Should I use additional repeater/AP/router for the sake of better connection?

[TukangUsapEmenq]

Here's the thing. I lived in a boarding house for a job, internet's actually impressive here (highest speed and lowest latency that I ever have, at least) and the caretaker actually did asked me to 'fix' their wi-fi issue (they set all of  the main AP and their side AP on the same channel, hence lots of interference, and one of their Tenda AP aren't transmitting anything). They use 2.4 GHz on all of their AP, and I didn't think it's an issue at all since no other signal (even cells, duh) can even get inside to the housing anyway, so no interference.
 

Problem is, because of the thickness of the concrete (yes, all of these walls are thick-enough concrete), even with such outdoor AP, somehow signal could be sucks in some spots. 

 

Details as below.

Spoiler

I got 2-3 bars of signal on my PC, since I'm using a PCI-e wireless card (card reused from an old laptop) and the antenna positioned on the back of the PC. I could get an extended cable antenna but... I don't think it's a viable choice because the price itself actually the same as a new home router. For my phone it works fine, but as soon as I enter the bathroom (red on the legend), well, no signal at all. Room size is around 4x3 meters I guess, not including the bathroom.

 

Here's some test result that I did with the PC and my phone (tested it in front of my room door, and inside the room when I sit in front of my PC).

 

PC:

Spoiler

Download actually varies between 10-30 Mbps. But the upload always below 2 Mbps.

 

Phone:

Spoiler

Result are kind the same between outside test and inside, so I only put one screenshot.

 

Well, I always get that 1 Mbps upload on the PC, I bet the antenna's struggling to send the data to the AP.

 

What I want is simply to have better internet on my PC (at least the upload speed, I can't really upload much on 1 Mbps), less sudden disconnect, better latency and jitter quality (as the upload's kind of janky either), and at least, I can use internet while I take a dump.

 

What I thought so far to fix this:

1. Pull a long cable from the main router to my PC. I could ask for the caretaker but.... Nah. Too complicated.
2. Buy a cheap router (I use it with 2 devices only anyway), like this or this. Put it close to my door (the door got a small ventilation window above it, and it have enough space to put a router on). Perhaps pull some LAN cable from it.

And here's below more detail on how I place the router later on:

Spoiler

 

Well, I might thought the 2nd way would be the best one, and I can reuse the router while I move to another place later on, but I'm all ears for suggestion from you all.

 

Thanks in advance.

[SupaKomputa]

Option 2 probably the best for you, especially if you extend it with lan.

[TukangUsapEmenq]

11 minutes ago, SupaKomputa said:

Option 2 probably the best for you, especially if you extend it with lan.

Need to confirm though if I put the router on wireless extender mode (as it needs to catch signal from the Tenda AP), can it actually use the LAN either?

[SupaKomputa]

Yes. you can also use the lan and wifi.

[Ralphred]

1 hour ago, TukangUsapEmenq said:

can it actually use the LAN either?

Depends on what you buy, it needs to support both "client mode" and "AP repeater" mode at the same time.

If you use it in client mode, and LAN it to your PC, you can use your PC's current wifi interface to make a mini wireless lan through the bathroom wall, and watch TV in the bath etc.

Bare in mind wifi signals are just low frequency light, if you can get "line of sight" between wifi interface aerials that's all the better.