Video plays a crucial role in defense and security, and video streams are now used in armored vehicles for target acquisition, Local Situation Awareness, and other military applications. GigE Vision is an Internet Protocol (IP) video transport standard that provides many benefits for these applications.

The requirements for video-over-IP transport applications in the defense and security sector include low latency, support for compressed and uncompressed video, interoperability with existing equipment, and transmission of video from one location to many (known as multicast).

GigE connectivity between different camera types and consoles in naval systems can be achieved with IP engine units, which convert different camera signals such as analog, LVDS, and CameraLink to GigE.

To make effective decisions, live video must be received instantly. For example, the driver of an armored vehicle has no or very limited natural line of sight, and must rely on up to three video monitors for all his or her visual guidance. If the latency is higher than approximately 100 milliseconds, the driver may have difficulty driving the vehicle and the time difference between visual stimuli and physical feedback could eventually lead to motion sickness. The support for compressed and uncompressed data is also crucial since the video and imaging data is often sent to multiple locations with different purposes and different receiving capabilities. Legacy equipment is still very present in the military infrastructure and new equipment has to interface properly and easily with existing equipment.

Full multicast support is a key requirement. Video signals are frequently sent simultaneously to multiple groups inside an armored vehicle — one stream to the driver, one stream to the gunner and commander in the turret, and one stream to the crew in the back.

Using the GigE Vision Standard

Military requirements for video transport are met by GigE Vision, an open standard that was developed for the machine vision industry in applications like quality assurance, post and parcel sorting, intelligent traffic monitoring, and more. GigE Vision is an open framework for transferring imaging data and control signals between cameras and PCs or displays over standard Gigabit Ethernet (GigE) networks.

One of the main benefits of delivering video over IP networks is the long distance. The camera can be up to 100 meters away from the computer or display without regeneration, giving GigE a distinct advantage over many competing technologies (~4-10 meters). The distance can also be increased with the use of GigE switches.

Second, GigE Vision permits deterministic, continuous data transfer at 1 Gb/s, enabling real-time, multi-mega pixel color imagery. Third, GigE Vision allows for net-working flexibility. Camera-to-PC connections and processing approaches can be tailored for each application. The standard is future-proof — the next generation of GigE, 10 GigE, offers transfer speeds of up to 10 Gb/s and is an established technology in backbone networks today.

The driver of an armored vehicle has no or very limited natural line of sight, and must rely on up to three video monitors for all his or her visual guidance.

The standard does not impose any limits on image size, image format, and data rate, and uses cost-effective off-the-shelf equipment such as a standard PC and Ethernet LAN equipment. There are no constraints on the host PC and there is no need for a frame grabber. As a PC is often required to do real-time image processing to the video stream, high-performance device drivers play an important role. The device drivers allow full bandwidth reception of video at the PC, while maintaining CPU availability for real-time image processing.

As GigE Vision is an open standard, it is not oriented to a single company’s technology, which avoids vendor lock-in. The standard fosters market growth, and makes systems easier to implement, use, and maintain.

The GigE Vision standard was initiated in 2004 by a group of leading machine vision companies, and is today managed by AIA, the Automated Imaging Associ - ation. The standard was ratified in 2006 and today GigE Vision has hundreds of customers and thousands of installations around the globe.

GigE Vision is used in conjunction with GenICam, which provides a generic programming interface and a single camera control for all camera types includ ing GigE Vision, CameraLink, 1394 (FireWire), and USB 2.0.

Meeting Military Requirements

GigE Vision meets the military’s most important requirements: low latency, support for uncompressed and compressed video, interoperability with legacy equipment, and full multicast support.

Latency requirements for driving, target acquisition, and surveillance are easily met in any GigE Vision systems built from quality components. The low, predictable, end-to-end latency is less than 500 microseconds.

GigE Vision does not add compression or alter the video in any way. The IP engines packetize video streams without “looking inside,” and support both compressed and uncompressed streams. For military applications, the process of compression and decompression adds latency to the signal flow, whereas uncompressed video has low latency but high bandwidth requirements. Any video-over-IP implementation has to find the correct balance between available bandwidth and tolerable image latency. JPEG2000 is a good option for modest compression, and allows users to send a 1.5-Gb/s HD-SDI stream inside a 1-Gb/s cable. Reduced bandwidth can also be achieved by reducing the frame rate, decimating the image, or by using features like Region of Interest.

GigE vision promotes interoperability between compliant hardware and software from different vendors, which results in fewer integration issues. The GigE Vision protocol allows for addition of sensors, displays, and processing resources without requiring changes to the underlying protocol, and the solution scales from a simple fit (i.e. 2 sensors and 1 display) to a more complicated fit (i.e. 10 sensors and 5 displays). For example, in an application that uses different camera formats such as LVDS, analog, CameraLink, and even IR cameras, deploying iPORT IP Engines between the cameras and the PC effectively converts all cameras to GigE cameras on a system level, making the application camera-independent and allowing the preservation of the investment in cameras while moving to the more flexible IP backplane.

Multicast video transmission is fully supported in the GigE Vision standard. This allows users to display a single video source on a number of displays simultaneously.

Implementation

It is important to note that the GigE Vision standard does not in itself define any performance metrics, nor does it specify any targets. Although GigE Vision can transmit up to 1 Gb/s, a high-performance, end-to-end solution requires high-quality hardware and software components throughout the signal chain, including the crucial device drivers.

The GigE Vision standard is a great fit for video transmission in defense and security applications. It meets the military’s requirements and offers many additional features that are not supported by other video transport standards. It is important to remember that the employed products, along with the quality of the implementation, will determine the performance of the video-over- IP application.

This article was written by Geoffrey MacGillivray, Product Manager, at Pleora Technologies, Kanata, ON, Canada. For more information, click here .