Powering IP Cameras When Using Fiber
Solving distance issues with fiber optic cable creates a new set of problems. Due to the lack of PoE, users must find a local power source and space for equipment connections, issues not found when using PoE and UTP. In this note, we examine this the logistical problems of using fiber, outlining the reasons fiber may be preferred, and solutions to these issues.
Fiber may be preferable to copper when installing cameras in distant locations, for several reasons:
- Distance: When the camera is more than 100m from the switch, fiber is most commonly used. Other options, such as Ethernet-over-coax converters and PoE extenders may also be used, but are not as common.
- Exposed locations: In areas prone to lightning strikes, users may wish to minimize the chance of equipment or cable damage by using fiber cables, which typically contain no metallic elements, and are buried in non-metallic conduit. Note that some specialized underground and aerial fiber cables may have metallic sheaths or support members, but these are normally found in telco distribution cables, not shorter runs which would be used for cameras.
- Interference: In industrial environments where high voltage equipment is present, interference may quickly degrade cable performance, affecting video quality. Fiber is often used to avoid this.
While these are all valid reasons to use fiber instead of UTP, these scenarios present the question of how to power cameras at the far end. This is is becoming more of an issue, as manufacturers have begun to remove low-voltage power inputs from cameras in favor of PoE-only operation. This means a low-voltage power supply local to the camera, traditionally used in these instances, is no longer an option. Many times users are forced to use a media converter, as well as a PoE injector. While functional, using both of these components requires multiple power outlets and an enclosure at the camera location, which may not be practical, depending on the site.
PoE Media Converters
One way to address these locations is media converters with PoE output. Instead of requiring multiple components, these devices build media converter and PoE injector into the same unit. This reduces complexity at the camera location, points of failure, and the footprint of the equipment. in many instances, such as pole-mounted cameras, space may be an aesthetic and security concern, as large enclosures may be unsightly, and are a larger target for vandals.
There are two main drawbacks to using PoE media converters:
- Local power required: Unlike using UTP/PoE for data and power, when using media converters, local power is required at the camera location. If no power is available, other options must be used, such as PoE extenders, EoC, or others.
- Not weatherproof: Few, if any, media converters are available in weatherproof form factors, with sealed connections. Instead, small non-metallic enclosures are typically used to house the media converter and fiber/UTP terminations. This adds bulk at the camera location, if room is not available in existing enclosures or the pole base. Enclosures are especially important in humid or marine environments, as even hardened media converters may quickly corrode under these conditions.
PoE media converters typically sell for between $300-400 USD online, with some hardened models costing $500 or more. Media converters with PoE output are available from a number of manufacturers, including:
- EtherWan EL1032 series [link no longer available]
- Moxa IMC-P101 [link no longer available]
- Omnitron OmniConverter PoE
- Transition Networks SPOEB family
All of these models are available in multiple configurations, depending on fiber and connector type, with some two-port models available. Note that all of the above offer models with 802.3af 15.4W output. Omnitron is the only one of these options with 30W 802.3at Hi-PoE output, which may be required when using PTZs or fixed cameras with heaters or blowers.
In pole locations without local power available, Berk-Tek's OneReach PoE fiber system may be an option. OneReach consists of a power injector, a hybrid fiber/copper runner cable, and a breakout box with PoE port at the far end. The powered endpoint supplies one or more PoE ports, drawing power from the copper in the runner cable, and data via the fiber. This setup eliminates the need for high-voltage power at the far end of the run, potentially providing savings when compared to having AC power installed in these locations. It also eliminates the need for specialized skills to terminate the fiber cable, since the runners ship pre-terminated.
The OneReach system adds some cost compared to standard fiber cable and media converters. OneReach PoE injectors and remote units can be found for $689 online, with one required on either end. The cost for the runner cable will vary widely, depending on length, termination types, copper wire gauge, and fiber type. Total cost is likely to be $1,500+. Though it is expensive, OneReach supports distances far greater than other PoE extension options, with a maximum distance of 3,850'. It also is the only option which adheres to all cabling standards, making it attractive for users with such concerns.