1 NOKIA 30/11/2003 RANPAR Version 1.1
Course Content
Radio Resource Management Overview
Parameter Configuration
Common Channels & Power Control
Load Control
Admission Control
Packet Scheduling
Handover Control
Resource Manager
2 NOKIA 30/11/2003 RANPAR Version 1.1
Course Objectives
At the end of the course you will be able to:
Name and describe the different handover types
Describe and list the steps of the handover procedure for each handover type
Name and describe the main RAN parameters related to handover reporting triggering
Describe the main difference between inter system handover and other handover types
Name and describe the main RAN parameters related to inter system handover
3 NOKIA 30/11/2003 RANPAR Version 1.1
Handover Control Handover Types Intra-Frequency handover:
Parameters Mapping SHO Events and Measurements Hard handover RRC Connection Release
Compressed-Mode Inter-Frequency & Inter-System handover:
Measurement triggering Inter-Frequency & Inter-System Measurements Inter-Frequency HO decision Inter-System HO decision
GSM ISHO Load Based Handover to WCDMA Cell Reselection to WCDMA
4 NOKIA 30/11/2003 RANPAR Version 1.1
Intra-Frequency Handovers Softer handover
Handover between sectors of the same Node B (handled by BTS) No extra transmissions across Iub interface Maximum Ratio Combining (MRC) is occurring in both the UL and DL
Soft handover MS simultaneously connected to multiple cells (from different Node Bs) Extra transmission across Iub, more channel cards are needed (compared to non-SHO) Mobile Evaluated HandOver (MEHO) DL/UE: MRC & UL/RNC: Frame selection combining
Hard handover Arises when inter-RNC SHO is not possible (Iur not supported or Iur congestion) Decision procedure is the same as SHO (MEHO and RNC controlled) Causes temporary disconnection of the (RT) user
Inter-Frequency Handover Can be intra-BS, intra-RNC, inter-RNC Network Evaluated HandOver (NEHO) Decision algorithm located in RNC
Inter-RAT Handover Handovers between GSM and WCDMA (NEHO)
Handover Types
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Soft Handover
Main method is soft/softer handover MS connected to two or more cells Up to 3 branches can be used (MaxActiveSetSize parameter) Seamless handover without any disconnection of UE-RAN connection softer handover probability about 5-15 % : soft handover probability about 20-50 %
Same power levels in use for all soft handover branches Optimum power levels for link quality and cell capacity Macro Diversity Combining (MDC) gain to reduce power levels
Mobile Evaluated HandOver (MEHO) Enables different cell sizes due to Common Pilot Channel Ec/No measurement Optimum fast close loop power control in use Outer loop PC after MDC controls the BLER according to set target and thus maintains the quality
WCDMA F1 WCDMA F1 WCDMA F1
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Handover Control Handover Types Intra-Frequency handover:
Parameters Mapping SHO Events and Measurements Hard handover RRC Connection Release
Compressed-Mode Inter-Frequency & Inter-System handover:
Measurement triggering Inter-Frequency & Inter-System Measurements Inter-Frequency HO decision Inter-System HO decision
GSM ISHO Load Based Handover to WCDMA Cell Reselection to WCDMA
7 NOKIA 30/11/2003 RANPAR Version 1.1
HC Parameter Database Structure
RNC = Radio Network Controller level parameters
WBTS = Node B level parameters
WCELL = Cell level parameters
FMCx = Frequency Measurement Control parameters (S=intra-frequency set; I=inter-frequency; G=inter-RAT)
ADJx = Adjacent Cell parameters (S=intra-frequency set; I=inter-frequency; G=inter-RAT)
HOPx = Handover Path parameters (S=intra- frequency set; I=inter-frequency; G=inter-RAT)
S:Intra-FrequencyS:Intra-
Frequency
I:Inter-FrequencyI:Inter-
Frequency
G:Inter-System
G:Inter-System
WCELL
ADJG
ADJI
ADJS
WBTS
RNC
FMCS
FMCI
FMCG
100
100
100
HOPS 100
HOPI 100
HOPG 100
32
48
32
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SHO: Neighbour Cell Definition
ADJS
ADJS
ADJS
FMCS(NRT)
FMCS(RT)
HOPS(RT)
HOPS(NRT)
HOPS(NRT)
HOPS(NRT)
HOPS(RT)
HOPS(RT)
HOPSid = 5
HOPSid = 10
FMCSid = 3
FMCSid = 40
ADJSid = 1
ADJSid = 2
ADJSid = 3
WCELWCELWCEL
WCEL
WCELWCELWCELWBTS
Each WCEL has 1 FMCS for NRT & 1 for RT which is used for all Ncells. FMCS parameters could be defined on a serving cell type basis (urban, rural, macro/micro/pico)
Each ADJS has 1 HOPS for NRT & 1 for RT which is used for all Ncells. HOPS parameters could be defined on a target cell type basis (urban, rural, macro/micro/pico)
NrtFmcsIdentifier = 3
RtFmcsIdentifier = 40
NrtHopsIdentifier = 5RtHopsIdentifier = 10
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ADJS, HOPS & FMCSHO Parameter Categories
Intra-Frequency
Inter-Frequency
Inter-System
Handover Control ParametersRNC parametersWCEL parametersHOPS parameters FMCS parametersADJS parameters HOPI parameters FMCI parametersADJI parameters HOPG parameters FMCG parameters ADJG parameters
100HOPS parametersCell Re-selection HCS PriorityCell Re-selection HCS ThresholdCell Re-selection Minimum QualityCell Re-selection Minimum RX LevelCell Re-selection Penalty TimeCell Re-selection Quality Offset 1Cell Re-selection Quality Offset 2Cell Re-selection Temporary Offset 1Cell Re-selection Temporary Offset 2CPICH Ec/No Averaging WindowEnable Inter-RNC Soft HandoverEnable RRC Connection ReleaseHHO Margin for Average Ec/NoHHO Margin for Peak Ec/NoRelease Margin for Average Ec/NoRelease Margin for Peak Ec/No
Define Target Cell Selection
1100
FMCS parametersActive Set Weighting CoefficientAddition Reporting IntervalAddition TimeAddition WindowCPICH Ec/No Filter CoefficientCPICH Ec/No HHO CancellationCPICH Ec/No HHO Cancellation TimeCPICH Ec/No HHO ThresholdCPICH Ec/No HHO Time HysteresisCPICH RSCP HHO CancellationCPICH RSCP HHO Cancellation TimeCPICH RSCP HHO Filter CoefficientCPICH RSCP HHO ThresholdCPICH RSCP HHO Time HysteresisDrop TimeDrop WindowMaximum Active Set SizeReplacement Reporting IntervalReplacement TimeReplacement Window
Define Adjacent Cell Measurement Control
132
In GSM: Define HO TriggerHoThresholdsLevDL Rx (LDR): -92 dBm Px (LDP): 3 Nx (LDN): 4
Define Target Cell SelectionRx Lev Min Cell: -95 dBm
Define Adj Cell
ADJS parameters Cell Identifier CPICH Ec/No Offset Disable Effect on Reporting Range Location Area Code Maximum UE TX Power on RACH Mobile Country Code Mobile Network Code Mobile Network Code LenPrimary CPICH power NRT HOPS Identifier Primary Scrambling Code RNC Identifier Routing Area Code RT HOPS Identifier Tx Diversity Indicator
Define Adj Cell
1
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Separate HandOver Parameter Set (HOPS) identifiers for real time(RT) & non-real time(NRT) traffic
RtHopsIdentifier - real time
NrtHopsIdentifier - non-real time
Each HOPS object is identified by a unique HOPSid (HOPS) in the RNC - on to which the RtHopsIdentifier and/or NrtHopsIdentifier parameters are mapped to identify the appropriate HOPS parameter set for that particular neighbour cell
Primary scrambling code for neighbour cell specified using AdjsScrCode
AdjsTxDiv specifies whether the neighbour cell is using Tx diversity
AdjsTxPwrRACH determines the maximum power the UE can use on the PRACH when accessing the neighbour cell
Neighbour Cell Definition
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SHO: Neighbour Cell Definition
Each intra-frequency neighbour (ADJS) is identified using ADJSid (ADJS)
The ADJS parameters provide information on the identity of each neighbour cell together with its properties (i.e. handover parameter set identifier, scrambling code etc.)
