Vamos Huawei

GSM BSS

VAMOSFeature Parameter Description

Copyright © Huawei Technologies Co., Ltd. 2012. All rights reserved.

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Contents1 About This Document

1.1 Scope

1.2 Intended Audience

1.3 Change History

2 Overview

3 Technical Description3.1 Overview

3.2 Key Terms

3.3 Modulation and Demodulation

3.3.1 Uplink SIC Demodulation

3.3.2 Downlink Alpha-QPSK Modulation

3.4 Multiplexing and Demultiplexing

3.4.1 Multiplexing

3.4.2 Demultiplexing

3.5 Power Control

3.5.1 Uplink SIC Power Control

Overview

Procedure of Uplink SIC Power Control

3.5.2 Downlink Alpha-QPSK Power Control

Overview

Procedure of Downlink Alpha-QPSK Power Control

4 Mute SAIC MS Identification

5 VAMOS Call Drop Solution

6 Automatic SAIC Capability Sharing

7 Related Features

8 Impact on the Network8.1 VAMOS

8.1.1 Impact on System Capacity

8.1.2 Impact on Network Performance

8.2 Mute SAIC MS Identification



8.3 VAMOS Call Drop Solution



9 Engineering Guidelines9.1 When to Use VAMOS

9.1.1 VAMOS

9.1.2 Mute SAIC MS Identification

9.1.3 VAMOS Call Drop Solution

9.2 Information to Be Collected

9.2.1 VAMOS



9.3 Network Planning

9.3.1 VAMOS



9.4 Deploying VAMOS

9.5 Deploying Mute SAIC MS Identification

9.6 Deploying VAMOS Call Drop Solution

9.7 Performance Optimization

9.7.1 VAMOS

9.7.2 Mute SAIC MS Identification and VAMOS Call Drop Solution

10 Parameters

11 Counters

12 Glossary

13 Reference Documents

1 About This Document

1.1 ScopeThis document describes the principles and functions of modulation, demodulation, multiplexing, demultiplexing, and power control of the Voice service over Adaptive Multi-user channels on One Slot (VAMOS) feature. It provides solutions to call drops that may occur when using the VAMOS feature and to identifying mute Single Antenna Interference Cancellation (SAIC) MSs. It also provides engineering guidelines for the configuration of this feature.

1.2 Intended AudienceThis document is intended for:

Personnel who need to understand the VAMOS feature

Personnel who work with Huawei GSM products

1.3 Change HistoryThis section provides information about the changes in different document versions.

There are two types of changes, which are defined as follows:

Feature change: refers to a change in the VAMOS feature of a specific product version.

Editorial change: refers to a change in wording or the addition of information that was not described in the earlier version.

Document Issues

The document issue is as follows:

01 (2012-04-28)

Draft A (2012-02-15)

01 (2012-04-28)

This is the first release of GBSS14.0.

Compared with issue draft A (2012-02-15) of GBSS14.0, issue 01 (2012-04-28) of GBSS14.0 has no change.

Draft A (2012-02-15)

This is a draft.

Compared with issue 01 (2011-03-31) of GBSS13.0, draft A (2012-02-15) of GBSS14.0 incorporates the changes described in the following table.

Change Type Change Description Parameter Change

Feature change

Added Chapter6 Automatic SAIC Capability Sharing None

Editorial change

Added the following chapters:

− Chapter 7 Related Features

− Chapter 8 Impact on the Network

Optimized Chapter 9 Engineering Guidelines

None

2 OverviewThe GBFD-115830 VAMOS feature is introduced in the GSM EDGE Radio Access Network (GERAN) evolution and is developed on the basis of Multi-User Reusing One Slot (MUROS). This feature expands the GERAN network capacity without adding transceivers (TRXs) or frequencies.

VAMOS applies to GSM networks for increasing voice service capacity. This feature multiplexes two calls onto one channel, especially one half-rate (HR) channel, to increase network capacity. Currently, Huawei's VAMOS allows two voice calls to be multiplexed only onto one HR channel. Figure 2-1 shows the uplink and downlink signal reception using VAMOS. On the uplink, the BTS receives signals from MS A and MS B and separately demodulates their signals. On the downlink, the BTS modulates the signals from MS A and MS B and then sends the modulated signals to the MSs simultaneously.

Figure 2-1 Uplink and downlink signal reception using VAMOS

To properly implement VAMOS, Huawei also provides the following VAMOS-related features:

GBFD-115831 Mute SAIC MS Identification

VAMOS uses a new modulation mode. Therefore, this feature requires that MSs support SAIC. On the live network, certain MSs support SAIC but report non-SAIC in the information element (IE) CLASSMARK3. These MSs are called mute SAIC MSs. Therefore, the GBFD-115831 Mute SAIC MS Identification feature is introduced. This feature enables the BSC to detect mute SAIC MSs, helping improve the VAMOS multiplexing rate.

GBFD-115832 Call Drop Solution

Currently, the mainstream multi-mode MSs in the market can report their SAIC capabilities to the BSC, but their calls may drop from VAMOS channels. Such call drops are caused by MSs with Automatic Frequency Correction (AFC) defects that are incompatible with VAMOS. To solve this problem, the GBFD-115832 Call Drop Solution feature is introduced.

Read documents Half-Rate Service Feature Parameter Description, Channel Management Feature Parameter Description, Handover Feature Parameter Description, and Power Control Feature Parameter Descriptionbefore reading this document.

3 Technical Description

3.1 OverviewVAMOS enables two calls to be multiplexed onto the same HR channel. In this way, voice signals of these calls are transmitted simultaneously. This may cause interference, deteriorating voice quality of the multiplexed calls. In addition, the power for the signals of the two calls overlaps, leading to an increase in the signal power on the HR channel and causing interference to the entire network. Therefore, when channel resources are congested, VAMOS multiplexing is recommended to improve network capacity; when the network load decreases, VAMOS demultiplexing is recommended to improve voice quality.

Assuming that two calls are multiplexed onto one HR channel:

On the uplink, the BTS receives voice signals of these two calls on the same HR channel simultaneously and needs to correctly demodulate these signals.

On the downlink, the BTS sends the voice signals to the two MSs on the same HR channel.

Therefore, VAMOS uses new modulation and demodulation algorithms: downlink Alpha-QPSK modulation and uplink SIC demodulation. For details, see chapter 3.3 Modulation and Demodulation.

When the traffic in a cell is heavy, HR channels are preferentially allocated to calls. If the radio resources are insufficient because the proportion of HR services reaches a threshold, VAMOS channels can be allocated to calls in the following situations:

For an established call, the BSC selects another established call that matches the call and converts them to VAMOS calls.

For a new call, the BSC selects an established call that matches the call and allocates the VAMOS HR channel used by the established call to the new call.

When channel resources are not congested, VAMOS demultiplexing is enabled to convert VAMOS HR channels back to common HR channels, improving voice quality.

For details about VAMOS multiplexing and demultiplexing, see section 3.4 Multiplexing and Demultiplexing.

