Hsdpa Performance Improvement

Method – PRX totalFor internal use
For internal use
HSDPA Performance Testing
Table below is Performance table in initial and final HSDPA mobility test report and it is our target to improve and HSDPA can have better performance (enhancement). However, some might not be easy to see improvement. So we can focus on some KPI
Application Throughput (Most important)
HSDPA Call Drop
EcNo and RSCP should not be focus because not much L1 optimization and EcNo might be worse if higher average throughput (more HSDPA using)
* © Nokia Siemens Networks Presentation / Author / Date
For internal use
HSDPA Performance Improvement (RN5.0)
Plot right is for Channel Type Distribution in Tainan Tech Park Cluster Test on April 24
73% is DCH99
23% is HSDSCH (HSDPA)
Application Throughput and HSDPA status can be optimized if we can increase HSDPA channel assignment or reduce Inter-frequency handover to carrier1 (No HSDPA service)
To reduce HSDPA Call Drop, we can tune handover related parameter and make cell change smoothly
For internal use
HSDPA Call Drop Case
UE sent e_1a at 11:32:25 but no cell change, it might cause not meet cell change criteria (SHO disable and Release Margin for Average Ec/No:2.5dB and Release Margin for Peak Ec/No:3.5dB)
For internal use
HSDPA mobility in RAS05
Serving Cell Change switches the user from HS-DSCH to Cell_FACH then back to HS-DSCH
HS-DSCH coverage
HS-DSCH coverage
UE on HS-DSCH
For internal use
Details on Cell Change via cell-FACH
HSDPA Serving Cell Change via Cell-FACH feature is used only in intra frequency handover cases, in case of IFHO or ISHO the original DCH switching procedures are used
If the user was moved to Cell-FACH because of intra frequency handover no HSDPA user penalty timers are used on Cell-FACH, the user will be immediately switched to a new HSDPA connection when there is a data volume request either from the UE or RNC
If the user was moved to Cell-FACH because of low throughput then the HSDPA user penalty timers are used on Cell-FACH
If the HSDPA user moves to non-HSDPA cell, the user in HO area will be moved to Cell-FACH. The user will be immediately switched to the DCH of the requested bit rate when there is a data volume request either from the UE or RNC (no need for first DCH0/0 DCH Initial bit rate DCH Final bit rate)
In RAS05, UE goes to cell_FACH in the current serving cell. Possible cell reselection to best server happens in cell_FACH.
For internal use
Measurement event 1A triggered HS-DSCH MAC-d flow release and parameter EnableRRCrelease is disabled:
UE is transferred to the CELL_FACH state and the radio bearer is mapped to
the FACH with the RRC: Radio bearer reconfiguration procedure.
For internal use
EcNo Filter coefficient (HSDPA FMCS) = 800ms
SHO of the HSDPA Capable UE (RNC) = disabled
Enable RRC release (HSDPA HOPS) = disabled
Release Margin Average EcNo (HSDPA HOPS) = 2dB
Release Margin Peak EcNo (HSDPA HOPS) = 3.5 dB
EcNo Averaging Window (HSDPA HOPS) = 8
RB_Reconfiguration (FACH)
Wei Yun (WY) - addition window cannot be set to negative value
In this case the AS is NOT full event 1A – otherwise it would be event 1C!
Determine reference level (either strongest CPICH or mixture of AS CPICH)
Threshold when to add new CPICH
How long the new CPICH has to be above threshold before is reported as 1A
If not added to AS when to notify network again
For internal use
Measurement event 1A triggered HS-DSCH MAC-d flow release and parameter EnableRRCrelease is enabled:
For users other than HS-DSCH allocated,
EnableRRCRelease indicates whether the RRC connection release (excluding emergency calls) is allowed due to non-optimum fast closed loop power control.
For users with a HS-DSCH,
If the RNC receives measurement event 1A and the EnableRRCRelease parameter is enabled, HS-DSCH MAC-d flow release is not allowed to be triggered directly.
When a cell has entered the reporting range and triggered event 1A and the RNC has not added the cell into the active set, the UE reverts to periodical reporting. This means that the UE continues reporting after the initial report by switching to periodical measurement reporting mode.
As the EnableRRCRelease parameter is enabled, the RNC’s decision on HSDSCH MAC-d flow release is based on CPICH Ec/No of the serving cell (EcNoDownlink), CPICH Ec/No of the neighbouring cell (EcNoNcell) and the ReleaseMarginAverageEcNo and ReleaseMarginPeakEcNo control parameters.
Based on the periodic measurement reporting mode and the control parameters, the UE is transferred to the CELL_FACH state and the radio bearer is mapped to the FACH with the RRC: Radio bearer reconfiguration procedure if the following conditions are effective:
(1) EcNoDownlink + ReleaseMarginPeakEcNo(n) < EcNoNcell(n)
(2) AveEcNoDownlink + ReleaseMarginAverageEcNo(n) < AveEcNoNcell(n)
- enabled
Wei Yun (WY) - if either one condition met, cell change will be triggered
For internal use
Enable RRC release (HSDPA HOPS) = enabled
ReleaseMarginAverageEcNo
ReleaseMarginPeakEcNo
RB_Reconfiguration (FACH)
Wei Yun (WY) - enable this parameter is to delay the cell change process
For internal use
HSDPA Call Drop Case (1)
UE sent e_1a at 11:32:25 but no cell change, it might cause not meet cell change criteria (SHO disable and Release Margin for Average Ec/No:2.5dB and Release Margin for Peak Ec/No:3.5dB)
For internal use
HSDPA Call Drop Case (2)
UE sent e_1a again at 11:32:36 but might be too late (addition window: 0dB and addition time: 320ms) to perform cell change, drop due to bad EcNo
Handover related parameter can be tuned to avoid this kind of drop
Signaling SHO can be performed in RAS5.1 and UE no need to enter cell-FACH for serving cell change. Can adjust addition window and time to perform SHO earlier
Drop
For internal use
In HSDPA service, UE will perform cell change after RRC release criteria fulfill
Parameters: Release Margin for Average Ec/No:2.5dB and Release Margin for Peak Ec/No:3.5dB
RNC refer to EcNo of active set and monitor set in e_1a MR
E_1a parameter in FMCS for HSDPA is used
Addition window:0dB
Addition time: 1280ms
Filter coefficient: 600ms
In case, 1st e_1a MR sent by UE but EcNo of active set is -23dB, cell change might not be performed properly (UE can’t decode RB reconfiguration)
SHO can be performed in RAS5.1
HSDPA Call Drop Case - adjust event_1a addition time and fc
For internal use
HSDPA Call Drop Case - adjust event_1a addition time and fc
Another case have the similar problem
Many call drop have similar situation
Delay cell change in HSDPA service must be considered because throughput gap in cell-FACH during cell change. But it can be controlled by parameters:
Release Margin for Average Ec/No:2.5dB
Release Margin for Peak Ec/No:3.5dB
E_1a parameter in FMCS for HSDPA can be adjusted to trigger earlier to avoid drop
Addition window:0dB
For internal use
Serving Cell Change Functionality Verification (SHO for HSDPA user) _ Message Flow (RN5.1)
After SW upgrade: Test on April 29
ASU to add SC 267
Measurement control to ask UE to perform Periodical EcNo reporting
Periodic EcNo report
RAB reconfiguration for Serving cell change to SC267
No RAB reconfiguration to ask UE to cell-FACH for Serving cell change
ASU to remove SC208
For internal use
HSDSCH to DCH
UE sent e_1f of SC169 11:34:25 (active set is 1 in HSDPA in RAN5.0)
Before compress mode (physical channel reconfiguration), RNC have sent two radio bearer reconfiguration. One is for 0/0 bit rate and another is for initial bit rate (64/64)
For internal use
maximum allowed power
FMCI: IFHOcauseUplinkQuality
FMCG: GSMcauseUplinkQuality
maximum allowed power, event 6A/6D
FMCI: IFHOcauseTxPwrUL
FMCG: GSMcauseTxPwrUL
- IMSI based HO
Frequency Measuring Control for Inter-System (GSM) = FMCG
For internal use
Reporting event: 1E: A P-CPICH exceeds an absolute threshold
1F: A P-CPICH falls below an absolute threshold (HO triggered if all)
time
For internal use
UE continually monitors pilot channels of BTSs in AS
If RSCP of a Node B falls below threshold, HHoRscpThreshold, UE sends event 1F report
RNC starts IF/IS measurements when event 1F occurs for all cells in AS
RNC stops IF/IS measurements when event 1E occurs for at least one cell of AS
Note:IF/IS measurements can be stopped if event 1Fs are cancelled by events 1E only when IFHO/ISHO was not successful and only inside the time between CM measurements, specified by the time InterFreqMinMeasInterval GsmMinMeasInterval/default 10s, recommendation 2s .
