Introduction to Cellular Wireless Data Cards


If travels take you away from your home and office you may have spent hours searching for nearby Wi-Fi hotspots in hotels, cafes, and airports. Cellular wireless data cards added to anyone’s laptop removes all that fuss and inconvenience. You’ll be able to telecommute from your favorite coffee shop, from the airport or anywhere you can utilize your wireless network provider.

What is Cellular Wireless Data?

You probably already carry a cellular telephone from a carrier such as Verizon Wireless or Sprint PCS or AT&T Wireless or T-Mobile.

A cellular wireless data card takes advantage of those same carrier’s networks to connect your laptop to the Internet. Like the Ethernet or Wi-Fi card built into your laptop, a cellular wireless data card can be used to check email or surf the Web. But, unlike those other cards that connect to your own home network or your company’s office network, a cellular wireless data card can only reach the Internet using a carrier’s network.

The primary advantage of cellular wireless data is that you’ll be able to reach the Internet from any location, indoors or outdoors, throughout your carrier’s data coverage area. The primary disadvantage is one that you know all too well from using a cellular telephone – cellular data coverage can be weak indoors, even absent in rural areas.

Broadband coverage -- cellular wireless data cards

For example, this map illustrates two flavors of cellular wireless data offered by Verizon Wireless near Philadelphia, PA – faster BroadbandAccess and slower NationalAccess. Coverage is pretty darn solid downtown and nearby suburbs, but the farther you get from center city and interstate highways, the more yellow and white appears, indicating slow or no data service, respectively.

This is just one typical example; cellular coverage varies by city and carrier, with high-speed data services now available in most major metropolitan areas across the United States.

What Can You Expect From Cellular Wireless Data Cards?

Cellular wireless data services have actually been around since the mid-90’s. But those early services were very slow and expensive compared to the $29/month unlimited Internet dial-up you may have used at home back then. By 2003, US cellular carriers offered enhanced data services at speeds approaching that of Internet dial-up. However, by then, many of us had already switched to fast residential broadband services such as cable or DSL. So cellular wireless data still felt pretty slow to most consumers, who quickly tired of waiting a minute or more to view a single Web page or email message.

Today, that situation has changed. Several U.S. carriers now offer unlimited “mobile broadband” data services at a performance and price that appear to satisfy many users. These newer services have fancy technical and product names (we’ll get to that later), but collectively they are often referred to as “third generation” or 3G services.

In truth, 3G cellular data services are not nearly as speedy as your home or office Internet connection. But home broadband services have gotten so fast that we don’t actually use their full capacity when we surf the Web or check email. In a good coverage area, performing those tasks over 3G cellular will feel very much like they do when using home broadband. Except that you won’t need to be close to an Ethernet jack or a Wi-Fi router. You’ll surf the Internet from trains, cabs and hotel rooms – anywhere that 3G reaches. Outside 3G coverage areas, those older slower cellular data services will still keep your laptop connected, kind of like automatically falling back to dial-up when your home broadband is down.

Using Cellular Wireless Data Cards

Nearly every laptop comes with built-in Ethernet and Wi-Fi adapters. Some new high-end business laptops come with built-in cellular wireless data adapters. This will become more popular in the future. Today, the rest of us can add cellular wireless data cards to existing laptops (or desktops).

Cellular wireless data cards

Cellular wireless data cards are now available in several form factors, illustrated here.PC Cards slip into a PCMCIA slot on the side of your laptop. Some new laptops have a slot that accommodates a slightly smaller Express Card. If your laptop does not have a free card slot, don’t worry – you can still purchase a USB modem that fits into one of those tiny slits commonly used to connect a mouse or thumb drive. Most users prefer PC or Express Cards because they are easier to leave in the laptop all the time and are often more reliable.

No matter what type of card you choose, you’ll need to install software on your laptop. Most cards come with a CD or DVD containing drivers and a connection manager program.

If your laptop runs Windows XP, just pop in the CD and follow prompts to complete installation. Do NOT insert your card into the laptop slot until you are prompted to do so.

If your laptop runs Windows Vista or Mac OS, choose a card that is compatible with that operating system. Support is not all that common today, but will improve over time.

