This guide explains how to connect a USB modem to a wireless router.
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Most routers come with a USB port, but not all routers support USB modem functionality. Therefore, check to see if your router supports this before attempting to use a USB modem to go online with your wireless router.
Set up your USB modem: You may need to add a SIM card or activate the dongle by inserting it into your PC or laptop. This depends on the service provider and model of USB modem, so check your manufacturer's website or manual if you need specific help for your model.
When you think the USB dongle is set up correctly, try to connect to the internet on the connected device. If it works, go to step 2. Otherwise, you need to do some network troubleshooting.