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Friday, June 3, 2011

WCDMA RAN 7 - Handover Types - SIDE 2


The actual Active Set size has been logged when driving a 10-minute route through a pilot-polluted area. The same route was driven four times, each time with different settings for parameters reportingRange1a and reportingRange1b, but keeping the delta between them constant. Parameter maxActiveSet was set to 3 during all measurements. As seen in the figure, the distribution of measurement points having different Active Set sizes change gradually. Using reportingRange1a = 3 [dB] and reportingRange1b = 5 [dB], the average number of cells in the Active Set is expected to have the following distribution: 60% for AS=1, 30% for AS=2, and 10% for AS=3. The highest parameter settings cause the UE to be in soft/softer handover in basically all spots along the route, a situation that is unfavorable for system capacity.
The recommended value for hysteresis1c is 1 dB. A higher value causes a decreased Active Set update rate, that is, a higher CPICH signal is required from a new cell to replace the weakest cell in the Active Set. What would make the Active Set update rate decrease is the reduction of event1c, since event1a and event1b are kept fairly constant. But a higher value of hysteresis1c may cause too late an addition of new cells in the Active Set.
It is important to remember that the measurements used for handover event evaluation are made on the downlink CPICH. This means that using different settings for primaryCpichPower (power assigned to the CPICH) on neighboring cells will create a more complicated situation. Unnecessary destructive interference might be the result in the UL, since the UE will not be power controlled by the weaker cell until it has been added to the Active Set.

12.2 IRAT and IFHO Introduction

The IRAT and IFHO functions are both triggered by coverage. The purpose with both functions is to save the connection by making a HO to either GSM or to another WCDMA frequency, when the coverage on the original WCDMA frequency deteriorates. Instead of dropping, the connection should preferably continue on another WCDMA frequency or in GSM.
To detect deteriorating coverage, the connection quality monitoring uses event 2d and event 6d to trigger bad coverage in DL or UL. When either event is triggered, the UE will start new measurements for either IF or GSM cells, to try to detect a new candidate cell for HO. This usually also involves starting the compressed mode.
The time required for the UE to detect a new cell varies between approximately 2 to 8 seconds, measured from the detection of bad coverage to detection of the new HO candidate cell. This time depends on signal levels UE measurement performance and the length of the neighbor cell lists. To make a reliable HO, instead of dropping the call, the deteriorating coverage must be detected early enough, and the neighbor cell lists should not be longer than necessary. It should be noted that UE measurement performance might also vary between different manufacturers.

12.2.1 Connection Quality Monitoring

Connection quality monitoring is common for both the IRAT and IFHO functions and consists of DL quality measurements based on WCDMA P-CPICH Ec/No and WCDMA P-CPICH RSCP running in parallel, and of UL UE Tx power measurements. The DL trigger, that is, the event 2d thresholds ( usedFreqThresh2dEcno and usedFreqThresh2dRscp + offsets), is set on cell level. If this threshold is set too low, the coverage problem will be detected too late and UE will not have time to do HO measurements and detect a candidate cell before the dropped calls. And if this threshold is set too early, there might be too many triggers, that is, start of compressed mode and users are handed over to GSM or other WCDMA carrier unnecessarily. If there are specific locations in a cell where the coverage falls very quickly, the call will probably drop anyway, since the UE will not have time to perform the measurements and detect a HO candidate cell. Due to the required measurement times, it is difficult to handle this type of situations.

12.2.1.1 Improved HO triggers from P6.0 and onwards

Two new parameters have been introduced in P6.0, serviceOffset2dEcNo and serviceOffset2dRscp. With these parameters, which are configured per RNC and per RAB (UeRc-state), the thresholds for event 2d ( and by that also 2b and 3a thresholds) can be configured differently for different services. If neither IFHO nor IRAT HO is enabled the setting of the parameters has no impact on the network.
The purpose of the parameters is to be able to set the coverage based HO triggers depending on the expected coverage for different services and RABs. The trigger thresholds can be set earlier or later than for speech depending on the expected coverage, which can differ between different services. The offsets can also be used to disable IF and IRAT HO for specific RABs or rates.
Note: This information is valid when upgrading from P5 to a later release.

12.2.1.2 Backward compatibility with P5

If IFHO but not IRAT HO is enabled then the default setting should be used in order to maintain P5 behaviour. The default setting is serviceOffsetEcNo=0 and serviceOffsetRscp=0 for all UeRc states, which will set the same triggering point for all RABs, and not disable any specific RAB or rate.
If IRAT HO but not IFHO is used then the offsets must be set differently in order to maintain the previous system behavior, which only allowed IRAT HO on interactive for the DL rate of 64 kbit/s. To disable IRAT HO for DL interactive rates of 128 and 384 then set serviceOffset2dEcNo=-20 and serviceOffset2dRSCP=-50 for the following RABs (UeRc-states):
6 Interact. PS (64/128 kbps)
7 Interact. PS (64/384 kbps)
18 Interact. PS (128/128 kbps)
30 Interact. PS (384/128 kbps)
31 Interact. PS (128/384 kbps)
32 Interact. PS (384/384 kbps)
For all other UeRc states the default setting can be kept, this will set the same triggering point for all RABs, and disable IRAT HO for the same interactive rates as in previous system releases.
Note: This information is valid when upgrading from P5 to a later release.

12.2.1.3 Tuning the offset parameters for interactive rates

When both IRAT and IF HO are enabled, special considerations must be taken when upgrading from P5 to a later release since complete backward compatibility can not be obtained.
When using a PS interactive connection and moving out of coverage, the DL rate is normally switched down in steps from 384 to 128 and then to 64 kbit/s. IRAT CC was previously never executed until a downswitch to a DL rate of 64 kbit/s was done, but IFHO was previously possible also for other DL rates if bad coverage is triggered.
From a user point of view it is preferred not to make IRAT CC too early. Assuming that the throughput is higher in WCDMA compared to GSM/GPRS, the user should remain in the WCDMA system as long as possible, and not perform IRAT CC while using DL rates of 384 or 128 kbit/s. However there is also a small risk that fast moving UEs will drop the connection before a HO to GSM can be made, if the triggering is delayed until a downswitch to 64 kbit/s has been done. An IFHO is made maintaining the same rate so the same reasoning does not apply, but the IFHO attempt must still be triggered in time so that the call does not drop for coverage reasons.
The 2d thresholds should be set after coverage, the triggering applies to both IF and IRAT, and for PS interactive the offsets can also be set per rate. One strategy is to disable IF and IRAT HO for DL rates of 384 kbit/s, and set the offsets to normal values for DL rates of 128 and 64 kbit/s, ie serviceOffset2dEcNo=-20 and serviceOffset2dRSCP=-50 for the following RABs (UeRc-states):
7 Interact. PS (64/384 kbps)
31 Interact. PS (128/384 kbps)
32 Interact. PS (384/384 kbps)
For other interactive DL rates (64 and 128) the serviceOffset2dEcNo and serviceOffset2dRscp should be tuned in order to obtain wanted behavior. A rule of thumb is to set the offsets a few dB lower than for speech. The exact values depend on many factors, for example that different UE brands behave different.
Note: This information is valid when upgrading from P5 to a later release.

12.2.2 Enabling IRAT or IFHO Functions

The IRAT or IFHO functions can be enabled on cell level. When poor connection quality has been triggered, the type of HO to be attempted is configurable for each cell. Parameters hoType can be set for each cell to GSM_PREFERRED, IFHO_PREFERRED, or to NONE. Parameter hoType set to NONE means that no IRAT or IFHO measurement is initiated from this cell. IRAT and IF HO measurements cannot be done simultaneously for the same UE. The decision whether or not to start GSM or IF measurements, is however based on the settings for parameters hoType and defaultHoType (DRNC cells) for all cells in the Active Set.
Generally, IFHO should be enabled for border cells on an additional carrier, and IRAT HO should be enabled for border cells on the first mainland carrier. IRAT HO could also be enabled for core cells with coverage problems and dropped calls inside the WCDMA system, not just for border cells.
Other strategies could be chosen for special reasons, for example, if there are substantial numbers of UEs that are not standard compliant and do not support IFHO. In this case, IRAT HO could be enabled for the additional carrier border cells instead.
It should be noted that due to Iur standard limitations, the value of parameter hoType cannot be read from DRNC cells. The preferred HO type can still be set for cells in a DRNC, but not for individual cells, only for a carrier frequency. For example, parameter defaultHoType can be set to GSM_PREFERRED for all underlaying WCDMA mainland DRNC cells, and to IFHO_PREFERRED for the additional WCDMA carrier DRNC cells.

12.2.3 General Tuning Procedure

The first step in the general tuning procedure is to locate the WCDMA border cells and the core cells that are coverage limited and decide whether GSM HO or IFHO should be enabled in these core cells to reduce the dropped calls caused by the coverage limitation. For these cells the GSM or the IF neighbor cell lists, or both, should be defined, keeping the lists short if possible and without defining unnecessary neighbor relations.
The next step is to set parameters for the IRAT and IFHO function. The event 2d threshold can be adjusted for each cell, and can be used if an early detection of the coverage problem is necessary in some cells or locations in order to make a successful HO. For example, a cell that has locations where the coverage falls quickly for many users, leading to dropped calls, might need a higher threshold setting for the event 2d.Thresholds event 2f, event 2b (used frequency), and event 3a are relative thresholds to event 2d and will also be for the cell level. The relative parameter values are set on the RNC level.
The purpose of this procedure is to decrease the amount of coverage-generated dropped calls, so that most of these calls instead can continue in GSM or on another WCDMA frequency, but without causing too many false triggers or too many users in compressed mode. Frequent starts and stops of compressed mode always come with a cost in terms of power and hardware resources. The dropped calls should be monitored during these procedures, and the total number of drops for each cell should be calculated before and after the GSM or IFHO function is enabled.

12.3 IRAT Handover

The GSM HO function can be used to reduce dropped calls in areas where the first carrier WCDMA coverage is limited and where there is instead good GSM coverage. The most obvious case is the border cells of the WCDMA system, where WCDMA system coverage ends. GSM HO can also be activated inside the WCDMA system in core cells where there are obvious coverage holes resulting in dropped calls. In cells where it is decided to use GSM HO, parameter hoType should be set to GSM_PREFERRED and GSM neighbor cell lists should be defined.

12.3.1 GSM Neighbor Cell Lists

The UE can measure on a maximum of 32 GSM cells. There are reasons to be restrictive when defining GSM neighbors, and it is recommended to not define GSM neighbors if it is not needed. The time it takes for a UE to find a candidate GSM cell generally increases with longer neighbor cell lists, and keeping the lists short should generally lead to less time in compressed mode and better retainability performance. If the WCDMA coverage falls quickly, the probability of quickly finding a suitable GSM candidate cell will increase if there are fewer GSM cells to measure on.
Note that the introduction of priorities for neighbor cells, as described in Section 12.1.2, are also applicable to IRAT neighbors.

