Android 4.1 Jelly Bean has been ported to many Android devices unofficially, but mostly ports has issues in Wi-Fi, Jelly Bean makes the Wi-Fi bit weak and it decrease the speed too. All Jelly Bean users facing this problem but don’t be worried now, a solution is available that will allow you to get rid of all Wi-Fi problems, thanks to XDA developer member mwalt2. The developer made a .zip file that can be flashed via recovery. Follow below guide to install the .zip file but first make sure that your device is rooted with ClockworkMod recovery is installed. Make a backup of your device data such as SMS, internet setting, contacts music files etc because the below procedure may wipe data, you can sync your contacts with Gmail account and for messages use SMS apps, lastly use file expert app to backup apps.
DISCLAIMER: Please proceed the below guide at your own risk, Android Egis will not be held responsible if your device lost data or get damaged following this guide.
Step #1: Download the .zip file from here [XDA LINK], download from first link to PC.
Step #2: Plug the device to PC using USB cable.
Step #3: Transfer the downloaded file to SD card of device.
Step #4: Disconnect the device from PC.
Step #5: Turn the device off.
Step #6: Reboot the device into recovery mode.
Step #7: Select “Install Zip from SD Card” then “Choose Zip from SD Card” and locate the downloaded file that you’ve transferred in above step and confirm installation. Wait till installation complete.
Step #8: Once the installation is completed, select “Go Back” after that select “Reboot System Now.”
That’s it, you can comment below for queries and also visit the original thread of XDA link give in first step.