After VAMOS is enabled, power control is required to eliminate interference caused by VAMOS multiplexing. Interference is generated between VAMOS calls, deteriorating their voice quality. In addition, VAMOS calls cause interference to other calls. Therefore, the overall network quality deteriorates. To solve these problems, uplink SIC power control and downlink Alpha-QPSK power control are introduced. For details, see section 3.5 Power Control.

3.2 Key Terms VAMOS HR channel

One timeslot on a TRX can be configured as one full-rate (FR) channel or two HR channels. After VAMOS is enabled, if a timeslot is configured as two HR channels, each HR channel serves as two VAMOS HR channels. In this way, one timeslot can be configured as four VAMOS HR channels. The following table lists the channel configuration.

FR Channel No. 0

HR Channel No. 0 1

VAMOS HR Channel No. 0 2 1 3

VAMOS HR channel multiplexing

Two calls occupy the same VAMOS HR channel on an HR channel. VAMOS HR channel multiplexing can be implemented using channel allocation or intra-cell handover.

VAMOS HR channel multiplexing handover

The BSC multiplexes two suitable calls onto one VAMOS HR channel of the same HR channel using intra-cell handover.

3.3 Modulation and Demodulation

3.3.1 Uplink SIC Demodulation

VAMOS uses SIC as the uplink demodulation algorithm. The BTS receives information from two MSs on the same HR channel, obtains the data to be decoded and the information in the measurement reports using high- and low-power user demodulation, and then decodes their respective data.

As shown in Figure 3-1, SIC first uses the Interference Rejection Combining (IRC) algorithm to demodulate the signals of the high-power MS to obtain its data using channel decoding, and then subtracts the signals of the high-power MS from the total received signals, and finally performs IRC demodulation on the signals of the low-power MS to obtain its data using channel decoding.

Figure 3-1 SIC demodulation

Uplink SIC demodulation requires that there be a power difference between the two multiplexed calls. Therefore, the power of these calls needs to be adjusted accordingly using VAMOS uplink power control.

3.3.2 Downlink Alpha-QPSK Modulation

VAMOS uses alpha-QPSK as the downlink modulation algorithm. Alpha-QPSK supports VAMOS multiplexing through handover and can adjust the modulation method of an ongoing call.

In alpha-QPSK modulation, the power of the two multiplexed calls can be adjusted by changing the value of α (0 ≤ α ≤ 21/2). Downlink alpha-QPSK demodulation requires that there be a power difference between two multiplexed calls. Therefore, their power needs to be adjusted accordingly using VAMOS downlink power control. Figure 3-2 shows the downlink alpha-QPSK modulation procedure.

Figure 3-2 Downlink alpha-QPSK modulation

3.4 Multiplexing and DemultiplexingVAMOS multiplexing enables several suitable calls to be multiplexed onto a channel without adding TRXs or frequencies. This helps expand the network capacity and maximize the network resource usage.

After VAMOS multiplexing is enabled, if the voice quality deteriorates or the cell load is lower than or equal to a specified threshold, VAMOS calls in the cell are demultiplexed using handover.

In addition, calls on a specified HR channel can be forcibly handed over to a VAMOS HR channel and calls on a VAMOS HR channel can be forcibly handed over to an idle HR channel using MML commands.

3.4.1 Multiplexing

VAMOS multiplexing involves candidate VAMOS call decision and VAMOS multiplexing decision, as shown in Figure 3-3.

Figure 3-3 VAMOS multiplexing

Candidate VAMOS Call Decision

A candidate VAMOS call decision is triggered when the cell load is greater than VamosMultLoadThd.

1. For common cells

Decision for selecting a new call as a candidate VAMOS call during channel allocation

If both VamosSwitch and VamosAssSwitch are set to ON(On), the decision for selecting a new call as a candidate VAMOS call during channel allocation can be performed.

Before allocating an HR channel to a new call during channel allocation, the BSC checks whether the call meets the requirements for candidate VAMOS calls. If the call meets the requirements, the BSC selects the call as a candidate VAMOS call and allocates the call an HR channel used by an established call in the candidate call queue.

A new call can be selected as a candidate VAMOS call when the following conditions are met:

− Adaptive Cell Border (ATCB) meets the requirement of a certain type of MS.

− Downlink receive level ≥ VamosIntraHoDlRxlevThd + VamosAssDlRxlevThdOffset

− Uplink receive quality ≤ VamosIntraHoUlQualThd – VamosAssUlQualThdOffset

− Downlink receive quality ≤ VamosIntraHoDlQualThd – VamosAssUlQualThdOffset

Decision for selecting an established call as a candidate VAMOS call

If VamosSwitch is set to ON(On), the decision for selecting an established call as a candidate VAMOS call can be performed.

After receiving measurement reports (MRs) of an established call on an HR channel, the BSC checks whether the call meets the requirements for candidate VAMOS calls. If the call meets the requirements, the BSC selects the call as a candidate VAMOS call and adds it to the corresponding candidate VAMOS call queue based on the MS's capability.

An established call can be selected as a candidate VAMOS call when the following conditions are met:

− ATCB meets the requirement of a certain type of MS.

− Downlink receive level ≥ VamosIntraHoDlRxlevThd

− Uplink receive quality ≤ VamosIntraHoUlQualThd

− Downlink receive quality ≤ VamosIntraHoDlQualThd

− The P/N criterion is satisfied. That is, the call meets the preceding three conditions for the period specified by VamosOldCallLastTimes (P) within the period specified byVamosOldCallStatTimes (N). The recommended value of P is 2, and the recommend value of N is 3.

2. For concentric cells:

Decision for selecting a new call as a candidate VAMOS call during channel allocation

− The process in the underlaid subcell is the same as that in a common cell.

The process in the overlaid subcell is as follows:

If both VamosSwitch and VamosAssSwitch are set to ON(On), the decision for selecting a new call as a candidate VAMOS call during channel allocation can be performed.

Before allocating an idle HR channel to a new call during channel allocation, the BSC checks whether the call meets the requirements for candidate VAMOS calls. If the call meets the requirements, the BSC selects the call as a candidate VAMOS call and allocates the call an HR channel used by an established call in the candidate call queue.

A new call can be selected as a candidate VAMOS call when the following conditions are met:


− Downlink receive level ≥ VamosIntraHoDlRxlevThd + VamosAssDlRxlevThdOffset + VAMOSOLRXLEVOFT

− Uplink receive quality ≤ VamosIntraHoUlQualThd – VamosAssUlQualThdOffset –VAMOSOLRXQUALOFT

− Downlink receive quality ≤ VamosIntraHoDlQualThd – VamosAssUlQualThdOffset –VAMOSOLRXQUALOFT

Decision for selecting an established call as a candidate VAMOS call

− The process in the underlaid subcell is the same as that in a common cell.

The process in the overlaid subcell is as follows:

If VamosSwitch is set to ON(On), the decision for selecting an established call as a candidate VAMOS call can be performed.

After receiving MRs of an established call on an HR channel, the BSC checks whether the call meets the requirements for candidate VAMOS calls. If the call meets the requirements, the BSC selects the call as a candidate VAMOS call and adds it to the corresponding candidate VAMOS call queue based on the MS's capability.