12.3.2 WCDMA to GSM HO Parameters

IRAT evaluation is started if IRAT neighboring cells exist and at least one cell in the Active Set has parameters hoType or defaultHoType set to GSM_PREFERRED and no cell has it set to IFHO_PREFERRED. The IRAT handover evaluation algorithm, evaluates whether IRAT HO (WCDMA RAN to GSM) or IRAT Cell Change should be proposed. IRAT HO or Cell Change decision is based on GSM quality measurements and WCDMA RAN quality measurements.
The parameter thresholds used for start of GSM measurements and IRAT HO can and should be tuned on cell level in the network. To make it easier it is recommended to divide the cells in the network into different types and then apply different set of parameters depending on what type the cell is classified. For example, the cells can be divided into WCDMA border cells and core cells.
The border cells are the last WCDMA cells that have WCDMA coverage before moving into GSM only coverage, the outskirts or transition area of the WCDMA coverage area.
The core cells are the cells inside the WCDMA coverage area of the border cells. The core cells should first be evaluated to determine whether or not they should have IRAT HO activated. The preferred choice for core cells is to have parameter hoType set to NONE if IRAT is not explicitly needed for coverage purposes in the cell. If IRAT HO is needed in a core cell it should, in most cases, have lower thresholds for GSM measurements and IRAT HO as compared to the border cells.
There are of course exceptions to this general classification in the network and cells needing different parameter settings should of course be identified and use different settings for IRAT performance. The decision as to which cells are to be classified as border cells and core cells must also be done and verified locally in the network.
The connection quality monitoring parameters usedFreqThresh2dRscp, usedFreqThresh2dEcno and when UE Tx power reaches maximum power (event 6d) are the thresholds for detecting a coverage problem and triggers start of GSM measurements. The event 2f parameter thresholds of usedFreqRelThresh2fRscp + usedFreqThresh2dRscp, usedFreqRelThresh2fEcno + usedFreqThresh2dEcno and ueTxPowerThresh6b are the thresholds to stop the GSM measurements. The parameter settings are a compromise between higher values, resulting in a larger proportion of the UE’s using compressed mode, and a lower setting, implying less time is available for making the GSM HO if the WCDMA signal drops rapidly.
If excessive triggering of event 2d and event 2f measurement report occurs, hysteresis values can be used together with the GSM measurement thresholds to reduce excessive event triggering of measurement reports. For more information about hysteresis, see Section 3.4
Note that the WCDMA P-CPICH Ec/No measurement quantity is load dependent and may vary up to 6–8 dB between low loaded and high loaded cells. Note also that the UE connection may be UL coverage limited although measured WCDMA P-CPICH Ec/No is high. This will typically happen at WCDMA coverage border areas where there is no inter-cell interference from adjacent WCDMA cells.
The IRAT HO from WCDMA to GSM will be proposed (event 3a occurs) when the WCDMA signal level goes below the values set for parameters utranRelThresh3aRscp + usedFreqThresh2dRscp or utranRelThresh3aEcno + usedFreqThresh2fEcno or utranRelThreshRscp + usedFreqThresh2dRscp + utranRelThresh3aRscp, depending on what measurement quantity started the GSM measurements, and the GSM RSSI level is above gsmThresh3a for a candidate GSM cell.
The condition must be fulfilled during the time to trigger for the event.
The following parameter values can be used initially for the WCDMA border cells (modification due to local radio condition variations not included here).
Start of GSM measurements (if any is fulfilled):
  • usedFreqThresh2dRscp = -105 dBm
  • usedFreqThresh2dEcno = -13 dB
  • Maximum UE Tx power is reached ( txPowerConnQualMonEnabled = TRUE)
Stop of GSM measurements (if all are fulfilled):
  • usedFreqRelThresh2fRscp + usedFreqThresh2dRscp = -102 dBm
  • usedFreqRelThresh2fEcno + usedFreqThresh2dEcno = -11 dB
  • ueTxPowerThresh6b = 18 dBm
Triggering IRAT HO or Cell Change execution:
  • utranRelThresh3aRscp + usedFreqThresh2dRscp = -105 dBm
  • utranRelThresh3aEcno + usedFreqThresh2dEcno = -13 dB
  • utranRelThreshRscp + usedFreqThresh2dRscp +
    utranRelThresh3aRscp = -100 dBm
  • gsmThresh3a = -95 dBm
A minimum setting for parameter gsmThresh3a would be -102 dBm. However, it is recommended to use a setting of the initial signal strength limit in the GSM cell to parameter gsmThresh3a = -95 dBm. The setting defines the typical minimum acceptable cell-planned RSSI level for the GSM cell, and should assure that an IRAT HO is not made to a GSM cell when coverage is about to be lost. However, good quality in the GSM cell is not assured by a signal strength limit, interference could also have an impact.
The parameter settings given here are the recommended initial values for WCDMA border cells. The final setting of IRAT parameters for border cells and core cells should be done after evaluating IRAT, WCDMA, and GSM performance together to find to most suitable settings for the given radio environment in the area to optimize the user experienced performance.


12.3.3 GSM to WCDMA Handover Parameters

Parameters in GSM and WCDMA should be aligned so that the desired IRAT HO behavior is achieved and ping-pong handovers are avoided. There is still a small risk of ping-pong behavior since the HO might be triggered differently from the respective system. For example, WCDMA to GSM HO might be triggered using RSCP, while GSM to WCDMA HO might be triggered by load and Ec/No. See User Description, GSM-UMTS Cell Reselection and Handover, 208/1553-HSC 103 12/7, Reference [4] for extensive information on GSM to WCDMA HO.
The key parameters controlling handovers from GSM to WCDMA are parameters QSC, ISHOLEV, and MRSL.
Parameter QSC defines when WCDMA neighbors will be monitored for handover. The parameter is set for each GSM cell. It can be set in four alternative ways, so that WCDMA neighbors are monitored as follows:
  1. always
  2. never
  3. when signal strength of the GSM cell is above a threshold
  4. when signal strength of the GSM cell is below a threshold
When deciding the setting of parameter QSC, take into account whether or not WCDMA and GSM sites are co-sited.
For WCDMA and GSM co-sited cells, parameter QSC could be set to ”always” or “when signal strength of GSM cell is above a threshold” making sure that the WCDMA cell is evaluated when well inside the GSM cell. For non co-sited cells, parameter QSC can be set to “always” or “when signal strength of GSM cell is below a threshold” making sure that the WCDMA cell is evaluated when at the GSM cell border.
When measurements on WCDMA have begun, two criteria must be fulfilled for a GSM to WCDMA IRAT HO to happen.
  • Percentage of idle traffic channels (TCH) in the serving cell <= ISHOLEV
The first criteria will be fulfilled when the percentage of idle traffic channels (TCH) in GSM is lower than or equal to the value of parameter ISHOLEV, which is set for each GSM cell. When the first criterion is fulfilled, the second criterion is tested separately for each neighboring WCDMA cell. The WCDMA neighbors having a measured Ec/No higher than the value of parameter MRSL are added to the handover candidate list.
If one intends to avoid the handovers from GSM to WCDMA to be triggered by percentage of idle traffic channels (TCH) in GSM the parameter ISHOLEV can be set to 99, which corresponds to a load higher than 1%. In practice, this turns that criterion off, and WCDMA would then be prioritized all the time when being measured. A setting of parameter ISHOLEV of 20, would only initiate an IRAT HO when the percentage of idle traffic channels is below 20% (that is, corresponding to a load higher than 80%). IRAT HO to WCDMA will take place as soon as the WCDMA P-CPICH Ec/No exceeds the value set for parameter MRSL. The value of parameter MRSL should be set so that an IRAT HO to WCDMA does not result in a ping-pong handover back to GSM. It may also be preferred not to start GSM measurements immediately when arriving in WCDMA. The following relation should avoid this:
MRSL > usedFreqThresh2dEcno + an hysteresis
If Ec/No is the most commonly triggered measurement quantity for event 2d and event 3a, then a suggested initial setting for parameter MRSL could be -9 dB. If RSCP is instead the most commonly triggered measurement quantity on the WCDMA side, it is not possible to compute the relation as above, and it is suggested to set parameter MRSL to -6 dB. This setting means that a higher WCDMA quality is required before the HO is attempted.
Depending on operator policy, the GSM to WCDMA HO could also be triggered by load in the GSM cell, by using parameter ISHOLEV. The default value of parameter ISHOLEV is 20%.
With the feature Combined Handover Triggering GSM to WCDMA it is possible to control the measurement reporting of WCDMA neighbouring cells. If the feature is enabled the parameter FDDREPTHR2 defines a threshold for the non reporting radio entity of the WCDMA cells. No WCDMA cells will be included in the measurement reports from the MS unless the non reporting WCDMA radio entity is above the defined threshold. Since WCDMA cells are reported using the radio entity CPICH Ec/No, the parameter FDDREPTHR2 is related to the WCDMA radio entity CPICH RSCP.
The threshold parameter FDDREPTHR2 assures a sufficient downlink signal strength of the UTRAN cell, which in turn increases the possibility for the mobile to reach the WCDMA cell in the uplink. The threshold parameter FDDREPTHR2 is used by MSs being in connected mode as well as MSs being in NC2 mode.
The setting of the FDDREPTRH2 parameter shall be set so that a handover to WCDMA is not immediately followed by a "ping-pong" handover back to GSM and to avoid starting GSM measurements directly when entering WCDMA if IRAT handover is enabled in both directions. This is achieved if the FDDREPTHR2 parameter has the following relation to the WCDMA parameter usedFreqThresh2dRscp:
FDDREPTHR2 > usedFreqThresh2dRscp + a hysteresis.
A recommended setting of -100dBm fulfills the relations above using a typical setting of the WCDMA parameter usedFreqThresh2dRscp.

12.3.4 WCDMA to GSM Cell Change for PS Interactive Services

The WCDMA to GSM cell change for PS interactive services normally experience quite long outage times before the session can be reestablished on the GSM side. There are no normal tuning activities that can be performed in the radio network to shorten this time.
The outage time can be divided into two parts.
The first radio outage part depends largely on the UE and consists of the time it takes for the UE to reselect to the GSM cell and then perform LA and RA updates. This typically takes 8–10 seconds.
The second part is the application outage that depends on the application, the protocol, and on the TCP/IP procedures, before the application is running normally again. For some applications, like FTP download, this time could be, in the worst case, around 10 seconds.

12.3.5 GSM to WCDMA Cell Reselection for PS Interactive Services

When a UE in GSM is in packet transfer mode, it is the idle mode cell reselection parameters that control when the IRAT cell reselection to WCDMA will take place. Therefore, it is necessary to also verify the idle mode settings in GSM to have a good coexistence between WCDMA and GSM for packet data connections.

12.4 IFHO

IFHO is needed when an additional WCDMA carrier is introduced in the system. If this additional carrier is introduced in a hot spot or in a limited cluster of cells, then IFHO is needed where the coverage of the additional carrier ends. Users that are connected to the additional carrier, when moving out of coverage, should then make an IFHO to the underlaying carrier. In cells where IFHO is to be used, parameter hoType should be set to IFHO_PREFERRED, and IF neighbor cell lists should be defined.
The function assumes that all UEs support IFHO within the same frequency band, according to the 3GPP standard. The UE capability information can only be used to determine whether or not the UE needs compressed mode when performing the IF measurement. If there are UEs present, which are not standard compliant and do not support IFHO, they will drop the connection if they move out of coverage of the additional carrier.
The function for distribution of traffic and load evenly between carriers is described in Idle Mode and Common Channel Behavior and in Load Sharing. These references give details about how the problem with the standard non-compliant UEs can be reduced, and also how the encoded message length of System Information Block type 11 (SIB11), carrying all neighbor cell information, will increase when some idle mode parameters are changed to other values than default. This has implications on the number of neighbors to be defined.

