Issue link: https://www.e-digitaleditions.com/i/1156106
24 I ICT TODAY BEYOND HDMI: OTHER AV TECHNOLOGIES Many AV technologies are competing for the position of "best media transport system." While HDMI is certainly the current leader in connecting high-definition AV equipment, there are a number of other technologies that are relevant and may even play a dominant role in content transport between devices. Below is a quick look at several of these technologies: Video Over Ethernet HDBaseT uses a proprietary method for packetizing high definition signals for transport over Category cable. HDBaseT packets cannot be directly transported over an Ethernet network or switched by standard Ethernet switches. However, technology for packetizing the signal directly into standard Ethernet frames is rapidly evolving. Video over Ethernet (also called Video over IP) enables the transfer of high definition signals directly on Cat- egory cable networks using standard Ethernet switches. The desire is to serve high quality high definition video signals on the same network that provides data connectivity. However, there are challenges to accomplish this. HD video transmission requires significant band- width. This bandwidth must be allocated to the AV stream because, unlike data connections where bad packets can be retransmitted, the AV stream is "real time" and is not tolerant of significant error correction or packet retrans- mission and latency like a normal data Ethernet trans- mission. This leaves several issues to resolve: • How to reduce the bandwidth required via compression or other techniques. • How to allocate or prioritize bandwidth for sensitive AV streams for uninterrupted smooth and synchronized audio and video. • How to design and support an efficient and cost-effective Ethernet network that can support the combined data and AV bandwidth demands. A number of manufacturers and industry alliances are working to solve these problems, including the Software Defined Video Over Ethernet Alliance (SDVOE), the AVNU Alliance, and the Alliance for IP Media Solutions (AIMS). DisplayPort The DisplayPort video interface standard was originally developed by the Video Electronics Standards Associ- ation (VESA) as the next generation personal computer- to-display interface replacing VGA and DVI. It competes with HDMI and can be made compatible with HDMI via cables and adapters. The DisplayPort standard is evolving, and the most recent adaptation is DisplayPort Alt Mode for USB Type-C, enabling the full DP interface using a USB Type-C connector and cable. This not only provides the AV interface, but it also becomes the single connection for data and power simultaneously on full-featured USB Type-C cables. Thunderbolt and USB Thunderbolt is a hardware interface developed by Intel Corporation in collaboration with Apple Inc. Starting with Thunderbolt back in 2011 at 10 Gb/s, then prog- ressing to Thunderbolt 2 in 2013 at 20 Gb/s, today the latest version is Thunderbolt 3 at 40 Gb/s. It supports USB 3.1 Gen 2 at 10 Gb/s and DisplayPort 1.4 capable of operating two 4K 60Hz displays. Thunderbolt 3 uses the USB Type-C connector. One of the most recent announcements in the pro- tocol arena is USB4. This protocol is based on Thunder- bolt and promises to provide data transfer rates up to 40 Gb/s, display interfaces and power delivery simultane- ously using USB Type-C cables and connectors. The specification is expected to be released in 2020 and promises to up the ante for device connectivity. When designing an AV system with the goal of reducing components and system complexity, two options are available: a centralized or decentralized system.