RF + Cat
Nov 18, 2013 12:13 PM,
By Dick Snyder
Active RF video distribution over Category cable in a commercial environment
Commercial applications that use multiple televisions and display devices are an optimal environment for the convergence of RF commercial television signals with Internet-based digital information.
Together, these signal streams can offer a full spectrum of viewing and entertainment options in one device and over one cable; this combination enables a wider range of user experiences, as well as more options for managing signal distribution within a facility or campus. Video display networks within businesses, schools, medical facilities, transportation centers, and entertainment venues can take advantage of new models for collaboration, data sharing, training, content presentation, and interactivity.
Video Distribution Options
Businesses that use multiple TV devices are faced with the challenge of determining the most effective way to distribute the video signal within their facility, or in the case of larger establishments, to multiple floors or several buildings. One popular option is RF broadband video distribution: In effect, RF TV distribution over Category cable is a new twist on a tried-and-true technology. The RF spectrum, or bandwidth, has been divided up for use with several different technologies with the RF television occupying the 5-860 MHz frequency range.
There are two types of RF video distribution systems over Category cable that can be used in a commercial setting: active and passive. The active system consists of a 12- or 24-port master video hub that serves as the system’s building block with additional hubs being easily added via a cascading process as needed. A remotely powered intelligent balun is installed at each television (attached to the back of the TV or imbedded in a wall box) to provide automatic amplification and equalization of the video signal. The master hub also supplies automatic gain control (AGC) to each connected hub and balun, providing enhanced picture quality to as many as 14,000 televisions. All of this is accomplished using only one pair of wires within a sheath of Category/Cat-5e or Cat-6 cable.
A passive RF system, on the other hand, is a much more labor-intensive RF system, as it requires the use of multiple splitters, amplifiers, and other components that must be integrated and balanced, and the distance known from the closet to each TV. Thus, the passive system does not offer the ease of use and flexibility of an active system, making it complex for systems consisting of 50 or more TVs on different floors, or when moves, adds, and changes are required. Nonetheless, a passive system equipment costs are less than an active systems, and the passive system is effective in providing high quality TV over Category cable in limited applications.
The Cat Cable Advantage
As mentioned, an active RF video distribution system uses one Cat-5e or Cat-6 cable as the signal transmission medium. The more technologically advanced Cat-6 is the preferred choice, in large part because it offers better bandwidth capacity than Cat-5e. Category cable, also known as Ethernet or computer cable, consists of four pairs of twisted copper wires. Two of these pairs (pins 1, 2, 3, and 6) are needed for standard 10/100 Ethernet transmission and one pair (pins 7 and 8) are dedicated to RF video distribution. This is how Cat-6 cable can provide clear, reliable video quality without consuming any network bandwidth. Business owners and installers will also appreciate the fact that Category cable generally costs less than plenum coax cable. And when you factor the accessories and additional labor that are part of the life of a coax-based distribution system, the overall expense can be even greater.
RF + Cat
Nov 18, 2013 12:13 PM,
By Dick Snyder
Active RF video distribution over Category cable in a commercial environment
More About Automatic Gain Control (AGC)
The use of AGC technology is a primary reason why an active RF distribution system is able to provide a consistent signal from closet to TV up a distance of 100 meters. AGC is deployed in the backbone from the master hub to the satellite hubs, as well as in the horizontal between the intermediate closet hubs and TV baluns. In the backbone, a 240MHz pilot tone is sent in a guard band between two RF channels. In the horizontal, the balun uses AGC to accurately measure the amount of signal loss contained in the reference voltage it receives from the hub. Taking into account the distance of the cable, the balun can then automatically compensate for any signal loss. What this means for the end-user is a consistent high-quality video signal to every TV without the need to make any manual adjustments, whether the system consists of 50 TVs or thousands.
Why Does An Active RF System Make the Most Sense for Large-Scale Video Distribution in Businesses?
More companies that need to distribute high- quality TV on a large scale are choosing an active RF system. The cascading process offers plug-and-play capability that makes it easy to execute changes without needing a high level of technical expertise. RF broadband TV distribution over Cat cable results in no network bandwidth consumption. This can help companies avoid the frustration and even the potential loss of business that can result from slow or unresponsive data networks.
RF video distribution systems can have a positive impact on what matters most: a business’s bottom line. Good-quality active RF systems can require little in the way of maintenance or upkeep, helping to minimize any associated operating costs. Because little technical knowledge or skill is required to make modifications, companies do not need to incur additional labor costs when system updates become necessary. While a business owner may experience higher upfront costs with an active RF system, the return on investment can offset this initial expense over time. What About New Building Design and Construction?
At some point, a thriving commercial enterprise may need to move its operations to a larger, newly constructed facility. By incorporating Cat cable into the horizontal distribution during the design and planning stage, the building’s cabling system can easily accommodate an active RF video distribution system. In fact, the use of Cat-6 cable is now considered a best practice in the construction of commercial/business, government, healthcare, hospitality, and educational facilities.
Cat Cable Is ANSI/TIA 568-C Series Compliant
The TIA 568-C standard states that the maximum horizontal distance of Cat cable from closet to destination is 100 meters. Active RF distribution systems are designed to adhere to this standard. The use of rackmounted video hub technology, as opposed to the wall-mounted technology employed by coax-based systems, also complies with the TIA standard.
Expanding RF Video Distribution System Reach With Fiber Optics
Some businesses operate several facilities that are spread out over a specific geographic market. An active RF video distribution system is fiber optics-compatible, which can effectively expand the system’s reach. With the use of single-mode optic fiber, the RF system backbone can cover a 25-plus-km (15-plus-mile) radius, making it ideal for campus or branch office operations.
An active RF video distribution system over twisted-pair cable may be the best choice for any business that’s planning to install high-definition video or replace a legacy coax system. The ease of adding hubs and baluns to the system along with the superior bandwidth capacities help alleviate any concerns over future enhancements and modifications.
Dick Snyder is principal/VP of marketing and sales at Z-Band Video.