This guide helps you in setting a mobile hotspot, using your mobile phone for accessing network on your computer, in the case your computer doesn't have access to any other network.
With this setting you use data from your mobile subscription, so be aware of disconnecting this setting when no longer needed.
Setup Mobile Hotspot - iphone
For setup a mobile hotspot for sharing the network on your iPhone, see instructions here
Setup Mobile Hotspot - Android
How to setup a Personal Hotspot on your Android mobile device for internet sharing with your computer.
Go to Settings
Tap Network & internet
Go to Hotspot & tethering
Tap Wi-Fi hotspot and set the Hotspot name
Set a passord and turn on the Use Wi-Fi hotspot switch to start sharing
On your computer:
Go to settings -> Wi-Fi and find your Android mobile phone on the list