AdjsName is the cell name provided by the network planner
Each neighbour cell is defined using the UTRAN cell identifier which comprises;
UTRAN Cell Identifier = MCC + MNC + RNC identifier + Cell identifier
MCC (Mobile Country Code) = AdjsMCCMNC (Mobile Network Code) = AdjsMNCRNC Identifier = AdjsRNCidCell Identifier = AdjsCI
The LAC (AdjsLAC) & RAC (AdjsRAC) are also in ADJS parameter set
ADJS Parameters
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SHO: Neighbour Cell Definition
AdjsMCCAdjsMNCAdjsRNCidAdjsCI
UTRAN Cell ID
ADJSid
MaxActiveSetSizeRNCAdjsScrCodeAdjsTxDivAdjsTxPwrRACH
RT HO Control Parameter: RtHopsIdentifier NRT HO Control Parameter: NrtHopsIdentifier
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Handover Control Handover Types Intra-Frequency handover:
Parameters Mapping SHO Events and Measurements Hard handover RRC Connection Release
Compressed-Mode Inter-Frequency & Inter-System handover:
Measurement triggering Inter-Frequency & Inter-System Measurements Inter-Frequency HO decision Inter-System HO decision
GSM ISHO Load Based Handover to WCDMA Cell Reselection to WCDMA
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Soft Handover
HC supports the following measurement reporting events: Event 1A: A primary CPICH enters the reporting range (Ncell addition) Event 1B: A primary CPICH leaves the reporting range (Ncell deletion) Event 1C: A non-active CPICH becomes better than an active primary CPICH (Ncell
replacement)
Cell individual offsets for modifying measurement reporting behaviour Mechanism for forbidding a neighbouring cell to affect the reporting range
Handover decision performed by RNC based on measurements and available resources
Admission Control can reject the branch addition in case the maximum load is achieved in DL (threshold + offset), valid both for RT and NRT bitrates.
Hard blocking may prevent branch addition
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The handover measurement is based on CPICH Ec/Io
The accuracy of pilot Ec/Io measurements is important for handover performance
Measurement accuracy depends on the filtering length and mobile speed. When a MS moves slowly or is stationary, filtering length (in ms) has to be just long enough to
avoid fast fades leading to errors and causing unnecessary handovers within a short period.
Long filtering length will cause handover delays to fast moving MS
UE can perform averaging on EC/IO measurement prior to the event reporting process
EcNoFilterCoefficient (FMCS) defines the measurement period for intra-frequency CPICH EC/IO measurements used by UE (default = 200ms)
RNC averages CPICH Ec/Io measurements using EcNoAveragingWindow (HOPS) - defines the number of event triggered or periodic intra-frequency measurement reports used by RNC to calculate averaged CPICH EC/IO (default = 8 Measurements)
SHO: Measurement Control
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SHO: Measurement Control
Node B
UTRAN
RNCUE
Measurement Control [ ]
I am in the CELL_DCH sub-state
Measurement Type: Intra-frequency measurements Reporting events:
1A: A primary CPICH enters the reporting range 1B: A primary CPICH leaves the reporting range 1C: A non-active CPICH becomes better than an active primary CPICH
Periodical reporting / event triggered Measurement quantity: CPICH Ec/No etc.
System Information [ ]
SIB 11/12 EcNoFilterCoefficient
Measurement accuracy depends on speed & Filter Coefficient
EcNoAveragingWindow
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1A: A Primary CPICH Enters the Reporting Range Reporting range defined by offset (point 1 on next slide) from either
(i) best CPICH Ec/Io in the AS, or(ii) sum of the AS measurement resultsset using ActiveSetWeightingCoefficient (FMCS) (0 = use best CPICH : 0 = use sum)
Offset defined using AdditionWindow (FMCS) Event 1A triggered when CPCIH3 Ec/Io enters UE reporting range (point 2)
If CPICH3 Ec/Io remains within reporting range for a time period defined by AdditionTime(FMCS) , and the AS is not full, UE sends measurement report to RNC which adds Ncell3 to AS if possible (point 3)
AdditionTime defines the 'time-to-trigger' interval between the Ncell first entering the reporting range and the UE sending the measurement report to the RNC
If RNC is unable to add Ncell to AS, UE will wait for a period of time, defined by AdditionReportingInterval (FMCS) (point 4) after the first measurement report, before sending further reports periodically, with interval AdditionReportingInterval, until (a) Ncell moves out of reporting range, or (b) RNC adds Ncell to AS.
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4
1A: A Primary CPICH Enters the Reporting Range
Strongest CPICH in AS
time
Ec/Io
P CPICH 3
P CPICH 1
P CPICH 2
1
2
3
AdditionWindow
AdditionTime
AdditionReportingInterval
RNC
MeasurementReport
Add tothe AS?
no
ActiveSetWeightingCoefficient
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Reporting criteria of event 1A in 25.331/RRC Measurement Control :
Reporting Cell Status: All active cells + 2 monitored cells.
Triggering Condition: Monitored Set cells
Reporting Range Constant AdditionWindow / 4 dB
Cells forbidden to affect Reporting range: AdjsDERR / Enable
W: ActiveSetWeightingCoefficient / 0
Time to trigger: AdditionTime / 0 = 0 ms
Reporting deactivation threshold: MaxActiveSetSize = 3
Amount of reporting: infinity
Reporting interval: AdditionReportingInterval / O.5 s
1A: A Primary CPICH Enters the Reporting Range
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1B: A Primary CPICH Leaves the Reporting Range
Event 1B triggered when CPICH3 EC/I0 drops out of the UE reporting range for a defined period of time (point 1 on next slide)
Reporting range = Strongest CPICH in AS - DropWindow (FMCS) (point 2) Time-to-trigger period set using DropTime (FMCS) (point 3) UE sends RNC measurement report on expiry of DropTime to remove Ncell (CPICH3) from AS. RNC drops the cell from the AS and UE drops the cell from the AS to the Neighbour Set
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Strongest CPICH in AS
time
Ec/Io
P CPICH 3
P CPICH 1
P CPICH 2
1
2
3
DropWindow
DropTime
MeasurementReport
1B: A Primary CPICH Leaves the Reporting Range
Remove the reported cell from the AS
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Reporting criteria of event 1B in 25.331/RRC Measurement Control :
Reporting cell Status: 3 active cells
Triggering Condition: Active cells
Reporting Range Constant: DropWindow / 4 dB
Cells forbidden to affect Reporting range AdjsDERR / Enable
W : ActiveSetWeightingCoefficient / 0
Time to trigger: DropTime / 320 ms
1B: A Primary CPICH Leaves the Reporting Range
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1C: A non-active CPICH becomes better than an active primary CPICH
UE AS full (MaxActiveSetSize = 3) Event 1C triggered when CPICH4 EC/IO > CPICH3 in AS by a defined margin,
ReplacementWindow (FMCS). (point 1 in next slide) Sending of measurement report to RNC can be delayed by using 'time-to-trigger' period set
by ReplacementTime (FMCS) If 'time-to-trigger' is used difference between CPICH4 and CPICH3 must be
ReplacementWindow for the period of ReplacementTime (point 2) If the RNC is not able to replace the Ncells, the UE continues to send measurement reports
periodically, with interval ReplacementReportingInterval, to the RNC until (a) CPICH4 falls out of ReplacementWindow or (b) RNC replaces CPICH4 by CPICH3 (point 3)
24 NOKIA 30/11/2003 RANPAR Version 1.1
time
weakest CPICH3 in AS
Ec/Io
P CPICH 3
P CPICH 1P CPICH 2P CPICH 4
AS has 3 cells
ReplacementReportingInterval3
1
2
ReplacementWindow
ReplacementTime
MeasurementReport
RNC
ASupdate?
no
1C: A non-active CPICH becomes better than an active primary CPICH
25 NOKIA 30/11/2003 RANPAR Version 1.1
Reporting criteria of event 1C in 25.331/RRC Measurement Control :
Reporting cell Status: All active cells + 2 monitored cells.
Hysteresis: ReplacementWindow / 2 dB
Time to trigger: ReplacementTime / 0 = 0 ms
Replacement activation threshold : MaxActiveSetSize / 3
Amount of reporting: infinity
Reporting interval: ReplacementReportingInterval / 0.5s
1C: A non-active CPICH becomes better than an active primary CPICH
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Individual Ncell Offset &Forbidding Neighbour Cell from Reporting Range
Individual Ncell Offset
cell individual offsets for modifying measurement reporting behaviour
effectively 'moves' cell border (shrinks or enlarges cell)
offset set using AdjsEcNoOffset (= CPICH Ec/No Offset) (ADJS) offset applied to Primary CPICH measurements before event evaluation by the UE
Forbidding Neighbour Cells from Reporting Range
the primary CPICH of certain cells can be forbidden from reporting range calculation in some instances
cells can be forbidden from reporting range using AdjsDERR (ADJS)
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Individual Ncell Offset
time
P CPICH 1
P CPICH 2
P CPICH 3
Reporting Range
Reporting Event 1B
Reporting Event 1A
AdjsEcNoOffset
Enlarging Cell 3 by x dB
Ec/Io
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Forbidding Neighbour Cell from Reporting Range
Time
P CPICH 1
P CPICH 2
P CPICH 3
PCPICH3 is forbidden to affect the reporting range as its quality is quite unstable.
