3G Parameter OptimizationCell Selection Parameter ID : QqualMin Value Range : -24...0 Step : 1 Unit : dB Default Value : -18 Description : The minimum required quality level in the cell (Ec/No). NSN Cell Selection & Reselection Parameter Parameter ID : QrxlevMin Value Range : -119...-25 Step : 2 Unit : dB Default Value : -115 Description : The minimum required RX level in the cell. Note: This parameter is also used to create value for the parameter DeltaQrxlevmin to be sent in SIB3/4 when the used value is < -115. NSN Cell Selection & Reselection Parameter Parameter ID : Sintersearch Value Range : 0...20 Step : 2 Unit : dB Default Value : 8 Description : The threshold for inter-frequency measurements, and for the HCS measurement rules. NSN Cell Selection & Reselection Parameter Parameter ID : Sintrasearch Value Range : 0...20 Step : 2 Unit : dB Default Value : 10 Description : The threshold for intra-frequency measurements, and for the HCS measurement rules. NSN Cell Selection & Reselection Parameter Parameter ID : SsearchRat Value Range : 0...20 Step : 2 Unit : dB Default Value : 4 Description : The RAT-specific threshold for inter-RAT measurement rules. NSN Cell Selection & Reselection Parameter Parameter ID : SintersearchCon Value Range : 0...20 Step : 2 Unit : dB Default Value : 8 Description : The parameter defines the threshold for inter- frequency measurements and for the HCS measurement rules. The value of the parameter should be between the values of the parameters SintrasearchConn and SsearchRATConn, but high enough to manage cell reselection. The parameter is used for cell selection and re-selection in connected mode. Note: The UE performs inter-frequency measurements continuously when CPICH Ec/No is lower than or equal to QqualMin + SintersearchConn. For example if QqualMin is -18 dB, the UE performs inter-frequency measurements continuously when Sintersearch value is 18 dB since CPICH Ec/No is always below 0 dB. NSN Cell Selection & Reselection Parameter Parameter ID : SintrasearchCon Value Range : 0...20 Step : 2 Unit : dB Default Value : 10 Description : The parameter defines the threshold for intra-frequency measurements and for the HCS measurement rules. UE will start the neighbouring measurements when CPICH EcNo < qualmin+SintrasearchConn (default: EcNo < -8 dB). The parameter is used for cell selection and re-selection in connected mode. Note: If no threshold is given, MS performs measurements. NSN Cell Selection & Reselection Parameter Parameter ID : SsearchRatCon Value Range : 0...20 Step : 2 Unit : dB Default Value : 4 Description : The parameter defines the RAT-specific threshold for inter-RAT measurement rules. GSM measurements will happen when it is not possible to maintain a call with good quality: CPICH EcNo < Ssearch_RATConn + Qqualmin (default: EcNo < -14 dB). The parameter is used for cell selection and re-selection in connected mode. Note: If no threshold is given, MS performs measurements. NSN Cell Selection & Reselection Parameter Parameter ID : Treselection Value Range : 0...31 Step : 1 Unit : s Default Value : 2 Description : The UE triggers the reselection of a new cell if the cell reselection criteria are fulfilled during the time interval Treselection. NSN Cell Selection & Reselection Parameter Parameter ID : TreselectionFACH Value Range : 0...6.2 Step : 0.2 Unit : s Default Value : 2 Description : This parameter is used for cell selection and re- selection in Cell_FACH. The UE triggers the reselection of a new cell if the cell reselection criteria are fulfilled during the time interval TreselectionFACH. The reselection time of 2s may avoid too many cell reselections between cells and hence LA/RA updates when crossing the LA/RA border. Thus, there are less signalling and less call failures at the LA/RA border due to the LA/RA update. The reselection time of 0s can be used in areas of high mobility, such as highways. NSN Cell Selection & Reselection Parameter Parameter ID : TreselectionPCH Value Range : 0...31 Step : 1 Unit : s Default Value : 2 Description : The parameter is used for cell selection and re- selection in Cell_PCH/URA_PCH. The UE triggers the reselection of a new cell if the cell reselection criteria are fulfilled during the time interval TreselectionPCH. The reselection time of 2s may avoid too many cell reselections between cells and hence LA/RA updates when crossing the LA/RA border. Thus, there are less signalling and less call failures at the LA/RA border due to the LA/RA update. The reselection time of 0s can be used in areas of high mobility, such as highways. NSN Cell Selection & Reselection Parameter Parameter ID : qQualMin Value Range : -24..0 Step : 1 Unit : dB Default Value : -18 Description : Minimum required (acceptable) quality level in the cell (dB). Used to set cell border between two cells. Used in UE functions for cell selection/reselection in idle mode and connected mode. EID Cell Selection & Reselection Parameter Parameter ID : qRxLevMin Value Range : -115..