How We Got to Where We Are
This is a history lesson, it is not meant to break new information, but to give a quick crash course in acronyms that far too many readers do not understand. If you know what AMPS, CDMA, GSM, iDEN, TDMA, UMTS, HSDPA, and EV-DO are, feel free to skip this article.
Big serious warning: This is the keep-it-simple-stupid set of articles. They will step on engineerï¿½s toes, generalizations will be made. Feel free to refine it further in the forums, but these articles are for the consumer, not the engineer.
In the beginning, there was AMPS (that’s Analog for those of you in Rio Linda), and it was beautiful. It just worked, and it worked across carriers. Even better, there was (and still is) only 800 MHz AMPS in the United States. While technologies came before it, and after it, AMPS still remains the lowest common denominator for all the carriers that existed when AMPS was the only choice.
Then everyone wanted to get digital, and fast. TDMA became the quick-ticket to it, and eventually diverged off into iDEN and GSM. GSM quickly took hold in Europe (thanks to government mandates, less area to cover, and GSMï¿½s development taking place largely in Europe). But during TDMAï¿½s reign in the U.S., Qualcomm had a new idea called CDMA. The TDMA/GSM world balked at its technical claims, calling them impossible and even if implemented, inferior. However, CDMA eventually launched, with Sprint taking a lead (after a short trip with GSM), and Verizon chose it over the TDMA-conversion trend for AMPS). Even with TDMA and CDMA, AMPS remained compatible through backwards-compatible chipsets, it was considered necessary.
Then GSM came to the U.S. in force, Cingular had begun deployment, but the turning point for GSM was AT&T Wirelessï¿½ launch of GSM. VoiceStream became T-Mobile and grabbed a national coverage hold, and Cingular began deploying GSM-only in markets that they were not in (though a lot of that took place over about a year or two, not exactly in that order). But, the devil is usually in the details. Cingular chose a strategy of maintaining GSM and TDMA+AMPS interoperability by deploying GAIT heavily, especially in emerging markets. AT&T chose GSM-only, with GAIT multiband phones ï¿½under the tableï¿½ for customers that ï¿½complainedï¿½ about coverage. VoiceStream maintained a GSM-only network. As it turns out, this appears to have been a ranking factor in the carriers, Cingular on top, VoiceStream below them, and AT&T, well, eaten.
So now we have GSM, iDEN, and CDMA. CDMA became 3G with CDMA2000 with 1xRTT (Vision on Sprint, and NationalAccess on Verizon). GSM became 3G Class 10 EDGE as well. And that brings us to about today. iDEN’s death has been determined by the Sprint Nextel merger, 1xRTT is being upgraded to 1xEV-DO, and the GSM world is finally starting to capitulate to CDMA with W-CDMA/UMTS eventually replacing GSM, and UMTS will be retrofitted with HSDPA in late 2006.
We hope you enjoyed this brief history lesson, now please, stop the emails as to if Sprint and Verizon are 3G, what GAIT is, if GSM works with older networks, if GSM is CDMA, what W-CDMA is, and if UMTS is GSM.