Introduction to Mobile Wi-Fi for Cars

Mobile Wi-Fi systems in cars consist of a local Wi-Fi network and (usually) wireless Internet connectivity. A car Wi-Fi network supports mobile personal devices like phones and portable computers. Note that car Wi-Fi is separate from the internal network automobiles use to control electronic systems like braking and lighting.

Why People Want Car Wi-Fi

Car Wi-FI systems replicate many of the same functions of a home wireless network. They're useful for several reasons:

• Many laptop computers, tablets, and portable media players lack the hardware needed for connecting directly to cell networks. These devices usually need Wi-Fi to get onto the Internet. Carpoolers needing to do work while riding can especially benefit from having Wi-Fi access.
• Connecting phones to a Wi-Fi network allows their data traffic to flow through its internet link instead of using the phone’s cellular carrier network and its data plan. Conserving bandwidth on a phone’s data plan can save money.
• If you regularly (or even incidentally) drive to areas with no cellular service or coverage, a mobile network will let you still access the internet for driving directions or roadside assistance.

Integrated vs. Portable Wi-Fi Systems

A mobile router serves as the centerpiece of a car Wi-Fi system. Mobile broadband routers provide Wi-Fi access for clients plus mobile Internet connectivity via a cellular modem.

Integrated Wi-Fi systems use routers you permanently attach to the vehicle. Some automakers install routers in their new cars at the factory, but many new vehicles still do not have them built-in. Owners of these vehicles, plus the many older ones in use, can set up mobile Wi-Fi systems with aftermarket hardware.

Aftermarket systems go in fixed locations, like under a seat, in the trunk, or inside the front dashboard. Professional installers of integrated in-car Wi-Fi offer warranties to their customers to cover cases of improper mounting or wiring. A person can also install their own car routers; the process is not much different from installing car stereo systems.

People may prefer to use portable routers for their car Wi-Fi setup instead of an integrated one. Portable routers — which you may also know as travel routers — function the same as integrated routers. But you can also easily remove them from the vehicle. Portable routers make sense especially when you want to share the unit among multiple vehicles or for users who regularly travel and need a portable router at places they stay while on trips.

Using a Car Wi-Fi System

When installed and powered up, the hardware in an integrated car Wi-Fi system allows other clients to join its network. You can do basic file sharing between devices the same as other kinds of Wi-Fi networks.

Accessing the Internet from a car Wi-Fi system requires obtaining a subscription from the provider for that type of router. In the U.S., for example, Autonet produces the CarFi branded line of automotive routers and associated Internet subscription packages.

To use a smartphone as a car’s mobile Wi-Fi system requires that the phone be capable of functioning as a portable hotspot. Most providers require an additional subscription (and fee) to use a phone for tethering and some do not support this option at all. (Check with the phone provider for details.)

What Is OnStar?

OnStar became popular in the 1990s as an emergency service system for vehicles made by General Motors. Using integrated global positioning and wireless connectivity, OnStar systems have commonly provided roadside assistance and tracked down stolen vehicles.

The OnStar service has expanded over time to offer additional communication and entertainment services including an option for mobile Wi-Fi Internet access. Newer generations of OnStar technology incorporate 4G LTE to support mobile Wi-Fi in some new vehicles (the service is not available with older OnStar systems). Their mobile Wi-Fi requires a separate subscription with daily, monthly, and annual options available.

What Is Uconnect Web?

The Uconnect service from Chrysler enables wireless access to a car’s sound system via Bluetooth. Similar to OnStar, Uconnect has expanded over the years with additional services. The Uconnect Web subscription service enables mobile Wi-Fi for vehicles that support it.

Safety and Security of Mobile Wi-Fi Systems

Internet access in a car gives occupants more ways to stay in contact with friends and families while traveling. Although many people with mobile Wi-Fi also subscribe to separate emergency services via OnStar, Uconnect, or other providers, some prefer to use the messaging and navigation apps on their own devices.

Having Wi-Fi and Internet connectivity in a car theoretically adds another source of distraction to drivers, however. Proponents of mobile Wi-Fi can argue that these services help keep children occupied and therefore reduce driver distraction, at least indirectly.

Hackers can target mobile Wi-Fi for​ an attack just like home and business networks. Because they are normally in motion, attacks on the Wi-Fi signal itself would need to come from other nearby vehicles. Another possible vulnerability is the network's public IP address, just like other Internet access points.