-25 Step : 2 Unit : dB Default Value : -115 Description : Minimum required (acceptable) RX level in the cell. Used in UE functions for cell selection/reselection in idle mode and connected mode. Value launched by System information (SIB11) for each intra-frequency measurement object corresponding to adjacent cells of serving cell. EID Cell Selection & Reselection Parameter Parameter ID : qualMeasQuantity Value Range : CPICH_RSCP = 1, CPICH_EC_NO = 2 Step : - Unit : - Default Value : CPICH_EC_NO Description : Used in UE functions for cell selection/reselection in idle and connected mode. Cell selection and reselection quality measure. Value launched by System information (SIB3, SIB11 and SIB12). EID Cell Selection & Reselection Parameter Parameter ID : sIntraSearch Value Range : 0..27 Step : 2 Unit : dB Default Value : 0 Description : The decision on when measurements on intra- frequencies shall be performed. Value mapping: 0 : not sent. 1 : -32 dB 2 : -30 dB ... 27 : 20 dB EID Cell Selection & Reselection Parameter Parameter ID : sInterSearch Value Range : 0..27 Step : 2 Unit : dB Default Value : 0 Description : The decision on when measurements on inter- frequencies shall be performed. Value mapping: 0 : not sent 1 : -32 dB 2 : -30 dB ... 27 : 20 dB EID Cell Selection & Reselection Parameter Parameter ID : sRatSearch Value Range : -32..20 Step : 2 Unit : dB Default Value : 4 Description : The decision on when measurements on GSM frequencies shall be performed is made using this parameter in relation with Squal. If S_qual > this parameter, UE need not perform measurements on GSM cells. If S_qual <= this parameter, UE shall perform measurements on GSM cells. If a negative value is configured the UE interprets the negative value as 0. EID Cell Selection & Reselection Parameter Parameter ID : sRatSearch Value Range : -32..20 Step : 2 Unit : dB Default Value : 4 Description : The decision on when measurements on GSM frequencies shall be performed is made using this parameter in relation with Squal. If S_qual > this parameter, UE need not perform measurements on GSM cells. If S_qual <= this parameter, UE shall perform measurements on GSM cells. If a negative value is configured the UE interprets the negative value as 0. EID Cell Selection & Reselection Parameter Parameter ID : sHcsRat Value Range : -105..91 Step : 2 Unit : dB Default Value : 3 Description : RAT specific threshold in the serving cell used in the inter-RAT measurement rules. This parameter is used by the UE to decide when to start GSM measurements for cell reselection, if the serving cell is indicated to belong to a Hierarchical Cell Structure (HCS) GSM measurements in idle mode and state CELL_FACH are started by the UE when RSCP <= qRxLevMin + sHscRat. If sHcsRat is set to a negative value, this will be interpreted as 0 by the UE (according to 3GPP TS 25.331). EID Cell Selection & Reselection Parameter Parameter ID : treSelection Value Range : 0..31 Step : - Unit : s Default Value : 2 Description : Control of cell selection/reselection. Time-to-trigger for cell reselection. Value launched by System information (SIB3). EID Cell Selection & Reselection Parameter Parameter ID : Qqualmin Value Range : -24~0 Step : - Unit : dB Default Value : -18 Description : The minimum required quality threshold corresponding to CPICH Ec/No. The UE can camp on the cell only when the measured CPICH Ec/No is greater than the value of this parameter. The higher the parameter value is, the more difficult it is for the UE to reside in the cell. The lower parameter value is, the easier it is for the UE to reside in the cell, but it is possible that the UE cannot receive the system messages that are sent through the PCCPCH. For detailed information, refer to the 3GPP TS 25.304. HUAWEI Cell Selection & Reselection Parameter Parameter ID : Qrxlevmin Value Range : -58~-13 Step : 2 Unit : dBm Default Value : -58 Description : Minimum RX level of the GSM cell.Before the UE camps on the cell, take the measurement of the signal quality in the cell. If the quality is better than this parameter, this indicates that the cell can obtain