(CNN) -- If you're a frequent overseas business traveler, you've likely encountered the frustrations of using a cell phone abroad.
CNN.com turned to Bob Schukai, the vice president of wireless and broadband technologies for Turner Broadcasting System -- of which CNN is a division -- for some advice.
Before departure, he said, find out whether your phone will work at your destination, and if so, whether you can activate the international roaming access function that would allow you to receive and make calls.
If the phone is not compatible with local technology, you'll have to consider renting, buying or borrowing a local cell phone.
If your phone is compatible, you'll need to decide whether you want to get your phone unlocked so that it can accept a local SIM card -- the ID chip that carries your local phone number.
The advantage behind that option? With a local phone number you can receive local calls and avoid the $1-$2 per minute international roaming charges you'd otherwise incur with a U.S.-based SIM card.
Unlike U.S.-based service, where you pay for both making and receiving calls, in Europe only the calling party pays, Schukai said. However, once you leave the country where you bought the local SIM card, the calls you receive from there will rack up international roaming charges.
One way to skirt that problem is to buy local SIM cards for every country you visit, provided that your phone is compatible. They are easy to find, even on eBay, Schukai said.
The hassle with that option: You have to inform your contacts of your new cell phone number each time.
Because companies generally foot the bill for business travelers, they may choose to forego the local SIM card option in favor of renting phones or using their own phones and swallowing the international roaming charges.
Americans are at a disadvantage when it comes to cell phones overseas, because most of the world uses a GSM (Global System for Mobile Communications) standard, Schukai said. While T-Mobile and Cingular use that standard, Verizon and Sprint operate on the CDMA (Code Division Multiple Access) standard, which is popular in North America but not supported everywhere else.
"If you go to the U.K. or Germany or most everywhere in the world, your Sprint or Verizon will not work," Schukai said.
Consider the battle between GSM and CDMA the equivalent of "Beta versus VHS" during the videotape format wars. "The GSM standard outsells the other flavor, the flavor used by Verizon and Sprint, by 4 to 1," Schukai said.
The Japanese anomaly
Travelers heading to Japan face a whole different ballgame.
"When you go there, your GSM phone won't work. You have to have a 3G (third generation) phone, which you can get in Europe," said Schukai, referring to the technology that gives cell phone users the "broadband experience" of a laptop with its high speed and data capacity.
While such phones are just starting to come out in the United States, "they don't operate on the same frequencies as they do in Japan or Europe," he said. A 3G phone purchased in the United States and taken to Europe would roll onto the networks there fine -- but would operate as a 2G or "second generation" phone there, with limited data capacity, Schukai added.
The same phone taken to Japan "would be a nice paperweight or a pocket warmer," Schukai mused.
Americans traveling to Japan can overcome that hurdle by renting 3G phones at the airport phone rental shop upon arrival, Schukai said.
Meanwhile, travelers from Japan or Europe to the United States will find that their 3G phones will roam on Cingular or T-Mobile 2G networks but without the 3G roaming experience they are used to.
Roaming worldwide
Schukai recommended GSM World's Web site as a good resource for finding out whether your network provider has a roaming agreement in the destination country.
Under the tab "GSM Roaming," a user can access GSM coverage maps and get information on a country's network providers, roaming partners and services.
Northern Africa and most of sub-Saharan Africa operate on the GSM standard and have good coverage, Schukai found. Central Africa is more hit-and-miss, "a function of government upheaval going on at any one time."
Meanwhile, "the hinterlands in China works great," Schukai said, recalling how he made phone calls from the Great Wall. "That's one of the coolest markets in the world."
Other options a road warrior might consider: an international call forwarding service, which is fee-based; text messaging, which is cheaper than a phone call; and Skype, a program that offers free calls to members over the Internet.
"Know what the rules are, based on the country you're in," Schukai advised.