Issue link: https://www.e-digitaleditions.com/i/1156106
October/November/December 2019 I 21 Centralized AV System A centralized AV system offers the benefits of greater control and easier overall system management. Every classroom system can be monitored and controlled from a single, central administrative location. With uniform system design for every classroom and patching into the school telecommunication room, a centralized AV system offers the benefits of easier system management and greater oversight of power use, including the ability to automate some processes. However, a centralized AV system is a complex system, not only in the number of components but also in the difficulty of installation and long-term maintenance needs. A single component failure can impact not one but multiple rooms—or even the entire school. This increases the potential for a high system life cycle cost that may be beyond most school budgets. cable is unable to provide signal reliability over long dis- tances. Cat 6 UTP cable may meet network signal require- ments and deliver acceptable performance in an educa- tional environment, but issues with alien crosstalk mean signal integrity cannot be reliably ensured. To eliminate alien crosstalk and avoid dropouts or link loss at high resolutions, a Cat 6A channel is recom- mended. Not only are Cat 6A UTP cabling systems able to provide infrastructure that is durable and typically less expensive than alternative forms of AV cabling, they also offer the ability to upgrade an AV system without upgrading the entire network. Furthermore, no other UTP cable option reliably supports AV signal integrity over long distances while offering easy installation com- pared with FTP (shielded) cable. A simple AV system built on a Cat 6A UTP cabling infrastructure offers maximum longevity and upgradability. School district budgets must accommodate many competing needs, and AV systems are often the final line item to be budgeted for and the last infrastructure component to be installed. Upgrades often occur only because of the failure of a key component, such as a display or projector. An AV system's total life cycle is often not budgeted for at all. System maintenance and upgrades over the lifetime of the system are frequently overlooked. Typical maintenance for a complex, professional AV system can include repairs to projector lamps, control software updates to touch panel systems, connectivity updates to accommodate newer technology such as VGA to 1080p to 4K, and IT service calls for systems that just "are not working" either due to end-user confusion or component failure (Figure 3). A simple AV system with minimal components, on the other hand, has a lower initial purchase price and installation cost, as well as a greatly reduced total system maintenance and upgrade budget. When design- ing an AV system with the goal of reducing components and system complexity, two options are available: a centralized or decentralized system. FIGURE 3: Common AV issues. Original projector malfunction Old dangling VGA cable Exposed cables create tripping hazard Exposed cables easily disrupted Temporary new projector distance too great for passive HDMI cable Exposed power connection 2. SYSTEM DESIGN: MINIMIZE THE NUMBER OF COMPONENTS Common Situation