Chicago GSM vs. CDMA/TDMA

First of all, TDMA is no longer supported by carriers, the carrier that did have it would have been the precursor carriers to Cingular, Nextel runs iDEN which is a motorola proprietary standard. GSM providers in the us are, national: Cingular, T-Mobile. Regional: Dobson (don't think it's actually in Chicago) Centennial Wireless I believe is in your area. CDMA Carriers: Verizon, Sprint, US Cellular, MetroPCS, Cricket.

Blackberry as well as most others primarily support CDMA and GSM, with GSM being the first to get support due to the global useage of GSM (if global market share was discussed CDMA/iDEN has perhaps 1 to 3% of the market) followed by CDMA.

Personally I don't see your points in regards to poorer service, duration, availability, etc. Cingular/T-Mobile have arguably the best coverage in your area as far as area and capacity is concerned and their nationwide coverage is superb, as far as direct Quality, GSM is usually associated with better voice quality, however, the difference is trully very hard to tell.

There is plenty of knowledge out there, but I feel it's important to note, on the end user aspect, there is no difference between GSM and CDMA, the difference is in the carrier you chose, what's available in your specific area, and the phone you chose. The biggest difference you would be most likely subject to run into, GSM uses a hotswappable "SIM" (Subscriber Information Module) Smart Card vs. CDMA carriers using a hardbranded "ESN" (Electronic Subscription Number) which is hard written to the phone.

 

It does take more towers to service the same amount of customers with GSM then CDMA. Because CDMA is more efficient and spreads the call out. GSM often has the latest phones because of the large market share globally as he said. But you won't be disappointed with what VZW or Sprint has to offer. My experience with GSM hasn't been that great, but it all depends on the area. There was one previous person on this forum that switched to Sprint from Cingular because of in building coverage issues, but that could be unique to his part of Chicago. The biggest difference that would affect in building coverage is what frequency a carrier uses in your area. The cellular band (800 mhz) travels further from the tower and penetrates buildings better. The PCS band (1900 mhz) doesn't do quite as well. Carriers often use repeaters to improve this. I'm not sure which carriers use which in Chicago though, and I've heard arguments both ways for if all things equal between GSM and CDMA about in building coverage....

 

That is correct, that the carriers that use 850 Mhz (800-same thing), have a signal that better-penetrates buildings, and reaches further, than carriers using 1900 Mhz. The 1900 Mhz - only providers generally need more towers, to provide equal coverage. Whether the 850 Mhz signal is CDMA or GSM, doesn't really matter. The original AT&T GSM was 1900 Mhz-only, on towers not spaced closely enough together, which was why most people didn't like it. Now, Cingular has GSM on 850 Mhz, wherever they or AT&T had 850 licenses, which is much better for coverage. That said, Cingular and Verizon both use 850 Mhz, in the Chicago area, and both have good coverage, there. If the OP would like to use a GSM smartphone, Cingular should work fine. Of course, in any particular spot, a 1900 Mhz carrier may still have a closer tower that works better than an 850 Mhz carrier's further-away tower, but in general, the 850 Mhz signal penetrates buildings better, and reaches further.

 

And again, this is another good time to remind, in areas such as chicago, carriers usually offer more than adequate coverage, which means that all carrier offerings are usually on equal footing. The question you have to ask yourself is what costs you're willing to assume, contract terms, carrier specific devices, etc.

 

Try it out. When I still had T-Mobile I never had problems while in Chicago.