better QoS and the UE is allowed to camp on this cell. Otherwise, the UE cannot obtain good QoS in this cell and does not camp on the cell. HUAWEI Cell Selection & Reselection Parameter Parameter ID : IDLESINTERSEARCH Value Range : -16~10, 127 Step : 2 Unit : dB Default Value : 4 Description : Threshold for inter-frequency cell reselection in idle mode. When the quality (CPICH Ec/No measured by UE) of the serving cell is lower than this threshold plus the [Qqualmin] of the cell, the inter-frequency cell reselection procedure will be started. This parameter is not configured when its value is 127. The intra-frequency cell reselection has a priority higher than the inter-frequency cell reselection and inter-RAT cell reselection, the intra-frequency cell reselection start threshold should be higher than the inter-frequency cell reselection start threshold and inter-RAT cell reselection start threshold. If the cell reselection threshold is set to a comparatively high value, the UE may frequently start cell reselections, and the battery of the UE may be largely consumed. If the cell reselection threshold is set to a comparatively low value, it is difficult for cell reselections to be started, and the UE may not timely reside in the cells with good quality, affecting the quality of communication between the UTRAN and the UE. For detailed information, refer to 3GPP TS 25.304. HUAWEI Cell Selection & Reselection Parameter Parameter ID : IDLESINTRASEARCH Value Range : -16~10, 127 Step : 2 Unit : dB Default Value : 5 Description : Threshold for intra-frequency cell reselection in idle mode. When the quality (CPICH Ec/No measured by the UE) of the serving cell is lower than this threshold plus the [Qqualmin] of the cell, the intra-frequency cell reselection procedure will be started. This parameter is not configured when its value is 127. The intra-frequency cell reselection has a priority higher than the inter-frequency cell reselection and inter-RAT cell reselection, the intra-frequency cell reselection start threshold should be higher than the inter-frequency cell reselection start threshold and inter-RAT cell reselection start threshold. If the cell reselection threshold is set to a comparatively high value, the UE may frequently start cell reselections, and the battery of the UE may be largely consumed. If the cell reselection threshold is set to a comparatively low value, it is difficult for cell reselections to be started, and the UE may not timely reside in the cells with good quality, affecting the quality of communication between the UTRAN and the UE. For detailed information, refer to 3GPP TS 25.304. HUAWEI Cell Selection & Reselection Parameter Parameter ID : SSEARCHRAT Value Range : -16~10, 127 Step : 2 Unit : dB Default Value : 2 Description : Threshold for inter-RAT cell reselection. When the quality (CPICH Ec/No measured by UE) of the serving cell is lower than this threshold plus the [Qqualmin] of the cell, the inter-RAT cell reselection procedure will be started. The optional IE RAT list of cell selection and re-selection info in SIB3/SIB4 of system information will be set null when the value of this parameter is 127. The intra-frequency cell reselection has a priority higher than the inter-frequency cell reselection and inter-RAT cell reselection, the intra-frequency cell reselection start threshold should be higher than the inter-frequency cell reselection start threshold and inter- RAT cell reselection start threshold. For detailed information, refer to 3GPP TS 25.304. HUAWEI Cell Selection & Reselection Parameter Parameter ID : CONNSINTERSEARCH Value Range : -16~10, 127 Step : 2 Unit : dB Default Value : 4 Description : Threshold for inter-frequency cell reselection in connected mode. When the quality (CPICH Ec/No measured by UE) of the serving cell is lower than this threshold plus the [Qqualmin] of the cell, the inter-frequency cell reselection procedure will be started. This parameter is not configured when its value is 127. The intra-frequency cell reselection has a priority higher than the inter-frequency cell reselection and inter-RAT cell reselection, the intra-frequency cell reselection start threshold should be higher than the inter-frequency cell reselection start threshold and inter-RAT cell reselection start threshold. If the cell reselection threshold is set to a comparatively high value, the UE may frequently start cell reselections, and the battery of the UE may be largely consumed. If the cell reselection threshold is set to a comparatively low value, it is difficult