and intelligent traffic systems.
In this blog, you’ll discover the benefits and capabilities of GMSL cameras, how they work, and how their use cases go beyond the automotive industry.
Key Features of GMSL Cameras
High-speed data transmission
GMSL2 is designed to transmit video data over long distances without significant signal degradation. It achieves this capability by using either a single coaxial cable or a pair of shielded twisted wires. The design of GMSL2 ensures reliable performance even under challenging conditions.
Low latency and reliable performance
One of the main advantages of GMSL2 is its ability to minimize latency, which is crucial for applications requiring real-time data transmission. This low latency, combined with the interface’s high reliability, makes GMSL2 ideal for use in environments where dependable performance is critical.
Seamless multi-camera synchronization
The synchronization support feature of GMSL cameras is crucial for applications requiring accurate timing and coordination between multiple camera units. They leverage frame synchronization to ensure that all connected cameras capture frames simultaneously. This minimizes the risk of data misalignment and ensures consistent image quality across all cameras.
Components of the GMSL Camera Interface
- Serializer/Deserializer (SerDes) technique: The serializer converts incoming parallel data into a sequential format. The deserializer then converts this sequential data back into its original parallel form at the destination.
- Cabling: GMSL typically uses coaxial cables for high-speed data transmission, although it can also function over twisted-pair cables.
- Data rate and resolution: GMSL supports high data rates, making it suitable for transmitting uncompressed video and high-resolution imagery.
- Multiple interface support: GMSL can interface with various data formats, including HDMI, CSI-2, DSI, eDP, and more.
- Bidirectional communication: GMSL supports bidirectional control data for devices to send and receive control signals over the same physical medium.
How the GMSL Interface Works
The GMSL camera interface operates on the principle of high-speed data serialization. After the camera sensor captures an image, the raw pixel data, typically in parallel format, is directed to the serializer.
The serializer converts this data into a serial format for long-distance transmission using the SerDes technique. The data is then sent through a coaxial or shielded twisted pair cable, which is resistant to noise and interference.
Upon reaching its destination, such as a display or processor, the data is deserialized back into its original parallel form. The GMSL protocol also supports bidirectional communication, allowing video data to travel in one direction and control commands to be sent back to the camera in real time.
Integrated error correction techniques ensure data integrity during transmission, and some GMSL configurations even allow power to be supplied to the camera over the same data cable, thereby simplifying the overall setup.
Newer Use Cases of GMSL Cameras
GMSL cameras are a popular choice for automotive applications, particularly Advanced Driver Assistance Systems (ADAS) and Autonomous Mobile Robots (AMRs). However, beyond the automotive sector, the use cases for GMSL cameras are rapidly expanding into fields such as robotics and intelligent traffic systems, where their ability to transmit data over long distances without degradation is proving invaluable.
Smart traffic management
In urban areas, managing traffic flow is crucial to reducing congestion and improving safety. GMSL cameras empower vision systems with real-time, high-resolution video data, which is essential for dynamic traffic management.
GMSL cameras can transmit high-speed, high-quality video data over long distances with minimal latency. This helps monitor traffic conditions at intersections and roadways. Traffic management systems use this information to adjust traffic signals dynamically, optimizing the flow of vehicles based on current traffic conditions.
Also, the ability of GMSL cameras to deliver detailed and clear video data enables the quick detection of incidents such as accidents, stalled vehicles, or pedestrian crossings. Traffic control centers can respond promptly by adjusting signal timings, dispatching emergency services, or providing alerts to drivers.
Intelligent transportation
GMSL cameras play an important role in vision systems used for intelligent transportation since they provide the right visual data at the right time. For instance, these cameras ensure automated toll collection by capturing high-resolution images of vehicles as they pass through toll booths. Thanks to the high data rates of GMSL cameras, the images of license plates and vehicle details are transmitted quickly to toll processing systems.
GMSL cameras are also used for traffic flow analysis, which involves collecting data on vehicle speeds, traffic density, and flow patterns. They transmit high-quality video data over long distances to drive continuous monitoring and analysis of traffic conditions across large areas. Traffic authorities can use this to identify bottlenecks, plan infrastructure improvements, and implement new measures.
Smart surveillance
GMSL cameras deliver critical visual data with exceptional timing for smart surveillance systems. They can enable 24/7 security monitoring by capturing high-resolution images in real-time. Due to the high data transfer rates of GMSL cameras, video feeds of areas such as entrances, exits, and restricted zones are transmitted quickly to central security systems. This ensures immediate intrusion detection and response.
Moreover, GMSL cameras can be used for crowd management. They gather detailed video data, making it easy to monitor crowd density, movement patterns, and unusual activities. The high-quality data transmission over long distances supports continuous perimeter surveillance and analysis.
Industrial inspection
In industrial settings, GMSL cameras enhance the capabilities of inspection robots to monitor and evaluate equipment and infrastructure, often in hazardous or hard-to-reach areas. They support high-resolution video transmission, which is critical for comprehensive visual inspections. The ability to transmit this data over long distances without major signal loss ensures that inspection robots can operate in large industrial facilities.
Also, GMSL cameras’ low latency and bidirectional communication capabilities enable live video feeds and real-time control signals. So, operators can easily make prompt decisions.
GMSL Cameras Offered By e-con Systems
e-con Systems has 20+ years of experience in designing, developing, and manufacturing OEM cameras. We offer cameras that leverage GMSL, GMSL2, and GMSL3 technologies, using the SerDes technique to transmit high-speed video, bidirectional control data, and power over a single coaxial cable.
Our GMSL cameras are perfect for long-distance applications, capable of being positioned up to 15 meters away from the host processor while maintaining low latency and high frame rates.
Check out our Camera Selector Page to see e-con Systems’ full portfolio of cameras.
If you require help in integrating GMSL cameras into your embedded vision products, please write to camerasolutions@e-consystems.com.
Suresh Madhu is the product marketing manager with 16+ years of experience in embedded product design, technical architecture, SOM product design, camera solutions, and product development. He has played an integral part in helping many customers build their products by integrating the right vision technology into them.