You need to connect to the Internet by using a 4G SIM card and an LTE (4G) modem and router appliance.
After powering up the LTE modem/router appliance and attaching the required antennas for mobile data signal management, you need to configure your modem with LTE connection settings. Also you need to ensure that you provide the 4G SIM card PIN number to unlock the SIM before proceeding with Internet data connectivity.
One example of a popular LTE (4G) modem and router is TP-Link 3G/4G modem and router appliance: https://www.tp-link.com/en/home-networking/3g-4g-router/. You may need to consult your Internet Service Provider (ISP) for 4G network connection settings. These include the Access Point (APN) name and type, as well as the username, password and authentication type (NONE vs CHAP vs PAP). You will need to create an Internet connection profile in which to provide all required mobile data settings. In the case of Greece’s ISP Cosmote, the mobile data settings to be setup in the example TP-Link modem/router appliance are the following.
PDP type: IPv4
APN type: Static
Password: blank (it gets populated automatically by a non-used masked password but this is ignored)
Authentication type: PAP
After providing the above APN mobile data settings and clicking save, you should notice that your WAN connection to the Internet is active and has a status of connected.
Next step is to configure your local devices with DHCP or with static IP addressing and DNS settings and connect them to your LTE router via Ethernet or WiFi. Depending on the LTE router appliance you can have more network settings to configure, such as NAT, DynDNS, static routing, IPv6 tunnel, USSD, NAT forwarding, Quality of Service (QoS), VPN server, security settings (such as firewall and access control lists) as well as parental controls.
Last but not least, ensure that you are running the latest firmware version in your LTE modem/router and take a backup of the router configuration, in case you need to re-build it. Also a best practice is to restrict router management access to HTTPS only and disable insecure HTTP.
If you are on a metered connection in a pay-as-you-go subscription and not under a contract for unlimited data, you know that every byte counts. For this reason, I have compiled a separate article on how to optimize your mobile data traffic to minimize your overall costs.