Tri-Band (900-1800-1900) vs Quad-Band (850-900-1800-1900)USA

[Guest Pintguinness]

I believe the T-Mobile SDA will be tri-band (900-1800-1900) and the Motorola MPX220 will be quad-band (850-900-188-1900). I also believe that T-mobile in the USA works on GSM 1900 and ATTWS works on GSM 850.

My question is:

Do GSM phones roam from one carrier to another and does this include changing GSM frequencies? Or put another way, will the MPX220 "roam over" to the GSM frequency of another carrier if the normal GSM frequency is unavailable in a given area? I'm looking to get the smartphone that provides me with the best PHONE and phone coverage. If I'm using the MPX220 with ATTWS (GSM 850) and ATTWS has no signal in an area, will the phone look for T-mobile on GSM1900?

If so, it would appear that the MPX220 is a better option for me over the SDA.

Hope this makes sense.............

[Guest Monolithix [MVP]]

You want to check the coverage for the area you live in for each mobile operator and pick the one with the best signal, if you move to an area with limited or no coverage for that carrier the phone should automagically switch over, or you should be able to force it. Don't quote me though, i'm not 100% sure how your crazy american system works ^_^

[Guest MaximilianWeisheit]

maybe this helps.

I am on T-Mobile with my SPV (GSM 900, 1800, 1900) located in New York. Last weekend I went to San Francisco, and for some wired reason I was roaming on ATT and Verizon. I saw T-Mobile stores in San Francisco, however searching for the network only came up with ATT and Verizon (or was it Cingular). - Didn't check my bill yet if I got charged for roaming.

Anyway to make it short. ATT and Cingular merged their netowrks which gives them GSM 800 (850) and 1900. - T-Mobile is only running on GSM 1900.

If you have ATT (including cingular) then Quad band is of course a lot better because in some areas (metro cities) you will have the overlapping 800 and 1900 networks = better coverage. - However if you are with T-Mobile than it doesn't matter because T-Mobile does not support 800 GSM anyway, thus it only responds to GSM 1900.

Hope that didn't confuse more than it shoud have made sense. ;-)

[Guest McHale]

If you have ATT (including cingular) then Quad band is of course a lot better because in some areas (metro cities) you will have the overlapping 800 and 1900 networks = better coverage. - However if you are with T-Mobile than it doesn't matter because T-Mobile does not support 800 GSM anyway, thus it only responds to GSM 1900.

not quite true.

AT&T's new phone is Tri-band, but the bands are 850, 1800, 1900. That is the US version of the TriBand. The "every other country" TriBand is 900, 1800, 1900.

T-Mobile has been selling the "every other country" TriBand since day 1. Had the US had the 850 band at that point, they'd be selling a US version.

The US use 850 and 1900. Having 900 or 1800 does you no good and they're wasted if you never travel outside of the US. You WANT 850 and 1900 if you live in the US regardless of which carrier you are on. Having 850 allows you to roam onto those towers if they are available (and 1900 isn't). You can have the best 900/1800 phone in the world. It will not work anyplace in the US.

Long story short. Make sure you get a phone with 850 and 1900 if you live in the US. Even if you travel outside of the US, you'll be 99% OK since you still have 1800.

-Mc

[Guest Confucious]

I don't know if it is the same in the USA but in Europe I would remain on my carrier in the UK but if I go abroad to just about anywhere in the world (apart from the USA) my phone will automativcally select a supplier but that is not necessarily the best one to use. The mobile operators all have roaming agreements and some are a LOT cheaper than others. When I go abroad I always cheack the prices before I go and make sure i lock onto the cheapest supplier in the country I am in.

I don't know if it's the same in the USA but roaming can get very expensive if you're not careful.

The rest of the world uses 900/1800 1900 was added for compatability with the USA and now you have 850 as well just to be different!

Good luck.

[Guest Pintguinness]

Great Information - Thanks to all. To recap:

For the best coverage in the US, go with a phone that has GSM 850 and 1900 regardless of the carrier. This would include The Audiovox SMT 5600 and Motorola MPX220. Stay away from the T-mobile SDA because it is lacking GSM 850 so it wont roam to another carrier if a GSM 1900 signal is not available.

For travel outside the US, GSM 1800 should be fine. Both the Audiovox SMT 5600 and the Motorola MPX220 have this band. The MPX220

also uses GSM 900. Can anyone tell me the disadvantages of not having the GSM 900 band on my phone?

[Guest Confucious]

Found this on CW geurnsey's site :

http://www.cw.com/guernsey/docs/products_s...description.pdf

On the second page it lists all their roaming partners and frequencies - as they use GSM900 the ones that don't say also use 900 - there seem to be quite a lot.....

[Guest McHale]

yes. This is a good example of why quad band may be the solution for you (MPx220).

By not having 900, there may be times in other countries (outside the US) where 1800 may not be available. This is the same as not having 850. There are areas in the Chicago suburbs where I can onlly get 850 (no 1900). If my phone only had 1900, I wouldn't get any coverage at all. Same thing for 900.

Personally, I would go quad band. If that's not an option for you, choose your phone based on where you will be the most.

-Mc

Great Information - Thanks to all.  To recap:

For the best coverage in the US, go with a phone that has GSM 850 and 1900 regardless of the carrier.  This would include The Audiovox SMT 5600 and Motorola MPX220.  Stay away from the T-mobile SDA because it is lacking GSM 850 so it wont roam to another carrier if a GSM 1900 signal is not available.

For travel outside the US, GSM 1800 should be fine.  Both the Audiovox SMT 5600 and the Motorola MPX220 have this band.  The MPX220

also uses GSM 900.  Can anyone tell me the disadvantages of not having the GSM 900 band on my phone?