HUAWEI handover Algorithm

Load HO AllowedThis parameter specifies whether a traffic load-sharing handover is enabled.The load handover helps to reduce cell congestion, improve success rate of channel assignment, and balance the traffic load among cells, thus improving the network performance. The load handover functions between the TCHs within one BSC or the TCHs in the cells of the same layer.The load handover is used as an emergency measure instead of a primary measure to adjust abnormal traffic burst in partial areas. If load handovers occur frequently in a partial area, the cell and TRX configuration of BTSs and the network layout should be adjusted.

MS Fast Moving HO AllowedThis parameter specifies whether an MS that moves fast in a micro cell can be handed over to a macro cell. If this parameter is set to Yes, the MS that moves fast in a micro cell can be handed over to a macro cell, thus reducing the number of handovers. It is recommended that this handover be applied only in special areas such as highways to reduce the CPU load. The fast-moving micro-to-macro cell handover algorithm is used only in special conditions.

Rx_Level_Drop HO AllowedThis parameter specifies whether to enable the rapid level drop handover. When this function is enabled, an MS can be handed over to a new cell before the occurrence call drop caused by the rapid drop of the receive level of the MS.In dual-band networking mode for densely populated urban areas, the level drops rapidly due to multiple barriers. The propagation loss of the 1800 MHz frequency band is greater than the propagation loss of the 900 MHz frequency band. Considering the preceding factors, you can enable the Rx_Level_Drop HO Allowed for the DCS1800 cell.Under normal conditions, this parameter is set to No. To support the rapid level drop handover, the BSC must have the original MR.

PBGT HO AllowedThis parameter specifies whether to enable the PBGT (POWER BUDGET) handover algorithm. Based on the path loss, the BSC uses the PBGT handover algorithm to search for a desired cell in real time and decides whether a handover should be performed. The cell must have less path loss and meet specific requirements. To avoid ping-pong handovers, the PBGT handover can be performed only on TCHs between the cells of the same layer and hierarchy. The PBGT handover cannot be performed on SDCCHs.Motorola recommends that the PBGT handover algorithm be enabled. Proper use of PBGT handovers helps to reduce cross coverage and to avoid co-channel interference and adjacent channel interference.

Level HO AllowedThis parameter specifies whether the layered hierarchical handover is enabled. Cells are set to different layers and different priorities to implement the layered hierarchical handover. Then, based on the layers and priorities, calls are handed over to the cells with high priority (priority is related to Layer of the Cell and Cell Priority).The lower the layer is, the higher the priority is. The lower the hierarchy is, the higher the priority is. The layered hierarchical handover cannot be triggered if the serving cell has the highest priority in the queue or if the level of the target cell is lower than the Inter-layer HO Threshold.If this parameter is set to Yes, a call is handed over to the target cell that has a higher priority than the serving cell.

Fringe HO Allowed (EDGE HO)This parameter specifies whether to enable the edge handover algorithm. When an MS makes a call at the edge of a cell, the call may drop if the receive level is too low. To avoid such a call drop, an edge handover can be performed. When the UL receive level of the serving cell is lower than the Edge HO UL RX_LEV Threshold or the DL receive level of the serving cell is lower than the Edge HO DL RX_LEV Threshold, the MS is handed over to a neighbor cell.Motorola recommends that this parameter be set to Yes. In other words, the edge handover algorithm is enabled.

BQ HO AllowedThis parameter specifies whether the bad quality (BQ) handover is enabled. Whether a BQ handover should be enabled depends on the UL and DL transmission quality (BER). When the UL signal quality or the DL signal quality exceeds the BQ handover threshold. a BQ emergency handover is performed. A rise in BER may result from too low a signal level or channel interference.TA HO AllowedThis parameter specifies whether the time advance (TA) handover is enabled. The TA handover determines whether the timing advance (TA) is higher than the predefined TA threshold. When the TA is higher than the predefined TA threshold, a TA handover is triggered. The TA is calculated based on the distance between the MS and the BTS. The longer the distance is, the greater the TA value is.Concentric Circles HO AllowedThis parameter specifies whether the concentric cell handover is enabled. The concentric cell is used to achieve the wide coverage of the UL subcell and the aggressive frequency reuse of the OL subcell. The concentric cell handover can improve system capacity and conversation quality. The concentric cell handover can be classified into the UL subcell to OL subcell handover and the OL subcell to UL subcell handover.Interference HO AllowedThis parameter specifies whether the interference handover is enabled.When the receive level is higher the receive level threshold but the transmission quality is lower than the interference handover quality threshold, the interference handover is triggered. In other words, the MS is interfered and needs to be handed over.MR.PreprocessingThis parameter specifies whether the BTS should preprocess MRs. This parameter determines whether transmit power is controlled by the BTS or by the BSC. This parameter is set to YES if power control is performed by the BTS. This parameter is set to NO if power control is performed by the BSC.When this parameter is set to BSC Preprocessing, the BSC preprocesses the measurement reports. In this case, the Transfer Original MR, Transfer BS/MS Power Class, and Sent Freq.of preprocessed MR parameters are invalid.

