While the futurists in our industry tout the improved benefits of IP networked CCTV surveillance and insist that all should switch immediately to it today, the realists know that such a drastic, immediate change is sometimes not possible for a host of reasons, including investments in present analog equipment that continue to work successfully.
As CCTV suppliers provide bridges between analog and digital equipment, providing most of the benefits of an IP system while using legacy analog equipment and forging a pathway to ultimate 100 percent IP, too often forgotten is the transmission system. It, too, must be created for later migration. Fortunately, there is a way to implement such a system, providing both a solution for today's system and laying the groundwork for an extremely easy switchover to IP in the future.
RJ45 connectors and hubs that provide power, video and data (PVD) in conjunction with UTP (Unshielded Twisted Pair) wiring create exactly what the great majority of today's CCTV systems should employ.
Straightening Out Today's Jumble of Wires and Cables
It's well accepted that coaxial cable is more difficult to install than UTP wire in most video transmission applications, resulting in higher labor charges and larger hardware costs. In addition, coax systems do not comply with structured standards-based protocols such as 568B, while UTP wire does. Contrary to coax, RJ45-connected, UTP video solutions also provide an ultimate migration pathway to an all-digital solution.
However, far too many integrators and their customers are unaware of this simple remedy. Too add confusion, different trades use different techniques.
For installing CCTV, RG-59 has been historically used by security industry personnel to transmit video signals from the cameras to the receivers. Meanwhile, the telecommunications and data communications industries developed quite different standards. For instance, Token Ring runs on 150 ohm shielded twisted pair, IBM System 3270 runs on RG-62 coax, and Ethernet runs on RG-58 coax. Telephone signals are transmitted on quad wire or unrated UTP wire.
Needless to say, this has created monumental problems for installers. When using RG-59, installers have had to provide a nearby outlet and/or power transformer. Additionally, most P/T/Z control required yet another shielded twisted-pair cable. Between RG-59, RG-58, RG-62 and 150 ohm shielded twisted pair, the industry created a mess. There was no common wiring, bulky coax seemed to exist everywhere, and there was no way to organize and manage all of it. As multiple systems came to market, the clutter grew larger and more out of control.
As a result, the datacom and telecom industries developed a standard that evolved to what is now known as the EIA/TIA-568B. This common cabling system standard accommodates all applications in datacom and telecom. But, for the most part, security systems installers continued using RG-59.
Power, Video and Data - All on One Small UTP Cable
Contrary to the above, unshielded Twisted Pair (UTP) will transmit all signals within one 4-pair cable. For leading integrators, this type of video transmission technology is now widely accepted as a transmission option along with coax and fiber. Installers can deliver a high quality picture over the same wire used by phone systems. In fact, most facilities already have UTP cable for their phones and datacom needs. However, that's only the beginning.
Today, there is a full range of passive video transmission hubs featuring RJ45 connectivity (the same used to plug in your phone or computer) that are specifically designed for installers specializing in implementing digital-ready structured cabling systems in accordance with structured cabling standard EIA/TIA 568B. These new RJ45 video-input passive hubs let end-users and installers employ new or existing unshielded twisted pair wire (UTP) to deliver a high quality picture while cutting costs and simplifying installation versus standard coaxial cable.