CCTV moves online
IP-based digital video surveillance grows up.
By Ellen Messmer, Network World | Network World US | Published: 00:30, 29 December 2006
Video surveillance has traditionally been a closed-circuit analogue affair run by the physical security staff. But with the rise of IP-based digital systems, video surveillance has become another application on the corporate network managed by the IT department.
Motion-activated digital surveillance cameras, including those from Mobitex and Axis, are IP-based and capture better detail than analogue cameras, with video footage typically stored in corporate servers and shared over IP networks. But digital cameras tend to be almost double the price of analogue cameras, so organisations think twice about throwing their old cameras out. A transition step often involves converting analogue to digital streams to transmit video surveillance traffic over corporate LAN and WAN links.
That's the approach that the state of Utah is taking in two separate agencies, the Utah Department of Alcoholic Beverages (UDABC) and the state's Department of Transportation.
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The Department of Transportation owns 700 miles of fibre-optic cabling, and among other purposes, it's been used to stream traffic from 445 analogue cameras from several manufacturers, including Pelco, back to a central data transportation monitoring centre in Salt Lake City.
Richard Manser, the department's specialist for intelligent transportation systems, says the agency is halfway through a process of converting analogue video streams to digital through hardware upgrades, decoders and changes to its Transcore management application to support IP-based monitoring.
"IP Ethernet is much more flexible," Manser says. "Analogue requires dedicated fibre strands for each group of eight cameras. The cameras are streaming all the time and tying up bandwidth, typically 4.5 to 6Mbit/s per second per camera. With IP-based digital video, you can use on-demand and multicasting, which definitely is less bandwidth. Maintaining it is easier because we have people in IT experienced in network management."
UDABC, which controls liquor sales in the state, also decided on a similar analogue-to-digital transition step for its 38 state-run retail liquor stores that are monitored for theft by Toshiba cameras.
"We can convert the analogue Surveillix-brand cameras from Toshiba with their video-capture board now," says Kevin Perry, UDABC's tech support specialist supervisor. The state agency would prefer fully IP-based digital cameras because "digital's quality is better and analogue cameras are not motion-sensitive." But due to considerations about expense, the decision was made more than a year ago to make a gradual transition.
If a store manager suspects a theft has occurred, a review of video footage stored locally in servers may result in a video extraction that can be remotely viewed by authorised state employees or law enforcement.
The decision to share video surveillance footage over the state's WAN prompted bandwidth questions.
"We first looked at streaming 100 percent of the data from the cameras across the network" to the UDABC's main data centre in St. Lake City, Perry says. But with 15 frames-per-second (FPS) video taking up about 2Mbit/s of bandwidth, that idea was viewed as too bandwidth intensive. The state of Utah decided to set up storage-area networks locally in the liquor stores to warehouse a month or two of captured video.
As with other Windows XP-based computer systems, the Surveillix pan, tilt and zoom system has to undergo maintenance. "We do patch management and run anti-virus on it," Perry says.
Privacy laws apply
Managers of video surveillance systems need to be sure they understand the federal and state laws that may apply concerning privacy, Perry points out. And there are laws specifically prohibiting recording conversations so surveillance systems typically are visual but not audio recorders.
Network-equipment giant Cisco is bullish on IP-based video surveillance, getting into the business earlier this year through its acquisition of SyPixx Networks, a maker of physical-monitoring systems that support both pure digital IP-based video cameras or analogue-to-digital and digital-to-analogue traffic.
"98 percent of the installed video cameras are analogue today," says Mark Farino, general manager of converged security in Cisco's Emerging Market Technologies group. Farino says Cisco's strategy is to support the transition from analogue to digital, while introducing innovations of its own in the coming year.
Corporations can use the SyPixx gear to stream video traffic captured by different manufacturers' cameras over IP networks into the Linux -based SyPixx storage system, while the Stream Manager application enables viewing live video and playback of recorded video based on an interconnection of IP-based or analogue cameras.
Another firm, VidSys, also provides a way to integrate digital and analogue video surveillance cameras through its software, VidShield.
"A digital camera costs almost double the price of an analogue one, although prices are dropping, says Tony Lapolito, vice president of marketing. "So we're open to using anyone's decoders, encoders, cameras, storage and digital video recorders," with a VidSys integration project typically costing about US$70,000.
Integrating with physical security
Next year, Cisco -- which is dropping the SyPixx equipment name -- expects to introduce upgrades for IP-based video surveillance. Farino says Cisco is working on ways that its video surveillance system would be integrated with physical badge systems so a camera could be activated to zoom in on someone wearing a specific badge and be able to follow that individual.
Cisco also is working with IBM on its Smart Surveillance System announced in November, software that IBM says will provide advanced monitoring and stored search capabilities.
"IP-based surveillance is the future," says Gartner analyst Jeff Vining. "It used to be expensive but it's now mid-range."
Some of the most impressive technologies are to be found in the IP-based cameras, including Mobotix, and the search-and-retrieval systems from vendors such as 3VR Security, ObjectVideo and VistaScape Security Systems, Vining says.
IP-based digital video surveillance offers enormous flexibility in monitoring and archive search, but organisations should ensure video traffic is encrypted for security purposes, Vining adds.
In the most advanced systems, the software found in the camera picks up motions and can identify the difference between a "simple hug" of a person and "if I'm trying to strangle you," Vining says. To successfully use IP-based digital video, it pays to have a good infrastructure, Vining notes -- or use a dedicated network.
Cisco director of engineering Mark Geiger says bandwidth allowance depends on the camera's frames per second and the compression and pixel range. For example, a camera in MPEG-4 Compression Image Format running at 30 FPS would require about 3Mbit/s bandwidth.
At Mobotix, the German-based maker of IP-based digital cameras, CEO Dr Ralf Hinkel says the Mobotix cameras are designed specifically to lighten the network load.
The high-resolution IP-based Mobotix cameras for indoors and out contain Linux-based computers with software designed to store the recorded video footage triggered through motion detection rather than streaming it continuously to a server for processing.
The end result, according to Hinkel, "is that the camera does the recording because it's a PC, with 64MB for six minutes. It's motion sensitive, so if nothing happened, there's no network load from the camera." When transmitting video, the digital camera establishes a Secure HTTP tunnel to a designated computer storage system through a buffering process.
The 1.3 Mpixel Mobotix camera, supporting 30 FPS, also is a "standard IP telephone" based on SIP, Hinkel says. The camera can be set up to call an individual's PC and deliver a recorded voice message about a visual event. It costs about $700.
Based on Debian Linux, the IP digital camera has to be updated like any computer via software provided by Mobotix and the camera has a strictly controlled administrative password to deter tampering.