An established call can be selected as a candidate VAMOS call when the following conditions are met:


− Downlink receive level ≥ VamosIntraHoDlRxlevThd + VAMOSOLRXLEVOFT

− Uplink receive quality ≤ VamosIntraHoUlQualThd – VAMOSOLRXQUALOFT

− Downlink receive quality ≤ VamosIntraHoDlQualThd – VAMOSOLRXQUALOFT

− The P/N criterion is satisfied. That is, the call meets the preceding three conditions for the period specified by VamosOldCallStatTimes (P) within the period specified byVamosOldCallLastTimes (N). The recommended value of P is 2, and the recommend value of N is 3.

Decision on Triggering VAMOS Multiplexing

VAMOS multiplexing can be triggered either during channel allocation or intra-cell handover. Figure 3-4 shows the VAMOS multiplexing decision procedure.

Figure 3-4 Decision on triggering VAMOS multiplexing

VAMOS multiplexing during channel allocation

VAMOS multiplexing during channel allocation is triggered when a new call requests an HR channel. If VamosSwitch and VamosAssSwitch are set to ON(On), the BSC decides whether to trigger VAMOS multiplexing before allocating an idle HR channel to a call.

The BSC checks the cell load. If the cell load is higher than VamosMultLoadThd, the BSC determines whether this call can be selected as a candidate VAMOS call.

− If the call is a candidate VAMOS call, the BSC traverses the queues of all candidate established VAMOS calls and selects a suitable call to be multiplexed with the new call onto the same HR channel.

− If the call is not a candidate VAMOS call, the BSC allocates an idle HR channel to the call following the normal channel allocation procedure.

VAMOS multiplexing during intra-cell handover

If VamosSwitch and VamosIntraHoSwitch are set to ON(On), the BSC checks the cell load after selecting an idle HR channel for a call.

− When the cell load is higher than VamosMultLoadThd, the BSC selects some suitable candidate VAMOS calls from the corresponding queues for multiplexing and then initiates intra-cell handovers.

− When the cell load is lower than or equal to VamosMultLoadThd, the BSC stops VAMOS multiplexing.

3.4.2 Demultiplexing

If the voice quality of a multiplexed call deteriorates or the cell load is lower than VamosLoadReuseLoadThd after VAMOS multiplexing, VAMOS demultiplexing is triggered.

The handover for VAMOS demultiplexing, which is a type of intra-cell handover, takes precedence over the handover from an HR channel to an FR channel.

VAMOS Demultiplexing Due to Poor Voice Quality

If VamosSwitch and VamosQualReuseSwitch are set to ON(On), the BSC monitors the voice quality of multiplexed calls in real time. Based on the uplink or downlink receive quality of a multiplexed call, the BSC determines whether to trigger VAMOS demultiplexing by using the P/N criterion.

1. For common cells

The uplink or downlink receive quality requirements of a multiplexed call to be demultiplexed are as follows:

Uplink receive quality ≥ VamosQualReuseUpLinkQualThd.

Downlink receive quality ≥ VamosQualReuseDownLinkQualThd.

If the uplink or downlink receive quality of a multiplexed call meets these requirements, VAMOS demultiplexing is deemed necessary. In this case, the BSC hands over the call with better voice quality to an idle HR channel.

2. For concentric cells

The uplink or downlink receive quality requirements of a multiplexed call to be demultiplexed in the underlaid subcell are the same as those in a common cell.

The uplink or downlink receive quality requirements of a multiplexed call to be demultiplexed in the overlaid subcell are as follows:

− Uplink receive quality ≥ VamosQualReuseUpLinkQualThd –VAMOSDEPOLRXQUALOFT

− Downlink receive quality ≥ VamosQualReuseDownLinkQualThd –VAMOSDEPOLRXQUALOFT

VAMOS Demultiplexing Due to Low Cell Load

If VamosSwitch and VamosLoadReuseSwitch are set to ON(On), the BSC monitors the cell load in real time. If the cell load is lower than or equal to VamosLoadReuseLoadThd, the call with a larger ATCB value in each pair of multiplexed calls is handed over to an idle HR channel.

A call with a larger ATCB value is closer to the cell center. The other call continues to occupy the HR channel. If the cell load is higher than VamosLoadReuseLoadThd, no handling is required.

Channel Allocation After the Handover for VAMOS Demultiplexing

After the handover for VAMOS demultiplexing is triggered, an HR channel is preferentially selected. The procedure for selecting a target channel is the same as that in a common intra-cell handover. If there is no idle HR channel, the handover for VAMOS demultiplexing is terminated.

3.5 Power Control

3.5.1 Uplink SIC Power Control

Overview

When VAMOS is enabled in situations of loose frequency reuse and limited network capacity, the BSC enables uplink SIC power control on multiplexed calls after preprocessing the MRs for both calls to keep the power of these calls within an acceptable range.

Uplink SIC power control is enabled when both VamosSwitch and SicPwrCtrlSwitch are set to ON(On).

Uplink SIC power control is performed only on VAMOS calls multiplexed onto HR channels.

Procedure of Uplink SIC Power Control

After starting the uplink power control procedure, the BSC checks whether the current call for power control is multiplexed with another call on an HR channel for VAMOS multiplexing. If so, the uplink SIC power control procedure is started; if not, the common uplink power control procedure is started.

After the uplink SIC power control procedure has started, the BSC preprocesses the MRs for both calls and then decides whether to enable joint power control on the multiplexed calls. With joint power control, the receive levels of the two calls can be kept within an acceptable range. Before the BSC enables joint power control, the initial uplink power levels of the two calls remain unchanged.

Figure 3-5 shows the uplink SIC power control procedure.

Figure 3-5 Uplink SIC power control procedure

In Figure 3-5, the uplink SIC power control decision, as well as the execution of power control, is triggered on the two multiplexed calls simultaneously.

1. MR preprocessing

The MRs of two multiplexed calls are preprocessed separately. In uplink SIC power control, MR preprocessing procedures, such as interpolating and filtering, are the same as those in the optimized Huawei power control algorithm III.

2. Power control procedure selection

After preprocessing the MRs of a call, the BSC checks whether the call is multiplexed with another call on an HR channel for VAMOS multiplexing. If the call is not multiplexed with another call on an HR channel, the BSC enables common power control on this call. If the call is multiplexed with another call on an HR channel, the BSC checks whether VamosSwitch andSicPwrCtrlSwitch are set to ON(On). If they are set to ON(On), the BSC enables joint uplink SIC power control on the two calls; if either is set to OFF(Off), the BSC terminates the uplink power control procedure.

3. MR synchronization

The power control decision is triggered by an MR. Therefore, either of the MRs of the two multiplexed calls can trigger the power control decision because their MRs are preprocessed separately. The BSC makes the uplink SIC joint power control decision after preprocessing the MRs of both calls.

4. Uplink SIC power control decision

The decision on whether to trigger uplink SIC power control consists of the calculation of power control steps, estimation of receive levels, and adjustment of power control steps.

