Extending Wi-Fi Signal with Second Router: TPLINK WR841N & Airlive G Duo, WDS+AP, Gateway+AP Modes

I have problems with the Internet. I rent a room and it so happens that the router (TPLINK WR841N) is at the other end of the apartment and you can't move it. The signal is consistently weak, but there is still enough for everything (YouTube, online games). However, sometimes (in the evening, I think everybody uses the internet at the time and that's why) it starts hanging down terribly Ping in online games, video on YT takes a long time to load. Everything is starting to hang. At such moments I took a laptop and went inside the apartment and all problems disappeared and everything began to work normally. As I understand it, the reason is a weak signal.

I have a second router (airlive g Duo) and I want to use it to strengthen the signal, set the router in the center of the apartment, there are several modes:
WISP + AP mode
Client + AP mode
Dual AP mode
Gateway + AP
WDS + AP

Not quite knowing which is better, I tried to use the WDS + AP mode and it did not work, and then the WISP + AP mode and I did it, at first it seemed that everything was done but when I started testing, the signal definitely stopped better because the other router is closer, but in fact, when I start to download something, the speed decreases and the ping increases (performed in the console "ping google.com -t" .

My testing file download speed:
through the main router in my room (WiFi) - 3.5mbps, ping - 100-200ms
through the main router in the middle of the apartment (WiFi) - 5mb / s, ping - 100-200ms
through the second router in the middle of the apartment (WiFi) - 300kb / s, ping - 500-3000ms
through the second router in the middle of the apartment (cable) - 1.2mbps, ping - 200-500ms

What is the reason? How can I solve my problem?

Plug in in client + ap mode, you should have delays of 10-20ms between devices. Do not expect miracles, the more users currently use the network, the greater the pings, remember that the router to which "everyone" is connected automatically prioritizes data packets, you would have to set QoS rules on this main device, restrict other transfers or redirect specific game ports online directly to your address.

@roxio , I did in client + ap mode, it's exactly the same as wisp + ap, i.e. I have

through the second router in the middle of the apartment (WiFi) - 300kb / s, ping - 500-3000ms
through the second router in the middle of the apartment (cable) - 1.2mbps, ping - 200-500ms

I don't expect miracles, but now it's because of this second ping router and the download speed is worse than if I just used the main router and I just want to have better coverage and I can accept even lower speed, I just need stable ping because I play in game, I talk to someone and all this requires a stable connection.

dupti wrote:

What is the reason?

The amplifier is the worst solution.

dupti wrote:

How can I solve my problem?

Connect wired to the main router and then do an additional AP.

To have something to strengthen, you need to have a stable and reliable signal in place of the repeater.

Install InSSIDera v2 / Home and insert the network measurement result here.

@ KOCUREK1970 , unfortunately it is not possible to connect to the main router via cable, I have access to the admin panel, but unfortunately I cannot move the router and connect via cable.

Only that the signal from TP Link should be measured in the place of placing the amplifier - and you probably measured yourself?
The first of you with Duo is ok, the second DNO.

dupti wrote:

What is the reason? How can I solve my problem?

You don't have anything other than this airlive? Something from 802.11n? Once that speed 3 x greater two that better range. If ok in the middle of the apartment on the laptop, then properly configured and connected router must also work properly.