Good afternoon.

I currently have two networks operating in an environment. One is a standard home network with ethernet and wifi with the router connected to the internet through my Spark fibre ONT.

The other network uses an older Huawei router, supplied free by Spark on sign-up I believe, which has wifi and ethernet and is used to run a surveillance system. Eight IP cameras connected through POE switches, a recording unit, etc. This network is not connected to the internet so is currently only available by connecting to the wifi to view the footage and interact with it. This router does not have a SIM slot.

On occasion I will move the "internet" cable from the home router to the surveillance router to give it an internet connection so I can perform firmware and OS updates. I have once before left this router connected to the internet when we were on holiday for a week so I could log in and see what was happening at the house over the internet. This all worked well. However, with my home network offline, certain "smart" aspects of that were unable to function correctly.

I'm now looking for a solution where I can purchase a SIM with a data pack and somehow connect it to the WAN port of my surveillance router to give that network easy internet access, without having to remove the internet access from my home network. I could go to the hassle of purchasing a new router with a SIM slot, but that would require me to configure the surveillance items on that new router to get them up and running and that's something I'd rather avoid if possible. I haven't been able to Google up a solution that seems appropriate - I have seen suggestions from using a third router for internet access (I'm not sure how this would interact with the existing router) to using a phone as the access point and plugging it into the router's USB port (I'm not sure if this router can get internet access through USB?)

Is anyone able to offer some help by suggesting a solution that will allow me to put a SIM into a device that I can then plug into the WAN port of the router so the router simply sees that as an internet connection and will be happy to be online?

I'll probably only need this SIM connection for a month or so while we're on holiday during the summer, then I can shelve it until we go on holiday again. Any thoughts around providers or data plans are a different conversation to this one I think.

Thanks in advance. Much appreciated.

Chris.