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View Full Version : Question E******* HSDPA optimization



a19997104
2012-06-02, 12:30 PM
hello experts, i need help with these parameters:

downswitchTimer: Time after which a connection with low throughput is downswitched from dedicated channel to FACH/RACH.
Once the throughput on both the uplink and downlink has fallen below the value of downswitchThreshold, a downswitch to FACH/RACH is normally requested after this length of time. However, the downswitch is not requested if the throughput has subsequently increased above the value of downswitchTimerThreshold.
If CELL_FACH state is not available, the connection is switched down to IDLE state.
Special values:
0 is used to disable traffic-volume-initiated channel switching from dedicated channel to FACH/RACH.

hsdschInactivityTimer: Time after which a connection with low throughput is downswitched from HS-DSCH to CELL_FACH.
Once the throughput on both the uplink and downlink has fallen below the value of downswitchThreshold, a downswitch to FACH/RACH is normally requested after this length of time. However, the downswitch is not requested if the throughput has subsequently increased above the value of downswitchTimerThreshold. If CELL_FACH state is not available, the connection is switched down to IDLE state. Applicable only for radio connections without CPC.

basically whats the difference? i have found that in my network the PS calls make transition just after the RAB assigment, and the cause is "hs-dsch inactivity timer expire", its set to 2seconds (default E/// value)

jackkarpar
2012-06-02, 02:26 PM
In my opinion, the first one is downswitch from dch to fach/idle, and the second is downswitch from HS-DSCH to fach/idle. they're for different UE state.

a19997104
2012-06-04, 10:18 PM
In my opinion, the first one is downswitch from dch to fach/idle, and the second is downswitch from HS-DSCH to fach/idle. they're for different UE state.

to which value do you have the parameter hsdschInactivityTimer? this is causing that the users feel very low throughput at the beggining of the call

topoffenders
2012-06-04, 10:39 PM
downswitchTimer : triggered due to Small data transaction which is not required HS connection.
hsdschInactivityTimer : tiggered due to user in activity, beside network setting, it is also depend on Phone manufactures implementation, some phone do it quickly to save battery. (refer to fast dormancy)