Reporting Range
AdjsDERR
Ec/Io
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Event 1A(Add)
Event 1B(Drop)
Event 1C(Replace)
Active set cells +2 monitored set
cells
Monitored set cells
Addition Window/4 dB
Active set cells Active set cellsDrop Window/
6 dB
Active set cells +2 monitored set
cells- Replacement Window/4 dB
Addition Time/0 ms
AdditionReportingInterval/0.5 s
Drop time/320 ms -
Replacementtime/0 ms
ReplacementReportingInterval/
1s
Event Reporting cell statusTriggering Condition
Reporting Range/Hysteresis Time to Trigger
Reporting Interval
Cells forbidden to affect Reporting range (for 1A and 1B) : AdjsDERR / default Enable
For 1A and 1B: ActiveSetWeightingCoefficient / default 0
For 1A: Reporting deactivation threshold: MaxActiveSetSize 1 / default 2
For 1C: Replacement activation threshold : MaxActiveSetSize / default 3
SHO Summary
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SHO for synchronisation reason: Event 6F: The UE Rx-Tx time difference for a Radio Link (RL) included in
the active set becomes larger than an absolute threshold Reporting Reporting event 6G: The UE Rx-Tx time difference for a RL included in
the active set becomes smaller than an absolute threshold Estimation of these events:
Based on UE Rx-Tx time difference Measurement configuration:
Time-to-trigger: not used. 6F: UE Rx-Tx time difference threshold: UpperRxTxTimeDiffdefault: 1174 chips, range:1152 ... 1280 chips, step 1 chip
6G: UE Rx-Tx time difference threshold: LowerRxTxTimeDiffdefault: 874 chips range: 768 ... 896 chips, step 1 chip
NOTE: Some UE does not support these events
UE Internal Measurements
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Node B
UTRAN
RNCUE
Measurement Control [ ] I am in the
CELL_DCH sub-state
Measurement Type: UE Internal measurements Reporting events:
6F: The UE Rx-Tx time difference for a RL included in the active set becomes larger than an absolute threshold Reporting 6G: The UE Rx-Tx time difference for a RL included in the active set becomes smaller than an absolute threshold
DLnom
time
T0
UL DPCH
time
time
6F 6G
UE Internal Measurements
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Measurement reporting criteria are cell specific
Neighbouring cells (ADJS and HOPS parameters) are defined on a controlling cell (cell from which the call has been started or best cell in case the original cell has been deleted from the active set)
During SHO the measurement reporting criteria are taken from the cell where the UE has started the connection
The measurement reporting criteria are updated only when the original cell leaves the Active Set (Nokia Implementation), according to the strongest cell in the Active Set, by sending the MEASUREMENT CONTROL message, transmitted on the downlink DCCH. Standard would allow to update reporting criteria, according the current best server.
When the UE receives a MEASUREMENT CONTROL message, the UE shall stop monitoring and measurement reporting and shall replace the measurement reporting criteria with the new information received in the MEASUREMENT CONTROL message.
Measurement Report Updating
33 NOKIA 30/11/2003 RANPAR Version 1.1
Measurements Reporting Criteria Updating during Soft handover
Cell 1 Cell 2
Neighbour ListCell1 Addition WindowCell1Drop WindowCell1Drop TimeCell1
1. Idle Mode
System Information
(BCCH)
BEST Server: Cell 1BEST Server: Cell 1
2. Connected Mode: Cell_DCH
The UE shall continue monitoring the list of
neighbouring cells assigned in System Information during Idle
Mode
The UE shall continue monitoring the list of
neighbouring cells assigned in System Information during Idle
Mode
Measurement Reporting Criteria according to Cell 1
Measurement Reporting Criteria according to Cell 1
The UE shall send the MEASUREMENT REPORT message when reporting
criteria are fulfilled.
The UE shall send the MEASUREMENT REPORT message when reporting
criteria are fulfilled.
Connected Mode: Cell_DCH
3. MEASUREMENT REPORT (DCCH)
Measurement Reporting Criteria according to Cell 1
Measurement Reporting Criteria according to Cell 1
Intra-frequency MeasurementIntra-frequency Measurement
The measurement reporting criteria are updated as soon as the original cell drops out from the Active Set (Nokia
Implementation).
The measurement reporting criteria are updated as soon as the original cell drops out from the Active Set (Nokia
Implementation).
Connected Mode: Cell_DCH
4. MEASUREMENT
CONTROL (DCCH)
Neighbour ListCell2Addition WindowCell2Drop WindowCell2Drop TimeCell2
BEST Server: Cell 2BEST Server: Cell 2
Measurement Reporting Criteria according to Cell 2
Measurement Reporting Criteria according to Cell 2
Reporting Criteria
Updating
34 NOKIA 30/11/2003 RANPAR Version 1.1
Neighbour List Measurement during SHO
Cell 1 Cell 2
Intra-frequency MeasurementIntra-frequency Measurement
Addition WindowCell1Drop WindowCell1Drop TimeCell1
1. System Information (BCCH)
BEST Server: Cell 1BEST Server: Cell 1
Neighbour List Cell 1Neighbour List Cell 1
Measurement Reporting Criteria according to
Cell 1
Measurement Reporting Criteria according to
Cell 1
Active Set: Cell 1Active Set: Cell 1
2
3
5
2
3
5
3. MEASUREMENT REPORT (DCCH)
1A1B6. MEASUREMENT REPORT
(DCCH)
4. ACTIVE SET UPDATE
8. MEASUREMENT CONTROL (DCCH)
Addition WindowCell2Drop WindowCell2Drop TimeCell2
BEST Server: Cell 2BEST Server: Cell 2
Measurement Reporting Criteria according to Cell 2Measurement Reporting
Criteria according to Cell 2
Neighbour List Update
1
3
4
1
3
4
Neighbour List Cell 2Neighbour List Cell 2
Active Set: Cell 2Active Set: Cell 2Meas. Rep.
Criteria Update
Measurement Reporting Criteria according to
Cell 1
Measurement Reporting Criteria according to
Cell 1
3
1
4
2
5
3
1
4
2
5
Neighbour List CombinationNeighbour List Combination
Neighbour List Update
5. MEASUREMENT CONTROL (DCCH)
Active Set: Cell1 - Cell2Active Set: Cell1 - Cell2
2. Setup Call
2. Setup Call
7. ACTIVE SET UPDATE
35 NOKIA 30/11/2003 RANPAR Version 1.1
Inter-RNC soft handovers are performed if: RNC: IurUPSupport indicates the support of the user plane over Iur HOPS: EnableInterRNCsho indicates whether cell can participate in a SHO
Otherwise, HC checks whether Hard Handover is possible. HHO decision is made by the RNC if either;
AveEcNoDownlink + HHoMarginForAveEcNo(n) < AvEcNoNcell(n)
EcNoDownlink + HHoMarginPeakEcNo(n) < EcNoNcell(n)
AveEcNoDownlink and AvEcNoNcell(n) = measured values for the best AS cell and the nth NS cell, averaged over EcNoAveragingWindow measurements
EcNoDownlink and EcNoNcell(n) = instantaneous values
HHoMarginForAveEcNo (HOPS) = average Ec/N0 margin [-6 6]dB, default 1dB HHOMarginPeakEcNo (HOPS) = peak Ec/N0 margin [-6 6]dB, default 2dB
Inter-RNC Soft HO and Hard HO
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Inter-RNC Soft HO
cell3 cell2
cell1
cell4cell6
cell5
RNC RNCIurUPSupport
EnableInterRNCsho
EnableInterRNCsho
37 NOKIA 30/11/2003 RANPAR Version 1.1
Handover Control Handover Types Intra-Frequency handover:
Parameters Mapping SHO Events and Measurements Hard handover RRC Connection Release
Compressed-Mode Inter-Frequency & Inter-System handover:
Measurement triggering Inter-Frequency & Inter-System Measurements Inter-Frequency HO decision Inter-System HO decision
GSM ISHO Load Based Handover to WCDMA Cell Reselection to WCDMA
38 NOKIA 30/11/2003 RANPAR Version 1.1
If RNC is not able to add (Event 1A) to or replace (Event 1C) an Ncell from the AS, UE sends periodic measurement reports (AdditionReportingInterval / ReplacementReportingInterval) until; Ncell is added/replaced in to AS Ncell leaves reporting range HO no longer required (e.g. different Ncell enters AS)
RNC may not be able to add/replace Ncell due to (a) Iur congestion or (b) inter-RNC SHO is prevented due to setting of EnableInterRNCsho (HOPS) (point1 on next slide)
