As traditional CCTV surveillance starts to migrate towards IP network camera surveillance, a new method of supplying power to cameras via local area network data cables is offering the security industry more cost effective installation of remote video cameras, in locations where separate power outlets are impractical or not available, writes Yuval Berson, Director of Product Management, PowerDsine Ltd.
This means that cameras can be sited where they are most effective, rather than where the nearest AC power outlet is.
Powering Network Cameras over the Ethernet:
Power over Ethernet (PoE) is a technology for the delivery of power as well as data on the same cabling. In June 2003 the IEEE 802.3af Task Force ratified the technology into the Ethernet standard. The standard involves delivering power over existing cable plant, including Category 5, 5e, patch cables, patch-panels and connecting hardware. It is endorsed by all network players that power IP-connected devices, such as security cameras, IP phones and wireless LAN access points over the existing LAN cabling infrastructure. This not only allows for a very convenient and cost-effective method of installation, but also a simple, centralised power protection of the whole installation directly from the switch or wiring closet.
The power delivered over the Ethernet infrastructure is automatically activated when a compatible terminal is identified, and blocked to non-compliant devices, such as desktop computers, laptops, etc. This feature allows users to freely and safely mix non-compliant and PoE-compatible devices, on their network.
Benefits of Power over Ethernet:
Power over Ethernet technology saves on the time and cost of installing separate power cabling, AC outlets and wall points, as well as eliminating the need for a dedicated Uninterruptible Power Supply (UPS) for individual devices – a single UPS can be installed in the comms cabinet and used to back all end devices powered over the network.
PoE technology also offers the benefits of enhanced security through remote management; reduced downtime; and lowered installation and maintenance costs. So businesses can upgrade their surveillance system, while reducing the cost of deploying additional network cameras.
Industry acceptance of PoE:
Last year Sony announced that its range of IP video cameras had been tested with PowerDsine’s family of PoE Midspans and Active Splitters for supplying reliable and uninterrupted power using existing cable infrastructure. This eliminates the need for separate power cabling, thereby saving time and costs for surveillance system upgrades to IP.
Sony’s SNC-Z20N model is the first IP camera in the industry to be compliant with the IEEE 802.3af Power over Ethernet standard. With the current SNC-RZ30N; SNC-Z20N and SNC-CS3N models, Sony now offers a comprehensive suite of IP surveillance cameras.
Network industry experts anticipate increasing demand for Power over Ethernet in the IP surveillance market. The latest market analysis from IDC predicts aggressive growth of Power over Ethernet: from 11.7 million ports in 2003 to 134 million ports in 2008. This growth in PoE is being driven by ratification of electrical industry standards and the uptake of IP video surveillance cameras, voice over IP and Wireless local area networks.
Benefits of using the same cable for power and data:
Network cameras are traditionally installed in open high places, such as corridor ceilings, airports or warehouses. Supplying power to these positions used to be a costly and time consuming affair, requiring a team of qualified electricians for the pulling in of power cables, changes to building plans and delays while safety approvals were granted.
Once operating, each surveillance device was connected to a specific electric circuit, which if down, meant an appearance of unacceptable "holes" in the security coverage.
By using PoE, network cameras can be installed where they will be most effective, rather than where the AC sockets are. This means that the actual number of cameras may also be reduced, further reducing implementation costs.
Once devices, such as network cameras or access control terminals are connected to the local area network (LAN) used for transmitting data, they still require power to run.
Power over Ethernet technology enables these devices to be powered over the LAN network, thus avoiding the need for separate power and data cable infrastructure and costly AC outlets near cameras, not to mention the removal of the need to hire qualified electricians for their installation.
The Revolution of Ethernet Based Security Systems
Security systems are only useful if they can communicate with and control the environment they secure. The video streaming from the Closed Circuit Television (CCTV) system should be watched or recorded, otherwise it is useless. In addition, access control devices enable authorised personnel to control the surveillance equipment.
Because of this, the use of readily available and cost effective LAN-based solutions, that permit remote management of the surveillance devices, is becoming more common.
New high-end surveillance cameras are typically dynamic, remotely controlled devices, which can move in all directions, allowing tracking of suspicious events or intruders (Figure 2).
The quick responding motors turn the camera rapidly to scan a larger area. But they also add to the camera’s power requirements.
High-Power PoE for Sophisticated Surveillance:
In 2004 PowerDsine launched the industry’s first high power PoE solution, the high power Midspan, which provides up to 39.5W power (more than doubling the power capability available), as well as data, over standard Ethernet cabling, while still supporting IEEE 802.3af detection and safety requirements.
The high-power PoE midspan now eliminates the need for external power supply and its associated AC/DC power cabling, thus providing a highly cost effective, safe and reliable means to power high power devices, such as Point Tilt Zoom (PTZ) network cameras, which were previously excluded from the advantages offered by PoE.
The new Sony SNC-CS3N and SNC-RZ30N high power network cameras with Pan/Zoom/Tilt capabilities support PoE technology when used with a PowerDsine PoE Active Splitter and PowerDsine’s 6000 Midspan and 8000 high-power PoE Midspan, respectively.
Benefits of Using Power over Ethernet in Surveillance Systems:
? Simple Means for Resetting Digital Cameras – Digital CCD cameras are complicated devices, which tend to need resetting from time to time. On a traditional system, when a "dark" camera requires resetting, the IT manager has to first locate the network camera on the system, reach it and then reset it. By using PoE, this becomes a simple matter of remotely resetting the camera via the its respective PoE port, instead of having to climb up to high ceiling installations.
? Easy Changes to Camera Positions as Needed – Altering a camera position, no longer requires a new AC installation. It is even possible to experiment with the camera position to achieve ultimate coverage results.
? UPS backup for the Security Network – By backing up a PoE midspan with an uninterruptable power supply in the comms cabinet, the entire camera network can continue operating during a power outage. This is imperative for high-end surveillance systems.
Features
Assured Safety with Advanced Line Terminal Detection – Line detection enables safe installation of PoE powered devices without worrying about high voltage damage to non-power ready devices, due to a misplaced connection. A faulty camera or an access control terminal can be detected and shut down, preventing damage to expensive switches and patch panels in the Ethernet network. This line detection is one of the reasons that PoE midspans are much more than an intelligent power source.
Conclusion
As the quality and rates at which video that could be transmitted over Ethernet improved, the arrival of professional CCTV systems, based on digital streaming of video over Ethernet, was a natural progression.
Power over Ethernet offers the security industry clear advantages of easy and cost effective installation. There are also major benefits to be gained through easier remote management of surveillance cameras and robustness of the network in the event of power failure.
