How Aircards Work For Mobile Computing

Broadband Internet access has become a standard utility for nearly all businesses and home office users. DSL and Cable Internet is readily available and reasonably priced for individuals. T1 lines, DS3 bandwidth, and Ethernet connections are the choice for most business locations. But what do you do when you leave the desktop environment and venture outside? Are you cast into a disconnected limbo between WiFi hotspots? How can you take your presentations, inventory access and order entry to a client's office when they all require a broadband Internet connection? For that you need a little accessory called the aircard.

An aircard or air card is a wireless modem that gives your laptop or notebook computer a 3G cellular broadband connection to the Internet. Generally, any place you can get cell phone reception you can get Internet access. Both the voice and data signals are coming from the same towers. Each cellular carrier has a certain number of channels available at each tower site. Some are assigned for voice calls. Some are assigned for broadband data. But you need a smartphone or plug-in aircard to access the data channels that supply Internet service.

Most aircards offered today are designed for 3G access, but will fall back to the slower 2.5G or 2G speeds if reception is poor or a particular tower site hasn't been upgraded for 3G. The largest carriers, AT&T, Verizon and Sprint, have been in a frenzy to get their tower site base stations upgraded over the last few years. There is a booming market for 3G access, both by aircard users and also for many of the newer smartphones that have 3G access built-in. The Apple iPhone and BlackBerry Storm are just a couple of examples. Broadband service is necessary to support streaming video as well as web-enabled applications and full HTML browser surfing. You can still get by with lower speeds for email and text messaging.

Aircards are specific to a particular carrier, just like cell phones. They also require service contracts, just like cell phones. Wireless service plans for aircards are currently running around $60 a month.

There are differences in the technology used to transmit cellular broadband. Verizon Wireless aircards, Sprint PCS aircards, and Alltel aircards run CDMA networks and use a technology called EVDO. The baseline EVDO service is similar to entry level DSL and offers download speeds of around 700 Kbps with bursts up to 2.4 Mbps when the network is lightly used. The upload link is much slower, typically around 150 Kbps. This network was designed for basic Web access and video clip download. The newly upgraded EVDO Rev A networks increase cellular broadband speeds to cable modem levels of 3.1 Mbps download bursts and a faster uplink of 1.8 Mbps.

AT&T aircards use a different technology called GSM that is more of a worldwide standard. Their basic wireless broadband service is called EDGE and runs at around 250 Kbps. This is the technology used by the first Apple iPhone. But AT&T has now moved to a faster network called HSUPA that has download burst speeds up to 7.2 Mbps with uploads as fast as 2 Mbps. Typical speeds in heavily used metropolitan areas are slower that this, but equivalent to what you'll get on the EVDO networks.

So how do you get an aircard for your laptop computer? That's easy enough. You can comparison shop for aircards by model and carrier right online. In addition to being carrier-specific, there are two styles of wireless modem available. The traditional form factor is a PCMCIA card that plugs into a slot on your laptop computer. But many newer laptops are smaller and have done away with the PCMCIA slots. For those you select the USB models that simply plug-into a USB port just like a USB flash drive. Take some time to check the features of each card you are interested in. Some work only with PCs. Others support both PC and Mac. Some of the USB aircards also have a slot to install microSD memory cards so you can use them as a flash drive as well as an aircard.