The 900 Mhz band.

The 900 mhz band isnt even used in the United States, the same with 1800. That's all overseas.

T-Mobile implements the 1900mhz band which is why it would be more compatible and better with T-Mobile. Cingular uses the 850/1900 band but 850 is much better and can reach into buildings more efficiently than the 1900 which is why Cingular implemented it in the first place. So wherever there is a 850 band around Cingular will use that but can roam on the 1900 band if needed for extra signal strength. Someone correct me if Im wrong but this is the way I understand it.

This does not make it more "compatible" to one service or the other. Just to keep this simple. It will work on the 1900mhz band if it is available on whatever provider he is using.

For the original poster...contact Cingular customer care if you want to use it with them and see if they can advise on whether you're in a 1900mhz area or an 850mhz. If they cannot, then yes I would advise T-Mobile if the area you are in has good coverage. You can check out the detailed coverage map of your area, down to the street, on their website.

Because that phones lacks the 850 band and t-mobile runs on 1900 only. Cingular runs on 850/1900 so in some areas that phone will not be albe to locate service.

No 850 which is the majority of our tower coverage.

I dont know about that. Looking at GSM coverage maps, the 850 band doesnt seem to be the majority at all, rather the 1900.

And also, if 850 is the majority, how could Cingular at one time offer phones with no 850?

In the early days of the GSM overlay T-Mobile was a key roaming partner.

But still, the coverage of GSM 850 in the United States appears to be very minimal on gsmworld.com, which I believe is a reliable source for info.

Yes but in my area it is all GSM 850 buy Cingular and AT&T. But some states have mixed coverage between both so u would be better off with a phone that has 850.

...If you happen to live in one of those states 😁

The non 850 phones were only offered in the CArolinas, NYC, and California, which were originally 1900 only markets too. 🙂

What about all the people who are still running around with old Nokia 3390's, 3395's and the like - all of which are single band 1900mhz phones. This would seem to indicate that most of the network is 1900mhz-based. Add to that that I know of a guy w/ an unlocked s700i & a girl w/ an unlocked k700i - both phones lack the 850 band and are being used for svc w/ Cingular. Both people are quite happy with the quality of the service they get on the phones & don't have problems with dead zones.

www.gsmworld.com (which I think you've referenced before in this forum) indicates that the only companies using 850 are little podunk regional providers - most of which I've never heard of.

Good point Adam. It's hard to believe that all in all 850 is the main frequency Cingular uses. I think im going to dig up my old SE T610 which lacks the 850 band and pop my SIM in that, take it with me like I would my S710a one day and see what kind of reception I get.

I find it hard to believe as well. I can tell you that in ohio, 1900mhz is used, based on my experience. My handset does not have 850 band and it works perfectly fine.

And like I stated in a previous thread, if Cingular works mainly off of 850... how were they once able to offer phones without 850? It would have been like selling a car without an engine.

cingular didn't turn on 850 until they started the switch from TDMA, before that NC/SC and CALI were the only GSM markets so they used 1900. i hope that clears up the confusion. 850 is primarily used in markets that used to be TDMA and switched to GSM.