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To: engineer who wrote (23697)	3/3/1999 10:40:00 AM
From: Bux	Read Replies (2) \| Respond to of 152472

Thanks Clark and Engineer for giving us something to chew on. Engineer, if the power numbers you provided can be taken at face value by the electrically challenged, this is very good for CDMA and Qualcomm if a link is established between exposure to RF energy and health effects. Do these power levels take into account that the signal is spread? That is the power of the entire frequency range is taken into account? And the TDMA power level, does it take into account the time-sharing nature of TDMA? I assume the phone only transmits in little bursts of RF energy when it is a particular phones time slot? If so, would it be necessary to multiply the TDMA power by the percentage of time it is transmitting to reflect the FR energy transmitted say each second? Any help here is much appreciated.

To: engineer who wrote (23697)	3/3/1999 10:44:00 AM
From: Ramus	Respond to of 152472

engineer, I've seen graphs of the distribution of the probability of power for urban and suburban environments for CDMA mobile (reverse link) systems. I have not seen similar statistics for TDMA systems. But statistically speaking I would imagine that your numbers are most correct with the ratios possibly even greater in real systems.....statistically speaking. As I recall CDMA mobiles saw a statistical peak around 0dBm with a probability of 50% and this fell off to +10dBm at maybe 5% to 10% probability. Peak powers of +20dBm occurred less than 2% of the time. Given that TDMA systems are much more prone to peak powers and are by nature less tightly power controlled.... as I said, I would imagine that your numbers are most correct with the ratios possibly even greater in real systems. Most of the time TDMA systems are putting out much more power. The Japanese explained in their W-CDMA proposal: "Low mobile station transmit power By means of technologies such as RAKE receiving, CDMA can improve the reception performance, thus, the required transmit power at the mobile station can be reduced with CDMA systems when compared to TDMA systems. Since intermittent transmission is employed in TDMA, the peak power to send information symbols will increase in relation to the number of timeslots. On the other hand, the peak power for CDMA can be kept low since continuous transmission is adopted. This is also advantageous in terms of keeping the impact in electromagnetic environment to a minimum. In TDMA, where various transmission rates are supported by setting up the number of timeslots to be allocated, the same level of peak power as the power needed for transmitting the highest rate service will be needed even for mobile terminals dedicated for voice service." Walt