I'm a complete newbie at doing mileage runs but I've been involved with wireless communications for a long time. Most of you frequent fliers will know this info already so please don't flame me for posting the obvious, but someone on their first mileage run might find this info useful, and I haven't seen it anywhere on the boards. Corrections are definitely appreciated! Note that I use the US, but this information is mostly true for Canada as well. By the way, while reading you will encounter asterisks after certain passages. These refer to further material at the bottom of the post.

Ok, so you're on your first mileage run, and you step off the plane in LGW/SYD/TPE/BKK and flip on your phone to call home, but it won't work. Either it shows no service, or it finds a signal but you can't dial out! Why not? Because unfortunately, most of the US based wireless world isn't quite that integrated with the rest of the world yet.

The US wireless industry is an alphabet soup of technologies, most of them incompatible. It's the wireless equivalent of the tower of babel, and it's also why sometimes you can travel to a city in the US that is of decent size, you see people using their phones, yet your phone won't work/shows no service.

Currently, there are five wireless voice technologies in use in the US. These are :

AMPS - Analog phone service, good 'ol cellular. Operates at 800 MHz, normally overlaid by either an IS-136 or CDMA network, although some places are still analog only.

IS-136 - Otherwise known as DAMPS or TDMA, this is the technology used by AT&T Wireless, Suncom, Rogers Cantel, and Cingular*. Operates at 800 and 1900MHz.

GSM-1900 - Also known as DCS-1900 and PCS-1900, this is the US flavor of the most prevalent worldwide wireless standard. This is used by VoiceStream, Cingular*,Fido, and Powertel (well until VoiceStream absorbs them too), as well as several regional companies. Operates at 1900 MHz in the US and some parts of Latin America, as well as US territories. For the rest of the world, GSM operates at 900/1800 MHz.

IS-95/JS-008 (I think) - Also known as CDMA, this is the technology used by Sprint PCS,Telus Mobility, Verizon, Alltel, US Cellular in some markets, and others. Operates at 800 Mhz and 1900 Mhz.

iDEN - The protocol of Nextel and Mike (and Southern Linc, for the three people that use them). Nextel operates at 850 MHz and uses a proprietary Motorola protocol that is a derivative of GSM which allows for their famous direct connect service.

This discussion can be fairly confusing, because terms and definitions are so often used, misused and abused within the industry. So, for ease of explanation, we will define some terms (possibly incorrectly).

For our purposes, cellular carriers are those which operate seamlessly off both the 800 and 1900 MHz frequency band. AT&T Wireless, and their affiliates (such as SunCom, Triton PCS, etc) as well as Verizon would fit into this category. You never know nor care what band you're using. PCS carriers are those which only operate in the 1900 MHz band and specifically roam onto the 800 MHz band. Sprint PCS and their dual-band phones are a prime example, as well as PrimeCo and Voicestream.

CDMA and AMPS/IS-136 are the two most prevalent technologies in the US, with GSM running an increasingly less distant third.

So, back to our original question, how do you stay in touch when on an international run?

For those of you that use a GSM carrier, unless they are a small regional operator you have it the easiest. If you already have a dual/tri-band phone (meaning one which operates at either 900/1900 or 900/1800/1900 MHz) you simply step off the plane and turn your phone on.**

Some Motorola models require that you manually switch from US to European bands, Nokia and Ericsson phones do not. (This DOESN'T apply to Japan, that's a special case I'll get to later.)Your normal phone number works just as it does in your home area, and anyone dialing it will get you in whatever country you're in. Makes for an AWFULLY expensive "Sorry, wrong number."

GSM is the only technology that provides for advanced features, such as call forwarding, call waiting, and caller ID while travelling, and allows you to modify them at will from any area in which you have service. Caller ID doesn't always work, but for me it's worked more often than not.

Nextel users fit into the GSM group as well. Being based on GSM, Nextel interoperates very well, although one requires a special phone (the i2000). Nextel's roaming prices are reasonable, although the I2000 phone is huge and using it is clunky. Telus' Mike service does not offer the I2000 nor does it offer international roaming.

Of all the cellular carriers, AT&T Wireless users have it the best. You enjoy the larger coverage area of the traditional cellular network, and the same phone you use daily will work in quite a few places internationally.

For the places it won't work,AT&T provide a service called WorldConnect, which allows you to use an international GSM phone that carries the same phone number of your local phone. Note that this is NOT always a good thing, especially when your irritating friend calls up at 3:00 AM local time wherever you are and wakes you out of a zonked sleep to shoot the breeze or complain about something.

The service is as seamless as GSM can be. Callers don't have a clue where you are, except for the savvy ones that pick up on the international 'ring'.

The coverage is very extensive and the rates are incredibly cheap (for international roaming), much cheaper than calling from a landline phone in the hotel! Unfortunately, both phones can't be used at once, your US phone must be turned off while your WorldConnect phone is in use. For more information visit

http://www.attws.com/business/lcorp/...world_connect/

Other cellular carriers may participate in the Worldconnect program or offer something similar***, inquire with your customer service department. If not, assume your phone WILL NOT work in the foreign country, even if there is compatible service. Non-GSM international roaming agreements are rare, and situations with carriers change constantly. Your service may work one trip, and not work on the next.

For example, I've been to Mexico many many times, and each time my experience is different. It will work in one city on one trip, and not the next, but then it works in a different city it didn't work in before. Or, (and this was my strangest experience) it will receive calls on one cellular carrier, but only dial out internationally on the other. Made life interesting.

