Let me start by saying this might be a little long but I want to give as much information as possible, because although I have some tech experience I still consider myself a newb !
My grandmother has a wireless connection in her house that she uses to surf the web and my little brother uses to play xbox (wired connection). She has a garage that was renovated a few years ago and turned into a catering business that ran for a few years and is now vacant. As she is getting older we want to give her freedom but still be close. So we are re-renovating the business into an apartment. As far as I am aware there is no coax cable because it used to be an old car garage.
Now to the questions and possible problems:
We are trying to optimize and internet connection between the 2 buildings now that would keep everyone as happy as possible. I called the cable company and they can install a second drop, but we would prefer not to have 2 bills cause she doesnt use enough internet to NOT share. My problem is that there is a coax cable run through the yard to the garage and just put through the wall but Im not sure if the signal loss is too great to use or how to share the internet that way.
I dont believe you can use 2 modems on the same coax line, so what i was considering doing was having her cancel her internet and putting it in the apt instead because low latency is important for me because I game. I was thinking I could get a high gain antenna to boost the signal up to her house but it still leaves my brother without a wired connection and possible bad speeds on his on xbox, and I am unsure how much boost I would need. The distance from the between the 2 building is about 75 ft so maybe 100 between router to garage.
I was doing some reading about a wireless access point or bridge and connecting our two routers and using hers to repeat the signal in her house, but do the ethernet ports on a repeater work still? If so is the speed drop gonna be terrible or latency super high?
TLDR: We are looking for a way to share an internet connection across 100ft with decent speeds and low latency as best as possible. Is a bridge, access point, repeater, high gain antenna an option?
Thanks ahead of time for any responses and taking the time to read.