Calculation of power control steps

Power control steps are calculated on the basis of the power level required by each multiplexed call. The power level required by each multiplexed call is calculated on the basis of their respective levels and quality after periodical filtering.

Estimation of receive levels

Receive levels in the subsequent measurement report period are estimated based on the level after compensation and filtering in the current measurement report period and the calculated power control step of each call.

Adjustment of power control steps

When the difference between estimated levels of two multiplexed calls is higher than SicDiffHighThd, the power control step of each call is adjusted so that the difference is equal toSicDiffHighThd.

5. Execution of power control

3.5.2 Downlink Alpha-QPSK Power Control

Overview

When VAMOS is enabled in situations of loose frequency reuse and limited network capacity, the BSC enables downlink alpha-QPSK power control on multiplexed calls. This guarantees the voice quality of multiplexed calls and reduces power consumption and interference.

Downlink alpha-QPSK power control is enabled when VamosSwitch and AlphaQpskCtrlSwitch are set to ON(On).

Downlink alpha-QPSK power control is performed only on VAMOS calls multiplexed onto HR channels.

Procedure of Downlink Alpha-QPSK Power Control

After the downlink power control procedure has started, the BSC checks whether the current candidate call for power control is multiplexed with another call on an HR channel for VAMOS multiplexing. If they are multiplexed, the downlink alpha-QPSK power control procedure is started; if they are not multiplexed, the common downlink power control procedure is started.

After the downlink alpha-QPSK power control procedure is started, the BSC preprocesses the MRs for both calls and then decides whether to enable joint power control on the two calls. Before the BSC enables joint power control, the initial BTS power level and the alpha value remain unchanged.

Figure 3-6 shows the downlink alpha-QPSK power control procedure.

Figure 3-6 Downlink alpha-QPSK power control procedure

In Figure 3-6, the downlink alpha-QPSK power control decision, as well as the execution of power control, is triggered on the two multiplexed calls simultaneously.

1. MR preprocessing

The MRs of two multiplexed calls are preprocessed separately. In downlink alpha-QPSK power control, the optimized Huawei power control algorithm III must be enabled. Additionally, MR preprocessing procedures, such as interpolating and filtering, are similar to those in the optimized Huawei power control algorithm III, but require additional processing that is not described in this document.

2. Power control procedure selection

After preprocessing the MRs of a call, the BSC checks whether the call is multiplexed with another call on an HR channel for VAMOS multiplexing. If the call is not multiplexed with another call on an HR channel, the BSC enables common power control on this call. If the call is multiplexed with another call on an HR channel, the BSC checks whether VamosSwitch andAlphaQpskCtrlSwitch are set to ON(On). If they are set to ON(On), the BSC initiates the downlink alpha-QPSK power control procedure; if either is set to OFF(Off), the BSC terminates the downlink power control procedure.

3. MR synchronization

The power control decision is triggered by an MR. Therefore, either of the MRs of the two multiplexed calls can trigger the power control decision because their MRs are preprocessed separately. The BSC makes the downlink alpha-QPSK power control decision after preprocessing the MRs of both calls.

4. Downlink alpha-QPSK power control decision

The decision on whether to trigger downlink alpha-QPSK power control consists of calculation of BTS power control step before adjusting the alpha value, adjustment of the alpha value, compensation for the BTS power control step before adjusting the alpha value, and determination of the final BTS power control step.

Calculation of the BTS power control step before alpha value adjustment

The BTS power control step before adjusting the alpha value is calculated on the basis of the power required by each multiplexed call. The power required by each call is calculated on the basis of their respective levels and quality after periodical filtering.

Adjustment of the alpha value

The alpha value is adjusted on the basis of the carrier-to-interface ratio (C/I) of each multiplexed call after filtering.

Compensation for the BTS power control step before alpha value adjustment

Determination of the final BTS power control step

5. Execution of power control

4 Mute SAIC MS IdentificationCertain MSs support SAIC but report non-SAIC in the IE CLASSMARK3. These MSs are called mute SAIC MSs. If an MS is considered as SAIC incapable, the BSS does not multiplex the MS with another one. As a result, the number of MSs for VAMOS multiplexing decreases and network capacity decreases.

To prevent the preceding situation, the Mute SAIC MS Identification feature is introduced. This feature is implemented as follows:

1. The BSC records the information about whether each model of MS is a mute SAIC MS.

2. Before allocating a channel to an MS, the BSC obtains the International Mobile Equipment Identity (IMEI) of the MS and then checks whether this MS is a mute SAIC MS.

3. The BSC multiplexes the mute SAIC MS with another MS based on the priority of the mute SAIC MS.

With this feature, the network can identify the MS capability correctly so that VAMOS multiplexing can be applied to all SAIC-capable MSs. This increases the number of MSs available for VAMOS multiplexing and therefore expands the network capacity.

This feature can be enabled in a cell by setting MuteSaicIdeSwitch to ON(On) and the function for processing mute SAIC MSs can be enabled by setting MuteSaicSwitch to ON(On).

5 VAMOS Call Drop SolutionCurrently, the mainstream MSs in the market support SAIC, however, call drops are likely to occur when the VAMOS feature is enabled. The call drops are caused by MSs with AFC defects that are incompatible with VAMOS.

To solve this issue, the VAMOS Call Drop Solution feature is introduced. This feature is implemented as follows:

1. The SAIC MS capability database is created on the BSC. The database contains the types of SAIC MSs. SAIC MSs are classified into the following types:

− White SAIC MS: refers to the MSs that support SAIC and can be properly used.

− Black SAIC MS: refers to the MSs that support SAIC but cannot be properly used.

− Gray SAIC MS: refers to problem SAIC MSs.

2. Before channel allocation, the BSC obtains the IMEIs of MSs and identifies the type of each MS based on the information recorded in the SAIC MS capability database during multiplexing.

3. White and gray SAIC MSs support VAMOS multiplexing. After VAMOS multiplexing is triggered, the BSC notifies the BTS of the power control policy for the calls performed by white or gray SAIC MSs.

With the help of this solution, call drops no longer occur when the MS with an AFC defect is multiplexed with another MS on an HR channel. This increases network capacity and guarantees service continuity.

Identification of problem SAIC MSs can be enabled in a cell by setting SaicProMsIdeSwitch to ON(On) and the function for processing problem SAIC MSs can be enabled by settingSaicProMsSwitch to ON(On).

6 Automatic SAIC Capability SharingThe VAMOS feature provides an SAIC MS capability database, which contains the VAMOS capabilities of different types of SAIC MSs. After identifying the SAIC capability of an MS, such as a mute SAIC MS, black SAIC MS, or gray SAIC MS, the BSC saves the information only to its own SAIC MS capability database. To share the SAIC capability data of the BSC with other BSCs, you need to copy the identification results to these BSCs and run MML commands to make the identification results take effect in these BSCs. Therefore, the automatic SAIC capability sharing function is introduced, which automatically allows a BSC to share its SAIC capability data with another BSC.

