Thursday, January 11, 2018

Economical UPS Systems for Outdoor WiFi Stability

I want to share a bit about a solution that we're putting together for one of our outdoor WiFi customers. Here's a video going through it and below is the blog post for more info!



We do a lot of outdoor Wi-Fi. Whether it's a construction site, an RV park, or for hospitality outside of a resort, we get involved in a lot of projects that require outdoor Wi-Fi coverage.


One of the problems that we run into are pretty frequently is power. It's not just about having power where we need it, it's about the quality of that power. We find ourselves dealing with GFCI's that are tripped all the time, wiring that shuts down out of nowhere, cabling that you don't really want to plug anything into, or brownouts. As an example, when someone comes in and parks a large RV at some of these parks it causes an immediate power drain at the post that can be enough to make a finicky WiFi access point reset.


The more of these outdoor environments we get into, the more important clean and reliable power is. We've always been on the hunt for a battery or a UPS (Uninterruptible Power Supply) or battery back-up solution that gives us the ability to keep our Wi-Fi equipment online through those brownouts or even if there's a short power outage.  Nothing has ever really been too cost-effective but over the holiday break we saw that the 425 model of the APC UPS had a dip in price and dropped it down to about $30. We were able to pick some up on Amazon and thought it would be a great opportunity to test em out and share the results with you all.



 The APC 425 has six three-prong ports on it. 4 of those are battery backed up and surge protection, the other two are surge protection only.

We are going to be testing this out using the Cambium cnPilot 3500 and the Cambium PMP450b Subscriber Module on the same battery. We will see how much run time we can get out of the battery and understand what to expect in a park or outdoor Wi-Fi deployment!


After about 30 minutes the battery went dead. I was expecting it to last a little bit longer, to be honest, but that's plenty of time. When I ran the numbers on each one of these pieces of hardware, I calculated the access point at 8W, max peak of 12.95W and the subscriber unit at 5W, max peak of 10 watts; between 13W and 22W on average. At that draw, the specs on the battery box say that we should get about an hour out of this. I didn't run a power meter to see what the draw was, but I'm guessing it was on the higher-side of the two :)


All in all, I think it's a great product for under $50 to provide at each AP location in a high-demand environment for outdoor Wi-Fi. At the rate we paid for it, it's about a buck a minute that you're paying for to keep these things online. Either way, it should be enough to hold over the wireless gear through a brownout or short power outage!

If you know of any other solutions that are more cost-effective and offer the same run time, drop a comment below!

No comments:

Post a Comment