What Is an AirCard?

An AirCard is a wireless modem that connects mobile devices to the internet through cellular networks. AirCards provide access to the internet from laptop computers that are outside the range of Wi-Fi hotspots. They can also be used as an alternative to home dial-up internet service in rural areas or areas without high-speed internet service. AirCards typically require a contract with a cellular provider in addition to an existing cellular contract.

Types of AirCards

In the past, cellular network service providers typically bundled and sometimes rebranded compatible wireless modems with their service contracts. In the U.S., for example, AT&T and Verizon used products from Sierra Wireless even though they were called AT&T AirCard and Verizon AirCard. AirCards are still available from major suppliers such as Netgear and Sierra Wireless. AirCard wireless modems come in three standard form factors, and each requires a compatible port or slot on a laptop to function properly.

PCMCIA PC card: The original standard cellular modem card for computers.ExpressCard: Provides an increase in bandwidth over the PCMCIA card it replaced.USB modem: Provides cellular connectivity to any computer with a USB port.

Wireless modems implement one or more of the common cellular network protocols. Late-model AirCards deliver broadband-quality speed in cities and slower speed in many rural areas.

Speeds

AirCards support higher data rates than dial-up connections. While many AirCards offer up to a 3.1 Mbps data rate for downloads and up to 1.8 Mbps for uploads, newer USB cellular modems reach 7.2 Mbps for downloads and 5.76 Mbps for uploads. Even though typical AirCard data rates achievable in practice are lower than these theoretical maximums, they still exceed the throughput of a dial-up connection.

Downsides of Using AirCards for Internet Connectivity

AirCards tend to suffer from high network latency that is sometimes higher than that of a dial-up connection, although as connection speeds have improved, so has the latency problem. Unless you are on at least a 4G connection, expect to experience sluggishness and slow response times when loading web pages over an AirCard connection. Network games are usually unplayable on AirCards for this reason. Most AirCards cannot compete with the overall performance levels of DSL or cable broadband internet connections, but the newest AirCards deliver speeds equal to their cellular providers, which in some instances is broadband quality.