for cell reselections to be started, and the UE may not timely reside in the cells with good quality, affecting the quality of communication between the UTRAN and the UE. For detailed information, refer to 3GPP TS 25.304. HUAWEI Cell Selection & Reselection Parameter Parameter ID : CONNSINTRAEARCH Value Range : -16~10, 127 Step : 2 Unit : dB Default Value : 5 Description : Threshold for intra-frequency cell reselection in connected mode. When the quality (CPICH Ec/No measured by the UE) of the serving cell is lower than this threshold plus the [Qqualmin] of the cell, the intra-frequency cell reselection procedure will be started. This parameter is not configured when its value is 127. The intra-frequency cell reselection has a priority higher than the inter-frequency cell reselection and inter-RAT cell reselection, the intra-frequency cell reselection start threshold should be higher than the inter-frequency cell reselection start threshold and inter-RAT cell reselection start threshold. If the cell reselection threshold is set to a comparatively high value, the UE may frequently start cell reselections, and the battery of the UE may be largely consumed. If the cell reselection threshold is set to a comparatively low value, it is difficult for cell reselections to be started, and the UE may not timely reside in the cells with good quality, affecting the quality of communication between the UTRAN and the UE. For detailed information, refer to 3GPP TS 25.304. HUAWEI Cell Selection & Reselection Parameter Parameter ID : TRESELECTIONS Value Range : 0~31 Step : - Unit : s Default Value : 1 Description : If the signal quality (CPICH Ec/No measured by the UE) of a neighboring cell is better than that of the serving cell during the specified time of this parameter, the UE reselects the neighboring cell. It is used to avoid ping-pong reselection between different cells. Note that the value 0 corresponds to the default value defined in the protocol. Set the parameter as follows: 1. Ensure that the UE can reselect a cell when crossing the non-soft-switch area of the cell and that the UE timely performs location updates, cell updates, or URA updates when necessary. 2. Ensure that the UE does not reselect a cell when it is in the soft-switch area of the cell. In this way, the unnecessary location updates, cell updates, and URA updates are avoided. 3. Consider the difference between cells that cover different areas, for example the cells covering highways and cells covering densely populated areas. TIf the parameter is set to a comparatively low value, the ping-pong reselections may be caused. The parameter can be increased in populated area and reduced in high-speed movement. If the parameter is set to a comparatively high value, the cell reselection delay may become excessively high, and thus cell reselections may be affected. For detailed information, refer to 3GPP TS 25.304. HUAWEI Cell Selection & Reselection Parameter Parameter ID : Treselectionsfach Value Range : {0~6.2}, {255} Step : - Unit : 0.2s Default Value : 255 Description : This parameter indicates the UE reselection delay in the CELL_FACH connection mode. This parameter is not configured when the value is 255. Instead, the Treselections parameter is used. For detailed information, refer to 3GPP TS 25.304. HUAWEI Cell Selection & Reselection Parameter Parameter ID : Treselectionspch Value Range : {0~31}, {255} Step : - Unit : s Default Value : 255 Description : This parameter indicates the UE reselection delay in the CELL_PCH or URA_PCH connection mode. This parameter is not configured when the value is 255. Instead, the Treselections parameter is used. For detailed information, refer to 3GPP TS 25.304. HUAWEI Cell Selection & Reselection Parameter Parameter ID : QualMeas Value Range : 1: CPICH Ec/No, 2: CPICH RSCP Step : - Unit : - Default Value : 1: CPICH Ec/No Description : This parameter indicates the measurement quantity for cell selection and reselection. ZTE Cell Selection & Reselection Parameter Parameter ID : SInterSearchPre Value Range : 0: False, 1: True Step : - Unit : - Default Value : 1: True Description : This parameter is a switch which indicates whether Sintersearch is configured or not. If the value is False, Sintersearch is not configured to UE, and UE performs the inter-frequency measurement periodically according to the period inicated by the parameter Treselections. If the value is True, Sintersearch is configured to UE, and UE judges whether to perform the inter-frequency measurement. ZTE Cell Selection & Reselection