UE filtering applied before event evaluation using HHoRscpFilterCoefficient (FMCS) /200ms, range 200…1600ms
For internal use
Event 1E (A primary CPICH exceeds an absolute threshold) parameters:
Triggering conditions: Active set cells
hysteresis: not used in 1E
Threshold used frequency: (FMCS) : HHoRscpCancel/ - 92 dBm
Time-to-trigger: (FMCS): HHoRscpCancelTime/ 1280 ms
Amount of reporting: infinity
Reporting interval: not applied
Reporting cell status: max 3 active cells
Event 1F (A primary CPICH falls below an absolute threshold) parameters:
Triggering conditions: Active set cells
Hysteresis: not used in 1F
Threshold used frequency: HHoRscpThreshold (FMCS)/ - 95 dBm
Time-to-trigger: HHoRscpTimeHysteresis (FMCS)/ 640 ms
Amount of reporting: infinity
Reporting interval: not applied
For internal use
HSDSCH to DCH but no Physical Channel Reconfiguration (CM mode didn’t be triggered) (1)
For internal use
HSDSCH to DCH but no Physical Channel Reconfiguration (CM mode didn’t be triggered) (2)
However, UE sent e_1e of SC169 11:34:27 (active set is 1 in HSDPA in RAN5.0), so compress mode didn’t start (no physical channel reconfiguration) and UE stay in Carrier2 (no IFHO)
But UE is in DCH99, not in HSDSCH channel, radio bearer reconfiguration is update UE to R99 Max bit rate in downlink, UL/DL: 64/384)
NRT SHO criteria will be used to perform SHO and might cause HSDPA didn’t be used again (resumption didn’t expire)
No IFHO but DCH99 is used due to signal fading, better to adjust e_1f criteria to avoid it.
For internal use
HS-DSCH guard time after switching to DCH due to HO
The parameter determines a period of time during which the HS-DSCH allocation is denied after successful channel type switching from HS-DSCH to DCH 0/0 kbps due to handover reasons(e1F, e6A).
Timer is not applied if UE is transferred directly to the CELL_FACH state due to reporting event 1A.
Range and step 0...30 s, step 1 s
Default value 5 s
For internal use
Inter-Frequency Handover (1)
Different with previous case, no e_1e from UE, so compress mode is triggered (first physical channel reconfiguration)
Measurement report to report ADJI measure. If fulfill HO criteria, RNC send second physical channel reconfiguration to ask UE to carrier1
For internal use
Inter-Frequency Handover (2)
UE is in carrier1 and DCH99 is used because HSDPA didn’t implement in carrier1. NO chance to use HSDPA service because no ADJI setting in cell of carrier1.
HSDPA can be used in next call by DRRC function
To evaluate if this IFHO is necessary. If didn’t perform, will cause PS drop? try to adjust e_1f criteria to avoid IFHO and no drop.
For internal use
No HSDSCH assignment ( >1 active set before RAB reconfiguration)
More than 1 active set before RAB reconfiguration though SHO not allow for HSDPARRCDiversity parameter (follow RRC Release criteria for HO). RNC won’t assign HSDSCH, instead of DCH99
Parameters: Release Margin for Average Ec/No:2.5dB and Release Margin for Peak Ec/No:3.5dB can be considered to adjust, but drop must be avoided.
Cell reselection related parameter can adjust to avoid UE camp to worse cell to initial call
HSDPA can be assigned even Active set more than 1 in RAS5.1 and Serving cell change function but worse cell to initial call still need to avoid
For internal use
CHANNEL TYPE SELECTION
HS-DSCH is selected if all of the following conditions are met:
Traffic class and traffic handling priority are allowed on HS-DSCH
The operator can configure which traffic classes and handling priority are allowed to be used with HSDPA with HSDSCHQoSclasses parameter.
RAN05 only interactive and background traffic classes are supported
UE capability supports HS-DSCH
The cell supports HSDPA and HS-DSCH is enabled in the cell
No multi-RAB (RAN05) or supported multi-RAB combination (RAN05.1)
No multiRAB in RAN05
AMR + HSDPA possible in RAN05.1
The number of simultaneous HS-DSCH allocations in the BTS/cell is below the maximum number.
HsdschGuardTimerHO and HsdschGuardTimerLowThroughput guard timers are not runnig
Both guard timers are operator-configurable parameters
UE is not performing inter-frequency or inter-system measurements
Active set size = 1 (RAN05)
UE does not have DCHs scheduled with bit rates higher than 0kbps.
HS-DSCH physical layer category is supported
If there is no existing MAC-d flow in the cell, condition (A or B, depending on the HSDPApriority parameter) has to be valid.
A) PtxNC<=PtxtargetHSDPA
B) Ptxtotal<=PtxtargetHSDPA
For internal use
- Diversity handover of stand-alone signalling link
If the active set size is greater than one, allocation of a HS-DSCH transport channel to the UE is prohibited.
The operator can disable diversity handover of the RRC connection (stand-alone signalling link) of a HSDPA-capable UE with the HSDPARRCdiversity parameter to maximise the use of the HS-DSCH.
The value of the parameter HSDPARRCdiversity shall be checked immediately after a successful RRC connection setup procedure.
If SHO of the RRC connection (stand-alone signalling link) of the HSDPA-capable UE is not allowed, the active set size is limited to one for the RRC connection.