12.4.1 IFHO Neighbor Cell Lists

The UE can measure on a maximum of 32 IF cells, and on a maximum of two other non-used inter-frequencies. When an additional carrier is introduced in clusters of co-located cells, the initial IF neighbor list for the additional cell could be defined by copying the corresponding neighbor list from the co-located underlaying cell and adding the co-located neighbor.
However, if the coverage for the IF cell deteriorates quickly and it is important that the IFHO can be performed fast, then the IF neighbor lists should be as short as possible. The time it takes for a UE to find a candidate IF cell generally increases with longer neighbor cell lists, and keeping the list short should generally lead to less time in compressed mode and better retainability performance.
When a second carrier is deployed as a hotspot cell, two-way neighbor cell relationships should be defined only between the underlaying f1 cell and the overlaying f2 cell. One-way neighbor cell relationships are defined from the f2 cell to all the surrounding f1 cells. The main benefits with this setup are the elimination of IFHO from the surrounding f1 cell to the f2 cell, the decreased risk of CPM starts in the f1 layer, and the shorter neighbor lists. With one-way definitions, all surrounding f1 cells become blind to the f2 cell.
It should also be noted that the P-CPICH power settings should initially be set to the same values for the f2 cells as for the co-located f1 cells. The f2 to f2 neighbor lists for the second carrier cells could also initially be determined by using the f1 neighbor lists for the corresponding co-located cells.
The same principles with neighbor lists and power settings are also valid for carriers f3 and f4.
There are no main differencies between adding a carrier to a single WCDMA carrier system and adding a fourth carrier to a three WCDMA carrier system. However no more than two of the three carriers should be defined as neighbors in any case, since the UE should not support more than two other frequencies according the 3GPP specifications. Mobility across four carriers can still be achieved by making sure the non-used frequencies has IF neighbors defined between each other. This will result in that all carriers can be reached, but in some cases it takes two IFHO to go from one carrier to another.
Note that the introduction of priorities for neighbor cells, as described in Section 12.1.2, are also applicable to IFHO neighbors.

12.4.2 IFHO Parameters

The IFHO evaluation is started if IFHO neighboring cells are configured and at least one cell in the Active Set has parameter hoType or parameter defaultHoType set to IFHO_PREFERRED. The IFHO evaluation algorithm evaluates whether Inter-Frequency measurement will be started and based on those measurements and whether IFHO execution should be done.
The connection quality monitoring parameters usedFreqThresh2dRscp, usedFreqThresh2dEcno, and when UE Tx power reaches maximum power (event 6d) are the thresholds for detecting a coverage problem and triggers start of IF measurements. The event 2f parameter thresholds of usedFreqRelThresh2fRscp + usedFreqThresh2dRscp, usedFreqRelThresh2fEcno + usedFreqThresh2dEcno, and ueTxPowerThresh6b are the thresholds to stop IF measurements. The parameter settings are a compromise between higher values, resulting in a larger proportion of the UE’s using compressed mode, and a lower setting, implying less time is available for making the IF handover if the WCDMA signal drops rapidly.
If excessive triggering of event 2d and event 2f measurement report occurs, hysteresis values can be used together with the IF measurement thresholds to reduce excessive event triggering of measurement reports. For more information about hysteresis, see Section 3.4
Note that WCDMA P-CPICH Ec/No measurement quantity is load dependent and may vary up to 6–8 dB between low loaded and high loaded cells. Note also that the UE connection may be UL coverage limited although measured CPICH Ec/No is high. This will typically happen at WCDMA coverage border areas where there is no inter-cell interference from adjacent WCDMA cells.
The IFHO from one WCDMA carrier to another will then be proposed (event 2b occurs) when the current signal level goes below the value set for parameters usedFreqRelThresh4_2bRscp + usedFreqThresh2dRscp or usedFreqRelThresh4_2bEcno + usedFreqThresh2dEcno or utranRelThreshRscp + usedFreqThresh2dRscp + usedFreqRelThresh4_2bEcno, and the level in the target IF cell is above the value set for parameters nonUsedFreqThresh4_2bRscp or nonUsedFreqThresh4_2bEcno , depending on what measurement quantity that started the IF measurements.
The condition must be fulfilled during the time to trigger for the event.
The following parameter values can be used initially for WCDMA border cells:
Start of IF measurements (if any is fulfilled):
  • usedFreqThresh2dRscp = -105 dBm
  • usedFreqThresh2dEcno = -13 dB
  • Maximum UE Tx power is reached ( txPowerConnQualMonEnabled = TRUE)
Stop of IF measurements (if all are fulfilled):
  • usedFreqRelThresh2fRscp + usedFreqThresh2dRscp = -102 dBm
  • usedFreqRelThresh2fEcno + usedFreqThresh2dEcno = -11 dB
  • ueTxPowerThresh6b = 18 dBm
Triggering IFHO execution:
  • usedFreqRelThresh4_2bRscp + usedFreqThresh2dRscp = -105 dBm
  • usedFreqRelThresh4_2bEcno + usedFreqThresh2dEcno = -13 dB
  • utranRelThreshRscp + usedFreqThresh2dRscp +
    usedFreqRelThresh4_2bEcno = -100 dBm
  • nonUsedFreqThresh4_2bRscp = -100 dBm
  • nonUsedFreqThresh4_2bEcno = -10 dB
The IFHO from one WCDMA carrier to another will then be proposed (event 2b occurs) when the current signal level goes below the used frequency threshold, and the level in the target IF cells is above the non-used frequency threshold.
The thresholds for the target non-used frequency could be set as a minimum acceptable quality, for example RSCP -105 dBm or Ec/No -13 dB. But this low setting might lead to that a new event 2d, compressed mode, and an IFHO attempt is immediately triggered after the IFHO to the new frequency. To avoid this, the target minimum quality could be set higher, for example RSCP -100 dBm or Ec/No -10 dB. Since only the event 2d thresholds can be set for each cell, these non-used frequency IFHO thresholds have to be set considering all cells where IFHO is enabled.

12.5 Service-Based Handover

Service Based Handover forces UE on dedicated channels using a “speech only” service, to move from WCDMA RAN coverage to GSM network coverage; thus allowing the operator to redirect speech users to GSM using a Service Indicator (SI) that can be set for each subscriber.
For service based handover to be initiated in a cell, parameter hoType in the particular cell must be set to GSM_PREFERRED or IFHO_PREFERRED. If parameter hoType is set to NONE, no service based handover to GSM attempt will be initiated. If service based handover to GSM is to be used in all cells, IRAT activity cannot be turned off by setting parameter hoType to NONE. Instead lower IRAT thresholds for event 2d and event 3a must be deployed in the cells to minimize GSM measurements and IRAT HO.

12.6 HSDPA Mobility Phase 1 and 2

It should be noted that all descriptions and recommendations given in this section are valid for both HSDPA Mobility Phase 1 and 2.
When the UE moves between cells that are HSDPA enabled (that is, when hsdpaCapability = HSDPA_CAPABLE), the HSDPA connection is maintained by means of the serving HS-DSCH cell change functionality, shortly, HS cell change.
HS-DSCH does not use soft handover as the dedicated channels (DCH) do. There is a trade-off between optimizing the radio quality of HS-DSCH (that is, frequent enough cell changes) and minimizing the impact on throughput at cell change (that is, as few cell changes as possible).

12.6.1 Serving cell change

Serving HS cell change is made between AS cells, which have A-DCH connections, and it is triggered by the soft/softer handover evaluation of A-DCH.
HS cell change is evaluated only if parameter hsCellChangeAllowed is set to TRUE. Its default value is FALSE. It is important not to forget to enable HS cell change by using this parameter, since keeping the default value causes throughput degradation and extra signaling for a moving UE. If this parameter is set to FALSE and the UE moves away from its current cell, then RNC will attempt to reconfigure to DCH instead.
The reconfiguration triggered by poor connection quality must not be enabled, except when HSDPA is deployed on both the first and the second carrier, and IFHO via reconfiguration to DCH is triggered. The reason being that coverage of HSDPA, enabling higher throughput than DCH and its associated compressed mode procedures, is at least as good as DCH. A HSDPA connection being maintained at the cell border would experience superior throughput performance on HSDPA compared with being reconfigured to DCH. The outage time is only slightly shorter when being reconfigured to DCH, and the IFHO is performed. In the IRAT case, the HSDPA coverage can really be limited in border cells if event 2d is tuned for speech service and IRAT when hsToDch.poorQualityDetected is enabled. The UE leaves HSDPA coverage for GSM too early and experience lower throughput.
In summary, the following recommendation on multi-valued parameter hsToDchTrigger is:
  • poorQualityDetected = OFF, except when HSDPA is deployed on both the first and the second carrier
The UE measurement criterion for HS cell change is determined by parameter hsQualityEstimate. It is recommended to keep the default value of this parameter, which is CPICH_RSCP, instead of CPICH_Ec/No, in order to have a more stable behavior (avoiding ping-pong situations) as CPICH RSCP is not load dependent and fluctuates less than Ec/No.
Another reason for avoiding CPICH_Ec/No as a quality measurement is that Ec/No degrades in cells carrying HSDPA traffic: after an HS cell change, Ec/No of the old serving HS cell improves whereas that of the new serving HS cell suddenly becomes worse. This might cause undesired ping-pong behavior.
A-DCH soft/softer HO evaluation is performed as for DCH except that there is a new event called 1d HS that is similar to event 1d but with a new set of parameters, namely hsHysteresis1d and hsTimeToTrigger1d, and with a new measurement quality, CPICH RSCP. When the CPICH RSCP of a cell in the AS becomes stronger than the best cell’s CPICH_RSCP + hsHysteresis1d/2, event 1d HS occurs, which means that the best cell is replaced by a new best cell.
The reason for having a separate event 1d HS is to be able to get UE reports triggered by AS cells only and to be able to use a different quality measurement with different parameter values than the ones used for the soft handover event 1d.
Serving HS cell change can be triggered by event 1d HS, event 1b, or event 1c. Note that event 1d HS is based on hsQualityEstimate = CPICH_RSCP measurements by default, whereas events 1b and 1c are based on measQuantity1, which is by default CPICH_Ec/No.

12.6.2 General Remarks

Results from field measurements have shown an Ec/No degradation in cells carrying HSDPA traffic. In the worst case, when measuring in the same good radio environment as the HSDPA UE is placed, degradation in the order of a couple of dB can be experienced. When measuring the degradation close to the cell border, where the fluctuations in Ec/No can impact handover and cell reselection, values in the order of only 1dB or less are measured. This last scenario is the only one potentially impacting traffic distributions in the cell and surrounding neighbors, and therefore the most relevant. The minor Ec/No fluctuations could have an impact on cell borders and consequently on all functions having Ec/No as triggering criterion, in networks where HSDPA is deployed on the same frequency as R99. This could in some cases lead to the Ec/No threshold for IF measurements and GSM measurements being modified in affected cells to a lower level, in order to avoid unnecessary triggering due to fluctuating Ec/No levels from HSDPA load in the network.

12.7 HSDPA and EUL Mobility

It should be noted that all descriptions and recommendations given in this section are valid for HSDPA Mobility Phase 1 and 2 combined with EUL.

