Education | AV Distribution Tutorial Cable-Based Distribution In-line based In-line extenders, installed at some point within a link, extend signals over their native cabling with no signal conversion occurring. These amplification or repeater types of devices are designed to equalize and amplify the signal to go greater distances. Some support daisychaining, so by stringing two of them together you can send data double the distance. But in-line extenders can only take the signal so far and typically use Non-networked CATx-based This method uses transmitters and receivers to extend converted signals over non-networked UTP cabling. They’re very cost-effective, enabling much longer distances than what’s ordinarily possible with analog or digital video cabling. Copper-based extension is also a great alternative to using standard video or RGB coax cables, which often can’t be easily pulled through tight conduits and can be more difficult to terminate (for more on the limitations of simply extending video cabling, see below). A bonus: In most buildings, copper cabling is already installed to service data communications. There’s no need to pull new cabling when existing wiring can be used for long-distance AV distribution instead. Another thing to consider: Coax- or VGA-cabled extension installations usually require a separate RS-232 or other line for transmitting the control signal for a display—yet another cable to fit into the conduit and another distance limitation (most serial signals can travel only a short distance over Non-networked fiber-based Using fiber-based technology has many advantages over copper-based distribution technology. Foremost, it enables you to deliver video at much longer distances than copper—without compromising the quality of the original video signal. This makes it an ideal distribution method for digital signage. Plus, it supports high resolutions and the sending of large, bandwidthconsuming files, particularly in electronically noisy environments, such as in transit stations. Because fiber is made of glass, which is an insulator, no electric current can flow through. This makes it immune to EMI/RFI interference. You can run fiber next to industrial equipment without worry. And, compared with copper cable, fiber cable is less susceptible to temperature fluctuations. In addition, fiber distribution is ideal for applications where data security is a priority, such as in medical, military, and government environments. That’s because fiber cable is extremely difficult to tap. Why not just run longer cables? An analog video signal can be run over long lengths of native VGA cable as long as its diameter and shielding is good enough. However, regardless of the cable quality, signal attenuation increases with video frequency and cable length. This means that after 30 to 50 feet, the image quality will start to degrade. This leads to color skew and smeared-looking text. To solve for signal degradation in VGA video applications, use an equalizer, or an extender that compensates for signal loss. A good extender has separate adjustments for high and low frequencies; HF loss is usually greater than LF loss. 4 Analog signals travel in a sine-like wave form; digital DVI and HDMI signals travel in a square-like waveform. The signal is broken into a binary format where the audio or video data is represented by a series of 1s and 0s. Like analog signals, digital video also suffers from cable loss, but as long as the cable is of sufficient quality and within the maximum supported distance, the signals don’t suffer blurring or color skew. So what happens when the maximum supported length is exceeded? You get the “cliff” effect, where the signal drops off and you completely lose the picture. To overcome distance limitations, use extenders or repeaters. Tech Support 030 - 241 77 99 | Sales 030 - 241 77 77 | On-Site Services 030 - 241 77 44 And fiber cable is more durable than copper cable, and it’s thinner. Its size makes it easier to handle, and it takes up less space in cabling ducts. Yes, fiber is more expensive, but many fiber-based extenders use just a single strand of fiber, for a more economical use of your fiber count. traditional cable). Some CATx-based extenders also extend serial control signals in addition to video and audio. Therefore the cable can deliver both the video and control signals through a single transmission medium. Plus, CATx extension technology continues to evolve. Newer HDBaseT™ technology uses sophisticated encoding and equalization techniques to deliver uncompressed DVI or HDMI video and audio, 100BASE-T Ethernet, power, and control signals to a remote screen—all over a single CATx cable. HDBaseT has made it possible to transmit the video signal as well as the peripheral signals uncompressed up to 100 meters. CATx-Based Extender Transmitter and Receiver Blu-ray Player Remote Display HDMI Cable CATx Cable HDMI Cable DVD Player DVI Cable In-Line Extender DVI Cable amplification that not only boosts the video signal, but also boosts any noise on the cable. In addition, they don’t solve the problem of having to transmit bidirectional serial control signals to the display. Remote Display Laptop Audio Cable Fiber Optic Cable DVI Cables Local Monitor Fiber-Based DVI Extender Transmitter and Receiver DVI Cables Remote Displays
