Huge difference between RSSI, RSCP, EcIo of scan mode & active mode

[road2nowhere]

Hi,

Results from drive test conducted at the same time for scan & active (voice) mode.

But the values for RSCP, RSSI & Ec/Io vary significantly.


- RSCP is higher for scan mode (understandable as active mode may have missing nbrs, overshooters, handover issues)
- RSSI is higher for scan mode ( shouldn't it be the same for scan and active modes ?)
- Ec/Io is higher for active mode (shouldn't this be lower ? should we check scan Ec/Io or active Ec/Io for optimization ?)

Distribution is as below:



Attribute
Scan Mode
Voice Call


Coverage
RSCP CPICH Best
RSCP Best Active Set


>= -75
68.62%
41.35%


>= -85 and < -75
22.62%
33.43%


< -85 and >= -95
7.39%
20.31%


< -95
1.38%
4.92%


Quality
Ec/No CPICH Best
Ec/No Best Active Set


>= -5
10.92%
29.83%


>= -10 and < -5
59.46%
58.12%


>= -15 and < -10
28.36%
10.71%


< -15
1.26%
1.34%


RSSI Comparison
Wideband RSSI
Carrier RSSI


>= -75
91.57%
65.41%


>= -85 and < -75
7.46%
26.48%


< -85 and >= -95
0.93%
6.16%


< -95
0.04%
1.94%




Looking forward to your insights.

[chefo2068]

if you see big difference in RSSI, check your equipment hardware - mainly antennas, cables, and connectors, this is where it most often fails.
I would propose the following: make stationary test and compare the RSSI from MS Idle, MS DCH, and scanner. If you notice big difference, switch the antennas and compare again, thus you will be sure if your RF part is ok.