Why Ec/Io Can be measured in 3G Idle mode but no Rxqual in Idle mode in 2G?

[RF Engr]

Hi Friends,

I an confused that what is the reason that in 3G Ec/Io can be measured even when MS is in Idle mode as compared to 2G where MS can not measure Rxqual values in Idle mode.

[eritelecom]

EcNo = CPICH power/ RSSI which are usually available as signals however RxQual is measured through BER (bit error rate) in time slot of one communication (than no idle mode measurement)

[fdanaei]

Hi dear friend, the answer is related to GSM and WCDMA (3G) standards in idle mode. In GSM standard, only signal level has been considered for cell selection and reselection (and related C1 and C2 parameters).
But in WCDMA standard, not only signal level of cells (RSCP: Received Signal Code Power of CPICH) is used for cell selection and Reselection but also CPICH Ec/N0 condition of cells (that is quality criteria in Idle Mode) is used (related Squal and Srxlev Parameters).
Maybe, I think, it was better to use C/I for cell selection/reselection in GSM standard too (that didn’t) but it was not as necessary as WCDMA. WCDMA system is more affected by C/I (quality) in Idle mode than GSM system that we can discuss about this issue later.
In some old GSM phones like SE T610 it was possible to extract C/I in Idle mode for test purpose only.

Hi Friends,

I am confused that what is the reason that in 3G Ec/Io can be measured even when MS is in Idle mode as compared to 2G where MS can not measure Rxqual values in Idle mode.