When this parameter is set to BTS Preprocessing, the signaling on the Abis interface and the load of the BSC are reduced. Thus, the response time is shortened and the network performance is improved.When setting this parameter, you should determine whether the BTS supports the configured power control algorithms.Related parameters: Transfer Original MR, Transfer BS/MS Power Class, Sent Freq.of preprocessed MR. For channels on the Abis interface operating at 16 kbit/s, if a TRX is configured with two or more SDCCHs, or if SD Dynamic Allocation Allowed is set to Yes, you are advised to set MR Preprocessing to Yes. Motorola recommends that the measurement report is reported once per second.Transfer Original MRThis parameter specifies whether the BTS should send the original measurement report to the BSC. If this parameter is set to Yes, the BTS should send the preprocessed MR and the original MR to the BSC.In 4:1 multiplexing mode, if there are more than two timeslots configured in SDCCH/8 scheme, then this parameter should be set to No.Transfer BS/MS Power ClassThis parameter specifies whether the BS/MS power class should be transferred from the BTS to the BSC.When MR preprocessing is enabled, the UL and DL balance measurement is affected if Transfer BS/MS Power Class is set to No. In addition, the handovers (such as PBGT handovers, load handovers, and concentric cell handovers) that require power compensation may fail.Allowed M.R Number LostThis parameter specifies the allowed number of consecutive MRs that are lost during interpolation.If the number of consecutive MRs that are lost is equal to or smaller than the value of this parameter, the linear interpolation processing of the lost MRs is performed according to two consecutive MRs that are lost.If the number of consecutive MRs that are lost is greater than the value of this parameter, all lost MRs are discarded, and calculations are made again when new MRs are received.

Measurement reports fail to be decoded correctly when the signal strength in the serving cell is poor. When the number of consecutive MRs that are lost is greater than the value of this parameter, all previous measurement reports are discarded and the handover may fail. Therefore, Motorola recommends that this parameter be set to a great value for emergency handovers.Penalty Level after HO FailThis parameter specifies the penalty level imposed on the target cell.This parameter is valid only within the duration of the cell penalty time.The penalty level values 0 through 63 map to -110 dBm to -47 dBm.This parameter specifies the penalty level imposed on a target cell. A penalty level is imposed on a target cell to avoid further attempts when a handover fails due to any of the following reasons: cell congestion, a message indicating internal handover refusal is received, a message indicating Um interface handover failure is received during out-going BSC handover, or a message indicating Um interface handover failure is received during internal handover. This parameter is valid only within the duration of the cell penalty time.Penalty Level after BQ HOThis parameter specifies the degree of penalty imposed on the original serving cell where an emergency handover associated with bad signal quality is initiated. This parameter is defined to avoid ping-pong handover and is valid only within the Penalty Time after BQ HO.After an emergency handover is performed due to bad quality, the receive level of the serving cell is decreased by the penalty level. Thus, other cells are given higher priority and handover to the serving cell is not allowed.The penalty level values 0 through 63 map to -110 dBm to -47 dBm.If this parameter is set to a lower value, the MS is likely to be handed over to the original serving cell, thus leading to ping-pong handovers. If this parameter is set to a higher value, the MS is unlikely to be handed over to the original serving cell.Penalty Level after TA HOThis parameter specifies the penalty on the signal strength of the original serving cell to avoid ping-pong handovers after an emergency handover due to the timing advance. This parameter is valid only within the Penalty Time after TA HO.

