Combination Cards

• Some cellular providers market air cards that can connect to both Wi-Fi networks and wireless broadband. These cards do not allow the user to be connected to both types of networks at the same time, though.
  
  

Built-In Wi-Fi

• Most air cards connect to your laptop through a USB port or with a slide-in module. If your computer has a separate built-in Wi-Fi card, that card can be connected to a Wi-Fi network while your separate air card is connected to the cellular network.
  
  

Using Two Internet Sources

• Without changing advanced settings, it is difficult to be simultaneously connected to two different Internet providers and to have these connections run in unison. It is much easier to have only a single network connection that provides Internet access so that your computer does not become confused which connection to use for a particular data stream.
  
  

How To Choose a Single Connection

• Since using two simultaneous connections is difficult, you must choose which connection to use if you have both a Wi-Fi and cellular network within range. Usually, Wi-Fi networks provide faster access, although new 4G technologies promise faster speeds than most public Wi-Fi networks provide. Wi-Fi is not as secure, though, and cannot be maintained across long distances.
  
  

Summary

• While it is possible to set up parallel connections using both an air card and a wireless router, there aren't very many good reasons to do so. Unless you can create software that will tell your computer which Internet connection to use for certain traffic, it's easier to only keep one active connection at a time.