i have followed this forum for a few months, but this is my first time posting. many thanks to all who have posted. i've learned a lot.

my daughter travels to western europe later this summer for about a month. she has an unlocked tri-band sony-ericsson z500a (850/1800/1900). i'm wondering if we need to buy a cheap 900/1800 phone instead of relying on her se. i've looked at the coverage maps on the http://www.gsmworld.com/roaming/gsminfo/index.shtml site, but i must be a little color-blind because i have trouble telling whether the maps show light (1800) or dark (900) red. she plans to visit london then eurail to paris, south of france, rome, florence, possibly venice, switzerland, berlin and amsterdam. probably additional stops in nurenburg and den haug where we have friends. any advice from those who have gone before?

by the way, we're planning on using a um type sim with callbackworld (to be purchased).

There should be no problem in the places you've listed. It's sort of like having only GSM-1900 in the USA. No problem as long as you stick to cities and major highways. If you had said "West Coast of Ireland", "Rural Norway" or "Egypt" the advice would have been to buy a phone with 900 & 1800. In NL the 900 & 1800 coverages are virtually identical.

If you are planning for her to buy prepaid SIMs be sure that the carrier she picks supports GSM-1800-only operation.

thanks for the advice. re the 1800-only sim suggestion, i assume that applies to any sim, whether local or international. sounds like you know folks who have been bitten by this before. should i go to the point of sending an email to the vendor before purchase or should i just look for phone model compatibility on a vendor's web page?

I think DR is saying that she should be OK with the z500a. The international SIMs usually have multiple providers with multiple frequencies, especially in the places you mentioned.

Stan

What Dr. meant is that, since you have only the 1800 band of the 2 bands used in europe, you would be better off with an 1800 only carrier, instead of a carrier with both bands. Just like if you have a 1900 only phone in the US, you would be better off with tmobile rather than cingular that uses both bands (850/1900).

Most european countries have an 1800 only carrier, Since their entire network is 1800 only you would have service whereever they have coverage. For example, in the UK Orange, Virgin (uses Tmobile's network) are examples of 1800 only carriers. So, you would be better with them rather than say vodafone that used both bands.

http://www.prepaidgsm.net/en/uk.html

excellent. makes perfect sense. thanks to all.

Good point, DRN.
And it doesn't have to be only the matter of coverage.
Once I read that using a 1800-no-900 phone may encounter problems in 900/1800 networks, even when you're in 1800 service area. It's because some networks are configured to "force" the phone to use 900 first, and 1800 later, if 900 is busy. That's 1800 only phones may be useless despite there's 1800 coverage.
I don't know if it's true - I couldn't check it by myself because I've never had a 1800-only phone :). Does anyone know more about the problem menstioned above?

And one more, general remark.
I don't understand what is the sense in producing 850/1800/1900 tribands? For American users 850/900/1900 would be more useful. And, I think that GSM phones nowadays should be produced as 900/1800, 850/1900 (for Uncle Sam and the neighbourhood :)), or quad-bands 850/900/1800/1900....

GSM 850/1800/1900 has sense because Brazil is 1800 only and also several little central American countries are using 1800 as well. That's the reason why Cingular has this kind of triband phones.

Anyway I agree with my Polish friend, I fear she could have some problems in Europe with a 1800 only phone.

- London: no problems using Orange or T-Mobile
- Paris: there can be some problems, she must use Bouygues (probably weak coverage on the rail between London and Paris)
- South of France: she must use Bouygues, can have problems wit that too
- Rome, Florence, Venice: she must use Wind, coverage should be good. Probably no coverage (or weak) moving from one city to another
- Switzerland: she must use Orange, it should work well
- Berlin: no problems with E-Plus or O2
- Amsterdam: no problems with Telfort, Orange and T-Mobile

Generally speaking there should be no or little problems in big cities. France and Italy haven't a 1800-only operator, but Wind and Bouygues have mostly 1800 and usually 900 is on the EGSM band configured to be used when you don't have 1800 (so the opposite which Przemolog wrote, which applies to mainly 900MHz operators, with 1800 in cities). Something similar should happen in Switzerland. No problems in UK, DE, NL.

If she buys an international sim-card she has to check, first, if it has roaming agreements with the 1800 only (or mainly) operators. Which are usually 1 or (seldom) 2 per country (only NL has 3).

It seems to be harder to make a quad-band phone than a tri-band phone. So, when Cingular wanted to sell a phone for 850/1900 that was also "international" they (and the manufacturers) hit on a modification of the existing 900/1800/1900 phones. Changing from 900 to 850 is mostly a software modification. It was really a cheat, since 1800 provides only limited international coverage. However, as I said earlier, in this case it's good 'nuf.

great input. i appreciate the detail. sounds like i need to research roaming contracts for the international sim and compare with effendi's list. then i'll chat with my daughter about any holes in coverage and gage her level of comfort. then we'll make a decision on a 900/1800 phone.

at the moment i'm leaning toward getting a cheap, no frills, 900/1800 phone for backup. not a major investment. that way she'll have her se for sending pictures back to her sister. (that could get expensive!) and she could also use the backup with a local sim in case some of her travel friends decided to split up for the day.

thanks again to all for your feedback.