On the M2000, users can select several BSCs as source BSCs to provide VAMOS SAIC MS capability databases and select several BSCs as destination BSCs. As shown in Figure 6-1, for example, BSC 1 and BSC 2 serve as source BSCs; BSC 1, BSC 2, BSC 3, and BSC 4 serve as destination BSCs. Source BSCs upload data to the M2000, and the M2000 delivers the data to the destination BSCs to ensure data sharing.

Figure 6-1 Automatic SAIC capability sharing

The automatic SAIC capability sharing function has the following advantages:

Effectively improves inter-BSC data sharing capability.

Minimizes the impact of Mute SAIC MS Identification and VAMOS Call Drop Solution on KPIs.

Increases the commercial use probability of VAMOS by reducing manual invention.

7 Related FeaturesTable 7-1 Related features

Feature Prerequisite Feature

Mutually Exclusive Feature Affected Feature

VAMOS GBFD-117601 HUAWEI III Power Control Algorithm

GBFD-117301 Flex Abis or GBFD-118611 Abis IP over E1/T1 or GBFD-118601 Abis over IP

GBFD-115502 AMR HR or GBFD-113401 Half Rate Speech

GBFD-118103Network Support SAIC

GBFD-117501 Enhanced Measurement Report (EMR)

GBFD-117001 Flex MAIO

GBFD-510104 Multi-site Cell

GBFD-113521 A5/1 Encryption Flow Optimization

GBFD-510101 Automatic Frequency Correction (AFC)

GBFD-114001 Extended Cell

GBFD-113501 A5/1 and A5/2 Ciphering Algorithm

GBFD-113503 A5/3 Ciphering Algorithm

GBFD-114801 Discontinuous Transmission (DTX)-Downlink

GBFD-114803 Discontinuous Transmission (DTX)-Uplink

NOTE:The ciphering algorithms A5/1, A5/2, and A5/3 randomize signals of two multiplexed VAMOS calls, minimizing the correlation and improving the demodulation performance. After DTX is enabled, interference between these two calls is reduced, improving the demodulation performance.

Mute SAIC MS Identification

GBFD-115830 VAMOS

GBFD-115702 TrFO GBFD-113501 A5/1 and A5/2 Ciphering Algorithm or GBFD-113503 A5/3 Ciphering Algorithm

NOTE:The ciphering algorithms A5/1, A5/2, and A5/3 randomize signals of two multiplexed VAMOS calls, minimizing the correlation and improving the demodulation performance.

VAMOS Call Drop Solution

GBFD-115830 VAMOS

GBFD-115702 TrFO GBFD-113501 A5/1 and A5/2 Ciphering Algorithm or GBFD-113503 A5/3 Ciphering Algorithm

NOTE:The ciphering algorithms A5/1, A5/2, and A5/3 randomize signals of two multiplexed VAMOS calls, minimizing the correlation and improving the demodulation performance.

8 Impact on the Network

8.1 VAMOS


VAMOS aims to expand the capacity of a GSM network without adding TRXs or frequencies. Without additional any configurations, VAMOS increases the traffic volume. In the scenario with loose frequency reuse and a high VAMOS MS penetration rate, VAMOS can significantly increase the network capacity.


Although VAMOS expands the network capacity and reduces the network congestion rate, it affects the voice quality and deteriorates some other KPIs. The KPIs related to voice quality include the high quality indicator (HQI), call drop rate, handover success rate, and mean opinion score (MOS). Therefore, it is recommended that half-rate (HR) channels be preferentially enabled to increase network capacity and VAMOS be enabled only when network capacity needs to be further increased. VAMOS is not recommended for the operators that have high requirements for voice quality.

VAMOS increases resource usage. Therefore, after VAMOS is enabled, the transmission resource usage over the Abis and A interfaces, CPU and DSP usage of the hardware equipment, and memory usage increase.

8.2 Mute SAIC MS Identification


With the Mute SAIC MS Identification feature, the BSC can identify mute SAIC MSs. This helps increase the SAIC MS penetration rate, expand the VAMOS application range, and increases the system capacity.


This feature increases the call access delay and has a certain negative impact on the HQI and call drop rate. You are advised to disable this feature after information about mute SAIC MSs have been collected.

8.3 VAMOS Call Drop Solution


None


The VAMOS Call Drop Solution feature increases the call access delay and has a negative impact on the HQI and call drop rate.

You are advised to disable this feature after information about mute SAIC MSs have been collected. After this feature is disabled, the HQI increases and the call drop rate decreases.

9 Engineering Guidelines

9.1 When to Use VAMOS

9.1.1 VAMOS

If the current HR channel usage is greater than or equal to 75%, VAMOS multiplexing and demultiplexing are enabled.

Enabling VAMOS deteriorates the voice quality. Therefore, it is recommended that VAMOS not be used in areas with high voice quality requirements or for calls of high-priority users.


It is recommended that the Mute SAIC MS Identification feature be used in the early phase when VAMOS is enabled. After information about mute SAIC MSs is collected, disable this feature because it has a negative impact on KPIs. Set the MuteSaicIdeSwitch parameter to ON(On) at a certain interval to collect information about new MSs in the market.


It is recommended that the VAMOS Call Drop Solution feature be used in the early phase when VAMOS is enabled. After MS information is collected, set the SaicProMsIdeSwitch parameter to OFF(Off) and keep the SaicProMsSwitch parameter set to ON(On) . Set the SaicProMsIdeSwitch parameter to ON(On) at a certain interval to collect information about new MSs in the market.

9.2 Information to Be Collected

9.2.1 VAMOS

Before deploying VAMOS, collect the following information:

MS penetration rate

VAMOS requires support from MSs at least supporting SAIC. The proportion of VAMOS MSs should be greater than 40%.

Proportion of HR services

The proportion of HR services affects the gains using this feature because it supports only HR and AMR HR.

The gains using this feature are large when it is used in the scenario where the busy-hour traffic is heavy and the proportion of HR services is greater than 80%.

VAMOS area

According to the principle for VAMOS multiplexing call decision, VAMOS multiplexing can apply only to calls meeting the signal quality, receive level, and ATCB threshold. A VAMOS area refers to an area where the proportion of calls meeting the preceding requirements reaches a specified threshold in a cell.

Based on the MS penetration rate, proportion of HR services, and VAMOS areas, the gains using VAMOS can be estimated. You can compare the required gains and expected gains to determine whether to optimize the network before enabling VAMOS. The comparison result provides reference for verifying the VAMOS effect.

Traffic measurement counters and data configuration

Collect busy-hour traffic measurement counters and data configuration on the live network within at least one week before VAMOS is deployed.


None


None

9.3 Network Planning

9.3.1 VAMOS

TSC Planning

TSC planning method when VAMOS is not enabled

Training sequence codes (TSCs) and base station color codes (BCCs) are bound together on a network. TSCs are planned randomly.

TSC planning methods when VAMOS is enabled

Two MSs multiplexed onto the same VAMOS HR channel must use different TSCs. Currently, no VAMOS I or VAMOS II MSs are in use. Therefore, only TSCs from 0 to 7 can be used. If VAMOS is enabled for all cells on a network, each cell requires two TSCs. From the perspective of the entire network, the TSC reuse rate decreases, which shortens the distance between cells using the same TSCs.