Restriction is effective after RRC-connection establishment when SRB only or SRB and DCH 0/0 is/are allocated.
For internal use
The RNC ignores the parameter value (and allows diversity handover of standalone signalling link) if measurement event 1A is received and the reported CPICH Ec/No of the entering cell meets the following conditions (that is, the threshold to perform HS-DSCH to Cell_FACH transition is exceeded):
(1) EcNoDownlink + ReleaseMarginPeakEcNo(n) < EcNoNcell(n)
(2) AveEcNoDownlink + ReleaseMarginAverageEcNo(n) < AveEcNoNcell(n)
AveEcNoDownlink : averaged CPICH Ec/No of the serving cell
AveEcNoNcell(n) : averaged CPICH Ec/No of the entering cell
The comparison is applied when a cell has entered the reporting range, and triggered event 1A, and RNC has not added the cell into the active set.
In this case, the UE reverts to periodical reporting and continues reporting after the initial report by switching to the periodical measurement reporting mode.
ReleaseMarginPeakEcNo(n) determines the maximum allowed difference between the CPICH Ec/No of the entering cell (n) and the CPICH Ec/No of the serving cell so that active set update is not executed.
ReleaseMarginAverageEcNo(n) determines the maximum allowed difference between the averaged CPICH Ec/No of the entering cell(n) and the averaged CPICH Ec/No of the serving cell correspondingly.
The HSDPA-specific HOPS parameters are used in the equation.
HSDPARRCdiversity (2/4)
For internal use
Ec/No
Enable RRC release (HSDPA HOPS) = enabled
ReleaseMarginAverageEcNo
ReleaseMarginPeakEcNo
Stand-alone Signalling Link
For internal use
Ec/No
* HSDPA enabled for both Serving & Target Cells
For internal use
More than 1 active set before RAB reconfiguration though SHO not allow for HSDPARRCDiversity parameter (follow RRC Release criteria for HO). RNC won’t assign HSDSCH, instead of DCH99
Parameters: Release Margin for Average Ec/No:2.5dB and Release Margin for Peak Ec/No:3.5dB can be considered to adjust, but drop must be avoided.
Cell reselection related parameter can adjust to avoid UE camp to worse cell to initial call
Drop window and time can be adjusted
HSDPA can be assigned even Active set more than 1 in RAS5.1 and Serving cell change function but worse cell to initial call still need to avoid
No HSDSCH assignment - adjust event_1b drop time and window
For internal use
No HSDSCH assignment - adjust event_1b drop time and window
Objective: try to keep 1 active set as possible before HS-DSCH assignment (RAB reconfiguration.
No E_1b MR might cause drop-window (6dB) and time setting (640ms) though 5 dB difference between 2 active set. If change drop window smaller and drop time short (FMCS for HSDPA). Event_1b might be triggered and HS-DSCH might be assignment (active set is1)
E_1b parameter in FMCS for HSDPA is used in SRB period. It is not affect after RB assignment (RT/NRTFMCS will be used in RT/NRT DCH, Cell-change will be used in HSDPA)
Ping-pong addition and deletion? “NO”
SHO not allow for HSDPARRCDiversity
Addition window is 0dB
For internal use
- For reference and not for tuning)- RN5.1
HSDSCH can be assigned even more than 1 active set before RAB reconfiguration
For internal use
Test in RN42
Initial Test
For internal use
Test in RN42
Scenario1+ Scenario2
Filter Coefficient:300ms (from 600ms)
DropWindow: 2dB (from 6dB)
How to reduce drop?
For internal use
For internal use
Inter-Frequency Handover
In RAS 05, unnecessary CM preparation (HSDSCH to DCH) must be reduction (same as RAN5.0), no matter compress mode have been triggered or not
Except e_1f parameter can be adjusted, SHO related can be adjusted to avoid HSDSCH to DCH99
Measurement report to report ADJI measure. If fulfill HO criteria, RNC send second physical channel reconfiguration to ask UE to carrier1
Case left, UE sent e_1f earlier than e_1a (SC142:89). If add SC142 earlier, CM preparation (HSDSCH to DCH) or IFHO might not be performed
For internal use
NO dominator server
This area have mess signals and strength is very close (SC 161, 169, 142, 211 and 280)
L1 optimization can be considered if not affect carrier1 performance (Actual, L1 tuning might help to improve carrier1 performance, too)
For internal use
Original Active set is SC203 and SHO to add SC280
SC280 is stronger in periodic measurement EcNo report
RNC have sent two radio bearer reconfiguration. One is for 0/0 bit rate and another is for initial bit rate (64/64)-DCHR99 but no HSDSCH. Fail serving cell change?
Possible to cause by ULSIRError problem
Under investigation
For internal use
HSDPA Testing in Tainan Tech Park
HSDPA performance comparison between “before” and “after SW upgrade” might not be fair and corrected because the test area haven’t tuned and percentage of HSDPA using is low. Suggest to test in fine tuned area for comparison
After SCC SW upgrade: Test on April 28
Before SCC SW upgrade: Test on April 16
For internal use
Didn’t change back
Can’t say throughput is worse because most of time use cell-DCH
For internal use
Didn’t change back
Can’t say throughput is worse because most of time use cell-DCH
Scenario2: Change parameter in RNC
HSDPASIRErrorReportPeriod:0
For internal use
Problem in Scenario2 Test:
HS_DSCH assignment and throughput can be observed in test, should not have problem if set HSDPASIRErrorReportPeriod:0
For internal use
Problem in Scenario2 Test:
After data transfer and PDP deactivation, no detach from UE and no RRC release for long time. can’t sure if it is tool problem, better to re-test. If problem still, can add attach /detach in script
For internal use
change back
Throughput is much better but drop increase, should analyze and improve drop rate (Handover related parameter?)