Parameter Parameter ID : SInterSearch Value Range : [0, 20] Step : 2 Unit : db Default Value : 10 Description : This parameter indicates the inter- frequency measurement triggering threshold for cell reselection(Sintersearch) used by UE to judge whether inter-frequency measurement should be performed. When HCS is not used, if the quality of serving cell exceeds Sintersearch, UE may choose to not perform inter-frequency measurement; if the quality of serving cell is not larger than Sintersearch or if Sintersearch is not configured, UE performs inter-frequency measurement. ZTE Cell Selection & Reselection Parameter Parameter ID : SInterSearch Value Range : [0, 20] Step : 2 Unit : db Default Value : 10 Description : This parameter indicates the inter- frequency measurement triggering threshold for cell reselection(Sintersearch) used by UE to judge whether inter-frequency measurement should be performed. When HCS is not used, if the quality of serving cell exceeds Sintersearch, UE may choose to not perform inter-frequency measurement; if the quality of serving cell is not larger than Sintersearch or if Sintersearch is not configured, UE performs inter-frequency measurement. ZTE Cell Selection & Reselection Parameter Parameter ID : SIntraSearch Value Range : [0, 20] Step : 2 Unit : db Default Value : 14 Description : This parameter indicates the intra- frequency measurement triggering threshold for cell reselection (Sintrasearch) used by UE to judge whether intra-frequency measurement should be performed. When HCS is not used, if the quality of serving cell exceeds Sintrasearch, UE may choose to not perform intra-frequency measurement; if the quality of serving cell is not larger than Sintrasearch or if Sintrasearch is not configured, UE performs intra-frequency measurement. ZTE Cell Selection & Reselection Parameter Parameter ID : OtherRATInfoPre Value Range : 0: False, 1: True Step : - Unit : - Default Value : 1: True Description : This parameter is a switch indicating whether inter-RAT information parameters used for cell reselection are configured or not. If the value is False, inter-RAT information parameters are not configured to UE, and UE performs the inter-RAT measurement periodically according to the period inicated by the parameter Treselections. If the value is True, inter-RAT information parameters are configured to UE, and UE judges whether to perform the inter-RAT measurement. ZTE Cell Selection & Reselection Parameter Parameter ID : SSearchRat Value Range : [0, 20] Step : 2 Unit : db Default Value : 6 Description : This parameter is a switch indicating whether inter-RAT information parameters used for cell reselection are configured or not. If the value is False, inter-RAT information parameters are not configured to UE, and UE performs the inter-RAT measurement periodically according to the period inicated by the parameter Treselections. If the value is True, inter-RAT information parameters are configured to UE, and UE judges whether to perform the inter-RAT measurement. ZTE Cell Selection & Reselection Parameter Parameter ID : QQualMin Value Range : [-24, 0] Step : 1 Unit : db Default Value : -18 Description : This parameter indicates the minimum required quality level of the cell which satisfies the condition of being selected or reselected by UE. When the measurement quantity is CPICH Ec/No, only the measured quality of the cell is over Qqualmin can the cell be selected. ZTE Cell Selection & Reselection Parameter Parameter ID : QRxLevMin Value Range : [-115, -25] Step : 2 Unit : dBm Default Value : -115 Description : This parameter indicates the minimum required received power level of the cell which satisfies the condition of being selected or reselected by UE. When the measurement quantity is CPICH RSCP, only the measured received power level of the cell is over Qrxlevmin can the cell be selected. ZTE Cell Selection & Reselection Parameter HHO Trigger and Cancellation Parameter ID : HHoEcNoThreshold Value Range : -24...0 Step : 1 Unit : dB Default Value : -12 Description : If the inter-frequency or inter-RAT (GSM) handover caused by low measured absolute CPICH Ec/No is enabled, the UE transmits an event 1F triggered measurement report to the RNC when the CPICH Ec/No measurement result of an active set cell becomes worse than or equal to an absolute CPICH Ec/No threshold. The parameter HHoEcNoThreshold determines the absolute CPICH Ec/No threshold which is used by the UE to trigger the reporting event 1F. When the measured CPICH Ec/No of all active set cells has become worse than