12.7.1 Serving Cell Change

EUL serving cell and HSDPA serving cell are identical, and determined by the same mobility event 1d HS.
For the uplink throughput, the Ec/No triggering of event 1d HS (parameter hsQualityEstimate) shows slightly better throughput generally in field tests. This is not surprising, since the scheduler grants bit rate based on the “load” quantity, which is directly dependent on interference, that is Ec/No. The highest throughput is obtained by a fast setting of the triggering parameters hsHysteresis1d and hsTimeToTrigger1d and Ec/No triggering.
Note that the consideration above does not regard the downlink. Event 1d HS controls change of serving cell, which is valid for downlink as well as uplink. The HSDPA downlink data channel, HS-DSCH, cannot operate in soft handover. Therefore, and ideally, HSDPA would like a slow setting of the serving cell change to minimize the number of downlink channel reconfigurations. Each cell change produces a short transmission gap in the downlink. EUL, on the other hand, which indeed operates in soft handover, needs a fast setting to optimize throughput. The highest uplink throughput is obtained by the best cell from the uplink point of view, which is not always identical to the serving cell, which is determined from downlink measurements in the UE. EUL needs a relatively fast triggering of serving cell change to counteract these effects.
Thus, to properly optimize the parameters controlling event 1d HS, HSDPA as well as EUL need to be considered. Meanwhile, the default setting shows adequate performance.

12.7.2 Leaving EUL Coverage

An extremely “slow” setting of the parameters for 1d RNC will make the connection drag well into the non-EUL capable cell before that cell is brought into the active set. The UE output power will increase. On the other hand, the fact that the connection is retained longer on an E-DCH means that the higher throughput potential on E-DCH can be utilized and maintained longer.
If all sites are EUL enabled, 1d RNC need only happen at RNC borders. The setting of the 1d RNC parameters might then need to consider the general mobility strategy. From a pure EUL perspective, a “fast” setting of the parameters for 1d RNC is recommended in case hsToDchTrigger.servHsChangeInterRnc is set to OFF. Such a configuration makes EUL pick up again as soon as possible on the other side of the RNC border. If hsToDchTrigger.servHsChangeInterRnc is set to ON, a “slow” setting is recommended so that EUL is maintained longer.
A proper setting of the parameters is a balance between the increased interference and the higher throughput potential on E-DCH. It is recommended to let the concern about interference be the determining factor for the setting. Thus the default setting, which is a fast setting, is recommended. Note that the downlink also needs to be considered when choosing values for parameter hsToDchTrigger.

