>Can someone confirm whether CDMA is actually technically superior?

Sure. I have worked extensively on the R&D side of the cellular industry, and have taught Cellular Technology courses for nearly a decade. No doubt, CDMA is very slick stuff, the best technology I've seen. Kinda like the Sony Beta VCR format when compared with GSM.

GSM is also excellent, but not as versatile as CDMA, or as efficient in use of the airwaves. But it *is* good enough, and is the defacto universal VHS .. er.. digital standard nearly everywhere in the world.

Where the two basically differ is in the channelization scheme. GSM divides the airwaves into 200Khz frequency chunks called "RF channels", and then multiplexes 8 time slots of voice/data within each RF channel. The original North American CDMA scheme uses RF channels of 1.25Mhz each, and uses digital coding to mutliplex up to 20-30 streams of voice/data within each RF channel.

At first glance, it would appear that GSM gets more bang for the bandwidth, but it suffers a common radio flaw in that the same RF channels cannot be re-used in adjacent cells or sectors (a sector is a directional slice of a cell, kinda like a slice of a pie). So for GSM, each RF channel can only be used in every fourth cell or so. With CDMA, each RF channel gets reused in every cell, and even every sector of every cell.. and it actually works better when this is done than it would otherwise.. because the codes are different in each sector/cell, they generally sum to a nice white noise like background, preventing interference and reflections from having as much negative impact as they would have against a quieter or less-even background level.

CDMA improves further as larger RF channels are used -- newer schemes use 5Mhz and 10Mhz channels.

Cheers