Answers to 12 Commonly Asked IP Power Questions
The move to IP communications has created new power requirements, but also has fostered new power capabilities. Get answers to these 12 common questions about power for IP security.
Security systems — including video surveillance, access control and intrusion protection — increasingly are using digital communications over an Internet protocol (IP) network. Along with that come changes in how systems are powered, including new requirements as well as new opportunities. Here are some key questions that dealers may have about power for IP security systems, along with answers to those questions provided by specialists in this area.
1. What kind of backup power do I need?
Any equipment critical to life safety should be backed up by an uninterruptible power supply so that the device will continue to operate in the event of a power failure, notes Bill Allen, director of marketing for Carrollton, Tex.-based manufacturer Minuteman Power Technologies.
“If it plugs into the wall, it’s good to have protection,” Allen observes.
2. What size UPS do I need?
A variety of factors go into this equation, including minimum and maximum run time and the specifications for the device that needs backup. Minuteman developed a handy online tool at sizemyups.com that automatically calculates load when a dealer inputs information including the make and model of the device requiring backup.
3. Do I have to back up the Ethernet switch or router?
Yes, says Ken Gentile, product manager for Hartford, Conn.-based Fire-Lite Power. These devices generally do not have built-in backup.
If a dealer is installing a dedicated network for the IP security system, the switch, router, or cable or DSL modem will need a UPS backup power. If a dealer is connecting an IP security system over an existing Ethernet network, the network should already have backup. But the dealer will need to check with the client’s IT department about whether the existing UPS will provide sufficient backup time for the security system. And if the UPS will support power over Ethernet (PoE), the dealer should confirm that it provides sufficient power for all PoE devices.
4. What is power over Ethernet (PoE) and how does it work?
One of the advantages of the shift toward IP is that the security industry now can take advantage of technology developed for the broader Ethernet market. For example some video cameras and other security equipment now have the option of using Power over Ethernet, which delivers power over the same cabling that also supports Ethernet communications.
PoE was originally developed to power Wi-Fi access points and VoIP phones, explains David Engebretson, who isSDM’s technology editor as well as the president of Chicago-based security training company Slayton Solutions. PoE doesn’t deliver enough power for desktop computers, which still must be plugged into a traditional electrical wall outlet, he says. But it does provide enough power for some video cameras and other security devices.
Some switches and routers have PoE capability built into them and if a dealer is installing a new switch or router to support an IP security system, it’s a good idea to select equipment that supports PoE. Using PoE can help minimize cost and installation time by eliminating the need to provide traditional power at every device location.
When a dealer is using an existing switch or router that doesn’t support PoE, PoE capability can be added by installing a PoE mid-span device between the switch or router and the devices connected to it.
5.Can I put PoE and non-PoE devices on a PoE network?
PoE systems have built-in intelligence that prevents them from attempting to deliver power to non-PoE devices such as desktop computers that may be connected to the same network, Engebretson notes.
6.What is the maximum distance between the PoE device and the equipment it is powering?
When used over structured cabling, PoE standards specify a maximum separation of 100 meters (just over 300 feet). In comparison with analog systems, “IP systems require a bit more planning,” explains Ronnie Pennington, national accounts manager for Brooklyn, N.Y.-based manufacturer Altronix. “With analog . . . distance wasn’t much of a factor as RS485 could go thousands of feet. Distance is limited more by the amount of power an edge device requires than by data communications.”
John Oliver, senior vice president of marketing for LifeSafety Power, advises dealers to install the PoE mid-span device near the center of a building to increase the likelihood that no span will exceed 100 meters.
7. What are the different PoE standards?
There are two different PoE standards, Engebretson explains. The 802.3af standard, which some people refer to as a 15-watt standard, is assured to provide at least 12.95 watts at the end of a 100-meter copper structured cabling span. The 802.3at standard, sometimes referred to as a 30-watt standard, is assured to provide 25.5 watts of power at the end of a span. PoE equipment that works over coaxial cable is also available, and maximum distance is increased when coax is used.
It is critical for the switch or router and all PoE devices connected to it to conform to the same standard. Additionally dealers should make sure that the total amount of power required for all PoE devices connected to the network does not exceed the maximum capacity of the system.