If CPICH EC/NO of non-active Ncell continues to increase it will cause additional interference due to a non-optimal connection (point 2)
To avoid excessive uplink interference, RNC will perform an intra-frequency hard handover to the Ncell (CPICH3) if either of the following criteria are met (point 3);
AveEcNoDownlink + HHOMarginAveEcNo < AveEcNoNcellEcNoDownlink + HHOMarginPeakEcNo < EcNONcell
(Both HOPS)
Hard Handover
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Time
Ec/Io
P CPICH 3
P CPICH 1
P CPICH 2Reporting
range
AdditionReportingInterval
1
2
HHOMarginAverageEcNoHHOMarginPeakEcNo
1A (AdditionTime = 0)
AveEcNoDownlink + HHOMarginAveEcNo < AveEcNoNcellEcNoDownlink + HHOMarginPeakEcNo < EcNONcell
Hard Handover
3
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Handover Control Handover Types Intra-Frequency handover:
Parameters Mapping SHO Events and Measurements Hard handover RRC Connection Release
Compressed-Mode Inter-Frequency & Inter-System handover:
Measurement triggering Inter-Frequency & Inter-System Measurements Inter-Frequency HO decision Inter-System HO decision
GSM ISHO Load Based Handover to WCDMA Cell Reselection to WCDMA
41 NOKIA 30/11/2003 RANPAR Version 1.1
If difference between the best AS cell and the NS cell is too high and SHO is not performed, the RRC connection is released to avoid excessive interference
Why might an AS update not be possible? Excessive load in the neighbouring cell Hard blocking in the target BTS Unavailability of DL spreading codes Iub transport resources unavailable
This function is activated by EnableRRCRelease (HOPS parameter)/0=no (def),1 =yes
The RRC connection is released if either:
AveEcNoDownlink + ReleaseMarginForAveEcNo(n) < AvEcNoNcell(n)EcNoDownlink + ReleaseMarginPeakEcNo(n) < EcNoNcell(n)
ReleaseMarginForAveEcNo (HOPS) = average Eb/N0 margin [-6 6] dB, default 2.5dB ReleaseMarginPeakEcNo (HOPS) = peak Eb/N0 margin [-6 6] dB, default 3.5dB
Emergency calls are exempt from RRC Connection Release process
RRC Connection Release
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Handover Control Handover Types Intra-Frequency handover:
Parameters Mapping SHO Events and Measurements Hard handover RRC Connection Release
Compressed-Mode Inter-Frequency & Inter-System handover:
Measurement triggering Inter-Frequency & Inter-System Measurements Inter-Frequency HO decision Inter-System HO decision
GSM ISHO Load Based Handover to WCDMA Cell Reselection to WCDMA
43 NOKIA 30/11/2003 RANPAR Version 1.1
Compressed Mode in UplinkGSM BTS WCDMA BTS
DL
DL CM (this should be offwhen GSM is measured)
UL CM (needed to avoid interference)
During WCDMA transmissionsignal leakage will go to GSMRx also
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Compressed Mode (CM) CM was introduced to WCDMA to allow inter-frequency (system) handovers CM is used to create idle periods (gaps) in the transmission during which ncell measurements on
another frequency can be made
Gaps can be created using single or double frame approach (Nokia supports both) Because same data amount is sent in a shorter time more power is needed during CM (both in
UE and BTS)=> affects WCDMA coverage
Fast Power control information might be lost during the gap => higher Eb/No=> affects WCDMA capacity
Compressed frames may be lost if power control is not set correctly=> affects WCDMA quality
CM methods are Puncturing, Spreading Factor Halving and Higher Layer Scheduling
Normal frame Normal frame
Measurement gapMeasurement gapPower / Data Rate
CompressedMode
Normal frame
45 NOKIA 30/11/2003 RANPAR Version 1.1
AssumptionAssumption Effect to the capacityEffect to the capacity
Required Eb/No is 1.5 dB higher during compressed frames
Required Eb/No is 1.5 dB higher during compressed frames 1.5 dB = 41% more interference1.5 dB = 41% more interference
Every 3rd frame is compressedEvery 3rd frame is compressed 41% /3 = 14% more interference41% /3 = 14% more interference
10% of the users are measured at the same time
10% of the users are measured at the same time 14% /10 = 1.4% more interference
14% /10 = 1.4% more interference
Capacity degradation < 2%
Performance of Compressed Mode: Capacity
Exact increase in Eb/N0 depends on service, multipath diversity, antenna diversity, mobile speed, uplink or downlink, measurement gap length, compressed mode method (spreading factor or puncturing), and 1.5 dB represents a typical value.
Exact increase in Eb/N0 depends on service, multipath diversity, antenna diversity, mobile speed, uplink or downlink, measurement gap length, compressed mode method (spreading factor or puncturing), and 1.5 dB represents a typical value.
46 NOKIA 30/11/2003 RANPAR Version 1.1
Performance of Compressed Mode: CoverageAssumptionAssumption Effect to the coverageof real time services
Effect to the coverageof real time services
Required Eb/No is 1.5 dB higher during compressed frames
Required Eb/No is 1.5 dB higher during compressed frames 1.5 dB reduced coverage1.5 dB reduced coverage
7-slot gap is used7-slot gap is used 10*log10(15/8) = 2.7 dB reduced coverage
10*log10(15/8) = 2.7 dB reduced coverage
Every 2nd frame is compressed with 20 ms interleaving (speech)
Every 2nd frame is compressed with 20 ms interleaving (speech) 4.2 dB / 2 = 2.1 dB reduced coverage
4.2 dB / 2 = 2.1 dB reduced coverage
Total coverage reduction 2.1 dB
Compressedmode
Mobile max. power
Frame error if mobile hitsits maximum power
2.7 dB + 1.5 dB more power is needed during compressed mode
Non-real time services can reduce the bit rate during compressed frames no effect to coverage
Speech connection can switch to a lower AMR mode
47 NOKIA 30/11/2003 RANPAR Version 1.1
Measurement Gap
Min transmitted TSs per Frame: 8
radio frame radio frame
TGL
Length of gap:3, 4, 5, 7 timeslots
Single-frame method
radio frame radio frame
TGL
Double-frame method
Length of gap:3, 4, 5, 7, 10, or 14 timeslots
48 NOKIA 30/11/2003 RANPAR Version 1.1
Compressed mode methods Puncturing for Speech in DL
Reducing the physical channel bit amount (Channel Coding Convolution Coding) More Tx power is needed if same QoS requirements have to be satisfied Only if all DCHs have enough free puncturing capacity
RNC: DLPuncturingLimit/0.68 =puncturing from coding rate 1/3 to coding rate 1/2.
Halving Spreading Factor, SF/2 for RT and NRT services (UL and DL) Doubles temporarily the physical channel data rate, possible for all services Needs 3 dB more UE power due to halved spreading ratio If new channelization code is available from code tree in DL
WCEL: AltScramblingCodeCM/0=used (def), 1=not used
Higher Layer Scheduling, HLS (UL and DL) Only possible for PS services (RT or NRT) Does not cause extra load to the cell but reduces DCH user data HLS data rate or HLS data rate possible
Double frame is used in case of puncturing and HLS data rateSingle frame is used in case of spreading factor halving and HLS data rate.
49 NOKIA 30/11/2003 RANPAR Version 1.1
Compressed mode parameters CM can be activated/deactivated by CMmasterSwitch (RNC) /0=in use (def) HLS rate configurable using HLSModeSelection (RNC)/def 0=1/2 HSL , 1=3/4 HSL
Method used for voice: HLS not possible UL LowerULAMRmodeCM (RNC) /7.4 kbits/s defines AMR mode corresponding to SF/2 DL selection bit puncturing and SF/2 based on MinDLAMRmodeCM (RNC)/7.4 kbits/s
(range 4.75...12.2 kbits/s)
Method used for RT and NRT services SF/2 is allowed if: UE DL Tx Power < Max_UE_DL_Tx_Pwr PowerMarginCMcodeHalving (RNC)/3 dB (range 0..10, step 0.25)
Maximum number of UEs in CM is controlled through MaxNumbUECMcoverHO (RNC)/16 (range 0..255)
The number of UEs in DL CM depends on the PtxTotal value The number of UEs in UL CM depends on the PrxTotal value
50 NOKIA 30/11/2003 RANPAR Version 1.1
How many UEs in Compressed Mode ?
