Reader mail: Difference between smartphone and mobile broadband data plans?

Reader quarrell15 writes: I read your recent posts about how unlimited mobile broadband plans are going away and got totally confused. The prices you quoted for AT&T are totally different than what I'm paying for 3G data on my iPhone. What gives?

Answer: Yep, you are paying a different price for 3G data on your smartphone through AT&T than what I quoted for AT&T mobile broadband — and that's because 3G smartphone plans and mobile broadband plans are two very different animals. Looking back, I should have done a better job of explaining that in my original post, but hey — better late than never.

So, let's start with smartphones — which, just to muddy the waters even further, live in a different category than "feature" phones (sometimes called "dumbphones") with pared-down data features and thus cheaper data plans (usually about $10 a month for e-mail and light Web browsing).

Anyone getting a new smartphone will need two basic types of wireless service: voice and data. First, you'll choose how many monthly minutes you want (including whether you want unlimited nights and weekends, etc.), and then you'll be asked to pick a data plan.

Smartphone data plans come in different shapes and sizes; some offer unlimited data for a flat monthly fee, others give you a monthly allotment or "cap," with carriers either a) charging you overage fees or b) slowing down the speed of your connection (a.k.a. "throttling") if you creep over the monthly limit.

Also, some carriers bundle voice, data, and SMS service (text-messaging plans could be a post unto themselves, so I won't cover them here) into a single (and typically unlimited) plan.

Here's what all standard 3G smartphone data plans have in common: They're intended only for data use on your smartphone, and not on any other device — namely, not on your laptop via Wi-Fi, USB or Bluetooth tethering.

Now, if you do want to tether your laptop to your smartphone for on-the-go data, most big carriers will be happy to offer the privilege for an extra fee, usually about $20 a month on top of your standard data plan.

Here's a quick summary of the individual 3G smartphone plans offered by the big four national carriers. (The carriers also offer family plans with multiple lines of service under a single account; in the interest of keeping things simple, I won't be covering family options here.)

AT&T
The once-exclusive carrier of the iPhone offers two main smartphone data plans: 2GB of data for $25 a month, or 200MB for $15/month. If you exceed your monthly allowance before your billing cycle is up, AT&T will charge you either $10 per extra gigabyte, in the case of its 2GB/month plan, or $15 for another 200MB for those subscribed to the 200MB/month plan.

Sprint
"Unlimited everything" is the mantra of the so-called "Now" network, which offers three main bundles of voice, data, and text messages. For $70 a month, you get unlimited 3G smartphone data and text messages, plus 450 voice minutes a month, while $90 ups the ante for voice minutes to 900. Want it all? Sprint's "Simply Everything" plan offers unlimited voice, texting, and data for $100 a month.

Not bad — but keep in mind that Sprint just announced that starting January 30, it will charge an additional $10-a-month "Premium Data" fee for all new 3G and 4G smartphone plans, or for anyone who upgrades their existing Sprint smartphone. ("Feature" phone users aren't subject to the new $10/month "premium" data fee, by the way.)

T-Mobile
The carrier of the first-ever Android phone offers both bundled and stand-alone data plans, with the various bundled voice/data offerings including either unlimited data for $30 a month or 200MB for $10 a month.

T-Mobile's "unlimited" 3G data comes with a catch, however. If you consume more than 5GB of data a month, the carrier will "throttle" your data speed to something akin to dial-up levels.

For those on the 200MB-a-month plan, expect to pay 10 cents for every MB of data you use over your standard 200MB monthly allowance.

Verizon Wireless
"Big Red" offers a $30-a-month "personal" plan for unlimited 3G smartphone data, or $45 a month for unlimited data plus corporate e-mail use. Another option: $15 a month for 150MB of data. If you use more than 150MB of data in a month, you'll be charged $15 for each additional 150MB bucket of data.

OK, that's it for the smartphone plans. Now, time to move on to mobile broadband.

These pricier data plans are intended for users with USB sticks that let laptops access wireless 3G data, or laptops that come with embedded 3G wireless chips. Portable Wi-Fi hotspots like the Mi-Fi also require mobile broadband plans.

So, wait — if you're already paying AT&T $25 a month for 2GB of monthly data on your iPhone, can you also use that same bucket of data with one of AT&T's USB mobile broadband modems? Well, no — and by the same token, your smartphone can't piggyback onto your mobile broadband plan. If you've got, say, the iPhone on AT&T as well as AT&T's version of the portable MiFi hotspot, you'll need a smartphone plan for the iPhone and a separate mobile broadband plan for the MiFi.

As I explained earlier, though, you can always pay $20 (or so) extra a month to tether your 3G smartphone to your laptop — although if you do so, you'll usually be subject to any caps, throttling, or other limits on your smartphone plan.

Got all that? Good. Now, on to the mobile broandband plans from the Big Four carriers:

AT&T
Two plans are available: the 5GB "DataConnect" plan for $60 a month (with overage fees of 5 cents for each extra MB), or $35 for 200MB a month (10 cents for each additional MB).

Sprint
The carrier has just one 3G-only mobile broadband plan: 5GB for $60 a month, with an overage fee of 5 cents/MB overage if you're in Sprint's coverage area or 25 cents/MB if you're roaming.

But if you're lucky enough to live within Sprint's 4G WiMax coverage area, you can also opt for a 4G/3G combo plan, which offers unlimited 4G data, as well as 5GB of 3G data (for times when there's no 4G signal) for $60 a month, same as the 3G-only plan. Another option: a 4G-only mobile broadband plan, with unlimited data for $50 a month.

Last but not least, Sprint has an unlimited 4G plan for desktop (i.e., non-mobile) modems for $45 a month.

T-Mobile
The carrier offers two plans: 5GB of data (including access to T-Mobile's speedy HSPA+ network, which it recently decided to go ahead and label "4G") for a relatively cheap $40 a month, or 200MB for $25 a month.

The catch? Again, T-Mobile will throttle subscribers of the 5GB/month plan who bust over the monthly limit, while those who opt for the 200MB-a-month option must fork over 10 cents for each MB over the monthly allowance.

Verizon Wireless
Four tiers of mobile 3G broadband service are available: 1GB for $20 a month (with $20 for each every GB), 3GB for $35 a month ($10 for each additional GB), 5GB for $50 a month (again, $10 per GB overage fee), or 10GB for $80/month.

You can also get a USB modem for Verizon's just-launched 4G LTE network, but only the latter two broadband plans — the 5GB and 10GB options, for $50 a $80 a month, respectively.

So … there you go; hope this helps.

Still have questions? Let me know.

— Ben Patterson is a technology writer for Yahoo! News.

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