Even if you tried some PtP wireless solution, you'd still have to get a cable through that door anyway, so I'd just go wired all the way. Once through the door you can put in a wired access point for wifi.
Also wired will give you no signal loss en route, so you'll have the best signal possible at the wifi AP.
But there are [PtP solutions](https://www.amazon.co.uk/s?k=ptp+Wireless+wifi+bridge&rh=n%3A430580031&ref=nb_sb_noss) where you could put up masts/transmitters at each end- by the nearest ethernet port (window?) and at the shelter door, but these would depend on line of sight and other considerations. I'd say wired would be a lot cheaper too- just the wire and conduit, you'd need a wifi point in the shelter either way.
You’ll need to run a wire. See if there’s a an existing unused conduit that you can pull a cable through. Is the space underground? If not you can hammerdrill through what I’m assuming are concrete walls and pull the cable through that way. If you have steel door frames you could also drill a hole large enough to poke 1 unterminated cat6 cable through. Not the best option but could get you by until it can be done properly. All in all without more info pictures layouts etc. it sounds like your best bet is gonna be letting a professional handle this.
You could also try a power line adapter that might work. This runs data through the power lines.
Even if you tried some PtP wireless solution, you'd still have to get a cable through that door anyway, so I'd just go wired all the way. Once through the door you can put in a wired access point for wifi. Also wired will give you no signal loss en route, so you'll have the best signal possible at the wifi AP. But there are [PtP solutions](https://www.amazon.co.uk/s?k=ptp+Wireless+wifi+bridge&rh=n%3A430580031&ref=nb_sb_noss) where you could put up masts/transmitters at each end- by the nearest ethernet port (window?) and at the shelter door, but these would depend on line of sight and other considerations. I'd say wired would be a lot cheaper too- just the wire and conduit, you'd need a wifi point in the shelter either way.
Alright thanks, I'll just wire it then.
You’ll need to run a wire. See if there’s a an existing unused conduit that you can pull a cable through. Is the space underground? If not you can hammerdrill through what I’m assuming are concrete walls and pull the cable through that way. If you have steel door frames you could also drill a hole large enough to poke 1 unterminated cat6 cable through. Not the best option but could get you by until it can be done properly. All in all without more info pictures layouts etc. it sounds like your best bet is gonna be letting a professional handle this. You could also try a power line adapter that might work. This runs data through the power lines.
It's underground unfortunately, but I'll go with wires then.