For internal use
HHoRSCP threshold/cancel parameter tuning
Border cell/ inner cell
KPI need to monitor
For internal use
HSDPA Serving Cell Change
Periodical UL SIRerror Measurements
Event 1B Triggered SCC
Event 1C Triggered SCC
RL Failure, Serving HS-DSCH Link Moved to DRNC, RL Removal Due to 6F, 6G
Too Frequent Serving Cell Changes
ISHO with SCC
For internal use
ISHO with SCC
For internal use
HSDPA Initial Serving Cell Selection
Note that in order to allocate HS-DSCH, HS-DSCH channel type selection algorithm must be successful, i.e. UE and Cell/BTS must fulfill all the criteria regarding HS-DSCH allocation
The serving HS-DSCH cell selection algorithm is executed when a NRT PS RAB is established and a capacity request leads to the HS-DSCH allocation
UL return channel allocation must also be successful in order to allocate HS-DSCH transport channel
Initial serving HS-DSCH cell selection is based on the latest received intra-frequency DL CPICH Ec/No measurement result reported by UE
If the size of the active set is one, i.e. there is only one cell in the active set, DL CPICH Ec/No is not used as criteria, but HS-DSCH allocation can be executed without taking it into account
For internal use
If the size of the active set is greater than one, i.e. there is more than one cell in the active set, DL CPICH Ec/No is used as criteria
All the HSDPA-capable cells, which fulfil the following condition, are selected as possible candidate cells for HS-DSCH allocation:
Where CPICHEc/NoCell is the CPICH Ec/No measurement of the candidate cell, CPICHEc/NoCell is the CPICH Ec/No measurement of the best cell in the active set and HSDPAServCellWindow (def. 2dB) is the management parameter, which determines the window – relative to the best cell in the active set – inside of which the serving HS-DSCH cell must be in order to allocate HS-DSCH
Wei Yun (WY) - condition to find candidate list
For internal use
When the cells, which fulfil the DL CPICH Ec/No condition are found, the serving HS-DSCH selection is executed according to the following priorities:
The cell, which has already HSDPA power allocated is chosen as the serving HS-DSCH cell
If several cells fulfil the criterion, DL CPICH Ec/No determines the order of the cells
The cell, which has the best DL CPICH Ec/No is chosen as the serving HS-DSCH cell
The cell, which has the next best DL CPICH Ec/No (first 2nd and then 3rd best) is chosen as the serving HS-DSCH cell
If the RL is out of synchronisation, it is excluded from the candidate list for the serving HS-DSCH cell
If allocation of the HS-DSCH fails or is unsuccessful due to any reason, the next best cell, in accordance with the priorities above, is attempted
If none of the cells in the active set can be chosen as the serving HS-DSCH cell, or if all the attempted allocations of the HS-DSCH are unsuccessful, DCH is scheduled immediately, i.e. capacity request is handled without queuing
For internal use
HSDPA Initial Serving Cell Selection – Resumption Timer
DCH to HS-DSCH switch is attempted if conditions for HSDPA connections are fulfilled for certain time period
This time period is defined by non hidden RNP parameter HSDPAResumptionTimer (def. not in use)
The Handover Control starts HSDPA resumption timer when the following preconditions are fulfilled:
PS I/B RB has been mapped to DCH > 0/0
UE is HSDPA capable
cell is HSDPA capable
Active set size is 1 RAN05 or in RAN05.1 when HSDPAMobility parameter is disabled
Active set contains at least one HSDPA capable cell in RAN05.1 when HSDPAMobility is activated
UE has suitable RAB configuration
(allowed RAB configurations can be found from requirement HSDPA.6)
Resumption timer functionality is activated (the value of the timer does not indicate it is off)
HSDPA resumption prevention timer is not active
The Handover Control stops the HSDPA resumption timer for the following reasons:
In RAN05 or in RAN05.1 when HSDPAMobility parameter is disabled
- Handover (active set change, compressed mode is initiated)
In RAN05.1 when HSDPAMobility parameter is enabled
- there is no HSDPA capable cell in the active set anymore
- compressed mode is initiated
RAB configuration changes so that HSDPA is not possible anymore
(allowed RAB configurations can be found from requirement HSDPA.6)
NRT DCH is released
For internal use
In RAN05.1, when the HSDPAMobility parameter is enabled, the periodic CPICH Ec/No measurement is used to check the quality of HSDPA capable cell (check the Periodical CPICH Ec/No Measurements section)
When the active set size is 1, then the Handover Control asks DCH to HS-DSCH switch from the UE specific PS if HSDPA resumption timer expires
When the active set size is bigger than 1, then the handover control checks condition for initial HSDPA service cell selection, after the resumption timer expires
This means that the switch can not be started until at least one CPICH Ec/No measurement report is received (for example in the case where the value of the resumption timer is 0 s)
If the condition is fulfilled (good enough HSDPA capable cells are found) then the handover control asks DCH to HS-DSCH switch from the UE specific PS
For internal use
Switch (DCH -> HS-DSCH) can be refused for the following reasons:
There exists parallel procedures for the UE (UE specific PS)
It is not possible to allocate HSDPA power to the cell (cell specific PS)
Nbr of HSDPA users is exceeded for the cell/BTS (cell specific PS)
HdschGuardTimerHO (def 5s) or HsdschGuardTimerLowThroughput (def 30s) is running
If the switch can not be done or is refused, then the Handover Control starts HSDPA resumption prevention timer (5s, 10s, 15s)
Resumption timer can be started again after HSDPA resumption prevention timer has expired
HSDPA resumption prevention timer is increased by 5 seconds every time it is started (i.e. every time the switch DCH -> HS-DSCH is consecutively refused)
However maximum value for HSDPA resumption prevention timer is 15 seconds
For internal use
When DCH to HS-DSCH switch is being made then the following things are done:
DCH is released
RB is mapped to DCH 0/0
normal channel type selection is made to get a HS-DSCH channel, when the next capacity request is received
The HS-DSCH allocation follows the principles specified for the MAC-d flow setup starting in the Cell-DCH state
A HS-DSCH is added, MAC-d flow setup and UL/DL DCH replaced with the unidirectional UL DCH with the same synchronised RRC- and NBAP-procedures
For internal use
ISHO with SCC
For internal use
Cell change via FACH causing typically 3 s break
HSDPA not available in soft handover soft handover is disabled for HSDPA connections
RAS05.1 solution with HSDPA serving cell change
Direct handover from Cell A HSDPA to Cell B HSDPA. Connection break in good case <100 ms.