After an emergency handover is performed due to TA, the receive level of the original serving cell is decreased by the penalty level. Thus, other cells are given higher priority and handover to the original serving cell is not allowed.The penalty level values 0 through 63 map to -110 dBm to -47 dBm.TA ThresholdAn emergency handover is triggered when TA is greater than or equal to the value of this parameter.This parameter determines the cell coverage for the TA emergency handover. In the areas with small space between BTSs and densely distributed BTSs, the coverage of the cell can be reduced if this parameter is set to a lower value.DL Qual. ThresholdThis parameter specifies the downlink receive quality threshold of an emergency handover. An emergency handover is triggered when the downlink receive quality is greater than or equal to the DL Qual. Threshold.When an emergency handover is triggered, an inter-cell handover should be preferentially selected. An intra-cell handover, however, is triggered if no candidate cell is available and if intra-cell handovers are allowed.The setting of this parameter affects the triggering of BQ handover of non-AMR calls. If it is set to a lower value, the downlink BQ handover is easily triggered.When frequency hopping or DTX of the cell is enabled, it is recommended that you set this parameter to 70.Uplink Level Short-term Filter LengthThis parameter specifies the number of MRs used by the BSC to filter the UL level for a short term. Filtering refers to averaging the value of several consecutive MRs. This ensures the reliability of the value.Filter Parameter A1This parameter is used for configuring the filter for the rapidly dropped receive level. Together with filter parameter B, it is one of the nine filter parameters. The corresponding formula is as follows (in the program, the value of A1 to A8 can be obtained by subtracting 10 from the configured value, and B is the negative value of the configured value):C1(nt) = A1 x C(nt) + A2 x C(nt-t) + A3 x C(nt-2t) +…+ A8 x C(nt-7t). Where, C(nt) is the uplink RX_Level of the serving cell in the MR received at the time of nt. If C1(nt) is smaller than B, and if C(nt) is

below the Edge HO RX_LEV Thrsh., then the signal level is considered to be rapid dropping.Filter parameters A1 to A8 may be smaller than or equal to 10. Parameters A1 to A8 correspond to a1 to a8 in the program, and ai = Ai-10 (i = 1-8). Therefore, among a1 to a8 in the program, there must be values smaller than or equal to 0.For example, if the receive level drops rapidly in a granularity period, you need to set A3 to A8 to 10, A1 to 0, and A2 to 20. In this case, C1(nt) = a1 x C (nt) + a2 x C(nt-t) = 10C(nt-t)-10C(nt). To trigger a rapid level drop handover, you should set C1(nt) to a value smaller than B. and then the fast level drop appears in a MR period. The formula reflects the rapid drop of the cell level in an MR.You can configure the filter to define the number of MRs used and the extent to which the level drops. However, the setting of this parameter is complicated.Filter parameters A1 to A8 must meet the following requirement: A1 + A2 + A3 + A4 + A5 + A6 + A7 + A8 = 80. The settings of A1 to A8 reflect the number of MRs in which the receive level drops rapidly.Filter Parameter BThis parameter is used for configuring the filter for the rapidly dropped receive level. This parameter indicate specifies the drop trend of the receive level within a period.If this parameter is set to a higher value, a more rapid level drop is required for triggering a rapid level drop handover. This parameter is used together with the Filter Parameters A1 to A8.For details, refer to Filter Parameters A1-A8.If this parameter is set to a higher value, a more rapid level drop is required for triggering a rapid level drop handover.No Dl Mr.HO AllowedThis parameter is used to control the no downlink measurement report handover algorithm.If this parameter is set to 0, the no downlink measurement report handover algorithm is disabled. Therefore, handover decision related to no downlink measurement report is not allowed in this cell.If this parameter is set to 1, the no downlink measurement report handover algorithm is enabled. Therefore, handover decision related to no downlink measurement report is allowed in this cell.This parameter is set according to the traffic volume.No Dl Mr.Ul Qual HO Limit