13 Parameters

This section lists the parameters that affect the behavior of the handover algorithms and functions. Some of them are radio network parameters, allowing the operator to manage the behavior of these functions in the whole radio network. Others relate to quantities connected to individual cells, allowing management of behavior at cell level. To change the default value of a parameter, the operator must use OSS-RC. See Radio Network Parameters (86/1553–HSD 101 02/7) for the corresponding OSS-RC parameter window and name.
Unless specifically stated, the parameter setting is valid for all cells and relations in an RNC.
cnhhoSupp
[CNHHO Support]
Description: Indicates whether the CNHHO is activated in the RNC. It applies for both Source and Target RNC.
Range: FALSE; TRUE
Default: FALSE
Resolution: Not Applicable
cellCapability
HS and EUL Iur mobility
Description: Defines for External Utran Cells if this DRNC cell supports HSDPA, both EUL and HSDPA, or also EUL 2 ms TTI. If edchSupport is set to On then hsdschSupport must also be set to On.
Range: hsdschSupport On / Off
edchSupport On / Off
edchTti2Support On/Off
Default: Off
Resolution: Not Applicable
cellCapabilityControl
HS and EUL Iur mobility
Description: Defines for each Iur link if the DRNC supports HSDPA, both EUL and HSDPA, or also EUL 2 ms TTI. If edchSupport is set to On then hsdschSupport must also be set to On.
Range: hsdschSupport On / Off
edchSupport On / Off
edchTti2Support On/Off
Default: Off
Resolution: Not Applicable
defaultHoType
[Handover type per DRNC per carrier
Description: Indicates per carrier for DRNCs if GSM HO, IFHO or no HO shall be attempted, in case both Inter-RAT HO, and Inter-Frequency HO are possible. This parameter can be defined for each DRNC and each used carrier, together with freqBand and uarfcnDl. If not defined a default value of GSM_PREFERRED is used.
Range: IFHO_PREFERRED; GSM_PREFERRED; NONE
Default: GSM_PREFERRED
Resolution: Not Applicable
event1dRncOffset
[event1dRncOffset]
Description: Specifies how much stronger than the serving cell that the 1a/1c event reports from a cell that does not have the same EUL capability must be to trigger the calculated event.
Range: -25 to 25
Default: 0
Resolution: 1
event1dRncThreshold
[event1dRncThreshold]
Description: Specifies how many 1a/1c event reports for the same cell that does not have the same EUL capability that must be received to trigger the calculated event.
Range: 0..60
Default: 4
Resolution: 1
fddGsmHOSupp
[FDD GSM handover support]
Description: Indicates if the RNC supports Inter-RAT Handover.
Range: FALSE; TRUE
Default: FALSE
Resolution: Not Applicable
fddIFHOSupp
[FDD Inter-Frequency handover support]
Description: Indicates if the RNC supports Inter-Frequency Handover.
Range: FALSE; TRUE
Default: FALSE
Resolution: Not Applicable
filterCoefficient1
[Filter Coefficient for 1.x events]
Description: Coefficient for layer 3 filtering before intra- frequency reporting evaluation.
Range: 0...9, 11, 13, 15, 17, 19
Default: 2
Resolution: 1
filterCoefficient2
[Filter Coefficient for 2.x events]
Description: Coefficient for layer 3 filtering before inter- frequency reporting evaluation.
Range: 0...9, 11, 13, 15, 17, 19
Default: 2
Resolution: 1
filterCoeff4_2b
[Filter Coefficient for measurement 4 event 2b]
Description: Coefficient for layer 3 filtering before inter- frequency reporting evaluation, for measurement 4 event 2b.
Range: 0...9, 11, 13, 15, 17, 19
Default: 2
Resolution: 1
filterCoeff6
[Filter Coefficient for 6d/6b events]
Description: Coefficient for layer 3 filtering before UE internal measurement reporting evaluation.
Range: 0...9, 11, 13, 15, 17, 19
Default: 19
Resolution: 1
freqBand
[Frequency band per RNC per carrier
Description: Indicates per carrier what 3GPP frequency band it belongs to. Should be defined if the system is using more than one Band.
Range: 0..22.
0 = Not defined
1 = 3GPP Band I
2 = 3GPP Band II
3 = 3GPP Band III
4= 3GPP Band VI Note !
5 = 3GPP Band IV Note !
6 = 3GPP Band V Note !
7 = 3GPP Band VII
8..22 = 3GPP Band VII — Band XXII
Default: 0
Resolution: Not Applicable
gsmAmountPropRepeat
[GSM amount proposal repeat]
Description: Maximum number of repeated proposals (not including the first proposal) of GSM cells for handover based on the same MEASUREMENT REPORT.
Range: 0 – 25
Default: 4
Resolution: 1
gsmFilterCoefficient3
[GSM Filter Coefficient for 3a event]
Description: Coefficient for layer 3 filtering of GSM quality before inter-RAT reporting evaluation.
Range: 0...9, 11, 13, 15, 17, 19
Default: 1
Resolution: 1
gsmPropRepeatInterval
[GSM proposal time interval]
Description: Minimum time interval between proposals of the same GSM cell for handover based on the same MEASUREMENT REPORT.
Range: 0 – 5 s
Default: 1.0 s
Resolution: 0.2 s
gsmThresh3a
[GSM threshold 3a]
Description: Threshold for event 3a (the estimated quality of the currently used WCDMA RAN frequency is below a certain threshold and the estimated quality of the GSM system is above a certain threshold) for GSM.
Range: Range is valid for GSM carrier RSSI. -115 – 0 dBm
Default: -102 dBm
Resolution: 1 dBm
hoType
[Handover Type]
Description: Indicates if Inter-RAT HO, Inter-Frequency Handover, or None shall be evaluated in case both Inter-RAT HO and Inter-Frequency HO are possible.
Range: IFHO_PREFERRED; GSM_PREFERRED; NONE
Default: GSM_PREFERRED
Resolution: Not Applicable
Scope Cell
hsCellChangeAllowed
[HS Cell Change Allowed]
Description: Turns serving HS-DSCH Cell Change on or off.
Range: FALSE; TRUE
Default: FALSE
Resolution: N/A
hsHysteresis1d
[HS Hysteresis 1d]
Description: Sets the event 1d HS hysteresis value specific for HS-DSCH connections.
Range: 0 – 7.5dB
Default: 1 dB
Resolution: 0.1 dB
hsQualityEstimate
[HS Quality Estimate]
Description: Indicates whether it is CPICH Ec/No or CPICH RSCP that should be used for indicating "best cell" for HS-DSCH Cell Change.
Range: Enum {CPICH Ec/No, CPICH RSCP}
Default: CPICH RSCP
Resolution: N/A
hsTimeToTrigger1d
[HS Time To Trigger 1d]
Description: Sets the event 1d HS Time to Trigger value specific for HS-DSCH connections.
Range: 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000
Default: 640 ms
Resolution: Not Applicable
hsToDchTrigger
[HS to DCH trigger allowed]
Description: Multi-valued parameter that allows or disables transitions to DCH for different trigger cases: changeOfBestCellIntraRnc, poorQualityDetected, servHsChangeIntraRnc, servHsChangeInterRnc, changeofBestCellInterRnc.
Range: ON=1; OFF=0
Default: OFF
Resolution: Not Applicable
hysteresis1a
[Hysteresis 1a]
Description: Hysteresis used for event 1a.
Range: 0 — 7.5 dB
Default: 0 dB
Resolution: 0.5 dB
Note: This parameter is NOT OSS-RC GUI supported.
hysteresis1b
[Hysteresis 1b]
Description: Hysteresis used for event 1b.
Range: 0 — 7.5 dB
Default: 0 dB
Resolution: 0.5 dB
Note: This parameter is NOT OSS-RC GUI supported.
hyst4_2b
[Hysteresis 2b]
Description: Hysteresis used for event 2b supporting Inter-Frequency evaluation.
Range: 0 – 7.5 dB
Default: 1 dB
Resolution: 0.1 dB
hysteresis1c
[Hysteresis 1c]
Description: Hysteresis used in replacement threshold in evaluation criteria for event 1c.
Range: 0 – 7.5 dB
Default: 1 dB
Resolution: 0.5 dB
hysteresis1d
[Hysteresis 1d]
Description: Hysteresis used in replacement threshold in drop window in evaluation criteria for event 1d.
Range: 0 – 7.5 dB
Default: 7.5 dB
Resolution: 0.5 dB
hysteresis2d
[Hysteresis 2d]
Description: Hysteresis used for event 2d.
Range: 0 – 14.5 dB
Default: 0 dB
Resolution: 0.5 dB
hysteresis2f
[Hysteresis2f]
Description: Hysteresis used for event 2f.
Range: 0 – 14.5 dB
Default: 0 dB
Resolution: 0.5 dB
hysteresis3a
[Hysteresis 3a]
Description: Hysteresis used for event 3a.
Range: 0 – 7.5 dB
Default: 0 dB
Resolution: 0.5 dB
ifHoAmountPropRepeat
[Inter-Frequency HO amount proposal repeat]
Description: Maximum number of repeated proposals of non-used frequency cell(s) for handover based on the same MEASUREMENT
REPORT, not including the first attempt.
Range: 0 – 25
Default: 4
Resolution: 1
ifHoPropRepeatInterval
[Inter-Frequency HO proposal time interval]
Description: Minimum time interval between proposals of the same non-used frequency cell for handover based on the same MEASUREMENT REPORT.
Range: 0 – 5 s
Default: 1.0 s
Resolution: 0.2 s
individualOffset
[Cell Individual offset, serving cell]
Description: Cell parameter. The offset is added to the measured quantity before the UE evaluates whether an event has occurred. Improper use of non-default values may result in instability and unequal cell borders.
Range: -10 – 10 dB
Default: 0 dB
Resolution: WCDMA RAN cells: 0.5 dB
Scope Cell
individualOffset
[Cell Individual offset, adjacent WCDMA cell]
Description: Cell parameter. The offset is added to the measured quantity before the UE evaluates whether an event has occurred. Improper use of non-default values may result in instability and unequal cell borders.
Range: -10 – 10 dB
Default: 0 dB
Resolution: 0.5 dB
Scope Cell
individualOffset
[Cell Individual offset, adjacent GSM cell]
Description: Cell parameter. The offset is added to the measured quantity before the UE evaluates whether an event has occurred. Improper use of non-default values may result in instability and unequal cell borders.
Range: -5 – 5dB
Default: 0 dB
Resolution: 0.5 dB
Scope Cell
intraFreqCnhhoPenalty
[Intra Frequency CNHHO penalty]
Description: Defines the 'penalty' given to a 'Non-Iur External UTRAN' cell compared to a normal intra-frequency cell for the event 1a, 1c and 1d.
Range: 0 – 25.0 dB
Default: 3 dB
Resolution: 0.5 dB
intraFreqCnhhoWeight
[Intra Frequency CNHHO weight]
Description: Scale number that defines the weight of the radio links in the active set, when comparing them to an intra-frequency CNHHO candidate. intraFreqCnhhoWeight=0 means that only the best cell in AS is considered, intraFreqCnhhoWeight>0 means that all radio links in the active set are considered, while intraFreqCnhhoWeight=1 means that all radio links in the active set are given equal importance.
Range: 0 – 1
Default: 0
Resolution: 0.1
interFreqCnhhoPenaltyEcno
[Inter Frequency CNHHO penalty Ec/No]
Description: Defines how much penalty is given to a 'Non-Iur External UTRAN' cell compared to a normal inter-frequency cell during Ec/No evaluation.
Range: 0 – 25.0 dB
Default: 3 dB
Resolution: 0.5
interFreqCnhhoPenaltyRscp
[Intra Frequency CNHHO penalty RSCP]
Description: Defines how much penalty is given to a 'Non-Iur External UTRAN' cell compared to a normal inter-frequency cell during RSCP evaluation.
Range: 0 – 25.0 dB
Default: 3 dB
Resolution: 0.5
maxActiveSet
[Max. cells in Active Set]
Description: Maximum number of cells allowed in the Active Set. Used in the RNC evaluations of event 1a, 1c, and 1d. If the number of cells in the Active Set is equal to maxActiveSet, the handover evaluation algorithm proposes a cell replacement (event 1c and 1d); otherwise, it proposes a cell addition (event 1a).
Range: 2 – 4
Default: 3
Resolution: 1
maxIefMonSubset
[Maximum IEF monitored subset]
Description: Maximum number of inter-frequency WCDMA RAN cells that the UE will measure on.
Range: 1 – 32
Default: 32
Resolution: 1 cell
maxGsmMonSubset
[Maximum GSM monitored subset]
Description: Maximum number of GSM cells that the UE will measure on.
Range: 1 – 32
Default: 32
Resolution: 1 cell
measQuantity1
[Meas. Quantity]
Description: Defines the measurement quantity for intra-frequency reporting evaluation.
Range: Enum {CPICH Ec/No, CPICH RSCP}
Default: CPICH Ec/No
Resolution: N/A
nonUsedFreqThresh4_2bEcno
[non-used frequency threshold for event 2b CPICH Ec/No]
Description: Threshold for event 2b for the non-used frequency when measurement quantity is Ec/No.
Range: -24 dB – 0 dB, Range is valid for CPICH Ec/No
Default: -13 dB
Resolution: 1dB
nonUsedFreqThresh4_2bRscp
[non-used frequency threshold for event 2b CPICH RSCP]
Description: Threshold for event 2b for the non-used frequency when measurement quantity is RSCP.
Range: -115 dBm – 25 dBm, Range is valid for CPICH RSCP
Default: -105 dBm
Resolution: 1 dBm
nonUsedFreqThreshW4_2b
[non-used frequency threshold for event 2b weighting factor]
Description: Weighting factor for event 2b for the non-used frequencies.
Range: 0.0 ... 2.0
Default: 0.0
Resolution: 1
releaseConnOffset
[Release Connection Offset]
Description: If UE enters a new cell area, and the quality Ec/No of the new cell is ReleaseConnOffset dB above the quality of the best cell in the Active Set, and for any reason, the new cell cannot be included in the Active Set, then the call shall be released.
The reason is that it is not permitted to stay (with an established connection) in a cell area without being power controlled by the cell serving that area. The UE may cause interference in the uplink.
Range: -3 — +25 dB
Default: 12 dB
Resolution: 0.5 dB
Note: This parameter is NOT OSS-RC GUI supported.
reportingInterval1a
[Reporting interval 1a]
Description: Time between periodic reports at event-triggered periodic reporting for event 1a.
Range: No reporting; 0.25; 0.5; 1; 2; 4; 8; 16
Default: 1 s
Resolution: Not Applicable
Note: This parameter is NOT OSS-RC GUI supported.
reportingInterval1c
[Reporting interval 1b]
Description: Time between periodic reports at event-triggered periodic reporting for event 1c.
Range: No reporting; 0.25; 0.5; 1; 2; 4; 8; 16
Default: 1 s
Resolution: Not Applicable
Note: This parameter is NOT OSS-RC GUI supported.
reportingRange1a
[Reporting range 1a]
Description: Relative threshold referred to the CPICH of the best cell in the Active Set used as evaluation criteria for event 1a (a primary CPICH enters the reporting range).
Range: 0 – 14.5 dB
Default: 3.0 dB
Resolution: 0.5 dB
reportingRange1b
[Reporting range 1b]
Description: Relative threshold referred to CPICH of the best cell in the Active Set used as evaluation criteria for event 1b (a primary CPICH leaves the reporting range).
Range: 0 – 14.5 dB
Default: 5.0 dB
Resolution: 0.5 dB
selectionPriority
[Selection Priority]
Description: Defines the priority for a neighbor cell. 1 is the highest priority, ie most important neighbor, while a large number means a low priority. If no value or a value of 0 is entered when a neighbor is defined, the system will automatically set it to the currently highest used value of selectionPriority, + 1, ie to the currently lowest prio definition for the source cell.
Range: 0 – Large Integer
Default: 0
Resolution: 1
selHoSup
[Selective Handover]
Description: Indicates if Selective Handover is supported.
Range: FALSE; TRUE
Default: FALSE
Resolution: N/A
serviceOffset2dEcno
[Coverage trigger offset per UeRc]
Description: Offset per UeRc-state that is added to the 2d, 2f, 3a and 2b Ec/No thresholds.
Range: -20 .. 20
Default: 0
Resolution: 1
serviceOffset2dRscp
[Covergae trigger offset per UeRc]
Description: Offset per UeRc state that is added to the 2d, 2f, 3a and 2b Rscp thresholds.
Range: -50 .. 50
Default: 0
Resolution: 1
timeToTrigger1a
[Time to Trigger 1a]
Description: Interval time. If event 1a condition is fulfilled during at least a time greater than or equal to timeToTrigger1a milliseconds, then event 1a occurs.
Range: 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 ms
Default: 320 ms
Resolution: Not Applicable
Note: This parameter is NOT OSS-RC GUI supported.
timeToTrigger1b
[Time to Trigger 1b]
Description: Interval time. If event 1b condition is fulfilled during at least a time greater than or equal to timeToTrigger1b milliseconds, then event 1b occurs.
Range: 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 ms
Default: 640 ms
Resolution: Not Applicable
Note: This parameter is NOT OSS-RC GUI supported.
timeToTrigger1c
[Time to Trigger 1c]
Description: Interval time. If event 1c condition is fulfilled during at least a time greater than or equal to timeToTrigger1c milliseconds, then event 1c occurs.
Range: 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 ms
Default: 320 ms
Resolution: Not Applicable
Note: This parameter is NOT OSS-RC GUI supported.
timeToTrigger1d
[Time to Trigger 1d]
Description: Interval time. If event 1d condition is fulfilled during at least a time greater than or equal to timeToTrigger1d milliseconds, then event 1d occurs.
Range: 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 ms
Default: 2560 ms
Resolution: Not Applicable
Note: This parameter is NOT OSS-RC GUI supported.
timeToTrigger2dEcno
[Time to Trigger 2d]
Description: Interval time between detection of event 2d and sending of the measurement report, when the measurement quantity is CPICH EC/NO. If event 2d condition is fulfilled during at least a time greater than or equal to timeToTrigger2dEcno milliseconds, then event 2d occurs. A setting of 5000 disables the 2d Ec/No measurement.
Range: 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 ms
Default: 320 ms
Resolution: Not Applicable
Note: This parameter is NOT OSS-RC GUI supported.
timeToTrigger2dRscp
[Time to Trigger 2d]
Description: Interval time between detection of event 2d and sending of the measurement report, when the measurement quantity is CPICH RSCP. If event 2d condition is fulfilled during at least a time greater than or equal to timeToTrigger2dRscp milliseconds, then event 2d occurs. A setting of 5000 disables the 2d Rscp measurement.
Range: 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 ms
Default: 320 ms
Resolution: Not Applicable
Note: This parameter is NOT OSS-RC GUI supported.
timeToTrigger2fEcno
[Time to Trigger 2f]
Description: Interval time between detection of event 2f and sending of the measurement report, when the measurement quantity is CPICH EC/NO. If event 2f condition is fulfilled during at least a time greater than or equal to timeToTrigger2fEcno milliseconds, then event 2f occurs.
Range: 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 ms
Default: 1280 ms
Resolution: Not Applicable
Note: This parameter is NOT OSS-RC GUI supported.
timeToTrigger2fRscp
[Time to Trigger 2f]
Description: Interval time between detection of event 2f and sending of the measurement report, when the measurement quantity is CPICH RSCP. If event 2f condition is fulfilled during at least a time greater than or equal to timeToTrigger2fRscp milliseconds, then event 2f occurs.
Range: 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 ms
Default: 1280 ms
Resolution: Not Applicable
Note: This parameter is NOT OSS-RC GUI supported.
timeToTrigger3a
[Time to Trigger 3a]
Description: Interval time. If event 3a condition is fulfilled during at least a time greater than or equal to timeToTrigger3a milliseconds, then event 3a occurs.
Range: 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 ms
Default: 100 ms
Resolution: Not Applicable
Note: This parameter is NOT OSS-RC GUI supported.
timeTrigg6d
[Time to Trigger 6d]
Description: Interval time. If event 6d condition is fulfilled during at least a time greater than or equal to timeTrigg6d milliseconds, then event 6d occurs.
Range: 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 ms
Default: 320 ms
Resolution: Not Applicable
Note: This parameter is NOT OSS-RC GUI supported.
timeTrigg6b
[Time to Trigger 6b]
Description: Interval time. If event 6b condition is fulfilled during at least a time greater than or equal to timeTrigg6b milliseconds, then event 6b occurs.
Range: 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 ms
Default: 1280 ms
Resolution: Not Applicable
Note: This parameter is NOT OSS-RC GUI supported.
timeTrigg4_2b
[Time to Trigger 2b fo rmaeasurment 4]
Description: Time between detection of event 2b and sending of mesurement report, for measurement 4.
Range: 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 ms
Default: 100 ms
Resolution: Not Applicable
Note: This parameter is NOT OSS-RC GUI supported.
txPowerConnQualMonEnabled
[Ue Tx power Connection Quality Monitoring Enabled]
Description: Enables or disables the connection quality monitoring based on UE Tx power.
Range: TRUE, FALSE
Default: TRUE
Resolution: Not Applicable
Note: This parameter is NOT OSS-RC GUI supported.
uarfcnDl
[Utran absolute radio frequency channel number DL
Description: Can be defined per carrier and RNC together with freqBand. Should be defined if the system is using more than one 3GPP Frequency Band.
Range: 0..16383
Default: Not applicable
Resolution: The mapping from channel number to physical frequency is described in 3GPP specification TS 25.104.
ueTxPowerThresh6b
[UE TX Power Threshold event 6b]
Description: The threshold used for trigger event 6b when UE TX power becomes less than an absolute threshold.
Range: -50 dBm — +33 dBm
Default: +18 dBm
Resolution: 1 dBm
usedFreqThresh2dEcno
[Threshold used freq. 2d (Ec/No)]
Description: Threshold for event 2d (the estimated quality of the currently used WCDMA RAN frequency is below a certain threshold). Used if measurement quantity is configured to be Ec/No.
Range: Valid range for CPICH Ec/No. -24 – 0 dB
Default: -12 dB
Resolution: 1 dB
Scope Cell
usedFreqThresh2dRscp
[Threshold used freq. 2d (RSCP)]
Description: Threshold for event 2d (the estimated power level of the currently used WCDMA RAN frequency is below a certain threshold).
Used if measurement quantity is configured to be Rscp.
Range: Valid range for CPICH Rscp. -115 — -25 dBm
Default: -97 dBm
Resolution: 1 dBm
Scope Cell
usedFreqThresh2dEcnoDrnc
[Threshold used freq. 2d DRNC (Ec/No)]
Description: Threshold for event 2d (the estimated quality of the currently used WCDMA RAN frequency for cells located in DRNC is below a certain threshold). Used if measurement quantity is configured to be Ec/No.
Range: Valid range for CPICH Ec/No. -24 – 0 dB
Default: -12 dB
Resolution: 1 dB
usedFreqThresh2dRscpDrnc
[Threshold used freq. 2d DRNC (RSCP)]
Description: Threshold for event 2d (the estimated power level of the currently used WCDMA RAN frequency for cells located in DRNC is below a certain threshold).
Used if measurement quantity is configured to be Rscp.
Range: Valid range for CPICH Rscp. -115 — -25 dBm
Default: -97 dBm
Resolution: 1 dBm
usedFreqRelThresh4_2bEcno
[used frequency relative threshold for event 2b CPICH Ec/No]
Description: Relative threshold for event 2b versus event 2d for the used frequency (the estimated quality of the currently used frequency is below a certain threshold + usedFreqThresh2dEcno and the estimated quality of a non-used frequency is above a certain threshold), when the 2d measurement quantity is Ec/No.
Range: -10 dB – 10 dB, Range is valid for CPICH Ec/No
Default: -1 dB
Resolution: 1dB
usedFreqRelThresh4_2bRscp
[Used frequency relative threshold for event 2b CPICH RSCP]
Description: Relative threshold for event 2b versus event 2d for the used frequency (the estimated quality of the currently used frequency is below a certain threshold + usedFreqThresh2dRscp and the estimated quality of a non-used frequency is above a certain threshold), when 2d measurement quantity is RSCP.
Range: -20 dB – 20 dB, Range is valid for CPICH RSCP
Default: -3 dB
Resolution: 1 dB
usedFreqRelThresh2fEcno
[Relative Threshold used freq. 2f (Ec/No)]
Description: Relative threshold for event 2f versus event 2d. The estimated quality of the currently used WCDMA RAN frequency is above a certain threshold + usedFreqThresh2dEcno .
Used if measurement quantity is configured to be Ec/No.
Range: 0 – 20 dB
Default: 1 dB
Resolution: 1 dB
usedFreqRelThresh2fRscp
[Relative threshold used freq. 2f (RSCP)]
Description: Relative threshold for event 2f versus event 2d. The estimated quality of the currently used WCDMA RAN frequency is above a certain threshold + usedFreqThresh2dRscp .
Used if measurement quantity is configured to be RSCP.
Range: 0 – 20 dB
Default: 3 dB
Resolution: 1 dB
usedFreqW2d
[used frequency threshold for event 2d weighting factor]
Description: Weighting factor for event 2d for the used frequency.
Range: 0.0 ... 2.0
Default: 0.0
Resolution: 1
usedFreqW2f
[used frequency threshold for event 2f weighting factor]
Description: Weighting factor for event 2f for the used frequency.
Range: 0.0 ... 2.0
Default: 0.0
Resolution: 1
usedFreqW4_2b
[used frequency threshold for event 2b weighting factor]
Description: Weighting factor for event 2b for the currently used frequency.
Range: 0.0 ... 2.0
Default: 0.0
Resolution: 1
utranFilterCoefficient3
[Utran Filter Coefficient for 3a event]
Description: Coefficient for layer 3 filtering of UTRAN quality before inter-RAT reporting evaluation.
Range: 0...9, 11, 13, 15, 17, 19
Default: 2
Resolution: 1
utranRelThresh3aEcno
[UTRAN relative threshold 3a (Ec/No)]
Description: Relative threshold for event 3a versus event 2d (the estimated quality of the currently used WCDMA RAN frequency is below a certain threshold + usedFreqThresh2dEcno and the estimated quality of the GSM system is above a certain threshold in the same time interval) for WCDMA RAN, when the 2d measurement quantity is CPICH Ec/No.
Range: Range is valid for CPICH Ec/No. -10 – 10 dB
Default: -1 dB
Resolution: 1 dB
utranRelThresh3aRscp
[UTRAN relative threshold 3a (RSCP)]
Description: Relative threshold for event 3a versus event 2d (the estimated power level of the currently used WCDMA RAN frequency is below a certain threshold + usedFreqThresh2dRscp and the estimated power level of the GSM carrier is above a certain threshold in the same time interval) for WCDMA RAN, when the 2d measurement quantity is CPICH RSCP.
Range: Range is valid for CPICH Rscp. -20 — 20 dB
Default: -3 dB
Resolution: 1 dB
utranRelThreshRscp
[UTRAN relative threshold (RSCP)]
Description: Relative threshold used together with (on top of) the relative thresholds + utranRelThresh3aRscp (for 3a measurements) and usedFreqRelThresh4_2bRscp (for 2b measurements).
The threshold is used to compute the absolute RSCP threshold for the used frequency for 3a or 2b measurements, when bad connection quality has been triggered in the UL.
Range: Range is valid for CPICH Rscp. 0 dB — 40 dB
Default: 5 dB
Resolution: 1 dB
utranW3a
[UTRAN event 3a weighting factor]
Description: Weighting factor for event 3a for UTRAN.
Range: 0.0 ... 2.0
Default: 0.0
Resolution: 1
w1a
[Event 1a weighting factor]
Description: Weighting factor for event 1a.
Range: 0.0 ... 2.0
Default: 0.0
Resolution: 1
w1b
[Event 1b weighting factor]
Description: Weighting factor for event 1b.
Range: 0.0 ... 2.0
Default: 0.0
Resolution: 1