When the timeslots of different cells are aligned, the cells may use the same frequencies and TSCs, which affects network performance. To avoid this, the TSCs must be replanned before VAMOS is enabled to maximize the distance between cells that use the same TSCs. After VAMOS is enabled, each cell requires two TSCs. In this case, the secondary TSC also needs to be planned to ensure that cells using the same TSCs are as far as possible from each other.

TSCs are planned as follows:

There are eight TSC groups.

Each group consists of primary and secondary TSCs.

Common calls use primary TSCs, and suitable VAMOS calls use both primary and secondary TSCs.

Eight TSC groups are as follows:

− Group 1: 0, 2

− Group 2: 1, 7

− Group 3: 5, 6

− Group 4: 4, 3

− Group 5: 2, 0

− Group 6: 7, 1

− Group 7: 6, 5

− Group 8: 3, 4

The TSC reuse distance between the BTSs using the same frequencies must be as long as possible.

The priorities for TSC groups are planned based on the TSC correlation and impact on network performance.

Capacity Planning

Based on the HR function, VAMOS HR allows four calls to share one timeslot. This saves channel resources, improves network capacity, and reduces the network congestion rate.

For an inventory network, enabling VAMOS does not affect the existing capacity planning. You only need to enable VAMOS-related functions in the areas with network congestion and adjust the VAMOS proportion by modifying related algorithm parameters to solve network congestion issues.

For a newly deployed network, VAMOS, equivalent to the HR function, helps capacity planning by estimating the VAMOS proportion and the traffic bearing capabilities of TRX boards.

The following example is used to describe capacity gains using VAMOS. Assume that MSs are evenly distributed and MSs with the C/I greater than 18 dB can use VAMOS HR. The procedure for estimating capacity gains is as follows:

Step 1 Evaluate the proportion of MSs with the C/I greater than 18 dB. For example, the bandwidth of a network is 17.5 MHz, the average site configuration mode is S6/6/5, and the C/I distribution is simulated as shown in Figure 9-1. The estimated proportion of MSs with the C/I greater than 18 dB is 53%.

Figure 9-1 Network C/I distribution

Step 2 Evaluate the SAIC MS penetration rate on the network. Based on raw traffic statistics, the ratio of ZTCA3352B to ZTCA3350G is the SAIC MS penetration rate, that is, 50%, as listed inTable 9-1.

Table 9-1 SAIC MS penetration rate

ZTCA3350G: Number of Calls Originated or Terminated by MSs Supporting Early Classmark Sending per BSC

ZTCA3352B: Number of Calls Originated or Terminated by MSs Supporting SAIC per BSC

SAIC MS Penetration Rate

Proportion of SAIC MSs

189804 95000 50.1%

Step 3 Evaluate the maximum VAMOS HR proportion. If MSs are evenly distributed, the maximum VAMOS HR proportion is the value of the proportion of MSs with the C/I greater than 18 dB multiplied by the SAIC MS penetration rate. In this example, the maximum VAMOS HR proportion is 26.5%, which is calculated by 53% multiplied by 50%.

Step 4 Evaluate capacity gains. If the maximum VAMOS HR proportion is 26.5% and each two SAIC MSs are combined, the SAIC MSs require only half of the original channel resources, that is, 13.25% (26.5% divided by 2). In this case, the network resources saved during busy hours is 13.25%, which is calculated with the following formula:Network resources saved during busy hours = 53% x 50% x 50%

----End

Capacity gains using VAMOS on other networks can be estimated according to the preceding procedure. When estimating capacity gains, pay attention to the following points:

The limitation of the BTS hardware to the VAMOS capability must be considered for estimating the maximum VAMOS HR proportion. If the maximum VAMOS HR proportion calculated on the basis of the SAIC MS penetration rate exceeds the BTS hardware capability, the maximum VAMOS HR proportion depends on the BTS hardware capability.

The VAMOS HR proportion is determined by the uplink and downlink quality bands of MSs, distance between an MS and the BTS, and the network load. Modifying related parameters lead to a change in the VAMOS HR proportion. The preceding example provides a simple evaluation of the maximum VAMOS HR proportion based on the VAMOS conversion conditions for the downlink quality.

The live network situation may differ from the network simulation and MS distribution. The VAMOS HR proportion calculated in the preceding example is an elementary evaluation.

The maximum VAMOS HR proportion is a theoretical value because VAMOS HR conversion is triggered only when the network is congested or the cell load is high.

VAMOS HR may have a negative impact on the network performance. The larger the VAMOS HR proportion, the more the network performance deteriorates. In this case, the VAMOS HR proportion should be decreased to meet requirements of operators for the acceptable performance deterioration degree. The impact of the VAMOS HR proportion on the network quality, MOS, and KPIs needs to be verified on the live network.

Currently, no VAMOS I or VAMOS II MSs are in use. Therefore, you only need to obtain the proportion of SAIC MSs on the live network.

Equipment Planning

1. Overview

VAMOS improves single-timeslot voice service capacity without adding frequencies. Therefore, VAMOS has an impact on network transmission resources and BSS equipment resources.

VAMOS has an impact on the BTS in the following aspects:

− Transmission resources

Abis transmission resources are E1/T1 cables, network cables, and optical fibers. VAMOS requires more Abis transmission resources when the configurations remain unchanged.

For example, when E1 transmission is used, E1 cables need to be added over the Abis interface to meet the increased traffic volume.

You can determine whether to add transmission resources by comparing the existing configured transmission resources with the expected configured transmission resources. If the existing transmission resources are sufficient and exceeds the transmission resources required by VAMOS, no additional transmission resource is required.

− Interface resources

When transmission resources are added, the Abis interface resources also need to be added. To be specific, you need to add interface boards to the BTS to provide more E1, T1, FE, or GE ports.

Whether to add interface resources is determined by the amount of configured interface resources together with the amount of required interface resources. You do not need to add interface resources if the configured interface resources can fully meet the requirements after VAMOS is enabled.

VAMOS has an impact on the BSC in the following aspects:

− Transmission resources

Transmission resources over the Abis, Ater, and A interfaces are E1/T1 cables, network cables, and optical fibers. When the configurations remain unchanged, more Abis, Ater, and A interface transmission resources are required after VAMOS is enabled.

Assume that the Abis, Ater, and A interfaces use E1 transmission. The existing E1 cables do not meet service requirements if the traffic volume increases after VAMOS is enabled. In this case, add E1 cables over the Abis, Ater, and A interfaces.

Whether to add transmission resources is determined by the amount of configured transmission resources together with the amount of required transmission resources. You do not need to add transmission resources if the configured transmission resources can fully meet service requirements after VAMOS is enabled.

− Interface resources

When transmission resources are added, the Abis, Ater, and A interface resources also need to be added. To be specific, you need to add interface boards to the BSC to provide more E1, T1, FE, or GE ports.

Whether to add interface resources is determined by the amount of configured interface resources together with the amount of required interface resources. You do not need to add interface resources if the configured interface resources can fully meet the requirements after VAMOS is enabled.