PtxTarget/PrxTarget
DL/ULtransmission power
Load
PtxOffset/PrxOffset
New UEs can be switched to CM when:Pxx_Total < Pxx_Target &
# of UEs in CM < MaxNumbUECMcoverHO
One new UE in CM can be allowedif the limit is not reached
No new UE can be in CM here
51 NOKIA 30/11/2003 RANPAR Version 1.1
Applicable methods for related services
Service UL CM method DL CM Method
AMR SF/2, HLS SF/2, Puncturing
PS NRT SF/2, HLS SF/2, HLS
CS Data SF/2 SF/2
AMR+PS 1. If the PS bit rate >> AMR bit rate it is possible to create idle gaps by applying frame compression to just the PS DCH. In this case the CM method selection is as in the case of stand-alone PS NRT.2. If both DCHs must be compressed then only the methods applicable to both can be used: i.e. in DL only SF/2 is possible
CM method Frame ModeSF/2 Single Frame
HLS Single Frame HLS Double Frame
Puncturing Double Frame
52 NOKIA 30/11/2003 RANPAR Version 1.1
Selection of DL CM Method
Channel coding>DLPuncturingLimit
Use puncturing(for AMR speech)
SF/2 code available Use SF/2 with thesame scrambling code
Reduce bit rate(for packet data)
DL CM is started with Puncturing instead of SF/2because puncturing needs less power, allow more puncturing if downlink capacity is orthogonal code limited
Link level powerlimit reached
Use SF/2 with anotherscrambling code
Yes
Yes
NoNo
Yes
AMR rate>MinDLAMRModeCM
Lower AMR rate (+ puncturing)
Yes
No
No
Alternative scrambling codeis used when the SF/2 codeis reserved
UL: LowerULAMRModeCMfor AMR rate
53 NOKIA 30/11/2003 RANPAR Version 1.1
Compressed mode method in RAN 1.5.2
Id Compressed mode method1 Puncturing (Not supported in RAN 1.5)
2 SF/23 SF/2 with alternative scrambling code4 HLS 1/25 HLS 3/4
Compressed mode method in NRT PSTriggering reason: Too high UE Tx powerParameter HHOMaxAllowedBitRateUL should be checkedCompressed mode method in Downlink (in priority order): 1,2,3,4,5Compressed mode method in Uplink (in priority order): 2,4,5Triggering reason: Too high DL DCH powerParameter HHOMaxAllowedBitRateDL should be checkedCompressed mode method in Downlink (in priority order): 4,5Compressed mode method in Uplink (in priority order): 2,4,5Triggering reason: Low CPICH EcNo, Low CPICH RSCP, poor UL DCHCompressed mode method in Downlink (in priority order): 2,3,4,5Compressed mode method in Uplink (in priority order): 2,4,5
54 NOKIA 30/11/2003 RANPAR Version 1.1
CM Pattern Parameters
TG Pattern 1
TGPattern 2
TG Pattern 1
TGPattern 2
TGPattern 2
TG Transmission Gap TGL Transmission Gap Length (3,4,5,7,10,14 SL)TGPL Transmission Gap Pattern Length (1-144 Frames) TGD Transmission Gap start Distance (15-269 SL)TGSN Transmission Gap Starting slot Number (1-14 SL)TGPRC TG Pattern Repeat Count
TG Pattern 1 TG Pattern 2
TGPL1 TGPL2
TGSNTGL1 TGL2TGL1TGL2
TGD TGD
#1 #2 #3 #4 #TGPRC
TGCNF transmission gap pattern sequence
GapPositionSingleFrame
TGSN
55 NOKIA 30/11/2003 RANPAR Version 1.1
Handover Control Handover Types Intra-Frequency handover:
Parameters Mapping SHO Events and Measurements Hard handover RRC Connection Release
Compressed-Mode Inter-Frequency & Inter-System handover:
Measurement triggering Inter-Frequency & Inter-System Measurements Inter-Frequency HO decision Inter-System HO decision
GSM ISHO Load Based Handover to WCDMA Cell Reselection to WCDMA
56 NOKIA 30/11/2003 RANPAR Version 1.1
IFHO/ISHO Process Overview
HO Triggering Thresholds set in RNCHO Triggering Thresholds set in RNC
Event Triggered Coverage/Capacitybased HO fulfilled in RNC
Event Triggered Coverage/Capacitybased HO fulfilled in RNC
RNC commands selected UE(s) to startIF/IS measurements
RNC commands selected UE(s) to startIF/IS measurements
Measurements are done in Compressed Mode (CM)
Measurements are done in Compressed Mode (CM)
UE reports GSM cells withstrongest RSSI signals to RNCUE reports GSM cells with
strongest RSSI signals to RNC
RNC makes HO decision andcommands UE to target cell
RNC makes HO decision andcommands UE to target cell
RSSI measurements and BSICverification for GSM cells
RSSI measurements and BSICverification for GSM cells
Different decision methods for IF HOOnly one decision method for IS HO
5 Coverage/Capacity HO Reasons
About 25 HO parameters
Reporting cells are active set cells (max 3) + max 6 IFHO, max 6 ISHO neighb.
Max 32 neighbours could be measured
(31 Intra-Freq neighbours)48 Inter-Freq neighbours 32 Inter-System neighbours can be measured
57 NOKIA 30/11/2003 RANPAR Version 1.1
IFHO/ISHO measurements- difference
IF measurements
IS measurements
WCDMA
IS-HOMeasurement
Trigger Target Cell found
RSSI meas. BSIC verification
IS-HODecision
WCDMA
IF-HOMeasurement
TriggerTarget Cell found
IF -measurements
IF-HODecision
58 NOKIA 30/11/2003 RANPAR Version 1.1
Handover Control Handover Types Intra-Frequency handover:
Parameters Mapping SHO Events and Measurements Hard handover RRC Connection Release
Compressed-Mode Inter-Frequency & Inter-System handover:
Measurement triggering Inter-Frequency & Inter-System Measurements Inter-Frequency HO decision Inter-System HO decision
GSM ISHO Load Based Handover to WCDMA Cell Reselection to WCDMA
59 NOKIA 30/11/2003 RANPAR Version 1.1
IF/IS Handover Triggering Reasons
1. DL DPCH approaches itsmaximum allowed powerFMCI: IFHOcauseTxPwrDLFMCG: GSMcauseTxPwrDL
2. Quality deterioration report from UL outer loop PCFMCI: IFHOcauseUplinkQualityFMCG: GSMcauseUplinkQuality
4. UE Tx power approaches itsmaximum allowed power, event 6A/6DFMCI: IFHOcauseTxPwrULFMCG: GSMcauseTxPwrUL
5 . Low measured absoluteCPICH RSCP, events 1E/1FFMCI: IFHOcauseCPICHrscp, FMCG: GSMcauseCPICHrscp
3. Low measured absolute CPICH Ec/No, event 1E/1FFMCI: IFHOcauseCPICHEcNoFMCG: GSMcauseCPICHEcNo
HO trigger
6 . Others (Not implemented in RAN 1.5):e.g. Traffic & load reason IS-HO, etc
Frequency Measuring Control for Inter-Frequency = FMCIFrequency Measuring Control for Inter-System (GSM) = FMCG
60 NOKIA 30/11/2003 RANPAR Version 1.1
Measurement triggering: DL Coverage RNC orders UE to make IF measurements when DL TX power of a single radio link reaches threshold
defined as: DL_code_PWR -PowerOffsetDLdpcchPilot > CPICH Pwr + DL Tx Pwr + DL_TPCH_TXPWR_Threshold
DL_CODE_PWR = measured DL code power PowerOffsetDLdpcchPilot = power offset for the DPCCH pilot bits relative to the DPDCHs power
default = 3 dB, range 0...6 dB, step size 0.25 dB DL Tx Pwr (DPCH) = measurement on DPCH Tx power, (reported by BTS)
RLMeasRepPeriod (WBTS) / default=500ms, range 0..2000ms, step 100ms CPICH Pwr = Tx power of the CPICH of an active cell
PtxPrimaryCPICH (serving RNC) or AdjsCPICHTxPwr (drifting RNC)/33 dBm, range -1050 dBm, step 0.1 dBm
DL_TPCH_TXPWR_Threshold = depends on the service type FMCI: InterfreqDLTxPwrThrAMR/CS/RtPS/NrtPS -1/-3/-3/-1 dB(range -10 dB..0, step 0.5 dB) FMCG: GSMDLTxPwrThrAMR/CS/RtPS/NrtPS -1/-3/-3/-1 dB(range -10 dB..0, step 0.5 dB)
In Addition, the DL data rate allocated to the user must not exceed WCEL: HHoMaxAllowedBitrateDL/64 kbits/s
NOTE: Either WCDMA or GSM will be measured, not both systems
-100dBm 3dB > 33dBm+XXX+(-1dB)
61 NOKIA 30/11/2003 RANPAR Version 1.1
Measurement triggering: DL Coverage
Node BRNC
DCH Data Frame
IubUE
PO1TPCPilotbitsTFCI Data 2 bitsData 1 bits
PO3PO2DL_CODE_PWR PowerOffsetDLdpcchPilot
CPICH_POWER + MAX_DL_DPCH_TXPWR + DL_DPCH_TXPWR_THRESHOLD
Max Power on DPCH (e.g. 33 dBm)
Serving WCDMA cell time
Its time to triggerHO measurements
in the UE
e.g. Radio Link Measurement Report(e.g. Transmitted Code Power Value)
HHoMaxAllowedBitrateDL
Example Speech:Power Data Bits > 33dBm + (-3dB) + (-1dB)
Power Data Bits > 29 dBm (~1W)
Max Power on Channel
62 NOKIA 30/11/2003 RANPAR Version 1.1
Measurement triggering: UL Quality RNC starts inter-frequency measurements based on UL outer-loop power control reports.
Enable reports from Outer-loop Power Control Controller to trigger inter-freq HO, RNC:EnableULQualDetRep/default 0=no, 1=yes
Time duration for which BER/BLER target has not been reached, despite SIR target at maximum level, RNC: ULQualDetRepThreshold/5 s, 0.5..5, step 0.5s
Periodic report, every RNC: ULQualDetRepThreshold seconds, while BLER/BLER target is not reached.