13.1 Descriptions

13.1.1 General

fddGsmHOSupp Indicates if the RNC supports Inter RAT Handover.
fddIFHOSupp Indicates if the RNC supports Inter-Frequency Handover.
hoType Parameter set per Cell. Indicates if Inter RAT Handover or Inter-Frequency HO or None shall be evaluated in case both Inter RAT and Inter-Frequency neighboring cells have been configured.
defaultHoType Parameter set per carrier per DRNC. Indicates handover type for external cells, if Inter RAT Handover or Inter-Frequency HO or None shall be attempted. If not defined then GSM_PREFERRED is used.
freqBand Parameter set per carrier per RNC. Defined together with uarfcnDl (and in DRNC also defaultHoType).
uarfcnDl Channel number set per carrier per RNC. Defined together with freqBand (and in DRNC also defaultHoType).
releaseConnOffset If a cell cannot be added to the active set, and this cell is stronger than the AS + releaseConnOffset, then the call shall be released.
selectionPriority Defines the priority of a neighbor cell, where 1 is the highest prio to be used for the most important neighbors.
selHoSup Indicates if Selective Handover is supported.

13.1.2 Intra Frequency Handover

filterCoefficient1 Coefficient for layer 3 filtering before intra-frequency reporting evaluation.
hysteresis1a Hysteresis used in addition-window in evaluation criteria for event 1a to avoid ping pong effects.
hysteresis1b Hysteresis used in the drop window in evaluation criteria for event type 1b.
hysteresis1c Hysteresis used in replacement threshold in evaluation criteria for event 1c (A non-active primary CPICH becomes better than an active primary CPICH).
hysteresis1d Hysteresis used in replacement threshold in drop window in evaluation criteria for event 1d (Change of best cell).
individual offset (serving cell) Cell parameter. The offset is added to the measured quantity before the UE evaluates whether an event has occurred. Improper use of non-default values may result in instability and unequal cell borders.
individual offset (adjacent WCDMA cell) Cell parameter. The offset is added to the measured quantity before the UE evaluates whether an event has occurred. Improper use of non-default values may result in instability and unequal cell borders.
maxActiveSet Maximum number of cells allowed in the Active Set. Used in the RNC evaluations of event 1a, 1c, and 1d. If the number of cells in the Active Set is equal to maxActiveSet, the handover evaluation algorithm proposes a cell replacement (event 1c and 1d); otherwise it proposes a cell addition (event 1a).
measQuantity1 Defines the measurement quantity for intra-frequency reporting evaluation.
reportingInterval1a Interval of event-triggered periodical reporting in case of 'cell addition failure' or 'cell replacement failure'. Indicates the interval of periodical reporting triggered by event 1a.
reportingInterval1c Interval of event-triggered periodical reporting in case of 'cell addition failure' or 'cell replacement failure'. Indicates the interval of periodical reporting triggered by event 1c.
reportingRange1a Relative threshold referred to the CPICH of the best cell in the Active Set used as evaluation criteria for event 1a (a primary CPICH enters the reporting range).
reportingRange1b Relative threshold referred to CPICH of the best cell in the Active Set used as evaluation criteria for event 1b (a primary CPICH leaves the reporting range).
timeToTrigger1a Time between detection of event 1a and sending of the measurement report.
timeToTrigger1b Time between detection of event 1b and sending of the measurement report.
timeToTrigger1c Time between detection of event 1c and sending of the measurement report.
timeToTrigger1d Time between detection of event 1d and sending of the measurement report.
w1a Weighting factor for event 1a.
w1b Weighting factor for event 1b.

