GMSL2 vs. Ethernet Camera module:A Comprehensive Analysis

Today's rising demand for high-speed data transmission, long distance support, data integrity and superior image quality in industry, surveillance and automation makes choosing the right camera technology increasingly important. And among all the existing technologies in the market, GMSL2 (Gigabit Multimedia Serial Link) camera modules and Ethernet camera modules stand out with their unique advantages and application scenarios. In this article, we will delve into a detailed comparison of these two technologies - GMSL2 Cameras and Ethernet Cameras - and analyze their differences in terms of transmission distance, data transfer speed, EMI/EMC performance, and cost-effectiveness to help industry professionals and decision makers make the right choice when selecting the camera module that best fits their project needs. to help industry professionals and decision makers make the right choice when selecting the camera that best fits their project needs.

What is a GMSL2 camera?

GMSL2 imager technology, the second generation of Gigabit Multimedia Serial Link, is a high-speed serial interface that connects via Shielded Twisted Pair (STP) cables or Shielded Parallel Pair (SPP) cables to provide a highly efficient method of transmitting data. At the heart of GMSL2 technology is the ability to transmit high-speed video, bi-directional control data and power over a single coaxial cable, enabling data transfer speeds of up to 6Gbps per channel.

 
GMSL2 cameras utilize SerDes (Serializer/Deserializer) technology, in which the serializer on the transmitter side is responsible for converting the data into a serial stream, while the deserializer on the receiver side converts the serial stream back into parallel data for processing. This efficient data transfer method allows the GMSL2 camera to maintain excellent performance over long distances and in high EMI environments, while at the same time, its performance in terms of electromagnetic compatibility (EMC) meets the most stringent requirements.

What is an Ethernet camera?

Ethernet camera technology, the cornerstone of modern network communications, is known for its reliability and wide range of applications.Ethernet cameras transmit images or video streams over Ethernet cables, which can be either Unshielded Twisted Pair (UTP) or Shielded Twisted Pair (STP ), with STP commonly used for its ability to reduce data corruption in high electromagnetic interference (EMI) environments.Ethernet cables are categorized based on their transmission speeds and maximum distances, ranging from 1Gbps for Cat 5e to 40Gbps for Cat 8, covering a wide range of application requirements.
 
A distinguishing feature of Ethernet cameras is their ability to transmit data and power over a single CATx Ethernet cable, thanks to Power over Ethernet (PoE) technology, which reduces the need for additional power cords by utilizing unused pairs of wires in the Ethernet cable to transmit data and power simultaneously. This technology offers significant advantages in terms of installation and maintenance costs, especially in application scenarios where remote power is required.
 
Ethernet cameras typically follow the ONVIF standard, a set of open-standard protocols created by the surveillance industry that ensures interoperability between cameras and compatibility with network video recorders (NVRs). In addition, each Ethernet camera is equipped with a processing chip that compresses images/video as they are captured or recorded to avoid consuming too much bandwidth, and then transmits the compressed images/video over the network.

What is Ethernet cable? What are the specific classifications?

Ethernet cable is a network cable consisting of an outer jacket in which copper wires are twisted around each other throughout the length of the cable. It is categorized as either unshielded twisted pair (UTP) or shielded twisted pair (STP). As the name suggests, STP cables have a shield inside the outer jacket. This type of STP is often used in high electromagnetic interference (EMI) environments to mitigate data corruption.

What is PoE technology?

Power over Ethernet (PoE) technology is an innovative solution that allows data and power to be transmitted simultaneously over a single Ethernet cable. It simplifies the installation and cabling requirements for equipment.about PoE technology view this.

Different standards of PoE technology, such as IEEE 802.3af (PoE), IEEE 802.3at (PoE+), and IEEE 802.3bt (PoE++), provide different levels of power output to meet the power needs of different devices. For example, the IEEE 802.3af standard provides up to 15.4 watts of power, while IEEE 802.3bt (PoE++) is capable of delivering up to 90 watts of power, which allows PoE technology to support a wider range of higher-powered devices such as digital signage and kiosks.

