Flexible video structure.
The efforts of installers are aimed at developing flexible solutions that combine the functions of analog and digital equipment, — today such a solution is Hybrid Video.
The factors that will determine the gradual replacement of analog video surveillance systems with IP-based systems are operating features, budget and flexibility of use. The latter factor concerns not only the product, but also the means of transmitting video images.
To best meet customer preferences for camera, image transmission and headend technology, CCTV installers are looking for solutions that integrate their existing analog and digital equipment. They want to be sure that the flexibility of their current systems will enable them to transition to a fully digital architecture in the future. At the same time, investing in excellent analog equipment today should not be a waste of money in the future.
Most of us are not aware that both analog and IP systems can use exactly the same transmission media. The transmission media are the link that allows for the implementation of cost-effective video surveillance systems that provide the necessary product flexibility according to customer requirements. Such a linking system is usually called a Hybrid IP System or simply a Hybrid System. A typical Hybrid System is based on UTP cable (unshielded twisted pair cable), it can also include fiber optics. The flexibility of a hybrid system based on UTP cable allows the use of modern cost-effective analog video cameras and recording systems, while providing an IP-ready solution that may be needed in the future, thanks to the use of a standard structured cabling network of the building.
The need to use a structured cabling network in all video surveillance systems
The transmission media used in a hybrid system reduces system cost and increases product flexibility, regardless of whether CCTV systems use analog or Ethernet (IP) transmission methods. Structured cabling has been used to transmit data over LANs in the telecommunications industry for decades. The network can be installed quickly, can be easily modified, and its performance can be standardized to an industry standard. This performance standard depends on the category of the components used (5e, 6, or optional category 6) and the installation rules developed by the EIA/TIA (Electronic Industries Association/Telecommunications Industry Association).
Coaxial Cable = No Flexibility
Currently, a structured cabling system allows the use of an analog system based on a UTP cable, and also provides the ability to reuse cables if there is a need to switch to IP-based video surveillance systems. If the user of a wired analog video system built on a coaxial cable decides to switch to IP video surveillance systems, then all coaxial cables will become unnecessary and will have to be dismantled. That is, such a system is not flexible and loses relevance over time.
4-pair UTP cable is truly «suitable» for data transmission, both for analog and IP video surveillance systems
The basic topology of any structured cabling network is a 4-pair UTP cable. Since only one pair of UTP cable is needed to transmit analog video, the remaining pairs in the same sheath can be used for other purposes. Typically, one pair is used to transmit video signals, two pairs are used to transmit low-voltage power (mid-line feed), and one pair is used to transmit control telemetry data. Therefore, one 4-pair UTP cable, when connected to a camera, can supply power to the camera, return the video signal, and control the PTZ (pan/tilt/zoom) camera. Three separate cable types are usually used to achieve the same functionality. IP-based systems have the same advantages as 4-pair UTP cable: one 4-pair cable can return the video signal, supply power to the camera (PoE), and control the PTZ camera.
Structured cabling network providing cost-effectiveness and flexibility
The cost of installing any CCTV cable system is significantly affected by labor costs, while the cost of individual components is only a small part of the total system cost. Significant reduction in the cost of commissioning analog video camera systems is achieved by using multi-pair UTP cable (25, 50, 100, 300 pairs, etc.) between the intermediate and main switching boards. Since only one pair is needed to transmit an analog video signal, a 50-pair UTP cable accommodates 50 video transmission channels. A 50-pair cable can be pulled in just one go, while it is almost impossible to pull 50 coaxial cables at once. Thus, pulling one multi-pair cable is significantly cheaper than pulling many coaxial cables.
Conclusions
The decisions made by professional installers should depend on the type of storage media used in the cable video infrastructure, which will provide greater flexibility and timeliness required by the end user. The most common means of data transmission via IP is UTP cable. Regardless of the type of system being installed — analog, hybrid or only IP-based, the UTP system deserves special attention.