If the downlink MRs are not included in the MRs received, and if the uplink receive quality is greater than or equal to the value of this parameter, a no downlink measurement report emergency handover is triggered.When an emergency handover is triggered, an inter-cell handover is preferentially selected. An intra-cell handover, however, is triggered if no candidate cell is available and if intra-cell handovers are allowed.The handover decision is allowed only when the uplink receive quality is greater than or equal to the value of this parameter. Therefore, if this parameter is set to a higher value, the no downlink measurement report handover cannot be triggered.System Flux Threshold for Load HOSystem flux thresholds correspond to the system flux obtained based on message packets, CPU load, and FID queuing load. The system flux level is the current flux control level of the system.0-11: There are 12 flow control levels. Where, 0 indicates the lowest level and 11 indicates the highest level.A load handover is allowed only when the system flux is lower than the value of this parameter. The handover performed over the maximum threshold may have tremendous impacts on the system. Thus, this parameter should not be set to a higher value. 1) The flow control level algorithm for the assigned system messages: [(Average Message Usage - Inner Flow Control Discard Begin Threshold)/(Inner Flow Control Discard All Threshold - Inner Flow Control Discard Begin Threshold) x 100]/10+1 (round-down for division operation). If the value is smaller than Inner Flow Control Discard Begin Threshold, Level 0 is used. If the value is equal to or greater than Inner Flow Control Discard Begin Threshold, the level is calculated. The value range is from 0 to 11.2) Flow control threshold for the CPU to start to discard the channel access messages and paging messages: 80%. Flow control threshold for the CPU to discard all channel access messages and paging messages: 100%. CPU usage smaller than 80% corresponds to level 0. CPU usage equal to or greater than CPU flow control threshold 80% corresponds to level 2. An increase of 5% means an increase of 2 levels. Level 10 is the highest. The level value can be 0, 2, 4, 6, 8, and 10.The value of this parameter should not be set too high. Load handover is allowed only when the system flow is lower than the

setting of this parameter. Otherwise, the load on the system is increased.Load HO ThresholdWhen Load HO Allowed is set to Yes, Load HO Threshold should be set to 85.The traffic load of a cell refers to the TCH seizure rate in the cell.The load handover is triggered when the traffic load in a cell is greater than the value of this parameter. In other words, the load handover is triggered when the ratio of TCHs occupied in a cell reaches the threshold defined for load handover.The setting of this parameter affects the triggering of the load handover. If it is set to a lower value, the number of load handovers increases.Load Req.on Candidate CellIf the cell load is smaller than the value of this parameter, the cell can receive the MSs handed over from other cells. Otherwise, the cell rejects the MSs handed over from other cells.The setting of this parameter affects the load handover targeted to the cell. If it is set to a lower value, the number of handover requests that are rejected increases.Load HO BandwidthThe setting of this parameter is dependent on the Edge HO DL RX_LEV Threshold parameter.Only when the receive level of the serving cell is within the range of (Edge HO DL RX_LEV Threshold, Edge HO DL RX_LEV Threshold + Load HO Bandwidth), a load handover is allowed.The value of this parameter ranges from 0 to 63 (corresponding to -110 dBm to -47 dBm).The setting of this parameter determines the maximum width of the handover strip during load handover.Load HO Step PeriodWhen the load of the cell is equal to or greater than the Load HO Threshold, all the calls served by the cell may send handover requests simultaneously, and the load on the CPU will increase rapidly as a consequence. In some cases, call drops may occur due to traffic congestion in the cell. Therefore, the hierarchical handover algorithm for load handover is used for the BSC to control the number of users to be handed over by levels.This parameter specifies the period for each load handover level.

The setting of this parameter affects the load handover time. If it is set to a too greater value, the handover time of each level is long.

Load HO Step LevelIn hierarchical load handover, the handover strip increases by one Load HO Step Level for every Load HO Step Period, starting from the Edge HO DL RX_LEV Threshold. The handovers are performed as such until all the calls whose receive levels are within the range of (Edge HO DL RX_LEV Threshold, Edge HO DL RX_LEV Threshold + Load HO Bandwidth) are handed off the current serving cell.The value of Load HO Step Level must be smaller than that of the Load HO Bandwidth.The value of this parameter ranges from 0 to 63 (corresponding to -110 dBm to -47 dBm).The setting of this parameter affects the width of the handover strip during load handover.Edge HO UL RX_LEV ThresholdIf the UL receive level remains lower than the Edge HO UL RX_LEV Threshold for a period, the edge handover is triggered. If the PBGT handover is enabled, the relevant edge handover threshold can be decreased. If the PBGT handover is not enabled and the edge handover threshold is not properly set, cross coverage, co-channel interference, and adjacent channel interference are likely to occur. The Edge HO UL RX_LEV Threshold should be adjusted based on the handover performance statistics and the actual network performance to achieve the UL/DL balance.The value of this parameter ranges from 0 to 63 (corresponding to -110 dBm to -47 dBm).This parameter should be adjusted as required. If the Edge HO UL RX_LEV Threshold is set to a too small value, call drop may easily occur. If the PBGT handover is enabled, the relevant edge handover threshold can be decreased.The typical configurations of this parameter are as follows:25: urban areas with PBGT handover disabled20: suburbs with a single BTS20: urban areas with PBGT handover enabledMS Fast-moving Watch CellsThe more the micro cells are configured, the more difficult the fast-moving micro-to-macro cell handover can be triggered.