13.1.3 Inter-Frequency and IRAT Handover

filterCoefficient2 Coefficient for layer 3 filtering before inter-frequency reporting evaluation.
filterCoeff6 Coefficient for layer 3 filtering before UE internal measurement reporting evaluation.
hysteresis2d Hysteresis used for event 2d (the estimated quality of the currently used UTRAN frequency is below a certain threshold).
hysteresis2f Hysteresis used for event 2f (the estimated quality of the currently used UTRAN frequency is above a certain threshold).
serviceOffset2dEcno Offset per UeRc state that is added to the 2d, 2f, 3a,and 2b Ec/No thresholds.
serviceOffset2dRscp Offset per UeRc state that is added to the 2d, 2f, 3a,and 2b Rscp thresholds.
timeToTrigger2dEcno Interval time between detection of event 2d and sending of the measurement report, when the measurement quantity is CPICH EC/NO. If event 2d condition is fulfilled during at least a time greater than or equal to timeToTrigger2dEcno milliseconds, then event 2d occurs. If the 2d event trigger decision is currently based on RSCP measurements, the parallel Ec/No measurement could be initially disabled by setting timeToTrigger2dEcno to 5000 [ms].
timeToTrigger2dRscp Interval time between detection of event 2d and sending of the measurement report, when the measurement quantity is CPICH RSCP. If event 2d condition is fulfilled during at least a time greater than or equal to timeToTrigger2dRscp milliseconds, then event 2d occurs. If the 2d event trigger decision is currently based on Ec/No measurements, the parallel RSCP measurement could be initially disabled by setting timeToTrigger2dRscp to 5000 [ms].
timeToTrigger2fEcno Interval time between detection of event 2f and sending of the measurement report, when the measurement quantity is CPICH EC/NO. If event 2f condition is fulfilled during at least a time greater than or equal to timeToTrigger2fEcno milliseconds, then event 2f occurs.
timeToTrigger2fRscp Interval time between detection of event 2f and sending of the measurement report, when the measurement quantity is CPICH RSCP. If event 2f condition is fulfilled during at least a time greater than or equal to timeToTrigger2fRscp milliseconds, then event 2f occurs.
timeTrigg6d Time between detection of event 6d and sending of the measurement report.
timeTrigg6b Time between detection of event 6b and sending of the measurement report.
usedFreqThresh2dEcno Threshold for event 2d (the estimated quality of the currently used UTRAN frequency is below a certain threshold). Used if measurement quantity is configured to be Ec/No.
usedFreqThresh2dRscp Threshold for event 2d (the estimated power level of the currently used UTRAN frequency is below a certain threshold). Used if measurement quantity is configured to be Rscp.
usedFreqThresh2dEcnoDrnc Defines the threshold for event 2d (the estimated quality of the currently used WCDMA RAN frequency for cells located in DRNC is below a certain threshold). Used if measurement quantity is configured to be Ec/No.
usedFreqThresh2dRscpDrnc Defines the threshold for event 2d (the estimated power level of the currently used WCDMA RAN frequency for cells located in DRNC is below a certain threshold). Used if measurement quantity is configured to be Rscp.
usedFreqRelThresh2fEcno Relative threshold for event 2f (the estimated quality of the currently used UTRAN frequency is above a certain threshold + usedFreqThresh2dEcNo). Used if measurement quantity is configured to be Ec/No.
usedFreqRelThresh2fRscp Relative threshold for event 2f (the estimated power level of the currently used UTRAN frequency is above a certain threshold + usedFreqThresh2dRscp). Used if measurement quantity is configured to be Rscp.
utranRelThreshRscp Relative threshold used together with (on top of) the relative thresholds + utranRelThresh3aRscp (for 3a measurements) and usedFreqRelThresh4_2bRscp (for 2b measurements). The threshold is used to compute the absolute RSCP threshold for the used frequency for 3a or 2b measurements, when bad connection quality has been triggered in the UL.
usedFreqW2d Weighting factor for event 2d for the used frequency.
usedFreqW2f Weighting factor for event 2f for the used frequency.
txPowerConnQualMonEnabled Enables or disables the connection quality monitoring based on UE Tx power.
ueTxPowerThresh6b The threshold used for trigger event 6b when UE TX power becomes less than an absolute threshold.

13.1.4 Inter-Frequency Handover only

filterCoeff4_2b Coefficient for layer 3 filtering before inter-frequency reporting evaluation, for measurement 4 event 2b.
hyst4_2b Hysteresis used for event 2b (the estimated quality of the currently used frequency is below a certain threshold and the estimated quality of a non-used frequency is above a certain threshold).
ifHoAmountPropRepeat Maximum number of repeated proposals of non-used frequency cell(s) for handover based on the same measurement report, not including the first attempt.
ifHoPropRepeatInterval Minimum time interval between proposals of the same non-used frequency cell for handover based on the same measurement report.
maxIefMonSubset Maximum number of inter-frequency WCDMA RAN cells that the UE will measure on.
nonUsedFreqThreshd4_2bEcno Defines the threshold for event 2b for the non-used frequency when measurement quantity is Ec/No. The initially check performed for both Ec/No and Rscp quality level of the target cell before an Inter-Frequency Handover is attempt, can also be disabled for the Ec/No measurement quantity, by setting the NonUsedFreqThresh4_2bEcno to its minimum value.
nonUsedFreqThresh4_2bRscp Defines the threshold for event 2b for the non-used frequency when measurement quantity is RSCP. The initially check performed for both Ec/No and RSCP quality level of the target cell before an Inter-Frequency Handover is attempt, can also be disabled for the RSCP measurement quantity, by setting the NonUsedFreqThresh4_2bRscp to its minimum value.
nonUsedFreqW4_2b Weighting factor for event 2b for the non-used frequency.
timeTrigg4_2b Time between detection of event 2b and sending of the measurement report, for measurement 4.
usedFreqRelThresh4_2bEcno Relative threshold for event 2b versus event 2d for the used frequency (the estimated quality of the currently used frequency is below a certain threshold + usedFreqThresh2dEcno and the estimated quality of a non-used frequency is above a certain threshold), when the 2d measurement quantity is Ec/No.
usedFreqRelThresh4_2bRscp Relative threshold for event 2b versus event 2d for the used frequency (the estimated quality of the currently used frequency is below a certain threshold + usedFreqThresh2dRscp and the estimated quality of a non-used frequency is above a certain threshold), when 2d measurement quantity is RSCP.
usedFreqW4_2b Weighting factor for event 2b for the currently used frequency.

13.1.5 Inter RAT Handover only

gsmAmountPropRepeat Maximum number of repeated proposals (that is, not including the first proposal) of GSM cell(s) for handover based on the same measurement report.
gsmFilterCoefficient3 Coefficient for layer 3 filtering of GSM quality before inter-RAT reporting evaluation.
gsmPropRepeatInterval Minimum time interval between proposals of the same GSM cell for handover based on the same measurement report.
gsmThresh3a Threshold for event 3a (the estimated quality of the currently used UTRAN RAN frequency is below a certain threshold and the estimated quality of the GSM system is above a certain threshold) for GSM.
hysteresis3a Hysteresis used for event 3a.
individual offset (adjacent GSM cell) Cell parameter. The offset is added to the measured quantity before the UE evaluates whether an event has occurred. Improper use of non-default values may result in instability and unequal cell borders.
maxGsmMonSubset Maximum number of GSM cells that the UE will measure on.
timeToTrigger3a Time between detection of event 3a and sending of the measurement report.
utranFilterCoefficient3 Coefficient for layer 3 filtering of UTRAN quality before inter-RAT reporting evaluation.
utranRelThresh3aEcno Relative threshold for event 3a versus event 2d (the estimated quality of the currently used WCDMA RAN frequency is below a certain threshold + usedFreqThresh2dEcno and the estimated quality of the GSM system is above a certain threshold in the same time interval) for WCDMA RAN, when the 2d measurement quantity is CPICH Ec/No.
utranRelThresh3aRscp Relative threshold for event 3a versus event 2d (the estimated power level of the currently used WCDMA RAN frequency is below a certain threshold + usedFreqThresh2dRscp and the estimated power level of the GSM carrier is above a certain threshold in the same time interval) for WCDMA RAN, when the 2d measurement quantity is CPICH RSCP.
utranW3a Weighting factor for event 3a for UTRAN.

13.1.6 Core Network Hard Handover

cnhhoSupp Indicates whether the CNHHO is activated in the RNC. It applies for both Source and Target RNC.
intraFreqCnhhoPenalty Defines the 'penalty' given to a 'Non-Iur External UTRAN' cell compared to a normal intra-frequency cell for the event 1a, 1c and 1d.
intraFreqCnhhoWeight Scale number that defines the weight of the radio links in the active set, when comparing them to an intra-frequency CNHHO candidate. intraFreqCnhhoWeight=0 means that only the best cell in AS is considered, intraFreqCnhhoWeight>0 means that all radio links in the active set are considered, while intraFreqCnhhoWeight=1 means that all radio links in the active set are given equal importance.
interFreqCnhhoPenaltyEcno Defines how much penalty is given to a 'Non-Iur External UTRAN' cell compared to a normal inter-frequency cell during Ec/No evaluation.
interFreqCnhhoPenaltyRscp Defines how much penalty is given to a 'Non-Iur External UTRAN' cell compared to a normal inter-frequency cell during RSCP evaluation.

13.1.7 HSDPA and EUL Mobility

cellCapability Indicates if an External DRNC cell supports HSDPA or EUL/HSDPA, or also EUL 2 ms TTI.
cellCapabilityControl Indicates if a DRNC supports HSDPA or EUL/HSDPA, or also EUL 2 ms TTI.
event1dRncOffset Specifies how much stronger than the serving cell a 1a/1c event report from a non-EUL cell must be to trigger a reconfiguration away from EUL.
event1dRncThreshold Specifies how many 1a/1c event reports from the same non-EUL cell that is needed to trigger a reconfiguration away from EUL.
hsCellChangeAllowed Turns serving HS-DSCH Cell Change on or off.
hsHysteresis1d Sets the event 1d HS hysteresis value specific for HS-DSCH connections.
hsQualityEstimate Indicates whether it is CPICH Ec/No or CPICH RSCP that should be used for indicating "best cell" for HS-DSCH Cell Change.
hsTimeToTrigger1d Sets the event 1d HS Time to Trigger value specific for HS-DSCH connections.
hsToDchTrigger Multi valued parameter that defines which switches from HS-DSCH to DCH that are allowed. The different cases can be set independently of each other.
poorQualityDetected: Applies to the case when triggered by bad connection quality
changeOfbestCellIntraRnc: Applies to the case when triggered by change of best cell, when the new best cell is an intra-RNC cell.
servHsChangeIntraRnc: Applies to the case when the serving cell is removed from the active set and the best cell is an intra-RNC cell.
servHsChangeInterRnc:Applies to the case when the serving cell is removed from the active set and the best cell is an inter-RNC external cell
changeOfBestCellInterRnc:Applies to the case when triggered by change of best cell, when the new best cell is an inter-RNC external cell.