In addition, the UL data rate allocated to the user must not exceed WCEL: HHoMaxAllowedBitrateUL/32 kbits/s
63 NOKIA 30/11/2003 RANPAR Version 1.1
Measurement triggering: UL QualityT
a
r
g
e
t
S
I
R
Max SIR target
Min SIR target
Actual SIR target
1st Quality deterioration report from PC to HC inside RNC
2nd Quality deterioration report (while the condition issatisfied the message is periodically repeated)
default 5s time
SIR SIR
RNC
ULQualDetRepThreshold
EnableULQualDetRepHHoMaxAllowedBitrateUL
RNC
64 NOKIA 30/11/2003 RANPAR Version 1.1
Measurement triggering: CPICH Ec/No RNC starts IF measurement when event 1F occurs for at least one cell of the active
set: A Primary CPICH becomes less than an absolute threshold
RNC stops IF measurement when event 1E occurs for at least one cell of the active set : A Primary CPICH becomes better than an absolute threshold
Filtering applied before event evaluation in the UE: FMCS: EcNoFilterCoefficient/0= 200ms filtering period
Event 1F parameters: Triggering conditions: Active set cells hysteresis: not used in 1F Threshold used frequency: FMCS : HHoEcNoThreshold / - 22 dB (range 0..-24 dB) Time-to-trigger: FMCS: HHoEcNoTimeHysteresis / 640 ms (range 0..5000ms) Amount of reporting: infinity Reporting interval: not applied. Reporting cell status: max 3 active cells.
65 NOKIA 30/11/2003 RANPAR Version 1.1
Measurement triggering: CPICH Ec/No Event 1E parameters:
Triggering conditions: Active set cells Hysteresis: not used in 1F Threshold used frequency: FMCS : HHoEcNoCancel/ -20 dB Time-to-trigger: FMCS: HHoEcNoCancelTime/ 1280 ms Amount of reporting: infinity Reporting interval: not applied. Reporting cell status: max 3 active cells.
66 NOKIA 30/11/2003 RANPAR Version 1.1
Measurement triggering: CPICH Ec/NoReporting event: 1E: A P-CPICH exceeds an absolute threshold (triggered if one)
1F: A P-CPICH falls below an absolute threshold (triggered if all)
time
Cell 1 Cell 2
Cell 3
absolutethreshold
e
.
g
.
P
-
C
P
I
C
H
E
c
/
N
o
1E: HHoEcNoCancel
1E: HHoEcNoCancelTime
1F: HHoEcNoThreshold
1F: HHoEcNoTimeHysteresis
67 NOKIA 30/11/2003 RANPAR Version 1.1
Measurement triggering: CPICH RSCP
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 measurements when event 1F occurs for all cells in AS
RNC stops IF measurements when event 1E occurs for at least one cell of AS
UE filtering applied before event evaluation using HHoRscpFilterCoefficient (FMCS) /200ms, range 2001600ms
68 NOKIA 30/11/2003 RANPAR Version 1.1
Measurement triggering: CPICH RSCP 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/ - 100 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)/ - 105 dBm Time-to-trigger: HHoRscpTimeHysteresis (FMCS)/ 640 ms Amount of reporting: infinity Reporting interval: not applied. Reporting cell status: max 3 active cells.
69 NOKIA 30/11/2003 RANPAR Version 1.1
Measurement triggering: UL Coverage RNC orders IF measurements when one of the following event occurs:
Event 6A: The UE Tx power becomes larger than an absolute threshold Event 6D: The UE Tx power reaches its maximum value Also GSM measurements could be measured first depending on UE Tx power values
in IFHO and ISHO parameters Only lower threshold is send to UE, so either WCDMA or GSM is measured first,
but also other RAT could be measured if not good enough neighbour is found In addition, the UL data rate allocated to the user must not exceed WCEL:
HHoMaxAllowedBitrateUL/32 kbits/s RNC calls off inter-frequency measurements when event 6B occurs: the UE Tx power
becomes less than an absolute threshold. Filtering applied before event evaluation in the UE.
FMCI : InterfreqUETxPwrFilterCoeff/8=10ms (range 10..480ms) FMCG: GSMUETxPwrFilterCoeff/8 =10ms (range 10..480ms)
NOTE: Not all UE vendors support 6A event
70 NOKIA 30/11/2003 RANPAR Version 1.1
Measurement triggering: UL Coverage Event 6A parameters:
Time-to-trigger: 0s UE Transmitted Power threshold = min (UEtxPowerMaxDPCH, Pmax)
UE_TX_POWER_thresholdwhere:
UEtxPowerMaxDPCH is the maximum allowed UL tx power on DPCH in the active cell (range -50..24 dBm, step 1, default 21 dBm)
Pmax is the maximum RF output power UE_TX_POWER_Threshold depends on the type of service:
FMCI: InterfreqUETxPwrThrAMR/-3 dB (range -10..0, step1) FMCI: InterfreqUETxPwrThrCS/-3 dB (same range and step) FMCI: InterfreqUETxPwrThrNrtPS/-3 dB FMCI: InterfreqUETxPwrThrRtPS/-3 dB FMCG: GSMUETxPwrThrAMR/CS/NrtPS/RtPS -1/-3/-1/-3/ dB
Event 6B parameters: time-to-trigger: FMCI: InterfreqUETxPwrTimeHyst/1280 ms FMCG: GSMUETxPwrTimeHyst/1280 ms
Event 6D parameter:Time-to-trigger: 0s
71 NOKIA 30/11/2003 RANPAR Version 1.1
Reporting Events 6A, 6B and 6D
timetime totrigger
U
E
T
x
P
o
w
e
r
UE Transmitted Power Tx Threshold
6B6A
6Dmin(UEtxPowerMaxDPCH, P_MAX)
6A: The UE Tx power exceeds an absolute threshold 6B: The UE Tx power falls below an absolute threshold 6D: The UE Tx power reaches its maximum value
InterfreqUETxPwrTimeHystGSMUETxPwrTimeHyst
72 NOKIA 30/11/2003 RANPAR Version 1.1
Handover Control Handover Types Intra-Frequency handover:
Parameters Mapping SHO Events and Measurements Hard handover RRC Connection Release
Compressed-Mode Inter-Frequency & Inter-System handover:
Measurement triggering Inter-Frequency & Inter-System Measurements Inter-Frequency HO decision Inter-System HO decision
GSM ISHO Load Based Handover to WCDMA Cell Reselection to WCDMA
73 NOKIA 30/11/2003 RANPAR Version 1.1
Node B
UTRAN
RNCUE
Measurement Control [ ]
I am in the CELL_DCH sub-state
Measurement Type: Inter-frequency measurements Reporting events:
2A: Change of best frequency2B: The estimated quality of the currently used frequency is belowa certain threshold and the estimated quality of a non-used frequency is above a certain threshold.2C: The estimated quality of a non-used frequency is above a certain threshold2D: The estimated quality of the currently used frequency is belowa certain threshold2E: The estimated quality of a non-used frequency is below a certain threshold2F: The estimated quality of the currently used frequency is above a certain threshold
IFHO Measurements
System Information [ ]
SIB 11/12 EcNoFilterCoefficient
74 NOKIA 30/11/2003 RANPAR Version 1.1
IFHO measurements After HO triggering message is sent to RNC, a RRC message Measurement Control is
sent to UE containing details of the measurement that the UE must execute. Measurement reporting is periodical. Max 6 IF cells can be reported
Upon reception of the measurements reported by the UE, RNC applies a sliding averaging window to the CPICH Ec/No & CPICH RSCP measurements. The averaged levels are used as input to the inter-frequency decision algorithm.
From each cell in active set (max=3) also intra-frequency measurements are done at same time
RNCRRC: Measurement control message
("carrier 2" measurements)
UE
RNC
CPICH Ec/No and CPICH RSCP measurements are reported through Measurement report messages
UE
RRC: Measurement report
RRC: Measurement report
In one measurement report there is both intra-and inter-frequency
results, no measurement filtering is used in UEAdjiMeasRepInterval
(default 0.5s)
3 neighbour info send to UE:UTRA RF channel, cell
individual offset (Ec/No) and primary scrambling code
75 NOKIA 30/11/2003 RANPAR Version 1.1
IFHO measurement control When there are more than 32 neighbouring inter-frequency cells, list of cell to be monitored is
built with priority: HOPI: AdjiPriorityQuality/0, 0..7 (0=lowest priority) HOPI: AdjiPriorityCoverage/0, 07 (0=lowest priority)
Only periodic inter-frequency measurements are used
No filtering in the UE
Reporting cell status: up to 6 monitored set cells.