If this parameter is set to a too great value, the system traffic volume cannot be reduced effectively; if this parameter is set to a too small value, the judgment on whether the MS fast passes a cell may be incorrect.MS Fast-moving Time ThresholdThe time threshold is calculated based on the cell radius (r) and the velocity (v). The threshold equals 2r/v. If the time taken by an MS to pass a cell is smaller than this threshold, the MS is regarded as moving fast. Otherwise, the MS is regarded as moving slow.When the cell radius is fixed, the smaller the value of this parameter is (the required velocity is higher), the more the difficult fast-moving micro-to-macro cell handover can be triggered.MAX Consecutive HO TimesThis parameter determines the maximum number of consecutive intra-cell handovers allowed.If the interval of two continuous intra-cell handovers is shorter than a specified threshold, the two handovers are regarded as consecutive handovers. If multiple consecutive intra-cell handovers occur, the intra-cell handover is forbidden for a period.f this parameter is set to a too small value, the intra-cell handover may not be timely; if this parameter is set to a too great value, the system resources may be wasted when intra-cell handovers occur frequently.Forbidden time after MAX TimesWhen the number of consecutive intra-cell handovers reaches the maximum allowed, a timer is started to forbid the intra-cell handover.Intra-cell handovers are allowed only when the timer expires.【1，200】20This parameter to used to disable the intra-cell handover for a certain period.Interval for  Consecutive HO Jud.The two intra-cell handovers that occur during the period specified by this parameter are regarded as consecutive handovers.【1，200】6Cell TypeThis parameter specifies whether a cell is a normal cell or a concentric cell.TRXs in a concentric cell differ in coverage; thus, two subcells with different radiuses form a concentric cell.

Due to the difference in coverage, the OL subcell and the UL subcell can be regarded as two cells logically. The OL subcell carries most of the traffic because more channels are available, and thus serves most users in the coverage of the cell. The UL subcell is used to maximize the coverage and provide services for the area beyond the coverage of the OL subcell. The UL subcell covers the OL subcell and can share some traffic.As specified in Motorola concentric cell technology, a concentric cell is divided into an OL subcell and a UL subcell. The TRXs of the OL subcell and of the UL subcell can use different frequency reuse modes.The concentric cell technology can be combined with the frequency planning technology. Thus, the network capacity can be increased and the network quality can be improved.Inter-layer HO ThresholdThis parameter is one bit of the 16 bits that are used by the BSC to sort the candidate cells for handovers.If the DL receive level of a cell is lower than the Inter-layer HO Threshold, the cell is listed in the candidate cells based on the receive level. The cell takes a low priority for handovers.The value of this parameter ranges from 0 to 63 (corresponding to -110 dBm to -47 dBm).Inter-layer HO HysteresisThis parameter specifies the hysteresis of an inter-layer or inter-priority handover. This parameter is used to avoid inter-layer ping-pong handovers.Actual Inter-layer HO Threshold of a serving cell = configured Inter-layer HO Threshold - Inter-layer HO HysteresisActual Inter-layer HO Threshold of an adjacent cell = configured Inter-layer HO Threshold + Inter-layer HO Hysteresis of an adjacent cell - 64.The value of this parameter ranges from 0 to 63 (corresponding to -110 dBm to -47 dBm).[0,63]3dBPenalty on MS Fast Moving HOIf an MS is moving fast, the BSC performs penalty on the adjacent cells of the cell where the MS is located. This parameter specifies the penalty value. Only when the MS is located at the Umbrella layer and the adjacent cells are located at the Macro, Micro, or Pico layer, penalty is performed.

This parameter is valid within only the Penalty Time on Fast Moving HO.The level values 0 through 63 map to -110 dBm to -47 dBm.

