Internet connectivity is available nearly everywhere in the U.S., whether in the form of Wi-Fi networks or 3G cellular networks. In some cases, especially if you travel frequently, you may wish you had your own wireless network to use instead of a wired Ethernet connection or a 3G connection. A 3G Wi-Fi router might meet your needs perfectly, letting you set up your own wireless network anywhere you have a 3G signal.
Standard Wi-Fi routers connect to the Internet using a wired Ethernet connection, and then they broadcast a wireless network that you can use to get online. These are common in places like coffee shops and airports, though you may have Wi-Fi at work or in your home. Since wireless networks allow people to connect to the Internet without using cords, many networks are secure, meaning they require you to type in a password to connect; otherwise anyone within range could use the network without permission. Networks that aren't secured are called open-access.
A 3G Wi-Fi router typically has all of the features of a standard Wi-Fi router but doesn't connect to the Internet with an Ethernet cord. Its own Internet connection is also wireless: It uses a 3G signal from cellular networks, similar to the way many smartphones get online. The main advantage of these routers is portability; you can use them to create a network anywhere that you have a 3G signal. Some of these routers even have their own battery power supplies, while others require power from an electrical outlet.
To connect to the Internet, a 3G Wi-Fi router must use another component to get online, since it can't actually establish a 3G connection on its own. Different routers have different options, but some of the most common are PC cards, USB dongles and even 3G cellphones. If you use a 3G Wi-Fi router, you'll need to insert the card or dongle into the router or connect your phone with a cord so that the router has a Internet connection and can then get other devices online.
A 4G Wi-Fi router works just like a 3G router does except it has a faster Internet connection over 4G networks; 4G just stands for fourth generation, and it's the successor to 3G in cellular network technology. These networks have faster Internet speeds than 3G networks, though data rates are variable across different carriers and in different areas. Typically you can expect download rates between about 1.5 megabits per second and 19Mbps, compared to 1Mbps for 3G. Many 4G Wi-Fi routers can also connect to 3G networks if a 4G signal is unavailable.