Keep ST up and connected to internet even in power loss

I’m trying to make ST as reliable as possible as a security system, and that includes getting intrusion, smoke, and leak notifications even when the power is out or internet is down. Most of the security devices are battery powered so they will at least report to ST Hub when there is an issue. Just need to make sure ST can send the notifications to you. For that you need internet and power for those devices 24/7 no matter what.

You’ll need 4 things:

  1. UPS Battery backup
  2. Router with 4G Failover capability
  3. 4G USB Modem for the 4G Router
  4. Sim card with service for the 4G Modem

1) UPS. I am using a $40 APC battery backup UPS
It’s designed for Modems/Routers with low power draw and should last a few hours. My Cable modem, WiFi Router, and ST hub get plugged into this.


2) 4G WiFi Router. The PepWave Surf SOHO ($169) is a 1700AC Gigabit router with 4G and WiFi as WAN Failover capabilities. This will replace my current WiFi router.
It will use your cable modem’s internet connection primarily. If cable goes down, it will then use the 4G USB modem. If you have free WiFi near you, you can also setup WiFi as WAN and use that as failover as well.
The failover happens automatically. Your devices stay connected to the router and this router determines which internet connections to use, with no noticeable loss of internet to your devices (internet speed will obviously vary depending on which connection is being used).
This router has 5 gigabit Ethernet ports, 3 external antenna’s, 3x3 MIMO, 450Mbps on 2.4Ghz and 1300Mbps on 5Ghz concurrently. Has a range of 300’ radius indoors.
There are cheaper options, but these aren’t something I’d want to use as my full time router. If you want to keep your existing router, you could use a cheaper one, plug the cable modem into it, then plug your good wifi router into the cheap 4G router. The cheap 4G Router will provide internet to your good WiFi router, automatically failing over to 4G if your cable goes down.



3) USB Modem. You need to get a USB modem that is compatible with the 4G service you get. Your options are CDMA (Verizon, Sprint, US Cellular) and GSM (AT&T and T-Mobile)
I plan on using a GSM carrier so am getting the AT&T 340U Beam 4G USB modem for around $40. Make sure you get one unlocked.

4) 4G Sim Card and service. Who you go with depends on where you are (coverage) and what you need (data allowance). I plan on only using it for ST when cable modem is down which requires very little data, so cheap is a priority. H20Wireless has 4G Pay as you Go plans for only $3/mo ($10 for 90 days). If you renew within the 90 days any unused balanced rolls over. If you let it expire, not only do you lose the unused balance, but eventually the sim card expires too and you need to get another one. This is typical of most plans. You can find cheap/free sim cards on Amazon.

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Yup, good info. I’ve had my networking gear on UPS for a while, now. In my area, there has to be a really substantial power disruption before my internet service drops, which is nice. For that reason, I haven’t bothered to implement cellular backup yet.

An option for cell provider would be Google’s Project Fi. They have a data-only sim option as an add-on to existing accounts. Not sure of their compatibility with the usb adapter you’ve specified, though.

You also have to have a regular plan with Fi before they let you order a data-only SIM, and you must activate the service first, using an Android phone. I haven’t tried using their SIM on an aircard, but I’d imagine that if you get a Sprint device it should work… not sure about AT&T.

I haven’t considered using my Project Fi SIM on a Verizon aircard I have, but I’ll give it a shot one of these days.

The first part is correct-- you must have a normal Project Fi line first.
The second part I’m not sure about. Their FAQ page makes a distinction between known compatible devices and “other” devices, but they do not state any requirement to active the data-only sim on an android phone first.

Sorry, I meant that you can’t just order Fi and then get a data-only SIM card without going in through the whole process.

You need to sign up / port your number / whatever, get a “regular” Project Fi SIM card, put it in your phone and activate the service using your Android phone and the app. THEN you can go into your account and order a data-only SIM.

Like I said, I haven’t gone through this with my Project Fi account, but I’ll try later and see if I can. All I know is that I couldn’t even order a data SIM before my account was active on a regular phone.

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Ah, yes, that is correct as I understand it. Cellular backup is on my B list of projects, and I’d be interested in hearing how it works with Project Fi. I’ve been generally happy with my ProjectFi service on my primary mobile phone.

Well there’s an interesting idea in this thread still developing which can be a combination / extension of this thread.

The hub doesn’t care what network it’s on, so it doesn’t even have to be on the same subnet – all it cares is that it has internet access.

So you’d have the hub, a wireless hotspot and a network extender connected to a UPS. You’d then connect the extender to the hotspot via WiFi and the hub to the extender via Ethernet. In theory, the hub should have internet access and battery backup.

@Scott_Barton, thanks for this info. It’s useful not only for ST (which does not have a cellular backup), but for any other security system with cellular backup as well. Because the cellular backup in other systems is limited to the base hub. In case of an internet outage, all the other IP devices, such as security cameras, will be disconnected. But the SIM-backed router setup guarantees all your IP devices staying alive.

I think your option of having 2 routers is the preferred one. If you only have a single router, imagine what happens when the internet goes down while you’re home watching Netflix or something. It will switch to cellular, and within a short time your limited data SIM will be depleted, and you will be left with no backup next time you leave home.

What if you make your main router as #1 in the chain, and plug your SIM (cheap) router into the main router (this is the opposite to what you recommended). Connect all your high-bandwidth devices (computers, phones) to the main router. Connect the ST hub, security cameras, and anything else you care about while you’re away into the 2nd SIM router. This way only your critical low-bandwidth devices will stay on cellular during an internet outage. Plus, if you’re home, you will immediately know your internet is down because your main router will be down, and you will avoid an unnoticed SIM depletion. Makes sense?

(Note: I have not tested this setup myself, this is just a thought exercise here. For example, will the 2nd SIM router automatically detect that your ISP is down while being plugged into your main router?? Actually, it’s a question even for your original setup. Is your setup only for a power outage scenario, when the cable modem is down and no signal going to the router WAN port? What about your ISP being down, can the the SIM router detect that? Your cable modem is still on and the router WAN port is lit, it’s just the fact that you cannot get to the outside gateways and DNS servers that has to be automatically detected, right ?)

UPDATE on the above: Pepwave routers support WAN health checks to detect your internet outage without power loss

Hi guys

Just curious about 2 things on this thread.

  1. Internet can go down a number of ways, either from the backbone, the telephone exchange or from the street box. It could also be cut down by an intruder if the cable is visible from the outside from the house. Some cables are and telephone wires are clearly visible from the outside that go into the house. So cutting down a cable from the outside is also a possibility that people should consider. Thieves, burglars and intruders will get smarter as we move to smarter homes. Please remember all of the above.

  2. I am concerned about the failover GSM / 4G connection. I have 50 devices at home, some of them are computers that are constantly on using the internet connection for software updates, uploading data to backup service providers etc etc. I currently use 5 TB of internet per month (in and out) on a 350MBPS connection. I am worried that a failover GSM connection would be totally consumed by everything in the house and will definitely delay data coming from the home to your smartphones in the event of an intrusion. This would mean that 1, data will not be able to travel out and 2, any cheap 4G deal that would only give you a couple of gig of data will run out instantaneously. Any ideas on how to limit the failover to just ST?

On your #2, did you read my post you were replying to?? I suggested a solution with 2 routers to address your exact concern.

On your #1, make sure you get a product that supports WAN health checks and quick failover. Pepwave and Cradlepoint offer such models. Stay away from cheaper TP-Links - their failover is limited because they do not support WAN health checks (at least the models I saw).

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