DoD’s new cabling standard calls for using single-mode fiber and CAT 6 cable
The diagram shows the likely configuration of such an installation. Government and military installations currently rely on television-distribution systems to transmit important programs such as training videos, command broadcasts and satellite transmissions. In addition to those operational uses, TV is a source of national and international news, sports and live entertainment for troops at military facilities, and a respite for patients, family and staff in military and veteran’s hospitals.
Radio frequency broadband distribution using Category/twisted pair cable is revolutionizing the way television is distributed and received in military and government environments.
With the aid of new RF television distribution technologies, high-bandwidth, unshielded twisted pair cable (CAT 5e/6a UTP) is now replacing traditional coaxial cable in many government buildings. In fact, it is becoming the cabling of choice in the design and construction of new structures.
End-users enjoy the benefit of a clear, reliable, high-definition signal that is simultaneously distributed to hundreds of televisions without the heavy bandwidth consumption that is an issue with alternatives such as IPTV. Active RF broadband systems over CAT cable can also provide the seamless convergence of data, voice and video using only a single piece of cable, thereby gaining precious conduit space in the process.
CAT CABLE DESIGNS
The transition from coax to CAT cable is made easier because many government and military facilities already have the wiring infrastructure in place to accommodate a RF/CAT distribution system, and can do so without having to run a separate CAT cable. The typical 10/100 Ethernet cable network uses only four of the eight pins found within a CAT cable, leaving four pins available for RF video transmission and video-on-demand functions.
In addition, the use of CAT cable is rapidly becoming a best practice in the design and construction of new government and military buildings, with the master-antenna systems at those buildings being used to accommodate a RF-television signal by incorporating CAT cable into its horizontal distribution. The system can also be specified within the “Division 27” portion of the design package, enabling the elimination of coax cable in the horizontal, and the standardization of CAT cable.
DOD INSTALLATION COMPATIBILITY
Twisted pair RF distribution systems are also compatible with the Department of Defense’s new cabling standard that requires the use of single-mode fiber and CAT 6 cable in place of coax cable on military bases and other installations. Single-mode fiber is especially important for any “secure compartmentalized information facility,” as no copper (coax) cabling is permitted to enter a SCIF for security reasons. TPRFD systems are now available that include a fiber receiver in the video hub.
While TPRFD requires the installation of a balun at each TV, that offers the benefit of an extra level of security that would prevent a technically-savvy individual from tapping into a piece of coax cable and accessing the system for non-authorized use. Should that occur it could compromise signal integrity and cause problems elsewhere in the system. With a TPRFD system, an active balun converts the balanced signal traveling over the twisted pair back to an unbalanced signal required at the TV, helping to condition and maintain signal integrity.
TWO TYPES OF RF SYSTEMS
Military and government installations can choose between an “active” and “passive” system to distribute RF signals throughout their facilities.
With an active distribution system using CAT cable, the signal is transmitted via a master unit, or video hub (not a switch), which can be connected together as needed (up to four in a series) through a process known as “cascading.” Using automatic gain control technology supplied by the master unit and cascaded through the additional hubs, remotely powered baluns at each TV provide automatic amplification and equalization of the TV signal, with the result being consistent high-quality TV throughout the facility.
Active systems are highly scalable a feature that is particularly attractive to mobile/non-permanent military installations for the system’s “plug and play” capability enables additional hubs and baluns to be added quickly. Video distribution to thousands of TVs is available from a single source using CAT cable. Because little technical expertise is required for set-up and maintenance, labor costs are significantly reduced.
The passive system alternative is much more labor-intensive and requires the use of additional splitters, amplifiers and other external components. Users may also face limitations on distribution distance and channel availability. Therefore, passive systems are normally recommended for use only with smaller video systems.
TPRFD AND IPTV INSTALLATIONS
While Internet protocol television is attracting attention, IPTV also faces numerous challenges that have to be dealt with before it can become a widespread, cost effective video-distribution solution. In particular, there are ongoing issues with transmission priority within the IP stream, and lingering legal issues regarding content that must be resolved.
In the interim, an effective solution is to use an active RF video-distribution system to deliver both RF and IP content over a single CAT cable. Users can deliver the majority of their entertainment content via RF while also integrating IP content for new Web/Internet enabled TVs. In a military hospital, accessing servers that provide IP-video content used in patient education can be a cost-effective video distribution solution. IP can also work well for internally generated video via IP camera or other devices for signage and mass alerts.
An active RF video-distribution system offers the flexibility to combine RF and IP content in a manner that maximizes the best that each technology has to offer. Users have the ability to customize video content to meet specific television needs.
THE FUTURE FOR GOVERNMENT, MILITARY
A reason RF video-distribution systems are expected to continue to grow in use by the government and military is because of their excellent future proofing potential. The system’s superior scalability and flexibility, which can be enhanced with the use of single- mode fiber optics in conjunction with CAT cable, can make it compatible with the ever changing and evolving needs of an institution. The superior bandwidth capacity offered by CAT 6, and single-mode fiber cable in particular, can meet the challenges of expanding broadcasting/distribution requirements.
In addition, an important RF advantage is that the reduced strain on the network leads to greater reliability and decreases the chances of interrupted or lost service and vulnerability to viruses, which are of prime importance for effective government and military functionality.
Joe Dalto is the director of government sales for Z-Band Inc.