or equal to the threshold in question, the RNC starts inter-frequency or inter-RAT (GSM) measurements in compressed mode for the purpose of hard handover. NSN HHO Trigger and Cancellation Parameter ID : HHoEcNoCancel Value Range : -24...0 Step : 1 Unit : dB Default Value : -9 Description : If the inter-frequency or inter-RAT (GSM) handover caused by low measured absolute CPICH Ec/No is enabled, the RNC starts the inter-frequency or GSM measurement in compressed mode when all active set cells have triggered the reporting event 1F for CPICH Ec/No. The RNC cancels the event 1F of an active set cell if the CPICH Ec/No measurement result of the active set cell becomes better than or equal to the threshold HHoEcNoCancel and the UE transmits the corresponding event 1E triggered Measurement Report to the RNC. Note that once the RNC has started the inter-frequency or inter-RAT (GSM) measurement for the purpose of hard handover due to low measured absolute CPICH Ec/No, the RNC does not break off the ongoing measurement, even if one or more active set cells trigger the reporting event 1E for CPICH Ec/No. NSN HHO Trigger and Cancellation Parameter ID : HHoRscpThreshold Value Range : -115...-25 Step : 1 Unit : dBm Default Value : -105 Description : If the inter-frequency or inter-RAT (GSM) handover caused by a low measured CPICH RSCP is enabled, the UE transmits an event 1F triggered measurement report to the RNC when the CPICH RSCP measurement result of an active set cell becomes worse than or equal to an absolute CPICH RSCP threshold. The parameter HHoRscpThreshold determines the absolute CPICH RSCP threshold which is used by the UE to trigger the reporting event 1F. When the measured CPICH RSCP of all active set cells has become worse than or equal to the threshold in question, the RNC starts inter-frequency or inter- RAT (GSM) measurements in compressed mode for the purpose of hard handover. NSN HHO Trigger and Cancellation Parameter ID : HHoRscpCancel Value Range : -115...-25 Step : 1 Unit : dBm Default Value : -102 Description : If the inter-frequency or inter-RAT (GSM) handover caused by low measured absolute CPICH RSCP is enabled, the RNC starts the inter-frequency or GSM measurement in compressed mode when all active set cells have triggered the reporting event 1F for CPICH RSCP. The RNC cancels the event 1F of an active set cell, if the CPICH RSCP measurement result of the active set cell becomes better than or equal to the threshold HHoRscpCancel and the UE transmits the corresponding event 1E triggered measurement report to the RNC. Note, that once the RNC has started the inter-frequency or inter-RAT (GSM) measurement for the purpose of hard handover due to low measured absolute CPICH RSCP, the RNC does not break off the ongoing measurement, even if one or more active set cells trigger the reporting event 1E for CPICH RSCP. NSN HHO Trigger and Cancellation Parameter ID : INTERFREQCSTHD2DECN0 Value Range : -24~0 Step : - Unit : db Default Value : -14 Description : Ec/No threshold of triggering the inter-frequency measurement for CS services. The threshold of triggering the inter-frequency measurement (namely, threshold of enabling the compression mode) is a key parameter in the inter-frequency handover policy. The setting of this parameter affects the proportion of the UEs in compression mode in a cell and the success rate of the hard handover. To set this parameter, consider the following factors: moving speed of the UE and cell radius. When Ec/No is used as the measurement quantity for CS services, the UE reports event 2D when the measured Ec/No value is lower than the value of this parameter. Then, the RNC sends the signaling to activate the compression mode and start the inter-frequency measurement. For the UE moving at a speed of 5 km/h, the recommended threshold is -17 dB; for the UE moving at a speed of 50 km/h, the recommended threshold is -14 dB; for the UE moving at a speed of 120 km/h, the recommended threshold is -12 dB. For the cell in which the UEs are moving at various speeds, set this parameter to -14 dB. The emulation result shows that the call drop rate remains low for the UEs moving at a speed of 120 km/h when this parameter is set to -14 dB. Event 2D and event 2F are used to enable and disable the compression mode respectively. To enable the compression mode earlier, increase the threshold of triggering event 2D; otherwise, decrease the threshold of triggering event 2D. To prevent the frequent enabling and disabling of the compression mode, increase the difference between the