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• the two bands that matter in the U S of A are 850 and 1900 for Cingular, while T-Mobile has only 1900 (weird regulations), and almos everywhere else in the world GSM is the main cellphone system with 900 and 1800 bands.
• phones do have quite different signal reception qualities. In my personal experience a Motorola P280 still remains possibly the best and a Sony Ericsson t68 probably the worst for 1900-only reception.
• Quad bands such as Motorola v400, various v5xx do quite well, albeit good old 900-only Startacs still remain in fond memories...

A good site for honest phone reviews is Steven Punter's Southern Ontario Cell Phone Page. No, he doesn't review this particular model, but he has interesting things to say about various popular North American phone models. Check it out....

Eric

So, lets take it from the beginning.

After checking your links I assume the service presented to you are data over the cellular network for mobile phones. Not WiFi.
The cards are of either PCS or GSM type, which in it self needs to be checked out, because these are not the same. The functionality is basically the same, but they are not compatible. To get a rough grip on what the situation is read this page.
http://www.arcx.com/sites/Technical%20Comparison.h tm
It is fairly short and rather accurate.

What it all is about is using the cellular (mobile phone) network as a carrier for data. This is a standard feature in later mobile systems, but there are enhancements.
Because of the burst characteristics of data communication operators and manufacturers realised data traffic needed a totally different architecture in the air interface not to overload the systems.
Today all systems are having enhancements to boost data traffic.
The drawback of Package Data on mobile systems is that operators down prioritize this in favour for traditional voice callas where they make more money.

In GSM data transmission is called GPRS with the enhancement EDGE.
Limitations in EDGE are among other things distance to nearest antenna, allocated resources and release level.
These are things you can not control easily, so I propose a "buy and try".
As I recall the maximum throughput is some theoretical 300+ Kb.
Count this one out as more than theoretical, but I have heard of people achieving very high, and even higher throughput on GSM/GPRS/EDGE.

I am not that familiar with PCS but when I worked with the package data node for GSM called GPRS I worked with PCS people for the Japan market. As I recall it is basically the amount of timeslots that differ, the rest same-same as GPRS/EDGE so from my perspective this is actually another TDMA technology under another brand name.
But ask the operator what throughput they think they can provide.
The important thing is that you make sure they are talking about package data (don't know if they call it GPRS in PCS).

UMTS or WCDMA is the best system for data transmission. I do not think The States are very hot on that. It is mainly us in Europe and Far East. I think US has said that 3G (third generation of mobile telephony) is going to be implemented via GSM and GPRS/EDGE.
The problem with UMTS is as always, you share resources with others and there area no guarantee of bandwidth.
None of the cards in the links were UMTS cards so I think we can rule out this one.

As an unorthodox proposal I think you could check out an antenna solution.
There are several suppliers for antennas so you can build a point-to-point solution. The only thing you need is "line of sight" and a friend at the other end having a xDSL or "broad band" connection.

Forgot to mention: Steve Punter's Southern Ontario Cell Phone Page is a great resource for information on the North American cellphone market from the consumer viewpoint. (Well, it's really about the Canadian market, but the same technologies are used in the US.) He has a good explanation of the various technologies available in the North American market, and links to all the carriers in Canada. I find the coverage maps (like this one for my area) pretty useful.

At least the BlackBerry is designed and built here, so we're not totally behind!

Forgot to mention: Steve Punter's Southern Ontario Cell Phone Page is a great resource for information on the North American cellphone market from the consumer viewpoint. (Well, it's really about the Canadian market, but the same technologies are used in the US.) He has a good explanation of the various technologies available in the North American market, and links to all the carriers in Canada. I find the coverage maps (like this one for my area) pretty useful.

At least the BlackBerry is designed and built here, so we're not totally behind!

Forgot to mention: Steve Punter's Southern Ontario Cell Phone Page is a great resource for information on the North American cellphone market from the consumer viewpoint. (Well, it's really about the Canadian market, but the same technologies are used in the US.) He has a good explanation of the various technologies available in the North American market, and links to all the carriers in Canada. I find the coverage maps (like this one for my area) pretty useful.

At least the BlackBerry is designed and built here, so we're not totally behind!

It sounds awfully low versus what I know about CDMA, but the system does have the ability to take advantage of many smaller cells in ways that GSM, at least until recently, couldn't. Clasically, GSM is even worse.

Switch to Verizon and you won't have to keep yelling can you hear me now. No seriously - CDMA which is used by Verizon and Sprint have positive feedback meaning that the phone continually transmits and receives; so what you say but what happens is you hear background noises and you perceive mentally that the person has your complete attention.

With other vendors that use TDMA such as ATT, Cingular, TMobile they have to electronic introduce background noise because this technology doesn't continually transmit. They introduce clicks and pops to simulate background noise. This gives you the perception that you have to yell to keep the other persons attention.

CDMA is Code Division Multiple Access, and doesn't have anything to do with "real & imaginary parts of the signal." Real and imaginary are useful ways to denote things in math and physics, but there's no such distinction in the real world. You can't broadcast a "real" or "imaginary" radio wave; it's just a radio wave.

TDMA is Time Division Multiple Access.

This page has a brief explanation of the two.

I've been using GSM phones since 900MHz-only years around the world, and when I finally got a GSM phone for using it in the States as well, I didn't realize that I needed to be careful about reception issues. Apparently, 1900MHz (the main -and until recently only- frequency for GSM phones in North America) is not as good as 900MHz for rural areas. That means that, while it's probably great in big cities, it's no good elsewhere around the States.

