Top 6 power and connectivity considerations in video surveillance
An effective video surveillance solution is the sum of many parts. While it may be easy to focus on the most ‘visible’ elements – such as the cameras and the video recorders – an installation will only meet a customer’s needs if every aspect works effectively and in harmony.
It might seem obvious that a camera or another network device needs to get power and send data over the network. But the power and connectivity aspect of a video surveillance solution is not always straightforward. In this blog post, we explore six key power and connectivity considerations that will help you successfully plan your video surveillance installations.
1. Considering power and connectivity from the planning stage
While providing power and data connections might seem simple – particularly when power over ethernet (PoE) gives a ‘single cable’ solution – there are numerous considerations that need to be taken into account and which are unique to every installation and use case. Failure to consider these during the planning phase can potentially result in poor solution performance, interruption to operation, unforeseen costs and increased maintenance.
The power and connectivity requirements of any specific solution need to be considered at the planning stage, ensuring that you are well-prepared and equipped when on-site with the customer.
2. Geographic location of the surveillance solution
The first question to ask is, where in the world are you? Or, rather, where in the world is the surveillance installation?
Geographic location can have a number of implications. From a technical perspective, given the differences in regulation that can apply across the globe, is the product you’re planning to install certified for use in that region? Again, thinking beyond just the video camera and recorder, it’s essential that every component in the system is certified for the specific region or country. Failure to do so could, at best, invalidate warranties; at worst it could affect the solution performance.
The reliability and robustness of the power grid can vary from region to region around the world. In some areas this can mean ‘brownouts’ (a drop in voltage across the power network), which need to be taken into account. In addition, power surges, which can cause substantial damage to devices, are an issue that it is critical to protect against. These can be particularly common in locations where electrical storms are a frequent occurrence, but can be caused by a variety of factors. In areas with a high likelihood for a power surge, a surge protector can be installed to shield the network device.
Another important external factor to consider is ambient temperature. Even without the effects of climate change, some regions of the world are either typically very hot, or very cold. Both extremes can have an impact on the power and connectivity solution employed. For example, could a midspan start up a product when it is -40 degrees Celsius (which coincidentally is also -40 degrees Fahrenheit)? Or would a midspan still have the same efficiency in very high temperatures given that it also creates heat itself? In this environment you might want to go for a robust, industrial grade midspan with a wide operating temperature.
3. The physical environment for surveillance devices
At a more local level, the approach to both power and network connectivity will be impacted by the physical environment the network devices are located.
Power and connectivity products for cameras placed externally will clearly need to be able to withstand potentially severe weather conditions, just like the cameras themselves. There is little point in a camera being designed to prevent water finding its way inside the casing if the power connections aren’t similarly robust, and certified as such.
Similarly, cameras located on poles will be designed to withstand high winds, and it’s essential that the same conditions won’t cause connections to become loose. An outdoor midspan, an outdoor network switch or an enclosure cabinet is suitable for such a user scenario.
The need to prevent connections working loose is also important for cameras placed inside. In some environments – for instance industrial plants – vibrations from machinery can loosen connections, not only resulting in a potential loss of data connection or power, but in more serious instances creating a fire or even explosion risk (some of the most catastrophic of which can be dust explosions).
On the subject of dust, in such locations it’s essential to choose power and connectivity components that have been suitably rated to prevent even the smallest particles finding their way inside them. For such an environment, you should look for power and connectivity products which are explosion-protected or have been specifically developed for hazardous areas.
The distance between a camera, its power supply and data storage can potentially be hundreds of meters, if not more. Power and the quality of network connectivity can deteriorate over distance, and it’s important to specify the appropriate connections to mitigate against these risks.
For connections up to around 100m distance, the best solution is Power-over-Ethernet (PoE) – where both power and data connection are provided through the same cable. PoE will still likely be the most appropriate solution for further distances – up to around 1km – but the use of PoE extenders will be required.
Once beyond 1km, the solution will need to consider separate power and data connections. Power may be drawn locally – for instance from infrastructure such as streetlights – while a fiber connection will be the highest-quality solution for data. This is where media converters come to the fore, interconnecting copper-based cabling systems to fiber optic-based cabling systems.
4. Type of devices and components to power and connect
Different cameras – and other network devices – will have different power requirements, and these need to be taken into account when planning the power budget for the total surveillance solution. A fixed dome camera requires less power, for instance, than a powerful pan, tilt, zoom (PTZ) camera. On device power up there’s a ‘handshake’ between the camera/device and the power network where the device communicates the power it will need for its operation. Cameras that have fluctuating power needs will specify the maximum power they might ever need to operate fully.
It’s also important to consider, however, that other connected components forming part of the solution, for example a PoE extender, will also require power themselves. The use of midspans supporting devices with different power requirements solves this issue for installers.
5. Using existing infrastructure
In a perfect world, system design starts with a clean sheet of paper and the ambition to make the best use of new technologies. But this isn’t always the case in reality. For various reasons, customers might need to use existing infrastructure as part of the power and connectivity in their surveillance system.
Again, the use of midspans will enable PoE from existing network infrastructure. And old analog surveillance solutions can be upgraded to network video through the use of adapters that bring PoE to existing Coax cables. There’s no need to rip and replace in making the move to network video surveillance from analog.
6. Building the strongest surveillance solution
A chain is only as strong as its weakest link. Every component and connection in a surveillance system, from sensor to server, has to work reliably if the solution is to deliver the functionality and quality required. In sourcing components from a single vendor – including power and network connectivity – you can rest assured that all elements have been designed and tested holistically and as an end-to-end, connected solution. At Axis, you can find a complete range of power and connectivity products and make the most of your video surveillance solution.
More information about the Axis power and connectivity portfolio can be found here.
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