Devices for Network Connection

Bluetooth 

It’s to transfer data or files like ring tones etc...from phones.
Also Bluetooth is to use a head set when driving. some cell phones have a Bluetooth but just for head set purposes.Bluetooth is a technology that allows for short distance wireless data transmission. It is used most commonly in phones for peripheral devices like headsets

Network Interface Cards

A network interface card (NIC) is a computer circuit board or card that is installed in a computer so that it can be connected to a network. Personal computers and workstations on a local area network (LAN) typically contain a network interface card specifically designed for the LAN transmission technology.

3G/4G

3G (3rd Generation) is a family of standards for mobile telecommunications including wide-area wireless voice telephone, video calls, and wireless data, all in a mobile environment.
3G or 3rd generation mobile telecommunications is a generation of standards for mobile phones and mobile telecommunication services fulfilling the International Mobile Telecommunications-2000 (IMT-2000) specifications by the International Telecommunication Union. Application services include wide-area wireless voice telephone, mobile Internet access, video calls and mobile TV, all in a mobile environment.

 4G is a technology that will transform wireless communications in a completely new way. It is also known as “beyond 3G," since it provides a comprehensive and secure IP (Internet Protocol) solution.

In telecommunications, 4G is the fourth generation of cell phone mobile communications standards. It is a successor of the third generation (3G) standards. A 4G system provides mobile ultra-broadband Internet access, for example to laptops with USB wireless modems, to Smartphone’s, and to other mobile devices