Selecting a wireless carrier is just as important as picking a phone. The provider, after all, delivers the network that makes your handset work. And since you’ll probably end up paying a healthy amount for that privilege, there’s no point in sticking with a bad user experience.

Five rules when choosing a carrier

1) Coverage is key
You can’t do much on your phone without a signal, so make sure that you can get coverage in the places that you’ll need it. That means looking beyond carrier slogans and coverage maps (though the latter is a good place to start) and doing your own research.

The best way to gauge coverage in your area is to ask your neighbors. See which carrier they use, and ask if they’re satisfied. You even can borrow a friend’s phone and use it at home and in your workplace to see if you’ll get the reception that you need. Sure, it’s a very unscientific method, but personal experience is really the best tool.

Just remember that no carrier network is perfect. Gaps exist, even in urban areas, and reception can vary by your precise location. For example, a carrier’s signal may not penetrate deep into buildings and underground, and it will vary according to how many people are using a network at a given time (think about how hard it is to get a signal at a big public event).

Another point to consider is whether a carrier uses GSM or CDMA. GSM (think T-Mobile and AT&T) is the dominant global technology and is used in almost every country around the world. So if you’re a globetrotter and want to take your phone on your travels, make sure it supports GSM. Though strong in North America, CDMA (think Sprint, Verizon Wireless, and most smaller carriers) is present in only a handful of countries outside of the United States. If your phone is CDMA-only, your international coverage will be limited. Fortunately, handsets that support both technologies are widely available.

2) Data speeds
Of course, making calls is just one thing that you’ll do on your phone. And if you’re like a lot of smartphone owners, it may be the last thing. That’s why you also need to carefully evaluate data networks. Data networks enables your handset to access the Internet, send e-mails, stream music and video, and download the apps that have become so popular.

Most U.S. carriers in the United States are now locked in an always-evolving race to build the largest and fastest 4G LTE data network. (T-Mobile uses a technology called HSPA+ that’s almost as fast.) So just like with a provider’s voice network, data coverage and strength will vary widely by area. If you want LTE (and really, why wouldn’t you?), know where the carrier has 4G coverage and how fast it is. And just like with calls, make sure you’ve tried a carrier’s data network before committing.

3) Plans
After coverage, your service plan is the most central component of your carrier experience. It dictates how long you have to stay with a carrier, how many calling minutes and how much data you’ll get, and the price that you’ll pay each month. Prices will largely depend on how many calling minutes and the amount of data that you expect to use. Be sure to get what you need, but don’t overspend either. And remember that monthly taxes and fees will add more dollars to your final bill.

The benefit of signing a contract is that you’ll get a heavy discount on the price of your phone. If that’s not your thing, month-by-month prepaid plans bring more freedom, but the services and available handsets may be more limited. Also, without a subsidy that comes with a contract, you’ll pay more for a handset up front. Here again, just think carefully about what’s right for you.

Pay equal attention to the plan’s terms. Though carriers now offer unlimited calling, some providers still have plans that limit the amount of minutes that you can use during weekdays (often called “anytime minutes”). Minutes for nights and weekends, on the other hand, are always unlimited. Messaging brings its own charges so be sure to explore your options. You’re better off buying a message bundle or paying for unlimited messaging than paying for each message that you send.

Data plan types also vary widely. Some deliver unlimited data while others restrict you to a certain amount for each month (what we call tiered plans). Once you go over your set data amount, you’ll have to pay big fees. Alternatively, if you’re getting service for a family or group of friends, shared plans will pool voice and data use across multiple devices. Note also that some carriers charge extra if you want to enjoy 4G speeds.

4) Your phone
If your heart is set on a particular phone that’s available with only one carrier, then you may have skipped the previous points entirely. But if you’ve yet to decide which handset you should buy, don’t assume that each carrier’s device lineup is the same. Selection varies widely, so it pays to think about which kind of phone you’d like and which carrier(s) offer it.

A welcome trend over the last year is that popular devices like the iPhone 5 and the Samsung Galaxy S3 now land at multiple providers. That may help make your decisions easier, but keep in mind that even on these common phones you can have a vastly different customer experience depending on your carrier choice.

5) Customer service
Unfortunately, there’s no way to predict this. For everyone who has a horror story with a provider, there probably are almost as many people who have had no problem. Also, though consumer studies singing the praises of different carriers continue to get headlines, there are no guarantees. So all you can do is make your choice, hope for the best, and be your own advocate if you aren’t pleased.

 

Carrier basics

Verizon

The biggest wireless carrier in United States, Verizon Wireless operates a robust and far-reaching 4G LTE network and a strong lineup of smartphones, feature phones, and basic handsets. A joint venture between Verizon Communications and Vodafone, Verizon Wireless was formed in 2000 through a merger between GTE Wireless and Bell Atlantic.

Things you should know about Verizon Wireless:

Verizon requires a “Share Everything” plan that includes unlimited and text and voice calls for multiple devices plus a monthly allotment of data use. The monthly price increases based on the number and type of devices you add to the plan and the amount of data that you elect to use.

As a CDMA carrier, Verizon’s international coverage is limited to a handful of countries, but it offers dual-mode CDMA/GSM handsets.

Verizon offers prepaid plans.