Some PoE equipment actually exceeds PoE standards, notes Joe Holland, vice president of engineering for Mundelein, Ill.-based LifeSafety Power. He notes, for example, that PoE equipment delivering up to 60 watts is available.
Alternatively, some manufacturers offer PoE equipment that is designed to exceed the maximum distances specified in the PoE standards. Pennington notes that some PoE equipment has a maximum range of 500 meters when used over Cat 5e or Cat 6 structured cabling networks.
8. Can I use an extender to increase the distance between the PoE mid-span device and the device that needs power?
An extender is a device added along a standard PoE Cat 5e span that exceeds 100 meters to increase the reach of the technology. Holland cautions, though, that a PoE mid-span device will not deliver its full wattage beyond the 100-meter mark. Dealers should consult the manufacturer’s specifications for details.
9. Can I use all of the ports on a PoE device at full wattage?
The answer depends on the manufacturer, explains Holland, Some products with, for example, four ports and a 30-watt rating might be capable of delivering full wattage to each port, while others might only be able to deliver 30 watts in total.
10. Do I need to back up the PoE device?
This answer also depends on the manufacturer, Holland observes. Some PoE mid-span devices have built-in backup power while others do not. Those without it need to be connected to a separate UPS.
11. What is managed PoE or a managed UPS?
Another benefit of the shift to IP is that more information can be communicated across the network than with analog systems. Managed PoE and UPS systems use this capability to send alerts about the system.
“With the communication available today, the integrator can generally know if the system is up or down before the proprietor,” Holland shares.
Authorized users also can use a Web browser to check on system status.
12. What is SNMP?
SNMP stands for “simple network management protocol.” It’s a standard that was developed to enable computer network managers to communicate with network devices — and vice versa — for operations and maintenance purposes. It also underlies managed UPS and PoE systems — and as Holland explains, the Security Industry Association is currently working on a new version of the standard designed specifically for the physical security industry.
“SNMP is going to be a term that security resellers are going to have to be familiar with,” Allen predicts.
These 12 questions address some of the common challenges with powering IP security products. Since the usage of IP products is only escalating in the security industry, expect more new power requirements and capabilities to continue to emerge. n
New Adaptive Transmission Solutions Drive Networked Systems and Integration
It used to be that upgrading from analog to IP video surveillance and access control was only possible by replacing all analog cabling and equipment, which was a very costly and laborious proposition. Fortunately legacy infrastructure is no longer an issue with the availability of new highly efficient adaptive transmission solutions. Over the last 12-18 months, these devices have made a significant impact on the market by changing the landscape for system design and deployment.
New adaptive transmission solutions fall into three primary infrastructure solution categories:
- Ethernet over Coax
- Ethernet over UTP (twisted pair)
- IP over long distances
New Ethernet over Coax solutions provide several distinct advantages and benefits. First and foremost is their ability to accommodate IP edge devices without the need to rip and replace coax with Ethernet cabling. These Ethernet over Coax solutions can transmit video and data signals, and pass or inject PoE, PoE+ and even High PoE (60W) over distances up to 500 meters without repeaters. That’s five times the distance of conventional Ethernet. You can also deploy multiple cameras or edge devices over a single coax cable to cost-effectively expand system capacity. This provides system designers and installers with extreme versatility when upgrading from analog to IP. Receivers are available with 1, 4, 8 and 16 ports to accommodate virtually any system capacity.
Other legacy systems utilize UTP (single twisted pair) cabling. Recently introduced Ethernet over UTP solutions allow this legacy infrastructure to be upgraded to accommodate IP security. Currently available in single port transceivers and receivers, Ethernet over UTP solutions can transmit video and data up to 150 meters – 1.5 times the distance of conventional Ethernet without the use of repeaters. These units also pass power to cameras and edge devices from virtually any midspan or endspan. This provides a highly cost-effective plug-and-play IP solution that is easy to install and implement when upgrading UTP.
The other benefit new adaptive transmission devices provide is the ability to dramatically increase the transmission distances of conventional Ethernet infrastructure, which is limited to 100 meters. In fact, Ethernet cabling can now be deployed at distances up to 500 meters without the need for repeaters. This allows you to increase the range of your security coverage along with the flexibly to locate cameras and edge devices at distances that were not previously possible. It’s an ideal solution for large venues such as distribution centers, arenas and stadiums, malls, airports and campuses.
