Issue link: https://www.e-digitaleditions.com/i/1156106
October/November/December 2019 I 7 October/November/ December 2019 I 7 AV SIGNALS AND SERVICES THAT USE NETWORK INFRASTRUCTURE Voice over Internet Protocol (VoIP) VoIP is the transport of voice communications over the internet. It can provide substantial savings over plain old telephone service (POTS) because it integrates into existing data networks. Any computer on the network can double as a telephone. There are no service charges based on time or distance, and services like call waiting, caller ID, call forwarding, and voicemail are included at no extra cost. Video and Audio Video and associated audio content can be transported point-to-point over twisted-pair uncompressed (HDBaseT) or it can be streamed compressed and packetized over Ethernet data networks and the internet (AV over IP). HDBaseT offers no-latency transmission of uncompressed ultra-high definition 4K video. Audio and control signals over shielded twisted-pair cable reaching up to 328 feet (100 meters) makes it a reliable plug-and-play AV content extension method in point-to-point applications. AV over IP is rapidly gaining favor for on-demand and real-time delivery of AV content to numerous and widely dispersed recipients over long distances. The cost effectiveness of transporting AV content over existing Ethernet infra- structure, the inherent scalability of Ethernet networks, and advances in visually lossless and low latency video compression algorithms are driving the move to AV over IP. Building Management Systems (BMS) These systems are comprised of devices and software that communicate over twisted-pair cable networks to control building systems, such as HVAC, lighting, power, fire, and security. AV and BMS are converging because AV control processors can support BMS protocols via soft- ware modules and device drivers. Not only can an AV control processor preserve lamp life by shutting down projectors after hours, but it can also reduce HVAC costs by drawing window shades during the heat of the day, open shades to harvest natural light, and adjust room temperature based on occupancy. Blending BMS and AV requires expertise with building automation protocols, such as building automation and control networking protocol (BACnet), Konnex (KNX), and digital addressable lighting interface (DALI): • BACnet to communicate between building automation end devices and building control systems • KNX for intelligently networking home and building systems • DALI for control of lighting via two-way communication bus BICSI Registered Communications Distribution Designer (RCDD) Certified Specialists Bring Their Expertise to the AV Team By joining AV design and installation firms or through ICT firms taking a lead role in AV design and installa- tion, RCDD certified personnel become integral members of an AV team. Therefore, it is important for them to understand the guidelines for distributing AV over the network. CONSIDERATIONS FOR MANAGING AV SIGNALS Connections There are four digital AV interfaces in widespread use: digital visual interface (DVI), high definition multi- media interface (HDMI), DisplayPort, and USB-C. DVI carries video only at resolutions up to 2560 x 1600. With higher resolutions becoming the norm, it is understandable that DVI has been supplanted by HDMI and other connections. The latest version of HDMI transports up to 10K video, multichannel audio,