Uplink soft handover can be used also for HSDPA connections
Cell with HSDPA capability
Cell without HSDPA capability
1
2
3
Wei Yun (WY) - In RAS5.1, SHO is capable in SRB and UL
For internal use
The serving HS-DSCH cell change is based on the intra-frequency CPICH Ec/No measurements reported periodically by the UE and dedicated UL SIRerror measurements reported periodically by the BTS
The serving HS-DSCH cell change may be categorized in regards to whether the decision of the target HS-DSCH cell is made by the UE or by the network
In Release 5 (RAN05.1), only network controlled serving HS-DSCH cell changes are supported
In the case of a network-controlled serving HS-DSCH cell change the network makes the decision of the target HS-DSCH cell, and the decision is based on UE and BTS measurement reports, different management parameters and available RNC and BTS resources
A network controlled HS-DSCH cell change is performed as RRC layer signaling procedures to UE
For internal use
With respect to synchronisation between UE and UTRAN as to when transmission and reception is stopped and re-started, two possibilities for a serving HS-DSCH cell change exist:
Synchronised serving HS-DSCH cell change: Start and stop of HS-DSCH transmission and reception is performed at a certain time typically selected by the network; (RAN05.1)
Unsynchronised serving HS-DSCH cell change: Start and stop of HS-DSCH transmission and reception is performed "as soon as possible" (stated by UE performance requirements) at either side (not supported in RAN05.1)
For internal use
The serving HS-DSCH cell change may be categorized with respect to the serving HS-DSCH Node B:
Intra-Node B serving HS-DSCH cell change: The source and target HS-DSCH cells are both controlled by the same Node B
The serving HS-DSCH Node B is not change
Inter-Node B serving HS-DSCH cell change: The Node B controlling the target HS-DSCH cell is different from the Node B controlling the source HS-DSCH cell
UE
HSDPA Traffic
Measurement Report (DCH) – e1A
NBAP: Radio Link Setup
NBAP: Radio Link Synchronisation
NBAP: Radio Link Reconfiguration Prepare
NBAP: Radio Link Reconfiguration Ready
RRC: Measurement Control
RRC: Physical Channel Reconfiguration
Measurement Report (DCH)
ALCAP : ERQ
ALCAP : ECF
RRC: Radio Bearer Reconfiguration
For internal use
Serving HS-DSCH cell change algorithm is executed when HS-DSCH is allocated and need for the serving HS-DSCH cell change is detected
The measurements and reasons, which may trigger serving HS-DSCH cell change are the following ones:
Periodical CPICH Ec/No measurement
Periodical UL SIRerror measurement
Measurement event 1C
Serving HS-DSCH cell is replaced with another cell
RL failure of the serving HS-DSCH radio link (loss of UL synchronisation)
Serving HS-DSCH radio link is deleted
Serving HS-DSCH radio link is handed over to DRNC
RL removal due to Rx-Tx time difference
Serving HS-DSCH radio link is deleted
Each case is specified in detail in separate requirements
For internal use
Following event triggered measurements are order by RNC to be performed by the UE having HS-DSCH allocation
Event 1A
Event 1B
Event 1C
Event 1E
Event 1F
Event 6F
Event 6G
Periodical CPICH Ec/No measurements (in case AS size > 1)
The serving HS-DSCH cell change is based on the intra-frequency CPICH Ec/No measurements reported periodically by the UE and dedicated UL SIRerror measurements reported periodically by the BTS
For internal use
ISHO with SCC
For internal use
Measurement reporting mode is fixed
Transfer Mode is 'Acknowledged mode RLC'
Reporting Mode is 'Periodical reporting'
Measurement quantity is CPICH Ec/No
Filtering of CPICH Ec/No measurement in UE is controlled with the RNP-parameter EcNoFilterCoefficient, defined by the HSDPAFmcsIdentifier or RTWithHSDPAFmcsIdentifier parameter set
Reporting quantity is CPICH Ec/No for active set cells – fixed
Reporting criteria is periodical reporting
The reporting interval is determined by the RNP-parameter HSDPACPICHreportPeriod
Wei Yun (WY) - will be triggered by network when there is > 1 active set
For internal use
Periodical CPICH Ec/No Measurements
Periodically reported DL CPICH Ec/No measurement results are averaged in RNC
HSDPACPICHAveWindow (def 3) is RNC specific parameter, which defines how many CPICH Ec/No measurements, which are received in the RRC: MEASUREMENT REPORT message, are included in the sliding window used in the averaging
CPICH Ec/No is averaged using the following formula:
Where CPICHEc/No (t) is the latest CPICHEc/No measurement and n equal to HSDPACPICHAveWindow
RNC starts the averaging already from the first measurement sample, that is, the RNC calculates the averaged values from those measurement samples which are available until the number of measurement samples is adequate to calculate averaged values over the whole averaging window (=> serving HS-DSCH cell change can be initiated based on 1st Measurement Report as longs as conditions are fulfilled)
RNC calculates the averaged values directly from the measured dB values, linear averaging is not used in this case
For internal use
Periodical CPICH Ec/No Measurements
Whenever the AS>1 for HSDPA call the RNC orders the UE to start to perform periodical CPICH Ec/No measurements
UE
RNC
Setting up periodical Ec/No measurements for HS-DSCH serving cell change procedure
Periodical CPICH Ec/No measurement are started only if the size of the active set is greater than one. If the size of the active set is one, periodical CPICH Ec/No reporting is not started and if on going stopped
DL-DCCH-Message {
integrityCheckInfo {
For internal use
ISHO with SCC
For internal use
HSDPA Serving Cell Change - Periodical CPICH Ec/No Measurement Triggered
When the serving HS-DSCH cell change due to any reason has successfully been executed, the timer is started
During the time period, determined by the parameter HSDPACellChangeMinInterval (def 3s), serving HS-DSCH cell change due to periodical CPICH Ec/No measurement, is not allowed for the particular UE
The serving HS-DSCH cell change due to any other reason is NOT forbidden even if the timer is running
Wei Yun (WY) - HSDPACellChangeMinInterval only valid for periodical CPICH measurement. If cell change triggered by other reason, this timer is ignored.
For internal use
When UE reports periodical intra-frequency CPICH Ec/No measurement report, need for the serving HS-DSCH cell change is evaluated (UE is ordered to report periodically the CPICH Ec/No values of the AS cells when AS size > 1)
If the CPICH Ec/No of the serving HS-DSCH cell is not close enough to the currently best cell in the active set, serving HS-DSCH cell change is initiated
The condition to initiate serving HS-DSCH cell change is defined in the inequality below
If CPICH Ec/No of the serving HS-DSCH cell is greater than or equal to the threshold, determined by the parameter HSDPACPICHEcNoThreshold (def -5dB), serving HS-DSCH cell change is not initiated but the current serving cell is kept
If the CPICH Ec/No of the serving HS-DSCH cell is greater than or equal to CPICH Ec/No of the best cell subtracted with the value of the parameter HSDPAServCellWindow (def 2dB), serving HS-DSCH cell change is not initiated
CPICHEc/NoServ_cell is the average CPICH Ec/No measurement result of the serving HS-DSCH cell
