Hack 17. Choose a Cellular Data Plan

If you're going to use your phone to connect to the Internet, make sure you've got the right data plan.

Your cellular phone can connect you to the Internet in a lot of ways, but it's going to cost you. Before you commit to a costly data plan, you need to consider what you'll do with the phone. Will you send and receive email on the phone? Do you plan to send a lot of camera phone pictures or video clips? How about posting to your weblog [Hack #18]? And most important, will you use your phone to connect (tether) your laptop to the Internet [Hack #4]?

It's possible for you to use your phone for a lot of what your computer can do, and yes, there are plenty of hotspots around for that data fix when you need it. But I think you'll give in and tether eventuallyjust wait until the first time you open up your laptop and find no WiFi signal while your phone is showing five bars!

Data plans come in two flavors: metered and unlimited. With a metered plan, you get anywhere between 1 and 20 MB per month as a base allotment, and if you go over, you pay by the kilobyte. There are two types of unlimited plans: handset plans and really, honest, we-mean-it unlimited plans that let you use your phone as a wireless modem for your laptop or PDA.

1.18.1. Flavors of Cellular Data

The phone typically relies on the wireless operator's data network to connect to the Internet. The underlying wireless network technology is known as the data bearer of the mobile data. Here's a quick overview of the data bearers available from today's wireless service plans.

GSM

The GSM network provides data access over the phone (data calls). It works in the same way as the dial-up modem on a PC. The benefit of this technology is that it is available everywhere you can get coverage. However, the drawbacks are the slow data rate (between 9.6 and 13.2 Kbps) and the dedicated phone call for the connection. Since the call must be connected for the entire data session, it counts against your airtime minutes. If you want to make a voice call, you must first disconnect the data call. GSM data is known as 2G (second generation).

GPRS

The GPRS network allows the phone to have direct access to the packet-switched data from the network. The phone does not need to dial any calls. This feature allows the phone to have always-on access to data without using up airtime minutes. GPRS is known as 2.5G (halfway between second and third generation). The data speed of 2.5G data bearers (between 20 and 40 Kbps) is also faster than that of the 2G data bearers.

EDGE

The EDGE network works much like the GPRS network, except that EDGE has a much faster data rate (up to 230 Kbps). The EDGE network coverage is still limited. In the United States, only AT&T Wireless (now part of Cingular Wireless) has national EDGE coverage. Only a handful of devices released since 2004 support the EDGE data bearer.

UMTS

The UMTS network is what's known as third-generation (3G) wireless networking technology. It offers broadband data speeds of around 384 Kbps. However, UMTS coverage is very limited. In the States, it is currently available in only a few selected cities. In addition, UMTS service plans can be very expensive. New phones such as the Nokia 6630 support UMTS.

1xRTT and 1xEV-DO

CDMA-based networks have two kinds of data bearers: Single Carrier Radio Transmission Technology (1xRTT) and Single Carrier Evolution Data-Only (1xEV-DO). 1xRTT has typical rates of 70120 Kbps, and 1xEV-DO has typical downstream speeds of 300500 Kbps (with upstream speeds the same as those of 1xRTT). In the States, 1xRTT is available nationwide from Verizon Wireless, but only selected cities have 1xEV-DO.

Which data bearer is available to you depends on your wireless operator, your location, and your service plan. GPRS service should be available from all GSM operators wherever you have voice coverage. Likewise, 1xRTT should also be available from most CDMA operators. If your current service plan does not include any data service, you can call up your wireless operator and add it for an extra monthly fee. The data service is typically metered by the bandwidth you use in a billing period. In the United States, most operators also offer flat-fee subscriptions for unlimited data use; for example, T-Mobile charges $20$30 per month for its GPRS-only network and Cingular charges $80 per month for its EDGE and GPRS networks.

1.18.2. Figure Out What You'll Need

This could be the hard part, but the good news is that you can just take a best guess. If the plan you select doesn't work out, most providers will let you change data plans midstream. Here are some considerations:

Web browsing

If you're going to browse the Web using your built-in browser, chances are good that you won't use a lot of data, simply because that browser doesn't offer the rich graphical and multimedia content you get with a desktop browserin this case, it might be OK to go with a metered plan. However, if you use a third-party browser, it's possible you could end up using a lot of data, especially if you find yourself turning to your phone for web surfing more than you do your laptop.

