The booming popularity of network technology has stimulated the development of larger bandwidth and more versatile media. In fact, the reality of "everything networked" will be here before we know it. The key purpose of a network is to transmit information, and how to transmit information accurately and quickly is of prime concern to most network users. In the past decade, network developers concentrated much of their effort on developing ways to transmit all kinds of data over the Internet and Ethernet. And as network technology matures, people have begun looking for ways to exploit the Internet/Ethernet to transmit voice and images in addition to the "just data." Implementing the so-called VOIP technology makes it possible for us to use the network the same way we use the telephone. The next step was hooking up video cameras to create a more complete communication experience.

"Seeing is believing" is an adage used by people everywhere. We all know that the best way to know if something is real is to see it with our own eyes. For this reason, the natural next step after the evolution from "Data over IP" to "Voice over IP" is to implement "Video over IP," which is becoming one of the key issues of network development in the 21 st Century.

In the past, video transmission over IP networks was greatly limited by the capability and availability of network bandwidth and media. This was true since the data bandwidth required for digital video data can be up to 100 times greater than what is needed for traditional data communication. Thanks to the improvements made in the past several years to video compression algorithms, video over IP transmission is now easier than ever before. Lower bandwidth and higher resolution video images have resulted in good video rate performance for capturing real-time images from remote sites over IP networks.

When video data is transmitted over a TCP/IP network, compression is needed to ease the loading of the network bandwidth. There are two main compression standards in use today -- JPEG (Joint Photographic Experts Group, founded in the mid-1980s) and MPEG (Motion Picture Experts Group, founded in the late 1980s). Most people see still digital JPEG pictures every day when surfing the Internet. For the most part, MPEG files are just sequences of JPEG figures strung together to form movies.

Even though video is compressed before being transmitted over an IP network, compared to Data over IP or VOIP, the amount of data that needs to be transmitted still occupies a lot of bandwidth. This is especially true if hundreds of videos are being transmitted over the same network simultaneously, which could result in slowing down network traffic by a significant amount. For example, for modern transportation systems you can see a large number of cameras on the roadside, at crossroads, on entrance/exit ramps, and at toll stations. The cameras are used to help traffic controllers see the actual traffic condition in real time. Some cameras even have special functions built in to generate statistical data or incident alarms. To collect video images from all of the distributed cameras, as well as to control the traffic signal, and even emergency telephones with the traffic controller in the traffic control room, a Fiber Gigabit IP network is needed to ensure that enough bandwidth is available to transmit all data/video/voice information.

Gigabit networks are used to transmit many kinds of data. How to manage the network so that all of this data is transmitted reliably and efficiently is an important issue for Gigabit network systems. Several technologies can be useful:

•  Redundant Ring structure for network reliability:
Most Gigabit networks are constructed for critical applications, and for this reason cannot be allowed to crash, especially for industrial applications such as Factory Automation, Power Supply, ITS, etc. In some cases, a large sum of money could be lost when the system shuts down, even if only for few minutes. By implementing a Redundant Ring infrastructure, the system can benefit from a quick recovery (for example, the recovery time of MOXA Turbo Ring is under 300 ms) to prevent broken network transmissions.

•  IGMP, VLAN, and QoS for efficient traffic and bandwidth management:
Network traffic collisions are a major problem that lowers transmission efficiency. System administrators may need to use the VLAN to separate various data networks, such as Video, Data, and Voice, to guarantee that each data network will not interfere with other data networks. IGMP can help to shrink bandwidth requirements, especially for video transmissions. With the help of QoS, the most important data can be given priority to ensure that it will be delivered and received in real time.

•  The 802.1x guarantee of network security:
For critical systems, the network needs to be protected to prevent unauthorized users from connecting to the network. Except for user account management, access IP limitation, or SSL, 802.1x (Port-based Network Access Control) can enhance user authentication for security purposes.

Networks are now one of man's basic living requirements, almost on the same level as power, phone, and perhaps even water. In the near future, we can be sure that all types of information can be obtained via the network, regardless of whether the information is data, voice, or video. It's time for system integrators to think about building a networking interface for system information and device connection. Make sure your system has enough bandwidth for future expandability, and of course, find the best solution to build a reliable, efficient, and secure system.