− Service processing resources

After VAMOS is enabled, the number of speech path increases. This requires that the BSC improve its capability in processing speech frames. Therefore, the processing capability of DPUC boards in TC subracks needs to be improved. A DPUC board, however, can process only a certain number of speech paths. Therefore, the number of DPUC boards needs to be increased.

Whether to add DPUC boards is determined by the number of configured DPUC boards together with the number of required DPUC boards. You do not need to add DPUC boards if the number of speech paths supported by the configured DPUC boards is more than that after VAMOS is enabled.

2. Scenario and configurations

The following scenario is used as an example to describe the impact of VAMOS on transmission and equipment resources for better equipment planning.

Figure 9-2 shows the network scenario. In this scenario, a BSC6900 manages 100 DBS3900s, and the TC subrack may be located either on the BSC or MSC side.

Figure 9-2 Network scenario

Table 9-2 and Table 9-3 describe basic BTS and BSC data configurations in this scenario.

Table 9-2 BTS data configuration

Data Type Data Item Value

Public parameters Site configuration mode S4/4/4

Transmission bandwidth usage 85%

Whether to enable IP MUX Yes/No

PS service parameters Number of busy-hour activated PDCHs 18

PS service coding scheme MCS-6

PS service activity factor 0.5

CS service parameters Proportion of HR services 75%

Full-rate coding scheme FR

Half-rate coding scheme HR

Um-interface congestion rate 2%

Peak-hour traffic volume (Erlang) 87.49

CS service activity factor 0.5

Each BTS is configured with one E1 cable.

Table 9-3 BSC data configuration

Data Type Data Name Value

Traffic model Peak-hour traffic volume (Erlang) 8749

Busy-hour traffic volume per user 0.02

Data Type Data Name Value

Average call duration (second) 45

Proportion of originated calls 35%

Proportion of terminated calls 65%

Number of busy-hour location updates 1.2

Number of busy-hour originated calls 0.56

Number of busy-hour terminated calls 1.04

Number of busy-hour sent short messages

1

Number of busy-hour received short messages

1

Intra-BSC handover 0.9

Inter-BSC handover 0.1

Proportion of HR services 75%

Full-rate coding scheme FR

Half-rate coding scheme HR

CS service activity factor 0.5

Um-interface congestion rate 2%

Transmission parameters A IP over FE/GE compression algorithm UDP MUX + cRTP

A IP over E1/T1 compression algorithm cRTP

Ater TDM compression algorithm Flex Ater

Ater IP over E1/T1 compression algorithm Ater MUX

Number of IP MUX packets 8

Load on an SS7 signaling link (Erlang) 0.3

Voice transmission bandwidth usage 85%

Each BTS under the BSC is configured with one E1 cable. Therefore, there are 100 E1 cables configured over the Abis interface.

There are two TC subracks with 12 DPUC boards configured in the BSC.

3. Impact on the BTS

This section provides the single-BTS specifications. Based on these specifications and the transmission type used over the Abis interface, you can determine whether to adjust transmission and equipment resources for a BTS. Table 9-4 lists the single-BTS specifications.

Table 9-4 Single-BTS specifications

Item Specifications

Number of 16 kbit/s TCHs 66

Maximum traffic volume over the Um interface 87

Number of busy-hour CS speech paths 116

Number of busy-hour FR speech paths 16

Number of busy-hour HR speech paths 100

Number of LAPD links (including RSLs and OMLs) 13

Number of required idle timeslots 54

Signaling load 18%

The single-BTS specifications in Table 9-4 are calculated as follows:

A BTS serves three cells, each of which has four TRXs. On each TRX, there is one BCCH and three SDCCHs (estimated based on the traffic volume). Therefore, the total number of 16 kbit/s TCHs is calculated with the following formula:

Total number of 16 kbit/s TCHs = (4 x 8 – 1 – 3) x 3 = 84

If six PDCHs are configured for each cell, the total number of 16 kbit/s TCHs is calculated with the following formula:

Total number of 16 kbit/s TCHs = 84 – 6 x 3 = 66

According to the ErlangB table, the maximum traffic volume in a cell is 87 Erlangs.

Based on the traffic volume, you can calculate that the number of busy-hour CS speech paths is 116. Based on the proportions of HR and FR channels, you can obtain the numbers of FR and HR speech paths.

The impact of VAMOS on BTS transmission and equipment resources varies according to the following Abis-interface transmission types:

Flex Abis

− Impact on transmission resources

In Abis over TDM mode, one E1 cable provides the bandwidth of 32 multiplied by 64 kbit/s. When VAMOS is not enabled, only one E1 cable is required to ensure Abis transmission. When VAMOS is enabled, however, the traffic volume increases and the total number of required Abis timeslots (with the bandwidth of 64 kbit/s) changes from 29 to 36. Therefore, two E1 cables are required to provide sufficient Abis-interface transmission bandwidth.

− Impact on interface resources

A basically configured transmission interface board of the BTS supports four E1 cables. This meets the bandwidth requirements in this scenario. Therefore, interface resources do not need to be added.

Table 9-5 Specifications before and after VAMOS is enabled in Flex Abis mode

Item Specifications Before VAMOS Is Enabled

Specifications After VAMOS Is Enabled

LAPD link multiplexing rate 6 4

Number of required CS timeslots (16 kbit/s) 66 91



Number of required PS timeslots (16 kbit/s) 36 36

Number of required signaling timeslots (64 kbit/s) 3 4

Number of required Abis timeslots (64 kbit/s) 29 36

The increase in the traffic volume leads to an increase in the required total bandwidth of RSLs. The average required bandwidth of RSLs also increases. Therefore, the LAPD link multiplexing rate reduces to 4.

As listed in Table 9-3, the proportion of HR services is 75%. Assuming that 50% HR channels are configured as VAMOS HR channels, the number of required CS timeslots is calculated with the following formula:

Number of required CS timeslots = 66 x (1 + 75% x 50%) ≈ 91

Therefore,

Total number of required Abis timeslots (64 kbit/s) = Number of required CS timeslots (16 kbit/s) + Number of required PS timeslots (16 kbit/s)/4 + Number of required signaling timeslots = (91 +36)/4 + 4 ≈ 36

IP over E1/T1


An E1 cable provides the bandwidth of 32 timeslots multiplied by 64 kbit/s. When VAMOS is not enabled, only one E1 cable is required to ensure Abis transmission. When VAMOS is enabled, however, the traffic volume increases and the total number of required Abis timeslots (with the bandwidth of 64 kbit/s) changes from 20 to 25, as listed in Table 9-6. In this case, one E1 cable still meets the Abis bandwidth requirements.


A basically configured transmission interface board of the BTS supports four E1 cables. This meets the bandwidth requirements in IP over E1/T1 mode. Therefore, interface resources do not need to be added.