CPICHEc/NoBest_cell is the average CPICH Ec/No measurement result of the best cell in the active set
HSDPAServCellWindow is the management parameter , which determines the window - relative to the best cell in the active set - inside of which the serving HS-DSCH cell must be in order to allocate HS-DSCH
For internal use
HSDPA Serving Cell Change – Impact of Other & Own Cell Interference
Looking into the target HSDPA service cell selection formula
The parameter HSDPAServCellWindow value should be set carefully, below is analysis which shows the impact of delaying the SCC too much or advancing it too much (analysis only takes 2 cells into account)
Preferable SCC execution area is achieved with HSDPAServCellWindow = 2dB
Also HSDPACPICHEcNoThreshold = -5dB means that there is no other cell interefrence present at all (assuming CPICH power 2W CCCH power 2W and HSDPA power 6W, the best possible CPICH Ec/No would be ~-7dB) -> -5dB includes nicely some measurement inaccuracies (spec allows +/- 3dB)
Wei Yun (WY) - SCC = serving cell change
For internal use
Clarifications of graph in previous slide
For internal use
Clarifications of graph in previous slide
For internal use
Periodical CPICH Ec/No measurement are started only if the size of the active set is greater than one
If the size of the active set is one, periodical CPICH Ec/No reporting are not started / if running are stopped
RRC: MEASUREMENT CONTROL message is used for starting and stopping of the CPICH Ec/No measurement
Periodical CPICH Ec/No measurement is not possible to switch off by operator, but the measurement is always active
For internal use
In order to execute inter-BTS serving the HS-DSCH cell change triggered by CPICH Ec/No measurements, the UL SIRerror of the target BTS must be above the threshold determined by the parameter HSDPASIRErrorTargetCell (def -2dB, typically used values -6dB) this has to be set according to HSDPASIRErrorServCell (def -3dB, typically used values -7dB)
SIRerror measurement to be utilised for evaluation is the latest averaged value
In the case of intra-BTS serving HS-DSCH cell change, UL SIRerror needs not to be checked
If UL SIRerror measurement of the target cell has not been received by RNC, handover control executes serving HS-DSCH cell change triggered by DL CPICH Ec/No without taking UL SIRerror measurement into account, i.e. missing UL SIRerror measurement does not prevent serving HS-DSCH cell change
It is possible to switch off usage of the UL SIRerror measurement by setting the reporting interval to 0
In this case, HS-DSCH allocation is executed without taking UL SIRerror into account
More about SIRerror measurements, check HSDPA Serving Cell Change – UL SIRerror Measurement
Wei Yun (WY) - SIRerror check only for inter Node B
For internal use
HSDPA power allocation shall also affect the selection of the serving HS-DSCH cell
All the HSDPA-capable cells, which fulfil the following condition, are selected as possible candidate cells for new serving HS-DSCH cells
CPICHEc/NoBest_cell is the CPICH Ec/No measurement of the best cell in the active set
CPICHEc/NoCell is the CPICH Ec/No measurement of the candidate
HSDPAServCellWindow is the management parameter , which determines the window - relative to the best cell in the active set - inside of which the serving HS-DSCH cell must be in order to allocate HS-DSCH
For internal use
When the cells, which fulfil the DL CPICH Ec/No and UL SIRerror conditions - as specified in the previous slide – are found, the serving HS-DSCH selection is executed according to the following priorities:
The cell, which has the next best DL CPICH Ec/No is chosen as the serving HS-DSCH cell
Note that in order to execute serving HS-DSCH cell change and allocate HS-DSCH at the target cell, channel type selection algorithm, must be successful, i.e. Cell/BTS must fulfill all the criteria regarding HS-DSCH allocation
If none of the cells in the active set can be chosen as serving HS-DSCH cell, i.e. serving HS-DSCH cell change cannot be executed, the current HS-DSCH allocation is kept
For internal use
HSDPA Serving Cell Change - Failure in the Selection of Serving Cell in the Serving HS-DSCH Cell Change
Failure in allocation of Iub AAL2 or RNC internal resources:
When the target cell for serving HS-DSCH cell change has been chosen and if the reservation of the RNC internal resources or Iub AAL2 for the MAC-d flow fails, other possible candidate cells are attempted
If similar failure occurs also for other candidate cells, serving HS-DSCH cell change is not executed
If the current serving HS-DSCH cell cannot be kept, e.g. due to low UL SIRerror or lost radio link, HS-DSCH shall be released and RB mapped to DCH 0/0
Failure in RL reconfiguration:
If the BTS with the serving HS-DSCH cell does not accept RL reconfiguration request and it returns some other general cause code than ‘Bearer re-arrangement needed', then serving HS-DSCH cell selection is interrupted
If some other BTS than BTS with serving HS-DSCH cell does not accept RL reconfiguration request, then possible other candidates for serving HS-DSCH cell are tried to be selected
If the serving HS-DSCH cell selection is interrupted or new cell can not be found, then current serving HS-DSCH cell is kept or HS-DSCH is released and RB mapped to DCH 0/0 (depending on handover reason)
For internal use
Due to Periodical Ec/No Measurements
UE
RNC
SGSN
For internal use
UE
RNC
SGSN
DL-DCCH-Message {
UL SF 16 (64kbps service) and
DL SF 256 and channelisation code 12
For internal use
UE
RNC
SGSN
CFN for the change to be taken into use: 252
NBAP: Radio Link Reconfiguration Commit
NBAP: Radio Link Reconfiguration Prepare:
Modifying the HS DSCH (HS-DPCCH in SHO for better ACK/NACK and CQI detection):
CQI Power Offset = 7 -> Delta CQI 4dB
ACK Power Offset = 7 -> Delta ACK 4dB
Nack Power Offset =7 -> Delta NACK 4dB
For internal use
UE
RNC
SGSN
For internal use
UE
RNC
SGSN
Setting up periodical Ec/No measurements for HS-DSCH serving cell change procedure
Periodical CPICH Ec/No measurement are started only if the size of the active set is greater than one. If the size of the active set is one, periodical CPICH Ec/No reporting is not started and if on going stopped
For internal use
UE
RNC
SGSN
For internal use
UL-DCCH-Message {
{ }, { } } } } } } } } }
Periodically reported DL CPICH Ec/No measurement results are averaged in RNC
HSDPACPICHAveWindow is RNC specific management parameter, which defines how many CPICH Ec/No measurements, which are received in the RRC: MEASUREMENT REPORT message, are included in the sliding window used in the averaging
RNC starts the averaging already from the first measurement sample (so the Serving cell change is possible after just one measurement report), that is, the RNC calculates the averaged values from those measurement samples which are available until the number of measurement samples is adequate to calculate averaged values over the whole averaging window
For internal use
UE
RNC
SGSN
Old BTS to delete the HS-DSCH user (MAC-d flow) and
to new BTS to set up the HS-DSCH (MAC-d flow) with
CQI Power Offset = 7 -> Delta CQI 4dB
ACK Power Offset = 7 -> Delta ACK 4dB
Nack Power Offset =7 -> Delta NACK 4dB
For internal use
UE
RNC
SGSN
ALCAP : ERQ
ALCAP : ECF
NBAP: Radio Link Reconfiguration Commit for both BTSs
to inform the CFN when the HS-DSCH serving cell change will be taken into use.