thresholds of triggering event 2D and event 2F. Huawei HHO Trigger and Cancellation Parameter ID : INTERFREQCSTHD2FECN0 Value Range : -24~0 Step : - Unit : db Default Value : -12 Description : Ec/No threshold of stopping the inter-frequency measurement for CS services. The threshold of stopping the inter-frequency measurement (namely, threshold of disabling the compression mode) is a key parameter in the inter-frequency handover policy. The setting of this parameter affects the proportion of the UEs in compression mode in a cell and the success rate of the hard handover. To set this parameter, consider the following factors: moving speed of the UE and cell radius. When Ec/No is used as the measurement quantity for CS services, the UE reports event 2F when the measured Ec/No value is higher than the value of this parameter. Then, the RNC sends the signaling to disable the compression mode and stop the inter-frequency measurement. Event 2D and event 2F are used to enable and disable the compression mode respectively. To enable the compression mode earlier, increase the threshold of triggering event 2D; otherwise, decrease the threshold of triggering event 2D. To prevent the frequent enabling and disabling of the compression mode, increase the difference between the thresholds of triggering event 2D and event 2F. Huawei HHO Trigger and Cancellation Parameter ID : INTERFREQCSTHD2DRSCP Value Range : -115~-25 Step : - Unit : dBm Default Value : -95 Description : RSCP threshold of triggering the inter-frequency measurement for CS services. The threshold of triggering the inter-frequency measurement (namely, threshold of enabling the compression mode) is a key parameter in the inter-frequency handover policy. The setting of this parameter affects the proportion of the UEs in compression mode in a cell and the success rate of the hard handover. To set this parameter, consider the following factors: moving speed of the UE and cell radius. When RSCP is used as the measurement quantity for CS services, the UE reports event 2D when the measured RSCP value is lower than the value of this parameter. Then, the RNC sends the signaling to activate the compression mode and start the inter-frequency measurement. For the UE moving at a speed of 5 km/h, the recommended threshold is -100 dBm; for the UE moving at a speed of 50 km/h, the recommended threshold is -97 dBm; for the UE moving at a speed of 120 km/h, the recommended threshold is -93 dBm. For the cell in which the UEs are moving at various speeds, set this parameter to -95 dBm. The emulation result shows that the call drop rate remains low for the UEs moving at a speed of 120 km/h when this parameter is set to -95 dBm. Event 2D and event 2F are used to enable and disable the compression mode respectively. To enable the compression mode earlier, increase the threshold of triggering event 2D; otherwise, decrease the threshold of triggering event 2D. To prevent the frequent enabling and disabling of the compression mode, increase the difference between the thresholds of triggering event 2D and event 2F. When the signals at the entrance to an elevator or a subway change too fast to perform handover, set this parameter to -90 dBm to enable the compression mode earlier. Huawei HHO Trigger and Cancellation Parameter ID : INTERFREQCSTHD2FRSCP Value Range : -115~-25 Step : - Unit : dBm Default Value : -92 Description : RSCP threshold of stopping the inter-frequency measurement for CS services. The threshold of stopping the inter-frequency measurement (namely, threshold of disabling the compression mode) is a key parameter in the inter-frequency handover policy. The setting of this parameter affects the proportion of the UEs in compression mode in a cell and the success rate of the hard handover. To set this parameter, consider the following factors: moving speed of the UE and cell radius. When RSCP is used as the measurement quantity for CS services, the UE reports event 2F when the measured RSCP value is higher than the value of this parameter. Then, the RNC sends the signaling to disable the compression mode and stop the inter-frequency measurement. Event 2D and event 2F are used to enable and disable the compression mode respectively. To enable the compression mode earlier, increase the threshold of triggering event 2D; otherwise, decrease the threshold of triggering event 2D. To prevent the frequent enabling and disabling of the compression mode, increase the difference between the thresholds of triggering event 2D and event 2F. Huawei HHO Trigger and Cancellation