The TDMA vs CDMA section of this TDMA tutorial from the International Engineering Consortium (IEC) provides a more realistic assessment:
webproforum.com
6. TDMA Versus CDMA
Since the introduction of CDMA in 1989, the wireless world has been occupied by a debate over the relative merits of TDMA and CDMAƒ¨¨a debate whose fervor makes it reminiscent, at times, of a religious debate.
The proponents of CDMA have claimed bandwidth efficiency of up to 13 times that of TDMA and between 20 to 40 times that of analog transmission. Moreover, they note that its spread-spectrum technology is both more secure and offers higher transmission quality than TDMA because of its increased resistance to multipath distortion.
The defenders of TDMA, on the other hand, point out that to date there has been no successful major trial of CDMA technology that support the capacity claims. Moreover, they point out that the theoretical improvements in bandwidth efficiency claimed for CDMA are now being approached by enhancements to TDMA technology. The evolution of TDMA will allow capacity increases of 20 to 40 fold over analog in the near future. This combined with the vastly more expensive technology needed for CDMA ($300,000 per base station compared with $80,000 for TDMA) calls into question what real savings CDMA technology can offer. So far, ISƒ¨¨136 TDMA is the proven leader as the most economical digital migration path for an existing AMPS network.
We still lack the final word in this debate. However, it seems clear that for the near future at least, TDMA will remain the dominant technology in the wireless market.
The very long final word may be the existing facts on the ground.
Again, analog and TDMA/GSM always had the time to market advantages and that is why there are 400 million TDMA/GSM subscribers TODAY. There are only 42-50 million CDMA subscribers with 3 million in Japan and 24 million in South Korea. Even Dr. Jacobs acknowledges the time to market advantages (1-1.5 years) of 3G WCDMA over 3G CDMA2000.
The easily verfiable facts speak for themselves. |