What are the differences between GMSL2 camera modules and Ethernet camera modules?

Both GMSL2 and Ethernet camera modules meet the growing demands of specific applications such as fast data rates, high bandwidth, integrity and better EMI/EMC performance. However, the GMSL2 imager is more advanced and is the preferred choice for embedded vision applications that require extreme speed and performance. Here's a look at what gaps exist in a few specific areas.

• Distance and speed
• EMI/EMC performance
• Cost

Distance and Speed

The GMSL2 Camera module provides good image quality, bandwidth and low latency over short distances (about 15 meters). In contrast, Ethernet Cameras can extend the transmission distance from 100 meters to much longer distances by using different categories of Ethernet cables, such as Cat 5e, Cat 6, Cat 6a, etc., depending on the category and quality of the cable. In addition, by using PoE (Power over Ethernet) technology, Ethernet camera modules can transmit data and power over a single cable without the need for additional power cables. It is important to note that as the transmission distance increases, the speed may be affected. For example, PoE extenders can extend the network range up to 200 meters, or even up to 500 meters by cascading, but this may reduce communication speeds, ranging from 100 Mbps to as high as 10 Gbps.

EMI/EMC Performance

GMSL2 technology improves the EMI performance of the link through the built-in programmable output spread spectrum capability, eliminating the need for additional spread spectrum clocking. In addition, the GMSL2 serializer is equipped with a High Immunity Mode (HIM) to further enhance the tolerance of the control channel for electromagnetic compatibility (EMC). In contrast, Ethernet technology typically utilizes Shielded Twisted Pair (STP) cables, which provide a degree of immunity that helps to minimize electromagnetic interference during data transmission. However, Ethernet cameras may not be as superior in terms of EMI/EMC performance compared to GMSL2 cameras, especially in high EMI environments.

Cost

Ethernet Cameras are less costly in new installations. This is because Ethernet cameras can utilize existing network infrastructure, reducing cabling complexity and cost. And with Power over Ethernet (PoE) technology, it is also possible to transmit both data and power over a single cable, further reducing the need for additional power cables. This not only saves on material costs, but also reduces installation time and labor costs.

GMSL2 Cameras, despite their performance advantages, are relatively expensive to install. This is mainly due to the fact that GMSL2 Cameras require the use of specialized coaxial cables and additional power cables, resulting in increased wiring and installation complexity. But the long-term benefits in certain high-end applications may make up for the initial cost if it.

GMSL technology and future trends in Ethernet camera modules

GMSL3 technology, the latest advancement, offers higher data transfer speeds, supporting transmission rates of up to 12 Gbps and the ability to transmit high frame rate 4K video (e.g., 90 fps) over distances of more than 14 m. The GMSL3 interface also supports backward compatibility modes, meaning that its components can be operated in GMSL2 mode, which provides flexibility for upgrading existing systems.

While Ethernet Camera module technology has evolved in both Single Pair Ethernet (SPE) and Advanced Physical Layer (APL), SPE extends the length of Ethernet cables with data and power by using only one pair of twisted pairs.APL, as SPE's Enhanced Physical Layer, based on 10BASE-T1L, further improves the efficiency and reliability of data transmission. These developments bode well for the use of Ethernet technology in future Industrial Internet of Things (IIoT) and smart city projects.

Sinoseen camera modules for GMSL and Ethernet technology

Sinoseen, as a well-established Chinese camera module manufacturer with more than a decade of experience in the embedded vision field, offers a series of GMSL and GigE camera modules. If you are interested in this, you can go to our camera module product list to check it out, in addition to GMSL and GigE camera modules, there are also other camera modules such as PoE, MIPI, DVP, tof, etc. for you to choose. Camera Modules Of course, if you have any questions, please feel free to contact us.