CFN 148
For internal use
UE
RNC
SGSN
ALCAP : ERQ
ALCAP : ECF
DL-DCCH-Message {
For internal use
UE
RNC
SGSN
ALCAP : ERQ
ALCAP : ECF
RRC: Radio Bearer Reconfiguration
ALCAP : Release Request
ALCAP : Release Confirm
For internal use
ISHO with SCC
For internal use
HSDPA Serving Cell Change – UL SIRerror Measurement Triggered
It is possible to switch off usage of the UL SIRerror measurement by setting the reporting interval to 0
In this case, HS-DSCH allocation is executed without taking UL SIRerror into account
In this case, serving HS-DSCH cell change due to UL SIRerror is not allowed
When BTS reports periodical dedicated UL SIRerror measurement, need for the serving HS-DSCH BTS change is evaluated
If UL SIRerror measurement of the serving cell is not received by RNC, HS-DSCH allocation is not interrupted but the handover control applies other available triggers for the serving HS-DSCH cell change procedure
If SIRerror of the current serving HS-DSCH BTS is below the threshold determined by the parameter HSDPASIRErrorServCell (def -3dB, typically used value -7dB), serving HS-DSCH BTS change is initiated
Wei Yun (WY) - not a must that target cell SIR is better, it can also be triggered if serving cell SIR is poor
For internal use
The new serving HS-DSCH cell is chosen as follows:
DL CPICH Ec/No and UL SIRerror are used as criteria
Note that CPICH Ec/No of the candidate cell does not have to fulfil equation below i.e. it does not have to be inside of the window in order to allocate HS-DSCH (this means that SCC due to UL SIRerror can change the HSDPA Service Cell to non optimal cell – in DL direction)
The CPICH Ec/No and UL SIRerror measurements to be used for evaluation are taken from the latest averaged value of periodical measurement reports from UE and BTS
UL SIRerror of the target cell must be above or equal to the threshold determined by the parameter HSDPASIRErrorTargetCell (def -2dB, typically used value -6dB) in order to allocate HS-DSCH, i.e. the target cell fulfills the following condition:
,where SIRerrorBTS is the SIRerror measurement of the candidate BTS and HSDPASIRErrorTargetCell is the threshold, which SIRerror of the candidate BTS must fulfill
For internal use
HSDPA Serving Cell Change – UL SIRerror Measurement Triggered
If UL SIRerror measurement of the target cell has not been received by RNC, handover control excludes this particular cell from the candidate list of the serving HS-DSCH cell change procedure triggered by UL SIRerror measurement of the serving cell
When the cells, which fulfil the UL SIRerror condition are found, the serving HS-DSCH selection is executed according to the following priorities:
Note that in order to execute serving HS-DSCH cell change and allocate HS-DSCH at the target cell, channel type selection algorithm must be successful, i.e. Cell/BTS must fulfill all the criteria regarding HS-DSCH allocation
If the cell, which fulfils the condition specified above cannot be found, HS-DSCH is released an switch to DCH 0/0 kbps executed
For internal use
ISHO with SCC
Wei Yun (WY) - periodic SIR report can only be seen in Iub
For internal use
HSDPA Serving Cell Change – UL SIRerror Measurement
UL SIRerror measurement is used as a criterion for serving HS-DSCH cell change
UL SIRerror can also initiate release of the HS-DSCH
After HS-DSCH is allocated to the UE, periodical UL SIRerror measurement is started
Dedicated UL SIRerror measurement is applied to the selection of the serving HS-DSCH cell and it is also used as criterion for a sufficient UL quality for HS-DPCCH transmission
Reporting is periodical, except when measurement report is filtered in BTS
Reporting criteria of the dedicated UL SIRerror measurement is determined in the following way
Dedicated measurement type is SIRerror
Dedicated measurement object type is ALL RLS
For internal use
Measurement filter coefficient is determined by the RNP-parameter HSDPASIRErrorFilterCoefficient
The parameter determines the value of filtering coefficient to be used in higher layer filtering of the measurement result
The filter coefficient parameter controls the higher layer filtering of physical layer UL SIRerror measurements before measurement reporting is performed by the BTS
The approximated weight of the latest measurement result with the different values of the parameter is as follows: Value (Weight): 0 (100%), 1 (71%), 2 (50%), 3 (35%), 4 (25%), 5 (18%), 6 (13%), 7 (9%), 8 (6%), 9 (4%), 11 (2%)
Higher layer filtering has been specified in the 3GPP TS 25.433
“The Measurement Filter Coefficient IE indicates how filtering of the measurement values shall be performed before measurement event evaluation and reporting.
The averaging shall be performed according to the following formula.
The variables in the formula are defined as follows:
Fn is the updated filtered measurement result
Fn-1 is the old filtered measurement result
Mn is the latest received measurement result from physical layer measurements, the unit used for Mn is the same unit as the reported unit in the COMMON MEASUREMENT INITIATION RESPONSE, COMMON MEASUREMENT REPORT messages or the unit used in the event evaluation (i.e. same unit as for Fn)
a = ½^(k/2) , where k is the parameter received in the Measurement Filter Coefficient IE. If the Measurement Filter Coefficient IE is not present, a shall be set to 1 (no filtering)
In order to initialise the averaging filter, F0 is set to M1 when the first measurement result from the physical layer measurement is received”
For internal use
The SIRerror measurements are specified in the TS 25.433, 25.133 and 25.215
25.133:
The measurement period is 80 ms
NOTE: The measurement period is the same as for the SIR measurement, SIRerror is calculated from SIR and SIRtarget (SIRerror = SIR – SIRtarget_ave )
The reporting range for SIRerror is from -31 ... 31 dB
In table 9.39 the mapping of measured quantity is defined. The range in the signalling may be larger than the guaranteed accuracy range.
For internal use
Report characteristics is periodic
NBAP: Dedicated Measurement Initiation procedure is used for starting and stopping of the UL SIRerror measurement
Periodical UL SIRerror reporting is possible to switch off by operator by setting the reporting interval to 0 with the management parameter HSDPASIRErrorReportPeriod
If reporting is switched off, UL SIRerror is used as a criterion for neither serving HS-DSCH cell change nor HS-DSCH release
For internal use
SIRerror is the difference between the SIRtarget used in the BTS for Fast Closed Loop PC and and the actual measured SIR as follows:
SIRerror = SIR – SIRtarget_ave
where:SIR is the SIR measured by the BTS and SIRtarget_ave is the SIRtarget averaged over the same time period as the SIR used in the SIRerror calculation
SIRerror measurement is specified in TS 25.215
From 25.215
“Signal to Interference Ratio, is defined as: (RSCP/ISCP)SF. The measurement shall be performed on the DPCCH of a Radio Link Set. In compressed mode the SIR shall not be measured in the transmission gap. The reference point for the SIR measurements shall be the Rx antenna connector. If the radio link set contains more than one radio link, the reported value shall be the linear summation of the SIR from each radio link of the radio link set. If Rx diversity is used in the Node B for a cell, the SIR for a radio link shall be the linear summation of the SIR from each Rx antenna for that radio link. When cell portions are defined in the cell, the SIR measurement shall be possible in each cell portion.
where:
RSCP = Received Signal Code Power, unbiased measurement of the received power on one code.
ISCP = Interference Signal Code Power, the interference on the received signal.
SF=The spreading factor used on the DPCCH.”