13.2 Values and Ranges

Table 7 shows parameters mentioned in this document. Default value, value range, resolution and unit are shown for each parameter. To facilitate reading, translation to a more convenient unit has been made wherever necessary. The translated properties are within brackets. For the latest recommended radio network parameter settings see Radio Network Parameters (86/1553–HSD 101 02/7).
Table 7 WCDMA RAN Handover Parameters
Parameter Name Default Value Value Range Resolution Unit
General
fddGsmHOSupp FALSE FALSE; TRUE - -
fddIfhoSupp FALSE FALSE; TRUE - -
hoType GSM_PREFERRED IFHO_PREFERRED; GSM_PREFERRED; NONE - -
defaultHoType GSM_PREFERRED IFHO_PREFERRED; GSM_PREFERRED; NONE - -
freqBand 0 0..22 - -
uarfcnDl N/A 0..16383 - -
releaseConnOffset 120 -30..250 5 0.1 dB
[12] [-3..25] [0.5] [dB]
selectionPriority 0 0..Large Integer 1 -
selHoSup FALSE FALSE; TRUE - -
Intra Frequency Handover
filterCoefficient1 2 0...9, 11, 13, 15, 17, 19 1 -
hysteresis1a 0 0..15 1 0.5 dB
[0] [0..7.5] [0.5] [dB]
hysteresis1b 0 0..15 1 0.5 dB
[0] [0..7.5] [0.5] [dB]
hysteresis1c 2 0..15 1 0.5 dB
[1] [0..7.5] [0.5] [dB]
hysteresis1d 15 0..15 1 0.5 dB
[7.5] [0..7.5] [0.5] [dB]
individualOffset (serving cell) 0 -100..100 5 0.1 dB
[0] [-10.0..10.0] [0.5] [dB]
individualOffset (adjacent WCDMA cell) 0 -100..100 5 0.1 dB
[0] [-10.0..10.0] [0.5] [dB]
maxActiveSet 3 2..4 1 # cells
measQuantity1 CPICH_EC_NO CPICH_EC_NO; CPICH_RSCP - -
reportingInterval1a 3 0..7 1 -
[1] [No reporting; 0.25; 0.5; 1; 2; 4; 8; 16] [-] [s]
reportingInterval1c 3 0..7 1 -
[1] [No reporting; 0.25; 0.5; 1; 2; 4; 8; 16] [-] [s]
reportingRange1a 6 0..29 1 0.5 dB
[3] [0..14.5] [0.5] [dB]
reportingRange1b 10 0..29 1 0.5 dB
[5] [0..14.5] [0.5] [dB]
timeToTrigger1a 11 0..15 1 -
[320] [0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000] [-] [ms]
timeToTrigger1b 12 0..15 1 -
[640] [0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000] [-] [ms]
timeToTrigger1c 11 0..15 1 -
[320] [0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000] [-] [ms]
timeToTrigger1d 14 0..15 1 -
[2560] [0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000] [-] [ms]
w1a 0.0 0.0...2.0 1 0.1
w1b 0.0 0.0...2.0 1 0.1
Inter-Frequency Handover & IRAT Handover
filterCoefficient2 2 0...9, 11, 13, 15, 17, 19 1 -
filterCoeff6 19 0...9, 11, 13, 15, 17, 19 1 -
hysteresis2d 0 0..29 1 0.5 dB
[0] [0..14.5] [0.5] [dB]
hysteresis2f 0 0..29 1 0.5 dB
[0] [0..14.5] [0.5] [dB]
serviceOffset2dEcno 0 -20..20 1 [dB]
serviceOffset2dRscp 0 -50..50 1 [dBm]
timeToTrigger2dEcno 320 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 - ms
timeToTrigger2dRscp 320 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 - ms
timeToTrigger2fEcno 1280 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 - ms
timeToTrigger2fRscp 1280 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 - ms
timeTrigg6d 320 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 - ms
timeTrigg6b 1280 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 - ms
usedFreqThresh2dEcno -12 -24..0 1 dB
usedFreqThresh2dRscp -97 -115..-25 1 dBm
usedFreqThresh2dEcnoDrnc -12 -24..0 1 dB
usedFreqThresh2dRscpDrnc -97 -115..-25 1 dBm
usedFreqRelThresh2fEcno 1 0..20 1 dB
usedFreqRelThresh2fRscp 3 0..20 1 dB
usedFreqW2d 0.0 0.0...2.0 1 0.1
usedFreqW2f 0.0 0.0...2.0 1 0.1
utranRelThreshRscp 5 0 ..40 1 dB
txPowerConnQualMonEnabled TRUE FALSE; TRUE 1 -
ueTxPowerThresh6b +18 -50..+33 1 dBm
Inter-Frequency Handover Only
filterCoeff4_2b 2 0...9, 11, 13, 15, 17, 19 1 -
hyst4_2b 10 0..75 1 0.1 dB
[1] [0..7.5] [0.1] [dB]
ifHoAmountPropRepeat 4 0..25 1 attempt
ifHoPropRepeatInterval 5 0..25 1 0.2 s
[1] [0..5.0] [0.2] [s]
maxIefMonSubset 32 1..32 1 cell
nonUsedFreqThresh4_2bEcno -13 -24..0 1 dB
nonUsedFreqThresh4_2bRscp -105 -115..25 1 dBm
nonUsedFreqW4_2b 0.0 0.0...2.0 1 0.1
timeTrigg4_2b 100 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 - ms
usedFreqRelThresh4_2bEcno -1 -10..10 1 dB
usedFreqRelThresh4_2bRscp -3 -20..20 1 dB
usedFreqW4_2b 0.0 0.0...2.0 1 0.1
Inter Radio Access Technology Handover
gsmAmountPropRepeat 4 0..25 1 attempt
gsmFilterCoefficient3 1 0...9, 11, 13, 15, 17, 19 1 -
gsmPropRepeatInterval 5 0..25 1 0.2 s
[1] [0..5.0] [0.2] [s]
gsmThresh3a -102 -115..0 1 dBm
hysteresis3a 0 0..15 1 0.5 dB
[0] [0..7.5] [0.5] [dB]
individualOffset (adjacent GSM cell) 0 -50..50 5 0.1 dB
[0] [-5.0..5.0] [0.5] [dB]
maxGsmMonSubset 32 1..32 1 cell
timeToTrigger3a 6 0..15 1 -
[100] [0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000] [-] [ms]
utranFilterCoefficient3 2 0...9, 11, 13, 15, 17, 19 1 -
utranRelThresh3aEcno -1 -10..10 1 dB
utranRelThresh3aRscp -3 -20..20 1 dB
utranW3a 0.0 0.0...2.0 1 0.1
Core Network Hard Handover
cnhhoSupp FALSE FALSE; TRUE - -
intraFreqCnhhoPenalty 30 0..250 5 0.1 dB
[3] [0..25.0] [0.5] [dB]
intraFreqCnhhoWeight 0 0..10 1 -
[0] [0..1] [0.1] [-]
interFreqCnhhoPenaltyEcno 30 0..250 5 0.1 dB
[3] [0..25.0] [0.5] [dB]
interFreqCnhhoPenaltyRscp 30 0..250 5 0.1 dB
[3] [0..25.0] [0.5] [dB]
HSDPA and EUL Mobility
cellCapability hsdschSupport : Off
edchSupport: Off
edchTti2Support: Off
hsdschSupport : On ; Off
edchSupport: On ; Off
edchTti2Support: On ; Off
cellCapabilityControl hsdschSupport : Off
edchSupport: Off
edchTti2Support: Off
hsdschSupport : On ; Off
edchSupport: On ; Off
edchTti2Support On ; Off
event1dRncOffset 0 -25..25 1 dB
event1dRncThreshold 4 0..60 1 -
hsCellChangeAllowed FALSE FALSE; TRUE - -
hsHysteresis1d 10 0..75 1 0.1 dB
[1] [0..7.5] [0.1] [dB]
hsQualityEstimate CPICH_ RSCP CPICH_EC_NO; CPICH_RSCP - -
hsTimeToTrigger1d 640 0; 10; 20; 40; 60; 80; 100; 120; 160; 200; 240; 320; 640; 1280; 2560; 5000 - ms
hsToDchTrigger
- poorQualityDetected
- changeOfBestCellIntraRnc
- changeOfBestCellInterRnc
- servHsChangeIntraRnc
- servHsChangeInterRnc
OFF for all transitions ON=1,OFF=0 -

14 Constants

Constants are hard-coded values and therefore cannot be changed by the operator. The values stated below could be changed by Ericsson without notice.
C_gsmHoAllowed
Description: Indicates per UeRc state if Inter-RAT HO is allowed
Value: 0= Not allowed, 1= Allowed
C_ifHoAllowed
Description: Indicates per UeRc state if Inter-Frequency HO is allowed
Value: 0= Not allowed, 1= Allowed
C_MaxBufferTime
Description: Maximum time in buffer for a buffered report
Value: 2 seconds
C_MaxSohoListSubset
Description: Maximum number of intra-frequency WCDMA RAN cells that the UE will measure on
Value: 32
C_utranThresh3aForcedGsm
Description: UTRAN threshold for event 3a for Service Based GSM Handover measurements using measurement quantity CPICH Ec/No
Value: 0

15 Timers

The following supervision timers are used by handover algorithms and functions. The values are hard coded and cannot be changed. The values stated below could be changed by Ericsson without notice.
T-ASU
Description: Timer used to supervise the RRC Active Set Update procedure.
Started at transmission of Active Set UPDATE message.
Stopped at reception of Active Set UPDATE COMPLETE message or Active Set UPDATE FAILURE message
Value: 5 seconds
T_RELOC_prep
Description: Timer for supervising the time to resource allocation in the target GSM system.
Started at transmission of RELOCATION REQUIRED message.
Stopped at reception of RELOCATION COMMAND or IU RELEASE REQUEST message.
Action at expiration: Cancel the function and send RELOCATION
CANCEL message to CS CN.
Value: 10 seconds

16 Feature Control

16.1 IRAT HO

IRAT HO can be activated or disabled with FddGsmHoSupp. If this parameter is set to FALSE, then all IRAT HO functionality will be blocked.

16.2 IF HO

IF HO can be activated or disabled with FddIfHoSupp. If this parameter is set to FALSE, then all IF HO functionality will be blocked.

16.3 HSDPA Mobility

Several aspects of HSDPA mobility are parameter controlled, and the functionality is also controlled by Licensing.
Serving HSDPA Cell Change can be turned On/Off with the parameter hsCellChangeAllowed.
Reconfigurations to DCH from HSDPA can be turned On/Off separately for different trigger cases with the parameter hsToDchTrigger.
Selection and reconfiguration to a coverage related cell can be turned On/Off with the parameter hsOnlyBestCell.
Iur Support can be configured per Iur link by setting cellCapabilityControl, hsdschSupport = On
The License Key for HSDPA Mobility phase 1 covers the functionality for Serving HSDPA Cell Change and for Selecting a coverage related cell at RAB establishment.
The License Key for HSDPA Mobility phase 2 covers the functionality for Reconfiguration to DCH and for Selecting a coverage related cell when triggered by activity. Note that the phase 1 Licensing Key is also a prerequisite for phase 2.
The Licence Key for IF/IRAT Mobility on HSDPA/EUL covers the ability to perform compressed mode and HO measurements while using HSDPA and 10 ms TTI EUL.

16.4 EUL Mobility

Enhanced UL is an optional feature, but EUL mobility part is basic when EUL is supported, so there is no explicit licence for EUL mobility.
Iur Support can be configured per Iur link by setting cellCapabilityControl, hsdschSupport = On, edchSupport/ edchTti2Support= On.
EUL mobility requires the corresponding HSDPA mobility licencies.

16.5 Service Based HO

Service Based HO to GSM is activated with the corresponding Licence Key.

16.6 Core Network Hard Handover

Core Network HHO can be activated or disabled by setting the parameter cnhhSupp to TRUE or FALSE.

17 Glossary

Acronyms and terms used in this description are listed in the Glossary of Terms and Acronyms.

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