How analogue and IP surveillance are similar, yet different
FeaturedWednesday June 15, 2011 Written by
If you’re an analogue surveillance system installer, you’re still part of the vast majority as IP systems in North American’s security market have yet to hit 30 per cent. But given the trend in formerly analogue industries such as music, movies and still photography, it won’t be long before the only alternative in the CCTV market will be to go all digital (i.e. IP).
But don’t let the new technology throw you for a loop. IP and analogue surveillance actually have a lot in common. But it’s where they part ways that IP surveillance delivers additional benefits your customers will definitely appreciate.
The easiest way to understand the similarities and difference is to compare IP surveillance to analogue CCTV in the following areas:
• recording devices
• switching gear
Network and analogue video cameras offer comparable capabilities: PTZ (pan/tilt/zoom), fixed box cameras, fixed dome cameras, and thermal cameras. The biggest difference is that a network camera is an intelligent device that creates digital signals within the camera itself. It’s really a combined camera/computer combined device. This provides much more functionality in terms of intelligent video and remote accessibility.
Additionally, though early network video wasn’t as high-quality as its analogue cousin, today’s network cameras deliver industry-standard HDTV resolutions such 720p, 1080i, and 1080p. To understand this amazing boost in image quality, think about how a hockey game used to look when you watched it on your old analogue tube TV compared to the eye-popping colors and sharp detail you now see on a high-definition TV. HDTV-quality network cameras provide a crisper, full-screen image better suited to the 16:9 aspect ratio now standard on large flat-screen video monitors. They also deliver greater clarity and color accuracy than their analogue predecessors, which is so critical to real-time surveillance and forensic investigations.
The recording device for network video serves the same purpose as an analogue system’s DVR. The main difference is that the DVR translates the analogue video feed from the camera into a digital video stream, whereas in an IP surveillance system the network camera does this conversion in-camera. Both systems let you view live data, search recorded data and export data to third parties.
Cost is another differentiator. As a dedicated and proprietary system, a DVR carries a higher price tag than a standard off-the-shelf PC system used by IP surveillance solutions to store network video recording. Being commodity hardware, PC pricing continues to drop even as storage capacity continues to grow.
Remember years ago working with multiplexers and matrix switches? Early version multiplexers allowed you to record simultaneously up to four analogue cameras onto a VCR and/or a quad-view monitor. While 16-port DVRs have since replaced most multiplexers, scaling is an issue because if your customer wants to add a 17th camera, you need to install an additional DVR to handle the load.
In an IP Surveillance installation, however, you can add network cameras in any increment you need, even one license at a time. Instead of hooking up analogue cameras to the multiplexer or the back of a DVR, you can connect IP cameras to a switch or router directly attached to the network. The switch or router allows the recording device to find a path to each network camera video feed. You use routers primarily to connect a LAN (Local Area Network) to the Internet or WAN (Wide Area Network). You typically use switches for managing your LANs. PoE switches commonly come with 48 video channels. But like DVRs, PoE switches also come in 8-, 16-, and 32- port varieties.
Both analogue and IP systems use cabling to create an uninterrupted path from the camera to the recording device. In the analogue world, you use coax cable similar to the kind used in your home. With network video, you commonly use twisted pair cabling. The main difference is how much cabling you need. Analogue systems typically require you to have “home runs” to the recording device and a separate cable for the power supply. With twisted pair you just need a short run to the nearest network switch or router. For PoE-enable cameras, the same cable can also power the network camera. Going forward, twisted pair technology will help you build a far more powerful LAN for your customers. Innovations in twisted pair wiring have led to ever-increasing bandwidth to support growing video traffic on the network. In the 1990s, LAN backbones ran at 10/100mbs. Nowadays 1/10gbs is not uncommon.
Analogue and IP system both let you view live or recorded data on a standard PC monitor. Where they differ is that in the past you might have had a dedicated analogue monitor. But if you are purchasing a system today you would be hard pressed to find an analogue monitor. IP systems have expanded your remote viewing options. In addition to access video streams on a laptop or desktop equipped with a standard browser and an Internet connection, you also can view your video on mobile devices such as smart phones and tablets.
With all the similarities between analogue and IP surveillance technology, the newer systems shouldn’t be any harder to deploy than what you are already installing. As with anything new, there will be some learning curve associated with the switchover. But with so many integrators entering our industry today who are already well-versed in everything digital, the transition from analogue to IP should be virtually seamless.