Moral of the story: I got burned badly with an Ericsson T68i, which I had replaced 4 times before finally giving up on it ever working well as a phone. Sure, it was one of the first phones with color, bluetooth, PDA-like capabilities, it could even iSync with my PBG4 and my Palm, but I expect a phone first of all to work fine - as a phone! Is that so unusual?

So I looked and looked, and finally found a good independent source of information about phone's reception qualities (since no phone company nor cellphone provider will tell you anything about which phone works better in terms of reception: I've tried asking a lot of them).

I ended up with a Motorola P280. It does what I need, in order of importance:

1. great reception on all 3 main bands (1900,1800,900MHz)
2. SMS with enough characters on the screen at once
3. it can sync phone numbers (even calendar entries?) with iSync (despite the fact that no documentation admits it, its icon appears happily on iSync's panel when connecting it with a USB cable).
4. if necessary, it can be used as a GPRS modem (again, through USB)

Apparently, Nokia's 3650 is a good phone despite the built-in gadgets. But the keypad... that's what I would not want to have when typing SMSs...

This site provides pretty good information about all the providers and their coverage throughout parts of Ontario.

There are also pretty good reviews on the different handsets. It's probably a pretty good format for other people looking to start a site on cell coverage to follow.

PCS is actually a general term for any sort of digital cell phone service. The difference between CDMA and TDMA is actually pretty similar to the difference between Ethernet and Token ring. They both get the same job done but they can't talk to each other directly. There's a good description of the differences at this page. The various phone companies are actually pretty good about sharing their customers as they go roaming about. When I travel to Chicago or Minneapolis there isn't any service from US Cellular, but AT&T picks up my phone transparently to me and it still rings if someone calls. But Sprint is never going to pick up my calls for me because they can't talk to my TDMA phone.
_____________

GSM/TDMA/CDMA/FDMA/etc are not really the same type of thing, and can't really be compared. CDMA/TDMA/FDMA are air interfaces - methods of moduating data & sharing spectrum among multiple users. GSM is an all-encompassing system for mobile phones which uses TDMA & FDMA to get it's data on the air. What most people think of as TDMA is actually a standard called IS-136 that happens to use TDMA, likewise IS-95 is often called CDMA, even though it is not the only system that uses CDMA and if things go well, GSM (3g) will soon use CDMA too.

Finally, the voice compression performance and quality is also, completely seperate from both the air interface and the over all system in place. GSM/IS-95/IS-136 can all use a number of different vocoders to compress your speech, all offering varying bandwidth/quality tradeoffs.

All this and more can be explained here:

http://www.arcx.com/sites/

http://www.arcx.com/sites/CDMAvsTDMA.htm

GSM/TDMA/CDMA/FDMA/etc are not really the same type of thing, and can't really be compared. CDMA/TDMA/FDMA are air interfaces - methods of moduating data & sharing spectrum among multiple users. GSM is an all-encompassing system for mobile phones which uses TDMA & FDMA to get it's data on the air. What most people think of as TDMA is actually a standard called IS-136 that happens to use TDMA, likewise IS-95 is often called CDMA, even though it is not the only system that uses CDMA and if things go well, GSM (3g) will soon use CDMA too.

Finally, the voice compression performance and quality is also, completely seperate from both the air interface and the over all system in place. GSM/IS-95/IS-136 can all use a number of different vocoders to compress your speech, all offering varying bandwidth/quality tradeoffs.

All this and more can be explained here:

http://www.arcx.com/sites/

http://www.arcx.com/sites/CDMAvsTDMA.htm

Sometimes the same series of phones has different features. The 6185 has a built-in vibrator; the 6190 requires a battery with a vibrator.

The first digit is the series number; the third digit usually indicates the technology:
xx1x GSM 900/1800 (europe)
xx2x TDMA 800
xx3x GSM 900/1800 (europe)
xx5x GSM 900/1800 (europe)
xx6x TDMA 800/1900
xx7x CDMA 1900
xx8x CDMA 800/1900
xx9x GSM 1900

2160, 2170, 2180, 2190
5110+, 5120, 5130+, 5160, 5170, 5180**, 5190
6110+, 6120, 6150+, 6160, 6161, 6162, 6185, 6188*, 6190

* = Canada only, + = European, **5180= CDMA 800 only

Two great sites are Steve Punter's PCS guide (lots of Canadian info) and Steve Romaine's west coast site (also has Canada-specific info). Even if you're not Canadian, there's tons of info on various phones and technologies.

Steve Punter has a good site for Canadian cell users. Non-Canadians might want to have a look too since it has a great deal of information about different kinds of phones.

What makes it a Canadian site is that he's ridden around on his bike and MAPPED all the cells in the Toronto area. He documents how to do this, so maybe someone in another city wants to copy the technique and map their area too :-)

Unfortunatelly, although there is some information to be found at that site, there are often errors (some of which I brought to the author's attention about a year ago and are mostly still there), so unless you already know much about these things you can't be too sure if what you're reading is true or not. Steve Punter is a very frequent contributor in the alt.cellular* groups, and really "gets it". He maintains a web page with a wealth of information that is very accurate, as far as I can tell, and it's quite objective as well (although he doesn't try to hide his personal preference). It's again Canadian, and it's Ontario-centric, but I found most information quite useful in British Columbia as well. His site can be found at www.arcx.com/sites/

Lots of detail on TDMA vs CDMA; IS-137 vs IS-95 vs GSM vs IDEN, phone reviews etc etc.