During installation, one or more connection managers will be copied onto your laptop. The following figure illustrates two programs – one used with all Sierra Wireless AirCards and another used with all AT&T Wireless (Cingular) data services. Like your cell phone, these programs indicate signal strength (or lack thereof) and tell you when the newer, faster 3G service is available. When signal is sufficient, the Connect button will get you on-line. If you don’t have unlimited service, be sure to disconnect when done!

Cellular Wireless Data Cards 3

How to Purchase Cellular Wireless Data Service

Notice that all cards sport a carrier logo. That’s because they are purchased from carriers, along with a cellular data service plan. It is possible to buy a card by itself, but the card cannot be used without service. So, start by choosing a carrier, then selecting a card sold by that carrier.

This is where messy details come into play. Not all carriers offer 3G in all areas. A carrier may say they offer “mobile broadband” but only deliver slower service where you live, work, or travel. Worse, some locations may not have coverage at all. If your cell phone doesn’t have signal, forget about data. If you can make a non-roaming voice call from a given location, there’s a decent chance you’ll have at least slower data service there too. But that doesn’t indicate if you’ll have 3G service there as well. Therefore, your first task is to look very closely at each carrier’s coverage map.

Unfortunately, at this stage, you can no longer avoid fancy acronyms and confusing product names. Currently, two cellular technologies are popular:

  • Gobal System for Mobile (GSM) is offered by AT&T Wireless and T-Mobile.
  • Code Division Multiple Access (CDMA) is offered by Verizon Wireless and Sprint.

There many other carriers in North America and throughout the world, but most currently use one of these technologies to deliver data services with various average speeds and maximum rates. For simplicity, we’ll lump today’s most common services into two categories:

Technology Slower: Feels
a lot like dial-up
Faster: Feels
like broadband
GSM Enhanced Data Rates for Global Evolution (EDGE) High Speed Downlink Packet Access
CDMA One Times Radio Transmission Technology (1XRTT) Evolution –
Data Optimized

Choose a carrier who can deliver 3G service wherever you expect to spend a lot of time on-line, and slower service in most other locations where you need Internet access. There will always be locations where cellular cannot reach, so this is a balancing act.

Every carrier will tell you his or her service is faster. Unless you’re a power user, just focus on finding one of the above 3G services and don’t sweat the details. Also, carriers have marketing folks who like to think up snazzy names, so you can’t just walk into a cellular store and buy “3G service.” Instead, here is what you must ask for:

AT&T Wireless HSDPA BroadbandConnect See Coverage
Sprint Nextel EV-DO Mobile Broadband See Coverage
T-Mobile Only GPRS and EDGE now available in U.S. See Coverage
Verizon Wireless EV-DO BroadbandAccess See Coverage

Finally, like buying a cell phone, buying a cellular wireless data card means paying for equipment (possibly discounted), a one-time activation fee, and a monthly usage fee with fixed and variable components. Unlike voice calls, measures in minutes, data usage is based on megabytes or kilobytes transferred. Entry-level plans build some usage into the base price, after which you’ll incur overage charges. A typical entry-level plan from Sprint, for example, is roughly $40 per month. There is a $99 cap on overage charges. Unlimited data plans cost more per month but have a fairly hefty upper limit that most users never exceed. Again, using the Sprint example, an unlimited plan is about $60 per month.

You can also use the service at home, but it’s impractical for anyone who lives with other people who want to access the Internet. However, there are products available to solve that problem, as in the Sonicwall TZ 190. The unit combines a router, firewall, wireless access point and VPN into one box that also offers 3G wireless broadband with Wi-Fi access.

Choose your service carefully, because you must sign an annual service contract with an early termination fee. Ask whether you’ll be able to cancel if it turns out that you don’t have coverage where you need it within the first few weeks of service. Hopefully, if you’ve done your homework, that won’t be necessary – and you’ll soon be surfing the Internet wherever, whenever you want to!


Photo credit: brandon shigeta via photo pin cc


  1. I am interested in learning more about wireless data cards for cell phones, per say I have a Motorola Atrix HD I believe and have no service as of yet but am interested in learning more about what providers have to offer for this particular phone preferably prepaid plans for both talk and text and additional data. Also I am looking for additional data ranging from 5GB to 10GB

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