Although broadband Internet connections servicing commercial buildings proliferate, inherent problems present themselves when using these communication paths for constant-use IP security video feeds.

Internet connections can fluctuate in performance and are often of such relatively narrow bandwidths that both the quality and the quantity of video signals must be reduced to fit within the available Internet pipe.

If the Internet connection is shared between the video feeds and enterprise data users, heavy non-security traffic will reduce the bandwidth available for video feeds, causing sporadic video slowdowns or outages.

A larger problem is that pushing security video over the Internet involves Internet service providers (ISPs) whose service may degrade or fail. ISP issues can be reflected onto security integration companies, because clients may blame the installing security company if a system fails when the problem may well lie with one of the ISPs servicing one end of a communication link or the other.

To maximize the value of IP-enabled video security systems, users want to be able to remotely access cameras and encoders from remote locations. If Internet connections are not optimal, what are the alternatives?

Fiber optic connections are ideal, because they provide RF- and EMI-free communications over great distances with huge potential bandwidth. Fiber is the choice if the fiber cables are pre-installed; new installations of fiber around an urban area or building campus may be difficult, time consuming, and certainly will be expensive.

Many installation companies are looking at wireless mesh networks to provide a large-bandwidth, high-security communication path to transmit IP security video around a client’s building campus or an urban area.

These systems operate on the existing 2.4 GHz and 5 GHz frequencies that are currently used for 802.11b/g Wi-Fi communications.

As seen in the graphic, mesh networks allow redundant paths of communication while potentially working around a topographic or man-made structure that may block the line of sight between two locations. Various types of antennas are available that can concentrate the transmission power in a specific direction, allowing the possibility of connections that are a mile or two apart, provided that line of sight can be achieved. IP access control, intercoms and other security signaling can be transmitted over the same mesh network as IP video. Dual frequency transceivers provide full-duplex communications, with data moving simultaneously between two network nodes.

Wireless mesh networks are the answer when many IP security cameras or other devices need to be securely connected across limited geographic areas.

When planning such an installation, it is very important for security integrators to consult with the chosen manufacturer. A careful site survey must be performed to verify device placement and antenna selection.


June 1, 2007 -- (Reprinted with permission from SDM magazine, Copyright 2007)