Inter-frequency HO could be forbidden during the first measurements reports from the UE, to let the UE report all the candidate inter-frequency cells in its neighbourhood. FMCI AdjiSearchPeriod / default=0 MeasReport Range 0 ... 20 MeasReport, step 1 MeasReport
Reporting interval: FMCI AdjiMeasRepInterval / 0.5 s def (1,2,3,4s possible also) Inter-frequency measurement stops if RNC has not been able to perform inter-frequency
handover after N reports. N is configured by FMCI: AdjiMaxMeasPeriod / 20, 1..20 step 1 measurement report
RNC can not initiate inter-frequency measurements if: The UE has recently performed an inter-frequency HO. FMCI AdjiMinHoInterval / 10s,
0..60, step 1 s An inter-frequency HO recently failed for this UE. FMCI AdjiMinMeasInterval / 10s,
0..60 step 1s
76 NOKIA 30/11/2003 RANPAR Version 1.1
ISHO measurements After HO triggering message is sent to RNC, a RRC message Measurement Control is
sent to UE containing details of the measurement that the UE must execute. Measurement reporting is periodical. Max 6 GSM cells could be measured by UE and reported to RNC.
Upon reception of the measurements reported by the UE, RNC applies a sliding averaging window to the RXLEV measurements. The averaged levels are used as input to the IS-HO decision algorithm.
RNCRRC: Measurement control message
(GSM RSSI measurements)
UE
RNC
RXLEV measurements are reported throughMeasurement report messages
UE
RRC: Measurement report
RRC: Measurement report
The first measurement report has info from the best GSM cell:
BCCH freq & RSSI, no filteringused in UE
GsmMeasRepInterval (default 0.5s)
77 NOKIA 30/11/2003 RANPAR Version 1.1
ISHO measurements Only periodic inter-system measurements are used
No filtering in the UE
Reporting cell status: up to 6 monitored set cells.
Reporting interval: FMCG GSMMeasRepInterval / 0.5 s def (1,2,3,4s also) Inter-system measurement stops if RNC has not been able to perform inter-system handover
after N reports. N is configured by FMCG: GSMMaxMeasPeriod / 20, 120, step 1 MeasReport RNC can not initiate inter-system measurements if:
The UE has recently performed an inter-system HO. FMCG: GSMMinHoInterval / 10s, 060, step 1s
An inter-system HO recently fails for this UE. FMCG: GSMMinMeasInterval / 10s, 060, step 1s
78 NOKIA 30/11/2003 RANPAR Version 1.1
ISHO: BSIC Verification After the selection of the target GSM cell, the RNC sends to UE the RRC message
"Measurement control which includes details to measure BSIC .
UE stops RSSI measurements and updates the transmission gap pattern to the pattern used for BSIC decoding. The measurement reports are sent periodically to RNC.
If the UE is unable to decode the BSIC during the given period, the BSIC measurement operation is aborted.
RNC
RRC: Measurement control message (BSIC decoding)
WCDMA
IS-HO trigger Target Cell foundIS-HO
command
RSSI meas. BSIC verification
Numbers of GSM cells in the neighbour cell list
Reporting intervalSliding averaging windowTransmission gap pattern forRSSI measurements
TBSIC depends on :
Transmission gap pattern forBSIC decoding
TRSSI depends on
79 NOKIA 30/11/2003 RANPAR Version 1.1
Handover Control Handover Types Intra-Frequency handover:
Parameters Mapping SHO Events and Measurements Hard handover RRC Connection Release
Compressed-Mode Inter-Frequency & Inter-System handover:
Measurement triggering Inter-Frequency & Inter-System Measurements Inter-Frequency HO decision Inter-System HO decision
GSM ISHO Load Based Handover to WCDMA Cell Reselection to WCDMA
80 NOKIA 30/11/2003 RANPAR Version 1.1
It is not sufficient to have triggers, which detect that a handover has to be done. Criteria are required to decide, whether to carry out an intra-frequency, inter-frequency, or inter-RAT handover if there is the possibility for a handover at all!
Conditions shown here have to be satisfied, before an inter-frequency handover can be conducted. The best neighbouring cell must fulfil following criteria (best according to Ec/No):
Quality Criterion in case trigger was DL DPCH Power or CPICH Ec/No:AVE_RSCP_NCELL (n) > AdjiMinRSCP(n) + max(0, AdjiTxPwrDPCH(n) - P_MAX)
Signal level from new cell > required Signal level in new cell + adjustment due to allowed power
AVE_EcNo_NCELL (n) > AVE_CPICH_EcNo + AdjiEcNoMargin(n)EcNo on new cell better than EcNo in old cell + margin
Pathloss Criterion in case trigger was UE Tx Power, CPICH RSCP or UL DPCH Quality:AVE_EcNo_NCELL (n) > AdjiMinEcNo(n)
EcNo on new cell better than required EcNo in new cell (default 14 dB)
CPICH_POWER - AVE_CPICH_RSCP > CPICH_POWER_NCELL (n) - AVE_RSCP_NCELL (n) + AdjiPlossMargin(n)
PathLoss in old cell > PathLoss in new cell + Margin (default 2 dB) (continued)
IFHO Decision
81 NOKIA 30/11/2003 RANPAR Version 1.1
best active setcell
best inter-frequencycell
HO?
a) AVE_EcNo_NCELL (n) > AdjiMinEcNo(n)b) AVE_EcNo_NCELL (n) > AVE_CPICH_EcNo + AdjiEcNoMargin(n)
Quality Criteria
AdjiMinEcNo(n)
A
V
E
_
E
c
N
o
_
N
C
E
L
L
(
n
)
AVE_CPICH_EcNo
AVE_EcNo_NCELL (n) > AVE_CPICH_EcNo
AdjiEcNoMargin(n)
AVE_EcNo_NCELL (n)
IFHO Decision
82 NOKIA 30/11/2003 RANPAR Version 1.1
The meaning of the parameters is: AVE_RSCP_NCELL (n) and AVE_EcNo_NCELL (n) are the averaged CPICH Ec/No and RSCP values of the
best (according to CPICH Ec/No) neighbour cell (n). AVE_CPICH_EcNo is the averaged CPICH Ec/No of the best active set cell. P_MAX is the maximum UE power capability. AdjiMinRSCP(n) determines the minimum required CPICH RSCP (dBm) level in the best neighbour cell
(n). AdjiTxPwrDPCH indicates the maximum transmission power level that an UE may use on the DPCH in
the neighbour cell AdjiEcNoMargin(n) determines the margin (dB) by which the CPICH Ec/No of the best neighbour cell
(n) must exceed before the inter-frequency handover is possible. AdjiMinEcNo(n) determines the minimum required CPICH Ec/No (dB) in the best neighbour cell (n). AdjiPlossMargin(n) determines the margin (dB) by which the propagation loss of the best active set cell
must exceed the propagation loss of the best neighbour cell (n) before the inter-frequency handover is possible.
IFHO Decision
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AVE_RSCP_NCELL (n) > AdjiMinRSCP(n) + max(0, AdjiTxPwrDPCH(n) - P_MAX)
RSCP Criterion
CPICH_POWER - AVE_CPICH_RSCP > CPICH_POWER_NCELL (n) - AVE_RSCP_NCELL (n) + AdjiPlossMargin(n)
AdjiMinRSCP(n)
max(0, AdjiTxPwrDPCH(n) - P_MAX)
Pathloss Criterion
best inter-frequencycell
best active setcell
AdjiPlossMargin(n)
IFHO Decision
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Handover Control Handover Types Intra-Frequency handover:
Parameters Mapping SHO Events and Measurements Hard handover RRC Connection Release
Compressed-Mode Inter-Frequency & Inter-System handover:
Measurement triggering Inter-Frequency & Inter-System Measurements Inter-Frequency HO decision Inter-System HO decision
GSM ISHO Load Based Handover to WCDMA Cell Reselection to WCDMA
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The following conditions have to be satisfied, before an inter-frequency handover can be conducted. The best neighbouring cell must fulfil following criterion (best according to Ec/No):AVE_RXLEV_NCell(n)
> AdjgRxLevMinHO(n) + max(0, AdjgTxPwrMaxTCH(n) - P_max)where
AVE_RXLEV _Ncell(n) is the averaged GSM carrier RSSI value of the GSM neighbour cell(n), averaging done directly from dBm values (no linear averaging); GSMMeasAveWindow / 6, 132 meas report.
AdjgRxLevMinHO(n) determines the minimum Required RSSI (dBm) level of the neighbour cell(n). AdjgTxPwrMaxTCH(n) indicated the maximum Tx power level (dBm) an UE may use in GSM neighbour
cell(n). P_MAX is the maximum UE power capability.
If several GSM cells fulfil the equation above, cells are ranked based on HOPG: AdjgPriorityCoverage/0, range 07
A cell is ranked higher than another cell if it has a higher priority level even though its signal strength condition was worse
Inter-system HO could be forbidden during the first measurements reports from the UE, to let the UE report all the candidate inter-system cells in its neighbourhood.