There are single and multiple output midspan injectors that provide PoE, PoE+ and High PoE (60W) for indoor and outdoor applications. These midspan injectors complement virtually any edge device and adaptive transmission solution to provide even greater design and deployment versatility.
The possibility exists to utilize these various new adaptive transmission solutions to integrate disparate infrastructure onto a single platform. This provides a highly practical and cost-efficient solution within large, mixed-use facilities and between stand-alone structures. The ability to integrate otherwise disparate infrastructure is a game changer as systems continue to grow in size, and as security management looks to integrate diverse video, access and security systems. This trend will only continue to grow as more communications and system management capabilities become available at affordable price points. — Contributed by Alan Forman, president, Altronix Corporation
IP Systems Also Require Re-Thinking Cabling
Unlike with analog devices, the equipment used in an IP-based security system is interconnected using structured cabling — the same type of two-pair twisted wiring and associated jacks that typically are used to connect computer work stations on a local area network to a switch or router in the client’s telecom closet.
When installing an IP camera, access control or security system, security dealers may have several choices, explains David Engebretson, Slayton Solutions.
If the client already has structured cabling in place to support a computer network, it may be possible to use that network in one of two ways.
One way is to simply add the security devices to the existing network by connecting them to unused jacks on the existing network — after coordinating any required switch or router reprogramming with the client’s information technology department. This saves the expense of installing a switch or router, but may be more complicated to manage as any changes or troubleshooting need to be coordinated with the IT department.
Alternatively, when the initial cabling was installed, the company that did the installation may have installed parallel structured cabling by running additional two-pair twisted cabling and connecting it to a second socket on each jack. This parallel network may be unused.
If so, and if the structured cabling was installed correctly, it may be possible for the security dealer to install its own switch or router in the telecom closet and connect the IP security devices to the unused jacks connected to the switch or router. With this approach, the security dealer establishes its own IP network that is separate from the corporate network, minimizing the dealer’s reliance on the IT department.
In any case, dealers should test the existing structured cabling before using it for a security system. Even if the customer has a functional local area network, Engebretson notes that it is possible that specific segments of the existing cabling may not be of high enough quality to assure sufficient bandwidth or, in the case of a power over Ethernet network, may not assure sufficient power. He advises testing with a time domain reflectometer so the dealer can make sure the cabling does not exceed distance limitations.
If the client doesn’t have a computer network or doesn’t want the dealer to use existing network resources, including any unused structured cabling, the security dealer may have to install its own structured cabling network or arrange for someone else to install it.
In this situation, the dealer should make sure that the structured cabling is installed in compliance with standards. Structured cabling standards are established by the American National Standards Institute (ANSI) and the Telecommunications Industry Association (TIA) explains Sam Hen, product specialist for Fullerton, Cal.-based cabling manufacturer ICC.
Hen advocates the installation of Category 6 wiring, which he says has better performance than Category 5 wiring. For example, he says video picture quality may be superior for cameras connected via Cat 6 wiring.
Another consideration involving cabling for IP security systems is whether to use power over Ethernet (PoE) — an option that uses structured cabling to deliver power to security equipment as well as to provide data transmission. See the main story for details about PoE.
Media Converters Open Up Other Options
When a dealer is upgrading a client’s existing analog video system to a digital IP-based system, there may be an alternative to using structured cabling, explains Frank Haight of Comnet.
“If there is fiber in place for the analog cameras, you can take out the cameras, put a fiber optic media converter there and use the existing fiber cable,” observes Haight. As he explains, the media converter enables an IP camera designed to connect to structured cabling to connect instead to the existing fiber, which typically already runs to the telecom closet. There the fiber from the camera can be connected to an Ethernet switch with a fiber port, notes Haight.
If a switch doesn’t have a fiber port, Engebretson notes that a dealer may be able use another media converter in the telecom closet to convert the fiber signal from the camera so that it can connect to a port designed to accept copper structured cabling. Engebretson also noted that media converters are available to enable an existing coaxial connection to connect to an IP camera or Ethernet switch designed to accept structured cabling.