So the camera loses connection every few days, and you need reboot it to make it work, while I think it is accepted, other devices,streaming will occupy most data traffic and will strengthen the load of the router/AP. 

While you still can do some troubleshooting; check the light status of the NC220 when it lost connection; Try to ping it from other devices in the same network at that point. And test can other devices access internet from the router/AP.

Did you setup static IP by log into the web interface and go  to Basic- network page to modify it? 

Besides, what is the signal strength showing on the camera info page？

Hi.

Thanks for your kind answer.

So the camera loses connection every few days, and you need reboot it to make it work, while I think it is accepted, other devices,streaming will occupy most data traffic and will strengthen the load of the router/AP. 

The camara is connected to an WLAN AP and shares the bandwidth with a SonOFF/Tasmota device that does not need much bandwidth at all.

While you still can do some troubleshooting; check the light status of the NC220 when it lost connection; Try to ping it from other devices in the same network at that point. And test can other devices access internet from the router/AP.

I have already checked the Led color and the ping test: I would say that, whenever there's IP traffic towards/from the camera it would not disconnect/reconnect. But I also think this should not be a solution...

Did you setup static IP by log into the web interface and go  to Basic- network page to modify it? 

Yes. I have throughly tested both options (Static & DHCP) to no avail.

Besides, what is the signal strength showing on the camera info page？

This screeshot shows 65% strength but most of the times it is well above 70%.

Best regards.

Hi.

What is the light status of the NC220 when it lost connection? 

The led switches between red and green when the connection is messy. When the connection is completely lost, solid red.

At that point, is there any error message pops up on the tpCamera APP? Like the camer is offline or so? Did it obtain IP address?

The app screen also switches between offline/online indications. Yes, it obtained an IP address before disconnection happened.

When it lost connection, can you get internet from the C7 by wireless? 

Yes. Other devices connected to the router can connect to internet without issues.

Have you ever tried to reserve an IP for the NC220 on the web interface of the main router. 

Sure. I tried static & dinamic IP address. It always works in the first hours/deays, but then again fails.

Besides, when and where did you buy this NC220? 

I got it last october in a Carrefour mall in Spain.

Best regards.