Min DL Power on HO Candidate CellThe M criterion supports the minimum value constraint of downlink receive level of an adjacent cell.Filtered downlink level of the adjacent cell >= (Minimum downlink power of the candidate cell for handover + Minimum access level offset)The M criterion is met if the Filtered uplink level of the adjacent cell >= (Minimum uplink power of the candidate cell for handover + Minimum access level offset); otherwise, the M criterion is not met.The value of this parameter ranges from 0 to 63 (corresponding to -110 dBm to -47 dBm).1. This parameter must be properly set because it limits the number of candidate cells. If this parameter is set to a too great value, some desired cells may be excluded from the candidate cells. If this parameter is set to a too small value, an unwanted cell may become the candidate cell. This leads to handover failures or call drops.2. A cell can become a candidate cell only when the receive level minus this parameter is greater than the minimum access level offset.UL Expected Level at HO AccessThis parameter specifies the expected uplink receive level on a new channel after an MS is handed over to a new cell. This parameter is used for the MS Power Prediction after HO. This parameter should be consistent with the UL RX_LEV Upper Threshold in II power control algorithm, thus ensuring a relatively high uplink receive level on the new channel after handover, increasing the transmit power of the MS, and avoiding call drops caused by too low a uplink receive level.The value of this parameter ranges from 0 to 63 (corresponding to -110 dBm to -47 dBm).If this parameter is set to a too small value, call drop may easily occur.K BiasThis parameter specifies the K offset used in K ranking.To reduce the ping-pong effect in an handover, you are advised to subtract K Bias from the actual downlink receive level of the candidate cells before ranking their downlink receive level based on the K principle.

Subtract K Bias from the actual downlink receive level of the candidate cells before ranking their downlink receive level based on the K principle. This parameter affects the ranking of candidate cells. Generally, it is set to 0.Intracell F-H HO AllowedThis parameter specifies whether the AMR handover is enabled. This parameter does not affect the dynamic non-AMR full-rate to half-rate handover.The AMR handover can be triggered only when the Intracell F-H HO Allowed parameter is set to Yes.Intracell F-H HO Stat Time(s)This parameter determines the period during which the triggering conditions of the intra-cell full-rate to half-rate handover are met.The intra-cell full-rate to half-rate handover must conform to the P/N criterion. That is, the triggering conditions of the intra-cell full-rate to half-rate handover are met for N consecutive seconds with P measurement seconds.This parameter corresponds to P of the P/N criterion. The triggering conditions of the intra-cell full-rate to half-rate handover are the F2H HO Threshold or the H2F HO Threshold. This parameter is used with the two parameters.The greater the value of this parameter is set, the more difficult the AMR handover can be triggered.Penalty Time after AMR TCHF-H HO Fail(s)This parameter specifies the penalty time for AMR full rate to half rate (FR-to-HR) handovers. Before the timer expires, no AMR FR-to-HR handover is allowed if the previous FR-to-HR handover fails due to channel unavailability or channel mismatch.The greater the value of this parameter is, the longer the penalty time after AMR TCHF-H HO Fail is. In other words, triggering AMR handover becomes more difficult.Min Power Level For Direct TryThis parameter is used to select the candidate cells during directed retry. If the receive level of an adjacent cell is greater than the value of this parameter, the adjacent cell can be selected as a candidate cell for directed retry.If the receive level of an adjacent cell is greater than or equal to the value of this parameter, this adjacent cell can be selected as a candidate cell for directed retry.