For those of you with CDMA PCS phones, particularly SprintPCS, your international roaming opportunities with your dual-band handset are not quite as far flung as AT&T's but they're rather more extensive. Roaming opportunities with the single band handset are virtually nil. For you single band users, Sprint has roaming agreements with Pegaso in Monterrey and Mexico City, Mexico, and your handset can be used on Guam and in Puerto Rico but that's about it.

However, there's still hope Sprint PCS customers; decent international roaming facilities are available but they come at a price. Sprint offers much the same service as AT&T does with WorldConnect (E.G. use a Sprint SIM in your phone and roam with your PCS phone number) but the rates are more than double.

Sprint does have one unique attraction in their international program. It is the ONLY carrier (that I know of) to offer a Japanese roaming facility in the US. You can rent or buy a Japanese PDC phone that roams with your US Sprint phone number. They have no facility for Korea.

For other CDMA PCS carriers, contact your customer service department, but I believe Sprint PCS and it's affiliates are the only ones that have international roaming facilities. I know PrimeCo does not.

For more information on roaming with Sprint internationally, visit :

http://www1.sprintpcs.com/explore/bu...InfoCenter.jsp and click on Intelligent Voice Services.

Finally, we get to the Japanese section. I'm sure more than one international FF'er has stepped off the plane in Japan and turned on their tri-band fully international capable GSM phone to find... nothing. That's because Japan (and Korea)use different cellular standards than the rest of the world does. I'm aware of one carrier in Korea which uses a US standard, but they do not provide roaming.

The predominant standard in Japan is a called PDC, it operates at 800 and 1500 Mhz. It is completely incompatible with everything else in the world, and no other country in the world uses it. Korea uses a variant of the US CDMA systems, but uses them on different bands than we do, and uses slightly different variants. I am not aware of a carrier that provides for roaming in Korea, however some companies in the US rent phones for use in Korea.

So, if you don't want to get a special phone for Japan or Korea, what do you do? Use a sat-phone! This is also great for those of you that like going off into remote areas, that no carrier would ever put a tower in. The scope of satellite services is too broad to get into here, so we'll stick to the services that utilize handheld terminals, Iridium and Globalstar.

Iridium, as most of you know, is the once-failed, risen-as-a-phoenix satellite network which used to sell phones for $3,995 and airtime for $5.00 per minute. Well, it's not like that anymore. Now, phones are available for as low as $500 and airtime can be had as cheaply as $.99 for volume users (I pay $20 per month and $1.19 per minute).

There are no roaming charges whatsoever, ANYWHERE, and no long distance charges. All you pay is your per minute rate. Coverage is anywhere the satellite constellation can see you, which means anywhere to within a few miles of the poles. The service is by no means a replacement for cellular as it requires line of site to the sky, and is only good for short conversations (it fades out quickly unless you have an unobstructed horizon to horizon view of the sky). The sound quality is pretty bad for those of you used to cellular, but it's bearable. For more information, visit:

HTTP://www.iridium.com

Globalstar is the other satellite entry. Due to different technology, it does NOT offer global coverage, as the system will not operate if one gets too far from a gateway. (For an explanation of why, Email me.) Globalstar also charges roaming once one leaves the continental US, their per minute rates vary from $1.19 to $3.50 per minute, and when one is out of the coverage area, one is out of luck. They do offer better quality voice than Iridium does, but cost more. For more information, visit :

HTTP://www.globalstar.com

This primer/whatever is by no means complete and is worth what you're paying to read it. So, no, I don't think I'm the final authority on this and if I'm wrong on anything, again, please correct me.


NOTES :

* Cingular uses two different technologies. They use GSM-1900 in South and North Carolina as well as California, and IS-136 everywhere else.

** This assumes you've called your carrier to have your international roaming/dialing enabled. If you don't have roaming enabled, or don't have a roaming agreement with at least one network operator for the country you're in, your phone will be deader than a doornail. You will see nothing but a blank screen with the battery icon on it, you won't even see a signal level!

This is one of the main problems with GSM. Unlike the other technologies in the US, if you are not allowed to roam on the network, you can't even call customer service from your phone to diagnose the problem. You must call from a landline.

Also, note that your bog standard Nokia 5190/8290/Ericsson T18z will NOT work internationally. Yes they're GSM. Yes they use a SIM card/smart chip, but they are single band and only work at 1900 MHz. This frequency is only used in the US and a few places in Latin America. If your phone doesn't say that it's a world phone/dual or tri band, it probably isn't.

One more note on GSM, when roaming internationally, it's not like being in the US or Canada. Except in rare instances, when travelling with GSM in the US you can only choose from one carrier while roaming. But when you're abroad you often have a choice of carriers when roaming.

If you are on WorldConnect, it doesn't matter what you use, but if you're on Voicestream or another GSM carrier, break out your phone's manual, and LEARN TO USE THE NETWORK SEARCH FEATURE. Check the website of your carrier, look for your destination and find which carriers/networks have the lowest roaming rate. When you get there, put your phone on manual registration, and lock it to that carrier. In some cases, this can save you up to a dollar a minute.

*** Former Bellsouth (except for S.C./N.C.) markets that are now Cingular have great roaming agreements in Latin America, in particular. Not sure about their GSM roaming, or if they have it. Verizon has an international program but does not have information on their website. For more info on pricing and coverage, call 1-800-2 JOIN IN.

[Edited for clarity... (yeah like I achieved THAT!)]

[Edited again for content correction RE:Sprint PCS roaming]

[This message has been edited by kanebear (edited 09-07-2001).]