For internal use
Periodically reported UL SIRerror measurement results are averaged in RNC
HSDPASIRErrorAveWindow (def. 3) is RNC specific management parameter, which defines how many SIRerror measurements, which are received in the NBAP: DEDICATED MEASUREMENT REPORT message, are included in the sliding window used in the averaging. SIRerror is averaged using the following formula:
Where SIRError (t) is the latest received SIRError measurement and n equals to HSDPASIRErrorAveWindow
RNC starts the averaging already from the first measurement sample, that is, the RNC calculates the averaged values from those measurement samples which are available until the number of measurement samples is adequate to calculate averaged values over the whole averaging window
RNC calculates the averaged values directly from the measured dB values, linear averaging is not used in this case
For internal use
ISHO with SCC
For internal use
HSDPA Serving Cell Change – Event 1B Triggered
Intra-frequency measurement event 1B (A primary CPICH leaves the reporting range) initiates serving HS-DSCH cell change if the cell to be removed from the active set is the serving HS-DSCH cell
Active set update is delayed until either serving HS-DSCH cell change or HS-DSCH release (switch to DCH 0/0) has been performed
Note that CPICH Ec/No of the candidate cell does not have to fulfil equation below i.e. it does not have to be inside of the window in order to allocate HS-DSCH
For internal use
DL CPICH Ec/No measurements used for the selection of the new serving HS-DSCH cell are taken from the reported measurement event 1B
If, for some reason, CPICH Ec/No measurement results of all the active set cells are not available in the measurement event 1B, the latest averaged value of periodical CPICH Ec/No measurement report is used
UL SIRerror of the target cell must be above or equal to the threshold determined by the parameter HSDPASIRErrorServCell in order to allocate HS-DSCH
If UL SIRerror measurement of the target cell has not been received by RNC, handover control execute serving HS-DSCH cell change triggered by measurement event 1B without taking UL SIRerror measurement into account, i.e. missing UL SIRerror measurement does not prevent serving HS-DSCH cell change
For internal use
Note that in order to execute serving HS-DSCH cell change and allocate HS-DSCH at the target cell, channel type selection algorithm, must be successful, i.e. Cell/BTS must fulfill all the criteria regarding HS-DSCH allocation
If a new serving HS-DSCH cell cannot be found, HS-DSCH is released and RB is mapped to DCH 0/0
For internal use
ISHO with SCC
For internal use
HSDPA Serving Cell Change – Event 1C Triggered
Intra-frequency measurement event 1C (A non-active primary CPICH becomes better than an active one) initiates serving HS-DSCH cell change if the cell to be removed from the active set is the serving HS-DSCH cell
Active set update is delayed until either serving HS-DSCH cell change or HS-DSCH release (switch to DCH 0/0) has been performed
For internal use
DL CPICH Ec/No measurements used for the selection of the new serving HS-DSCH cell are taken from the reported measurement event 1C
If, for some reason, CPICH Ec/No measurement results of all the active set cells are not available in the measurement event 1C, the latest averaged value of periodical measurement CPICH Ec/No measurement report is used.
If UL SIRerror measurement of the target cell has not been received by RNC, handover control executes serving HS-DSCH cell change triggered by measurement event 1C without taking UL SIRerror measurement into account, i.e missing UL SIRerror measurement does not prevent serving HS-DSCH cell change
For internal use
If a new serving HS-DSCH cell cannot be found, HS-DSCH is released and RB is mapped to DCH 0/0
For internal use
ISHO with SCC
For internal use
HSDPA Serving Cell Change – Removal of Radio Link Triggered
The following reasons, which may cause removal of the radio link from the active set initiate serving HS-DSCH cell change:
RL failure of the serving HS-DSCH radio link (loss of UL synchronisation)
If BTS sends NBAP: RADIO LINK FAILURE message (loss of UL synchronisation) to RNC regarding the current serving HS-DSCH radio link and there are other HSDPA-capable cells in the active set, the serving HS-DSCH cell change is executed
Serving HS-DSCH radio link is handed over to DRNC
If the current serving HS-DSCH radio link is handed over to DRNC, and there are other HSDPA-capable cells under SRNC in the active set, the serving HS-DSCH cell change is executed
The candidate cell must be located under SRNC in order to execute serving HS-DSCH cell change
RL removal due to Rx-Tx time difference
If the current serving HS-DSCH radio link is deleted from the active set due to Rx-Tx time difference measurement (Event 6F, 6G), and there are other HSDPA-capable cells in the active set, the serving HS-DSCH cell change is executed
For internal use
The new serving HS-DSCH cell shall be chosen as follows:
The CPICH Ec/No and UL SIRerror measurements to be used for evaluation are taken from the latest averaged value of periodical measurement reports from UE and BTS
If UL SIRerror measurement of the target cell has not been received by RNC, handover control executes serving HS-DSCH cell change triggered by removal of the radio link without taking UL SIRerror measurement into account, i.e. missing UL SIRerror measurement does not prevent serving HS-DSCH cell change
For internal use
HSDPA Serving Cell Change – Removal of Radio Link Triggered
If a new serving HS-DSCH cell cannot be found, HS-DSCH shall be released and RB is mapped to DCH 0/0
For internal use
ISHO with SCC
For internal use
HSDPA Serving Cell Change – Too Frequent Serving Cell Changes
Frequent serving HS-DSCH cell changes initiate HS-DSCH release and switching to DCH
The number of successful serving HS-DSCH cell changes due to any reason is counted
If the number of serving HS-DSCH cell changes, determined by the parameter HSDPAMaxCellChangeRepetition (def. 4), in a time period determined by the parameter HSDPACellChangeRepetitionTime (def. 10s), is exceeded, HS-DSCH is released and RB is mapped to DCH 0/0
HSDPACellChangeRepetitionTime determines a window in seconds during which calculation is made
Window is moved forward once per second with a step size of one second
For internal use
ISHO with SCC
For internal use
HSDPA Serving Cell Change – Existence with ISHO/IFHO
Inter System and Inter Frequency handovers can be triggered as with R99 DCH via event triggered measurement reports 1F or event 6A or UL Quality Deterioration report received by RNC
HS-DSCH is released and DCH is allocated instead
On DCH then the compressed mode can be started
Event Count%Uu_HSDPA_Status %
Attach Successful Rate 100.0%Total Time Spent in FACH 4%
Uu_PS_PDPAct_From_UE 60 Average EcNo dB
Uu_PS_PDPAct_From_UE_OK 60 Uu_ActiveSet_EcNo_0 -8.28
Uu_ActiveSet_RSCP_0 -86.19
Uu_HSDPACallSetup_Fail 0 App_Throughput_DL 681.63
Uu_HSDPA_CQI_Average 17.20
HSDPA Call Completion Rate 92.7%Uu_TrCh_DownlinkBlerAgg 2.9%
Log file for RAS5.0
Attach Successful Rate100.0%Total Time Spent in FACH0.11%
Uu_PS_PDPAct_From_UE16Average EcNodB
Uu_ActiveSet_RSCP_0-83.61
Uu_HSDPA_CQI_Average19.33
EventCount%Uu_HSDPA_Status%
Attach Successful Rate100.0%Total Time Spent in FACH0.0%
Uu_PS_PDPAct_From_UE16Average EcNodB
Uu_ActiveSet_RSCP_0-75.67
Uu_HSDPA_CQI_Average13.27
)_(
//
error
range specified in section 9.2.2.
Conditions Parameter Unit Accuracy [dB]
Range
Iob > -105 dBm/3.84 MHz
UTRAN_SIR_00 SIR < -11.0 dB
Measurement
Single NRT PS RAB AMR multi-service Single NRT PS RAB AMR multi-service
Event 1E
(CPICH Ec/No)
Cancel event 1F Cancel event 1F Cancel event 1F Cancel event 1F
Event 1E
(RSCP)
Cancel event 1F Cancel event 1F Cancel event 1F Cancel event 1F
Event 1F
(CPICH Ec/No)
Release HS-DSCH
Tx power)
Cancel event 6A Cancel event 6A Cancel event 6A Cancel event 6A
UL DCH quality

Documents

Hsdpa Performance Improvement