FMCG NcellSearchPeriod / 0
ISHO Decision
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AdjgRxLevMinHO(n)
max(0, AdjgTxPwrMaxTCH(n) - P_max)
AVE_RXLEV_NCell(n) > AdjgRxLevMinHO(n) + max(0, AdjgTxPwrMaxTCH(n) - P_max)
GSM cell
ISHO Decision
87 NOKIA 30/11/2003 RANPAR Version 1.1
Handover Control Handover Types Intra-Frequency handover:
Parameters Mapping SHO Events and Measurements Hard handover RRC Connection Release
Compressed-Mode Inter-Frequency & Inter-System handover:
Measurement triggering Inter-Frequency & Inter-System Measurements Inter-Frequency HO decision Inter-System HO decision
GSM ISHO Load Based Handover to WCDMA Cell Reselection to WCDMA
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Load based handover GSM -> WCDMA
100%
80%
0%
Load reason handoversfor speech
Load of GSM cellLoad of GSM cellLoad of GSM cellLoad of GSM cell
Packet Data to WCDMAregardless of GSM load
Packet Data to WCDMAregardless of GSM load
Speech to WCDMAonly with high GSM load
Speech to WCDMAonly with high GSM load
Higher bit ratesfor data users
Higher bit ratesfor data users
More capacity for speech
More capacity for speech
Packet BCCH parameters can be usedto push GPRS mobiles to WCDMA
Packet BCCH parameters can be usedto push GPRS mobiles to WCDMA
BSS10.5
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GSMGSM
GSMGSM
Load and Coverage Reason Handover
GSMGSM
GSM highloaded
WCDMA lowloaded
GSMGSM GSMGSM
WCDMAWCDMA WCDMAWCDMA
Load reason handover for speech and for HSCSD
Load reason handover for speech and for HSCSD
WCDMAWCDMA GSMGSM
Load reason handover
Coverage reason handover
WCDMA can be usedto relieve GSM overload
GSM can be used to extend WCDMA coverage area
WCDMA can be usedto relieve GSM overload
GSM can be used to extend WCDMA coverage area
Mobile moving
RAN1/ph1.5 and BSS10.5
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Load based Handover Process: GSM-> WCDMA
Handover Triggering Thresholds set in BSCHandover Triggering Thresholds set in BSC
Inter-RAT measurements starts in case The RXLEV of the serving cell is above or
below the given threshold Qsearch_C
Inter-RAT measurements starts in case The RXLEV of the serving cell is above or
below the given threshold Qsearch_C
Handover Decision is done in case ofLoad of the serving cell > Load_Thresholdand CPICH Ec/No> min Ec/No Threshold
Handover Decision is done in case ofLoad of the serving cell > Load_Thresholdand CPICH Ec/No> min Ec/No Threshold
MS selects the target UTRAN cell based on measurement results
MS selects the target UTRAN cell based on measurement results
Handover command is send to MSCHandover command is send to MSC
In the S10.5 MS is measuring the UTRAN cells continuously if they are defined as a neighbour,
The number of GSM neighbour reported could be 3-6 depending on the set value of parameter FDD_MULTIRAT_REPORT (0,1,2=def,3).The load is measured in the cell level by comparing the occupied TCHs to the available TCHs (20 s interval used)
Load Threshold for Speech Calls or Transparent Data inter-RAT Handover:utranHoThScTpdc (Min Traffic Load TDHO), default = 80%minEcnoThreshold (Min CPICH EC/NO Threshold), default 15 dB
Parameters are sent from the BSC to the mobilein the Measurement Information message
91 NOKIA 30/11/2003 RANPAR Version 1.1
Handover Control Handover Types Intra-Frequency handover:
Parameters Mapping SHO Events and Measurements Hard handover RRC Connection Release
Compressed-Mode Inter-Frequency & Inter-System handover:
Measurement triggering Inter-Frequency & Inter-System Measurements Inter-Frequency HO decision Inter-System HO decision
GSM ISHO Load Based Handover to WCDMA Cell Reselection to WCDMA
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Cell Reselection Algorithm from GSM to FDD-WCDMA (cs)Cell Reselection List
GSM MS starts WCDMA measurements if :RLA_C< F(Qsearch_I) for 0
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Cell Re-selection Parameters Range of Qsearch_I and Qsearch_P (either Below or Above values comp. to RLA_C)
Recommended value is 7 (measure always)
Range of FDD_Qoffset and FDD_GPRS_Offset Recommended value is 0 (select always if acceptable)
00
-98-98
88
-78-78
11 22
-94 -94 -90-90
99 1010
-74-74 -70-70
33
-86-86
1111
-66-66
44
-82-82
1212
-62-62
55
-78-78
1313
-58-58
66 77
-74-74 AlwaysAlways
1414 1515
-54-54 NeverNever
R_Below
dBm
R_Upper
dBm
00
-Always-Always
88
00
11 22
-28 -28 -24-24
99 1010
44 88
33
-20-20
1111
1212
44
-16-16
1212
1616
55
-12-12
1313
2020
66 77
-8-8 -4-4
1414 1515
2424 2828
Range
dBm
Range
dBm
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Cell Re-selection Parameters Range of FDD_Qmin
Recommended value is 7 (-13 dBm)
FDD_REP_QUANT defines the reporting quantity for UTRAN cell (1=Ec/No or 0=RSCP, default 1)
3G_Search_PRIO parameter allows to extend the BSIC reporting interval from 10 s to 13s by checking the BSICs from non-serving BCCH carriers and also make WCDMA measurements as often as possible. Range is 0=no, 1=yes, default value 1
Defined in the SI2quater and PSI3quater if PBCCH is allocated.
ParameterParameter
Name for Sys Info (SI)Name for
Sys Info (SI)
Qsearch_IQsearch_I
2quater2quater
Qsearch_PQsearch_P Qsearch_PQsearch_P
2quater2quater 3quater3quater
FDD_QMinFDD_QMin
2ter2ter
FDD_(GPRS)Qoffset
FDD_(GPRS)Qoffset
2quater2quater
FDD_REP_QUANT
FDD_REP_QUANT
2ter2ter
00
-20-20
11 22
-19 -19 -18-18
33
-17-17
44
-16-16
55
-15-15
66 77
-14-14 -13-13
Range
dBm
3G_search_PRIO
3G_search_PRIO
2(3)quarter(PBCCH)
2(3)quarter(PBCCH)
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Cell Re-selection Example-Weaker WCDMANon GPRS case
t
Serving GSM Cell
Neighbour WCDMA Cell
Ec/NoRSCP/RLA_C
5 sec.
Cell re-selection to WCDMA
FDD_Qmin=0(-20 dB)
FDD_Qoffset =6 (-8 dB)
Qsearch_I=0 (-98 dBm)
RLA_C
Measurements starts (serving cell)
Minimum Quality Requirement for WCDMA Ec/N0
RSCP
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Cell Re-selection Example-Weaker WCDMAGPRS case
t
Serving GSM Cell (Best)
Neighbour WCDMA Cell
Ec/NoRSCP/RLA_C
5 sec.
Cell re-selection to WCDMA
FDD_Qmin=-20 dB
FDD_GPRS_Qoffset =10 (8 dB)Qsearch_P=0(-98 dBm)
RLA_P
Measurements starts (serving cell)
Minimum Quality Requirement for WCDMA
Ec/N0
RSCP
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First ranking of all the cells based on CPICH RSCP (WCDMA) and RSSI (GSM)
Rs = CPICH RSCP + Qhyst1Rn= RXLEV(n) - Qoffset1
Rn higher in GSM cell
YesNo
Cell re-selection to GSMSecond ranking only for
WCDMA cells
Neighbour WCDMA or GSM cell calculation with offset
parameter
Serving WCDMA cell calculation, with
hysteresis parameterGSM cell measurementsavailable If :
CPICH Ec/No-QqualMin < Ssearch_RAT
WCDMA-> GSM cell reselection
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Nokia Strategy: reselect to GSM early Note: GSM cell could be 15 dB weaker
Qmeas (CPICH Ec/No)
t
Serving WCDMA Cell
Neighbour GSM Cell
Qhyst1=0 dBAdjgQoffset1=-15 dB
SsearchRAT= 2 (4 dB)
Rs
Qqualmin= -18 dB
SqualsRs
about -100 dBm level in GSM
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How to avoid ping pong ? When phone is camped on 3G, GSM measurements can start when CPICH Ec/Io of
serving cell is below Ssearch_RAT + QqualMin.
When phone is camped on GSM, cell reselection to 3G is possible if CPICH Ec/Io of the candidate is above FDD_Qmin.
Therefore, to avoid ping pongs between 3G and GSM the following condition should be met:
FDD_Qmin >= QqualMin+Ssearch_RAT
QqualMin=-18 dB
Ssearch_RAT=4 dB
CPICH Ec/Io
FDD_Qmin >= -13 dB
QqualMin +Ssearch_RAT
t
Camping on 3G Camping on GSM Camping on 3G
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Chapter 6-Handover Control-
1. What characterises intra frequency WCDMA hard handover?
2. Which handover types are mobile evaluated handovers?
3. What is the difference between soft and softer handover?
4. What conditions must be met, before a cell can be added to the active set?
5. What type of situations initiate inter-frequency handover?