Difference between carrier and signal in CINR/SNR

[rpcrazy]

What is the difference between CINR VS. SNR
In other words, why is it that if i'm viewing a BTS, I can see both a SNR and a CINR. What's the difference between Signal divided by noise versus Carrier divided by noise.

I'm assuming that the "carrier" in CINR is just the specific propagation modulation and that the "signal" is data. However it seems WIMAX BTS calculates both "dl SNR" and "CINR". The SNR seems to be the average difference between the RSSI and the average NI (which is usually around -130dB). So if the rssi is between -122 and 117 the SNR will be 10.xx. But everything I've read about what SNR really is seems to contradict this reading.

The reason I ask is because the sprint EVO has a "SNR" and an RSSI reading for 4g service. It's imperative I really understand what this dl SNR reading means relative to a good CINR, if the SNR on the phone is different from the "dl SNR" reading from the tower. There numerous cases of supposed "outages" or attenuation issues, and I feel I don't correctly understand the engineering logic between these terms and measurements.

[willusrp4free]

This is how I understand it:
SNR is a measure of signal power to noise, as defined by the Noise Index of the receiver, and the signal power at the receiver.

CINR is a measure of in-band interference caused by using OFDMA or CDMA systems. Is both cases you are sharing a single channel among many users. For CDMA, CINR measures the equivalent noise power for each additional CDMA signal that shares the band, but cannot be demodulated using your PN sequence. For OFDMA, CINR would measure the adjacent channel interference between sub-carriers. In both cases, given perfectly orthogonal PN codes or sub-carriers, the CINR would approach infinity, but since we live in the real world of finite length correlators and filters, we can only approximate orthogonality in all but trivial cases.

Think of SNR as indicative of the physical channel conditions which cannot be controlled by the operator, and CINR as an indication of aggregate channel usage. I am guessing that your confusion about the SNR stems from the fact that the RSSI is not signal power in the mathematical sense of the term, but instead is just a relative measure of the signal energy in a specific frequency bin. "dl SNR" is the downlink SNR from the BTS to the phone. The SNR reported by your phone is the uplink SNR from the phone to the tower. A high "dl SNR" means that the phone receives a strong signal from the tower, and a high CINR means that the channel on which you are trying to communicate has few other users. Does this make sense? Anybody can feel free to correct me if I am mistaking - I am not an expert on WiMax.