At 1900 MHz the FCC limits you to 1W maximum output; at 850 MHz it is 1.5W. Most cell phones will transmit up to that power level if required to maintain channel SNR (QOS measurements in-channel to determine required TX power levels or if another cell is better suited for use).
This is off topic, unless you are alleging that the IPhone 4 isn't transmitting properly. Are you? Do you have any data?
Now let's look at the receive signal attenuation again:
Your signal attenuation data shows clearly that how you hold any cell phone affects the signal. This isn't new. Also from your same source. "From my day of testing, I've determined that the iPhone 4 performs much better than the 3GS in situations where signal is very low, at -113 dBm (1 bar)." and "so it's readily apparent that the new baseband hardware is much more sensitive compared to what was in the 3GS. The difference is that reception is massively better on the iPhone 4 in actual use." Obviously the person who produced the comparison thought that the IPhone 4 was better than the 3GS, after testing.
Theoretically, when held naturally, I could use 125mW output from the Nexus One and have the same total channel SNR (TX plus RX) as the iPhone 4 at 1W output, due to the attenuation of the iPhone 4's RX sensitivity. That is a not-inconsequential difference.
Now we seem to be back to output, and again I am confused as to the point.
It's also interesting to note that the least sensitive phone has the antennas external; those with internal antennas have higher sensitivity. I wonder if this is because of the use of shielding against the front of the phone, creating a ground plane for enhanced directivity of the antennas?
What is the context that this statement is referring to? Without proper context it is a meaningless paragraph.
I'd expect a 4-6 dB increase in RX sensitivity from a half-space measurement versus a full-space measurement, and that would be equivalent to an internal antenna with full ground plane behind versus an external antennas on edge without ground plane.
Yes, and the point is?
PugetSoundSoldier, I am a little confused you have apparently taken 5 quotes out of context without sourcing them and apparently tried to say something.
What are you trying to show?
No, and I did not allege that. Total channel performance of a duplex communications channel is a combination of the TX and RX; assuming TX is the same, then RX becomes the dominant factor for SNR. And if you have weak RX you can compensate by higher TX (since TX+RX is your total channel performance).
"so it's readily apparent that the new baseband hardware is much more sensitive compared to what was in the 3GS. The difference is that reception is massively better on the iPhone 4 in actual use.
This conclusion is not logical, by the article writer. Sensitivity is NOT concluded to be higher, only that total channel performance is higher, and that noise cancellation and audio signal processing allow for the iPhone 4 to produce higher quality audio with weaker signals. Improved sensitivity is not required to generate the data the author reports.
With typical cell phones, when the signal is below -100 dBm then the phone tries to switch to a new cell; it may be that the new iPhone does not, and maintains its connection because of other processing in the phone. That will reduce audio effects due to switching, but at the cost of higher noise in the channel (reduced SNR), which can be ameliorated with improved noise gating and dynamic bandwidth limitation (something I've used many times in phone conferencing systems).
Or, you can crank up your TX level to full strength (something that is rarely done) to compensate as well. This results in increased battery power consumption, which is also being reported in some iPhones.
Knowing how total channel performance is a combination of TX and RX, you can compensate for some loss in RX performance by increasing TX output. And that may be what is happening with the iPhone 4, and provides some improvement in total performance.
There is nothing taken out of context, and I thought for someone with some RF background and an EE degree this would be pretty obvious. The relation of these facts and surmising should be obvious for most EEs.