Sharing your mobile device's Internet connection with other connected computers is tethering, or as a phone modem. You can connect via WLAN, Bluetooth, or a cable connection such as USB.

If tethering is over WLAN, the service can be used as a personal or mobile hotspot, allowing the device to act as a portable router. Mobile hotspots can be protected with a PIN or password.

For IPv4 networks, the tethering function is usually a NATworks over the existing data connection of the mobile device, so from a network point of view it is only one device with a single IPv4 network address, although it is technically possible to identify several devices.

Support for mobile operating systems

Many mobile devices have software that offers a tethering service. Windows Mobile 6.5, Windows Phone 7, Android (as of version 2.2), and iOS 3.0 (or later) provide a tethering connection via Bluetooth PAN or USB. Connecting to Wi-Fi, also known as Personal Hotspot, on iOS devices is available from iOS 4.2.5 (or later) on iPhones 4, 4S (2010), 5, iPad (3rd generation), certain Windows Mobile 6.5 devices such as HTC HD2, Windows Phone 7, 8 and 8.1 (depending on manufacturer and model) and many Android phones (depending on service provider, manufacturer and software version).

mobile Operators

For some mobile networks, tethering cannot be used by default, but only if the subscriber package includes this feature. This is primarily because the computer to which the Internet connection is shared can significantly increase mobile device traffic that was not originally included in the service provider’s pricing structure.

Some devices offered by mobile carriers also have carrier-specific software that disables the built-in tethering features of mobile devices and only allows them if subscribers pay an additional fee.

There have also been mobile operators who have asked Google or Android mobile device manufacturers to completely remove the tethering feature or its operating system support from certain devices.

There are several ways to use the tethering feature on a limited device without having to pay additional fees, including third-party USB tethering apps such as PDAnet, rooting Android devices, or jailbreaking iOS devices. and then installing tethering applications on the devices. Tethering applications are also available for other older platforms such as Symbian, MeeGo and WebOS devices.