Existing analog cameras continue on coax (or other) cabling and their signals are encoded prior to connection to an NVR or VMS (some units have built-in encoders), and IP cameras connect via Ethernet cable — CAT 6 — to a network switch. Another option along the migration path is to replace the existing analog cameras but, if they still have plenty of useful life, you can reuse the existing coax cables with converters at the camera and network switch ends of the cable. The cost is about $150 for the two converters which is considerably less expensive than replacing the cable. The video network that is now added (cable and switches) can be dedicated to the video system with no connections to the corporate network or can be part of the IT department’s infrastructure.
Full IP: The last step on the migration path is an all-IP solution with new IP cameras, Ethernet cable, network switches and an NVR/VMS head-end. To make most economic use of the existing IT infrastructure, the video network should be part of the corporate network, although a dedicated video network may still be an option.
Most network cabling uses Category cable which consists of four twisted pair of solid copper. Different grades of Ethernet cable — CAT 5, CAT 5e, CAT 6 and CAT 6e — have different performance characteristics, typically related to transmission speeds, but all of them are specified for distances up to 300 ft. between the IP device and the network switch.
If your IP device is further away and adding a switch as a repeater is not an option, alternative cabling schemes with Ethernet converters need to be considered. Candidate schemes include the use of coaxial cable for transmission up to 1000 ft., or fiber optic cable for transmission over miles. Fiber is for connection to exterior cameras where electrical surges from lightning strikes are a possibility.
The Ethernet cable will transmit video data from the camera to the VMS, camera configuration data back to the camera, and, if the device is a pan/tilt/zoom model, it can also transmit positioning data to the camera.
Whereas analog cameras require a separate power cable, an important benefit of using IP cameras with Category cable is the availability of Power-over-Ethernet (PoE). In addition to providing data signals, a PoE network switch can provide up to 15.4 watts (standard) or 25.5 watts (PoE Plus). A power injection device, separate from the network switch, can also be used. This is certainly enough power for most fixed cameras (make sure that the camera specs state that they will work with PoE power) and also most PTZ cameras. Separate power cabling is probably required is the camera requires environmental conditioning — heating and/or cooling.
Planning and Coordination with the IT Department
As discussed earlier, once you step foot in the IT department’s domain and look to add IP addressable security devices to their network (or even your own dedicated network), you become subject to their rules. They are tasked with ensuring high degrees of reliability, availability and maintainability for the business information “pipeline” that is their purview.
Security’s requirements for transmitting data — video, access control, alarm and administrative — must conform to their technology and business model without any negative impacts. IT’s planning and implementation processes may be far more rigorous than typically encountered in the security world, and someone on your team needs to understand their brand of techno-speak to successfully negotiate through the jungle.
Some of the requirements may include:
Computer hardware for the security system may need to conform to IT’s standard platform: IT may insist on purchasing and configuring this equipment themselves, including loading their current version of an operating system (OS), communications, computer security and database (DB) software. You must check if these systems are compatible with the security system manufacturer’s current offerings.
IT may require the development of a detailed test plan: This includes running the security system hardware and software configuration in a test environment, which may require the purchase of a separate test system.
IT will want to perform version control: IT will control installing updated versions for all of the support software as well as the security applications software and firmware. The test system noted above would be used to validate the proper functioning of these changes before being released to the production system.