Distribution Methods IP-Based Distribution IP-based distribution technologies use transmitters and receivers to extend signals over a TCP/IP network (a LAN or even a WAN, for instance). Oftentimes, they’re called IP streamers when used with codecs. But, when choosing one, be sure you’re not looking at the consumer-grade devices for streaming video in small office applications; be sure it’s a professional-grade multicasting product. These sophisticated extenders use CATx cabling infrastructure, but in comparison to standard non-networked CATx extenders, they multicast data over an active Ethernet network. They do this by packetizing media streams for delivery over an IP-based network, so source content can be delivered anywhere you have Ethernet wiring. PC By leveraging existing IP network connections to distribute multimedia content, businesses can avoid running expensive dedicated links from a back room to digital signage in lobbies or other public areas. Plus, the video is a lot less susceptible to interference, image skew, and compromised resolution. Compression makes it possible to run the signal over longer runs — and compression does not have to mean low-quality video. Compressions may be lossy or lossless. The IP-based extension methods we’re discussing use visually lossless compression with algorithms that make it possible to run Full HD video over the LAN without any visual loss in quality. They may even simulcast video and audio synchronously so there’s no latency, feature QoS prioritization and bandwidth-management controls, and the ability to use bidirectional (two-way) serial signals to query a remote display to, for example, shut it down and power it on or gather performance data. What’s more, the system you choose may even support bidirectional serial connections for use with interactive touchscreens. Also, they may or may not support existing networking standards. This is important if you need extra distance in your distribution application. If they do support Ethernet standards, you can extend video through networking switches to get extra-long distances, beyond the specified cabling distances of 100 meters per the Ethernet standard. Because IP-based extenders are based on standardized Ethernet protocols, you can even use media converters and run several miles over fiber cabling. Plus, these extenders transmit signals digitally from end to end, so digital content is never compromised. Meeting existing standards also allows for easy installation and expansion. Simply plug in as many receivers as you need for your remote screens and use a standard Gigabit network switch with IGMP snooping to control the traffic. IGMP is very important in multicasting. This stops an IP switch from passing on multicast data onto every port and prevents performance degradation and wasted network bandwidth. Switches with IGMP support Digital Signage Appliance HDMI Cable Multicast Transmitter IP LAN Layer 3 Switch with IGMP CATx Cable Multicast Transmitter “know” which devices on your IP network want to receive the multicast packet and who doesn’t. Otherwise, the traffic may be broadcasted to every end device on your network, slowing it to a halt. Multcasting isn’t limited to just video either. You can also use it for both video and peripheral signal extension and sharing (often called “KVM extension”) applications. These types of extenders feature keyboard/mouse emulation and emulation for other standard HID devices, while providing easy access to single-, dual-, or quad-head computers — ideal for applications requiring multiple graphic heads to be switched simultaneously from a single workstation. In command and control room setups, for example, you can multicast video and data to receivers attached to LCDs in video walls. Users can then interact with computers behind the scenes using separate keyboard, mice, and digital displays. QUESTI NS to ask. 1. How far do you need to transmit your video? Do you want to go farther than 95 meters? 2. Do you have copper (CATx or coax) wiring not in use? 3. How important is video quality? Do you intend to transmit medical images or detailed graphics renderings? 4. Is bandwidth an issue on your network? Is your LAN already being used for VoIP or data-intensive applications? 5. Do you want to transmit to one screen or multiple screens? 6. Will you need connectivity to serial touchscreens? 7. Is data privacy an important consideration? 8. Will you be distributing video near machinery? 9. Do your network switches support IGMP snooping? 10. Do you need peripheral support (for instance, for remote users who require keyboard and mouse control, or for command and control room applications)? Contact the experts at 030-241 77 99. 100% HDMI Cables CATx Cable Multicast Receivers CATx Cables CATx Cables Layer 3 Switch with IGMP Digital Displays 100% Picture quality of an analog signal gradually declines over longer lengths of cable. Cable Length For more information and our online store, visit www.blackbox.nl Picture quality of an digital signal (e.g. HDMI) suddenly drops at a certain length of cable (cliff effect). Cable Length 5 Picture Quality Picture Quality
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