Email

If you plan to use your phone for sending and receiving email, this won't take up a huge amount of data (but see the next item). For the most part, email is text, and unless you're likely to use your phone to work with office documents, you probably won't move a lot of data with email. As such, you could get away with a metered data plan. If you're going to be sending and receiving lots of photos and video, get yourself an unlimited plan.

Tethering

If you plan to connect your laptop to your cell phone to get online, welcome to what some folks think is a gray area. Here's the problem: most of the low-priced unlimited data plans are intended for use with your phone only. However, it's technically possible to connect your laptop to your phone and get online. You will probably get away with this if you don't use a lot of data. However, anecdotes abound concerning people who claim to have received nastygrams from their cellular operator after using large amounts of data in this way. It's insanely simple for a cell provider to distinguish between traffic that originates from a phone and traffic that originates from a laptop. For example, every web browser transmits a User-Agent identifier every time you load a page; this is a dead giveaway.

Some providers will bill you differently based on your usage. AT&T Wireless (which was being absorbed into Cingular at the time of this writing) had a $24.99 monthly handset data plan, but vowed it would charge $1 per megabyte to users who tethered a laptop or PDA to their mobile phone. Furthermore, cell providers routinely, and sometimes temporarily, block access to certain ports (there have been reports of SSH, secure IMAP, and POP for email, and even secure HTTP being blocked), with the (misguided) rationale that most handset users don't need those ports.

If you plan to use your cell phone as your laptop or PDA's lifeline to the Internet and you don't want to risk unexpected overages or a service disconnection, go with an unlimited plan that explicitly supports tethering.

SMS and MMS

In theory, SMS and MMS come out of a different billing bucket than does Internet data, so the number of messages you send and receive shouldn't affect your choice of a data plan.

All those guidelines aside, the best thing to do is choose an unlimited data plan, if one is available (otherwise, pick the most generous metered plan). That way, if you don't use a lot of data, you can progressively downgrade each month. If you do use a lot of data, at least you won't get whacked with per-kilobyte charges.

1.18.3. Compare the Plans

Although wireless data might seem as though it's brand-new, its pricing is settled, for the most part. Usually you'll pay around $5 to $10 per month for something that lets you do basic web surfing and email, and around $20 to $30 for more capabilities. So, if you're planning to use a lot of third-party network applications, such as instant messaging and RSS readers, you should go for the plan that gives you more. If you plan to use your phone as a wireless modem for your laptop, you should definitely choose an unlimited plan that supports tethering. Table 1-4 shows a few unlimited data plans that were current as of this writing.

If you think Table 1-4 looks very U.S.-centric, you're right. Although the United States lags behind in terms of the latest gizmos, it's a feeding frenzy for those who are determined to get all-you-can-eat data. In other parts of the world, metered data plans are more common. And the States has its share of those as well. Table 1-5 shows some of these plans, from the low-end to the high-end offerings, and includes the range of charges you can expect if you go over the metered limit.

In most cases, you'll choose the data plan when you sign up for your voice service. However, most providers will let you add or change your data plan at any time. But before you make a change, ask the all-important questions: will this require me to agree to a contract extension, and will I be charged a termination or activation fee to make this kind of change? If you don't like the answer to either question, you should reconsider adding a data plan until it's time to renew your contract, or look into setting up a data plan on a separate line of service.

Once you've selected a data plan, log into your provider's web site every day or so and keep an eye on your data usage as you goif you accidentally configure your email client to check mail every 30 seconds, you could be in for a surprise. The data total that shows up on the web site will probably be behind by 24 hours, perhaps more if you've used your data plan while roaming.

If you're on a metered plan and see yourself getting dangerously close to the limit, change plans right away. Although most providers will prorate the new plan after you change it, make sure you understand what exceptions are in place between the date you change the plan and the date your billing cycle resets. For example, suppose your billing cycle ends on the 28th of each month, and you are just shy of the 20MB limit on a metered plan when you switch to an unlimited plan on the 23rd of the month. You might think that you can use as much data as you want between the 23rd and 28th, but be sure to askwhen it comes to cellular billing, nothing is as simple as it appears.

Brian Jepson