Hi. I have got a 100Mbps network connection at my home. However, the internet on my laptop (running Zorin 16) disconnects often. Also, my router is a bit old too and my laptop is Lenovo Z50-70 20354 model. How do I know which is causing the problem? The WiFi chip on my laptop or my WiFi router itself? How do I find the odd one here?
I'll be happy to provide you more information.
try to follow the below website. that may can solve your problem
according to the above website
Step 1: Open Terminal using Ctrl+Alt+T.
Step 2: Update system packages using the following command.
sudo apt-get update
Step 3: Install the required packages using the following command.
sudo apt install git build-essential dkms
Step 4: Clone the Realtek RTL8821CE Driver using the following command.
git clone GitHub - tomaspinho/rtl8821ce
Step 5: Move to the repository directory using the following command.
cd rtl8821ce
Step 6: Use the following command to make the script of dkms-installation executable.
chmod +x dkms-install.sh
Step 7: Make the dkms-remove script executable.
chmod +x dkms-remove.sh
Step 8: Execute the installation script using the below-mentioned command.
sudo ./dkms-install.sh
After doing these steps restart your PC, and now you can see that the wireless network option is available.
But my WiFi chip model is RTL8723BE.
Please post the output from lspci to make sure. You can write that in the terminal.
Okay. Please wait
To late 
. Open up the terminal and write
sudo tee /etc/modprobe.d/rtl8723be.conf <<< "options rtl8723be ant_sel=1"
Yes, I did. Now the internet won't disconnect?
I bet you tell us if that happens 
Looks like it's working. No WiFi disconnect until now. I'll let you know if it happens again.
I don't think it will disconnect. Ubuntu 20.04 removed that part for your wifi card, we readded it.
If this fixed the issue, please mark the post that solved it.
Oh. All right. I will mark the fix as the solution now. Thank you for your assistance.
By the way, for now, I see that it's not disconnecting but I see lesser speeds on speed tests. I get around 10-15Mbps even if my ISP offers 100Mbps. Before changing the antenna config I used to get around 52Mbps (both up and down).
You can try to switch the antenna mode from 1 to 2. Easiest way is to open terminal and write
gedit /etc/modprobe.d/rtl8723be.conf
Edit the line ant_sel=1 to ant_sel=2 save and reboot.
I think I tried this already, might have caused the disconnection problem.
No that fixed your issue haha. We have set it to 1
Of course. Thanks for this, but I meant antenna 2. I've created a related post earlier. This one, regarding slow WiFi speed: WLAN Speed on Zorin - #7 by capriciousduck
The only thing you can try is ant_sel=0 which is default.
I think I'll stick with antenna 1 - a slow internet is okay to me than often disconnects.
I don't know, you also might try this