 

AT&T

AT&T is the second-largest wireless carrier in the United States after Verizon Wireless, at least for now. Today, AT&T has an extensive lineup of GSM devices, and it continues to grow its 4G LTE network. Originally formed in 2001 as Cingular Wireless, it changed its name to AT&T in 2007 to reflect its parent company.

Things you should know about AT&T:

Like Verizon, AT&T has shared plans with data tiers for smartphones customers, but customers can stick with an individual plan if they prefer.

As a GSM carrier, AT&T offers extensive international roaming.

AT&T offers prepaid and family plans.
Sprint

Though its merger with Nextel occurred way back in 2005, Sprint finally is phasing out the defunct carrier’s iDEN network while retaining push-to-talk service. Sprint was the first carrier to offer a 4G network through WiMax technology, but it is now transitioning to LTE. As such, its 4G coverage is far behind that of AT&T and Verizon for the time being. Sprint carrier offers handsets of all stripes, including a few handsets with rugged designs.

Things you should know about Sprint:

Sprint continues to offer unlimited calling and data plans.

Its international CDMA coverage has a smaller footprint than GSM, but Sprint has dual-mode CDMA/GSM handsets.

Sprint has family plans, though prepaid service is available only through its Boost Mobile and Virgin Mobile subsidiaries.

 

T-Mobile

After narrowly escaping a merger with AT&T in 2012, T-Mobile remains the smallest of the big four U.S. carriers. It doesn’t operate a true 4G network, but its HSPA+ “Faux G” network offers LTE-comparable speeds. T-Mobile doesn’t carry the iPhone, but it was an early leader in Android and now offers a decent variety of smartphones.

Things you should know about T-Mobile:

T-Mobile has unlimited calling and data plans. In 2009, it introduced Even More Plus plans that don’t require a contract, but don’t offer subsidies for phones. Its Even More plans require contracts, but also come with hardware subsidies.

As a GSM carrier and a subsidiary of Germany’s Deutsche Telekom, T-Mobile has extensive international roaming.

T-Mobile carrier offers prepaid and family plans.

 

U.S. Cellular

Based in Chicago, U.S. Cellular is a regional carrier serving 26 states in the Midwest, the Southeast, and the Northwest. Though many of its handsets are variants of models used by other carriers, it also has some unique devices including a few high-end smartphones. It launched its LTE network in 2012, though coverage is limited to larger urban areas. Unique among carriers, U.S. Cellular offers rewards points that long-term customers can redeem for new phones, accessories, and downloadable content.

Things you should know about U.S. Cellular:

You can opt for contract-based, prepaid, or family plans. U.S. Cellular carrier has unlimited calling, but data comes in tiered packages.

As a CDMA carrier, international coverage is limited.

U.S. Cellular’s home network isn’t nationwide, but it has roaming agreements with several partners for nationwide service.

 

MetroPCS
Serving customers in select markets in 15 states, MetroPCS is a completely prepaid carrier. Though its handset roster tends toward no-frills models, it has plenty of Android smartphones and touch-screen handsets. MetroPCS has a growing 4G LTE network, but coverage and speeds aren’t as robust as they are at the major carriers.

Things you should know about MetroPCS:

As a CDMA carrier, international coverage is limited.

Most plans include unlimited talk, text, and Web browsing.

MetroPCS’s home network isn’t nationwide, but it has roaming agreements with several carrier partners for nationwide service.

 

Cricket
A subsidiary of Leap Wireless International founded in 1999, Cricket serves select communities in 25 states and does not require contacts. It operates a small LTE network, but outside of the iPhone 5, its handset lineup trends toward basic and midrange models. Cricket’s Muve Music plan, launched in January 2011, gives customers unlimited music downloads and playbacks in addition to talk, text, and Internet.

Things you should know about Cricket:

As a CDMA carrier, international coverage is limited.

Cricket offers unlimited plans for talk, text, and data.

You’ll be using another carrier’s network when roaming outside the Cricket’s home network area.

 

Virgin Mobile

Virgin Mobile markets its prepaid service to the youth market. Virgin had yet to launch an LTE network, though it offers some devices that run on Sprint’s dwindling WiMax network. As for devices, it has a few smartphones including Android models and the iPhone 4S. First launched in 2001, Virgin Mobile is now fully owned by Sprint.

Things you should know about Virgin Mobile:

As a CDMA carrier, international coverage is limited.

The “Beyond Talk” monthly plans bring unlimited data and messaging, and you can opt for unlimited calling as well. The “PayLo” plans are cheaper, but you get fewer calling minutes and tiered data.

Virgin devices operate on Sprint’s network.

 

Boost

Like Virgin, Boost Mobile is wholly owned by Sprint and is geared toward budget-minded consumers. Boost does not require contracts, and its Shrinkage Plan offers reduced monthly rates over time. It carries mostly carries midrange Android models and a variety of basic phones, but it doesn’t have an LTE network yet (current 4G phones run on Sprint’s WiMax network). Originally launched in New Zealand and Australia in 2001, Boost USA launched in 2003.

Things you should know about Boost Mobile:

Boost handsets operate on Sprint network.

Boost offers a monthly plan with unlimited voice calls, text, and Web browsing. You also can pay for voice calling by the day or by the minute.

As a CDMA carrier, international coverage is limited.

(CNET’s Quick guide to cell phone carriers)