RX_QUAL Threshold for TIGHT BCCH HOThis parameter specifies the signal quality threshold of the TIGHT BCCH handover. To trigger an intra-cell TIGHT BCCH handover from a TCH to a BCCH, the downlink receive quality should be lower than the RX_QUAL Threshold for TIGHT BCCH HO.[0,7]3Load Threshold for TIGHT BCCH HOThis parameter specifies the load threshold of the TIGHT BCCH handover. To trigger an intra-cell TIGHT BCCH handover, the load of the non-BCCH frequencies should be higher than the Load Threshold for TIGHT BCCH HO.TIGHT BCCH HO Watch Time(s)This parameter corresponds to P of the P/N criterion for the TIGHT BCCH handover.According to the P/N criterion, if the load of a non-BCCH frequency is higher than the Load Threshold for TIGHT BCCH HO, the MS with conversation quality higher than the RX_QUAL Threshold for TIGHT BCCH HO and far from the cell edge is handed over to the TCH on the BCCH frequency. Thus, the TCHs on non-BCCH frequencies are reserved for other calls. This ensures the call performance of other calls.RXQUAL1If the receive level of the serving cell is smaller than or equal to 30, and if the uplink or downlink receive quality of the non-AMR FR voice service is greater than or equal to the value of this parameter, uplink interference or downlink interference exists.The value of this parameter corresponds to multiplying quality level 0 to 7 by 10.This parameter is used in handover decision. An uplink interference handover is easily triggered if this parameter is set to a too small value.RXLEVOffThis parameter specifies the quality level offset of the interface handover of the AMR FR service relative to non-AMR services or the AMR HR service (x 10). When determining whether an interference handover should be triggered, the system compares the receive quality of the MS minus the RXLEVOff with the handover threshold.For the AMR calls, this parameter, together with RXQUALn, is used in interference handover decision. An uplink interference handover is easily triggered if this parameter is set to a small value.

When n = 1, that is, when the receive level of the serving cell is smaller than or equal to 30, this parameter is invalid.For the AMR calls, this parameter, together with RXQUALn, is used in interference handover decision. An uplink interference handover is easily triggered if this parameter is set to a small value.DtxMeasUsedThis parameter is used as a switch to control the value determination method of measurement reports. When this parameter is set to Open, if DTX is used, the SUB values in the MR should be selected. Otherwise, the PULL values in the MR should be selected.When this parameter is set to 0 and if the measurement report indicates that DTX is not used, the FULLSET values should be selected. When this parameter is set to 0 and if the measurement report indicates that DTX is used, the SUBSET values should be selected. In latter cases, the SUBSET values should be used irrespective of how DTX is indicated in the subsequent measurement reports.When this parameter is set to 1, whether the FULLSET values or the SUBSET values should be selected depends on the DTX indication bit in the measurement report. That is, if the measurement report indicates that DTX is used, the SUBSET values should be selected; otherwise, the FULLSET values should be selected.Min UP Power on HO Candidate CellThe M criterion supports the minimum value constraint of uplink receive level of the adjacent cell.Expected uplink level of the adjacent cell >= (Min UP Power on HO Candidate Cell + Min Access Level Offset)The M criterion is met if the Filtered downlink level of the adjacent cell >= (Min DL Power on HO Candidate Cell + Min Access Level Offset); otherwise, the M criterion is not met.The value of this parameter ranges from 0 to 63 (corresponding to -110 dBm to -47 dBm).1. This parameter must be properly set because it limits the number of candidate cells. If this parameter is set to a too great value, some desired cells may be excluded from the candidate cells. If this parameter is set to a too small value, an unwanted cell may become the target cell. This leads to handover failures or call drops.2. A cell can become a candidate cell only when the uplink receive level minus this parameter is greater than the minimum access level offset.

Quick Handover Up Trigger Level(dB)During a measurement period, if the filtered uplink level of the serving cell is smaller than the value of this parameter, a fast handover is triggered.The level values 0 through 63 map to -110 dBm to -47 dBm.Quick Move Speed Threshold(m/s)During a measurement period, if the MS moves at a speed greater than the value of this parameter, a fast handover is triggered.Quick Handover Static Time(0.5s)The fast handover must comply with the P/N criterion. That is, the triggering conditions of fast handover must be met for N consecutive seconds within P seconds.This parameter corresponds to P of the P/N criterion. That is, if the triggering conditions of fast handover is met for a period longer than or equal to the value of this parameter, a fast handover is triggered.The greater the value of this parameter is set, the more difficult the fast-moving handover can be triggered.Serving Cell Filter Length MR NumberThis parameter specifies the number of measurement reports used for filtering after the BSC receives the measurement reports of the serving cell from the BTS. This helps to avoid improper handover decision based on a single inaccurate measurement report.If this parameter is set to a too great value, the filtered value is more accurate, but the time delay is longer. If this parameter is set to a too small value, the filtered value is inaccurate.[1,20]4Ignore Measurement Report NumberThis parameter specifies the allowed number of invalid measurement reports when the BSC uses the measurement reports for filtering. If the number of received measurement reports is smaller than or equal to the value of this parameter, no filtering is performed and no fast handover decision is made.This parameter can only be applied to the fast-moving handover.