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Traditionally audiovisual low voltage cabling has used a combination of coaxial, shielded twisted pair, low voltage control, unshielded pair cabling as well as proprietary cabling to transport audio video and control signals between rack devices and field devices to complete an audiovisual system.

The influence of networking and structured cabling topologies has led manufacturers to develop a class of products known as Audiovisual “Twisted Pair” products. These products transport virtually every common audiovisual signal type between two end points using one or more twisted pair cables; using Cat5E; Cat6; shielded versions or “skew free” versions of the cable. Skew Free cables is a specific cable type that has been manufactured to minimize the timing differential between the different twisted pairs within the cable, to synchronize the arrival times of the various color signals transported across the cable. This provides a good quality signal at the end point.

The best case for twisted pair products lies in the transport of high resolution video signals. VGA and higher (XGA WXGA UXGA etc), DVI, and HDMI are high resolution signals and due to the complications of connectorizations of these signals, a structured cabling solution presents a simple termination, and effective use in structured cable plant facilities.

Analog RGBHV uses 5 BNC connections at each end, for a single signal cable. DVI and HDMI connectors currently do not have a field termination connector available, and due to the size of the connector and cable construction, does not run within walls and ceilings, where fire rated cable and medium haul cabling is conventionally used.
Hence, the Twisted Pair solution for Analog RGBHV, DVI and HDMI is a necessary product and greatly assists the AV design engineer in providing a solution for clients when warranted.

In most facilities, the structured cable plant that supports the business operations uses Cat5E Cat6 for data and data connections and Coax cabling fopr CATV connections. The data network and connections can carry a host of various telecommunications services, Ethernet, ISDN for Phones, IP for Phones, ISDN BRI/PRI for video conferencing and other important business services. In many businesses structured cabling provides cable TV service as a number of manufacturers produce CATV over structured cable systems.

Structured Cabling can also host analog audiovisual signals that can run “Next to the Network”. Analog and Digital Signals running on twisted pair in many cases will work within the distance parameters of typical cable plants for structured cabling. Many, but not all, audiovisual twisted pair signals can run the maximum of 500 feet that may be required to connect 2 endpoints thru an IDF closet. These signals can be managed separately within the IDF closet by isolating the connections to a separate patch panel reserved for “AV Twisted Pair” connections. This will help prevent any improper cross connections within an IDF closet.

In such cases where high resolution analog and/or digital video is required, it is important to validate the total distance of cable required for a signal run. The higher the resolution required, the shorter the distance limitation gets. High Definition 1080P resolution can have a total distance limitation of 130 feet, while analog RGBHV running XGA rates can go as far as 500 feet.

In regards to Audio, multi-channel audio over twisted pair cabling exists in a number of different forms. The Analog and Digital Video twisted pair products generally include a stereo audio pair, or in the case of HDMI, include digital audio in the distribution of the signal over twisted pair. Other formats such as Cobranet, Anet (proprietary Aviom product), and Mongoose (proprietary Rane product) or Dante provide a medium for multi-channel audio to be transmitted over structured cabling in the medium haul range. Cobranet and Anet are Ethernet based protocols that require an isolated audio network in order to work properly.

Control Signals are the most akin to network operation, as the low bandwidth demand by “as needed” data traffic will integrate easily into most/all business networks. Ethernet communications technology has been conventionally implemented in audiovisual systems since the later part of the 20th century. We can completely managed Audiovisual network control systems with features that includes device monitoring, usage databasing, environmental control monitoring, and enterprise network integration. The feature rich environments that are offered by the major manufacturers allow the user to explore the possibility of total network integration with the Audiovisual Systems.

There are significant design opportunities for the AV designer, once structured cabling and the IDF closet become part of the audiovisual system. Centralized Switching and Control systems can reduce the cost of individual AV systems; Video and Audio Distribution between Conference Rooms become more cost effective. A tenant can also reduces installation costs by using the Telecom contractors as a single low voltage cable installer for both trades; where Audiovisual and networking signals run on the structured cabling system.

The Audiovisual Trade has gradually transitioned into a partner trade to the telecommunications industry. The variety of products that use Telecommunication standards as part of their electronic system, the availability of twisted pair products, and the growing need for IP/AV integrated products will continue to bring these two related trades closer together. The Audiovisual designer, however, will take the necessary skills of integrating a host of vastly difference devices into architectural space.