Q:

Wifi problems with rtl8723be in Ubuntu 14.04

I have dual booted my Windows 8 laptop with Ubuntu 14.04. The wifi driver is Realtek rtl8723be. It didn't use to work but I updated the kernel to 3.18 and reinstalled the driver and that seemed to solve the problem for a few hours. Then it would be connected for around 30 minutes and then the connection would stop, even though the icon on the system tray would still indicate it's connected. The only thing that works is restarting the computer but then, again, after 30 minutes the connection stops. 

A:

I was having these problem with rtl8723be on linux mint 17, and mint17.1. The same procedure should work on ubuntu 14.04 and derivates.
I had to install new module for realtek wifi cards where they solved the constant disconnects: 

install required packages
sudo apt-get install build-essential git

git clone new realtek wifi modules
git clone https://github.com/lwfinger/rtlwifi_new/

enter the directory
cd rtlwifi_new

build it
make

install
sudo make install

Now you can reboot or unload/load modules

unload modules
sudo modprobe -r rtl8723be

load new module
sudo modprobe rtl8723be

if it still doesn't work, try the solution from this post
echo "options rtl8723be fwlps=0" | sudo tee /etc/modprobe.d/rtl8723be.conf

Note: After each kernel update, you need to rebuild the modules. That is, 
After every kernel update:
cd rtlwifi_new

Clean previous builds
make clean

Update git repository
git pull

Compile
make clean && make

Install
sudo make install

reboot or unload/load modules
EDIT: It seems as of kernel 4.17 kernel APIs have changed: 
Note: If your kernel is 4.17 or newer, AND your card is not an RTL8723DE, then you should NOT be using the external driver. The built-in one is the same.
source: https://github.com/lwfinger/rtlwifi_new/

A:

My friend's HP laptop wouldn't display the available Wi-Fi networks. 
So I followed the steps from Miodrag Prelec's  answer till echo "options rtl8723be fwlps=0" | sudo tee /etc/modprobe.d/rtl8723be.conf 
Then, I did
sudo modprobe -r rtl8723be

Then either of:
sudo modprobe rtl8723be ant_sel=1
sudo modprobe rtl8723be ant_sel=2

(whichever works)
After doing this it would list the Wi-Fi signals in the menu. 
So I added these lines to /etc/rc.local (above exit 0) so that it would run each time my laptop boots up.
sleep 10
sudo modprobe -r rtl8723be
sudo modprobe rtl8723be ant_sel=1

Note: change ant_sel=1 to ant_sel=2 if required.
source

A:

Run the following command in terminal
echo "options rtl8723be fwlps=N ips=N" | sudo tee /etc/modprobe.d/rtl8723be.conf

as this will disable some of the power management of the card and usually helps.
And then you need to reboot or manually reload the driver
sudo modprobe -rv rtl8723be
sudo modprobe -v rtl8723be

This was found in ubuntuforums. Varunendra is very good troubleshooting the realtek cards.