Table 9-6 Specifications before and after VAMOS is enabled in IP over E1/T1 mode


Specifications with IP MUX Enabled Before VAMOS Is Enabled


Required CS channel bandwidth (kbit/s) 1152.05 520.95 740.41

Required PS channel bandwidth (kbit/s) 425.39 303.13 303.13

Required signaling bandwidth (kbit/s) 309.56 309.56 309.56

Required total Abis bandwidth (kbit/s) 2165.37 1279.05 1537.25

Total number of required Abis timeslots (64 kbit/s) 34 20 25

In Abis IP over E1/T1 mode, the IP MUX function needs to be enabled to save the overhead on headers increased with IP transmission, as listed in Table 9-6. Therefore, the total number of required Abis timeslots (64 kbit/s) decreases from 34 to 20.

Total number of required Abis timeslots (64 kbit/s) = Required total Abis bandwidth (kbit/s)/64 = 1537.25/64 = 25

The required total Abis bandwidth is calculated based on the rates of coding schemes and the number of channels.

IP over FE/GE


The Abis interface uses Ethernet cables or optical fibers with the bandwidth of more than 100 Mbit/s. Therefore, the Abis transmission bandwidth is ensured and transmission resources do not need to be added.


A basically configured interface board of the BTS has one FE port and one GE port. This meets the bandwidth requirements in IP over FE/GE mode. Therefore, interface resources do not need to be added.

Table 9-7 Specifications before and after VAMOS is enabled in IP over FE/GE mode


Specifications with IP MUX Enabled Before VAMOS Is Enabled


Required CS channel bandwidth (kbit/s) 1783.36 538.33 740.41

Required PS channel bandwidth (kbit/s) 534.38 315.23 315.23

Required signaling bandwidth (kbit/s) 422.64 422.64 422.64

Required total Abis bandwidth (kbit/s) 3149.39 1426.84 1708.09

Total number of required Abis timeslots (64 kbit/s) 50 23 27

In Abis IP over FE/GE mode, the IP MUX function needs to be enabled to save the overhead on headers increased with IP transmission, as listed in Table 9-7. Therefore, the total number of required Abis timeslots (64 kbit/s) decreases from 50 to 23.

Total number of required Abis timeslots (64 kbit/s) = Required total Abis bandwidth (kbit/s)/64 = 1708.09/64 = 27

The required total Abis bandwidth is calculated based on the rates of coding schemes and the number of channels.

4. Impact on the BSC

Impact on transmission resources

− Abis interface

In Abis over TDM mode, another one E1 cable must be added to each BTS to ensure Abis transmission. Therefore, the number of E1 cable for the BSC needs to be increased from 100 to 200 because each BTS needs two E1 cables in Flex Abis mode, as listed in Table 9-8 and Table 9-9.

In other transmission modes, no transmission resource is added to each BTS. Therefore, there is no impact on Abis transmission resources for the BSC.

− Ater and A interfaces

To ensure the A- and Ater-interface bandwidth, the number of E1 cables needs to be added according to the actual situation. In A IP over FE/GE mode, two 100 Mbit/s Ethernet cables are required when VAMOS is enabled, as listed in Table 9-8 and Table 9-9.

Impact on interface resources

An Abis interface board of the BSC supports the transmission bandwidth provided by 640 E1/T1 cables, 240 FE ports, and 80 GE ports. This meets the bandwidth requirements. Therefore, interface resources do not need to be added.

An A interface board of the BSC supports the transmission bandwidth provided by 640 E1/T1 cables, 240 FE ports, and 80 GE ports. This meets the bandwidth requirements. Therefore, interface resources do not need to be added.

An Ater interface board of the BSC supports the transmission bandwidth provided by 256 E1/T1 cables. This meets the bandwidth requirements. Therefore, interface resources do not need to be added.

Service processing resources

When VAMOS is enabled, the number of speech paths supported by the BSC increases, leading to an increase in requiring TC resources. In this scenario, six DPUC boards need to be added without adding a subrack, as listed in Table 9-10.

Table 9-8 Ater/A-interface transmission bandwidth before VAMOS is enabled

Transmission Mode

Required Bandwidth of SS7 Signaling Links (kbit/s)

Required Bandwidth of SS7 Signaling Links (64 kbit/s per Timeslot)

Required Speech Path Bandwidth (kbit/s)

Required Number of 64 kbit/s Timeslots

Required Total Bandwidth (Mbit/s)

Required Total Number of E1 Cables

A TDM N/A 100 N/A 10000 N/A 326

A IP over FE/GE

14,006.00 219 80,013.00 1250 94.02 47

A IP over E1/T1

10,192.00 159 65,652.00 1026 75.84 38

Ater TDM N/A 100 N/A 1500 N/A 52

Ater IP over E1/T1

5,394.00 84 67,662.00 1057 73.06 37

Table 9-9 Ater/A-interface transmission bandwidth after VAMOS is enabled

Transmission Mode

Required Bandwidth of SS7 Signaling Links (kbit/s)

Required Bandwidth of SS7 Signaling Links (64 kbit/s per Timeslot)

Required Speech Path Bandwidth (kbit/s)

Required Number of 64 kbit/s Timeslots

Required Total Bandwidth (Mbit/s)

Required Total Number of E1 Cables

A TDM N/A 200 N/A 12500 N/A 407

A IP over FE/GE

17,929.00 280 100,016.00 1563 117.95 59

A IP over E1/T1

13,047.00 204 82,065.00 1282 95.11 48

Ater TDM N/A 200 N/A 1800 N/A 65

Ater IP over E1/T1

6,904.00 108 84,578.00 1322 91.48 46

When VAMOS is enabled, the increase in the network capacity leads to an increase in the traffic volume. Therefore, more A- and Ater-interface transmission resources are required. After VAMOS is enabled, if half of HR services use VAMOS when the proportion of HR services reaches 75%, the traffic volume for a BSC increases to 11200 Erlangs, which is calculated by 112 multiplied by 100.

Table 9-10 Number of speech paths before and after VAMOS is enabled



Number of busy-hour CS speech paths 115 165

Number of busy-hour FR speech paths 16 16

Number of busy-hour HR speech paths 99 49

Number of busy-hour VAMOS speech paths None 50 x 2 = 100

In A over TDM mode, each DPUC board supports a maximum of 960 speech paths. When VAMOS is not enabled, the number of speech paths is calculated with the following format:

Number of speech paths supported by a BTS = 16 (FR) + 99 (HR) = 115

Number of speech paths supported by a BSC managing 100 same BTSs = 115 x 100 = 11500.

Therefore, a total of 12 DPUC boards are required, which is calculated by 11500 divided by 960. When VAMOS is enabled, the number of speech paths is calculated with the following format:

Number of speech paths supported by a BTS = 16 (FR) + 49 (HR) + 100 (VAMOS HR) =165

Number of speech paths supported by a BSC managing 100 same BTSs = 165 x 100 = 16500

Therefore, a total of 18 DPUC boards are required, which is calculated by 16500 divided by 960.

Currently, a BSC is configured with a maximum of four TC subracks and each of the TC subrack has 10 DPUC boards (9+1 redundancy). Therefore, the 18 DPUC boards can be installed in two existing TC subracks.

5. Conclusion

According to the preceding analysis, VAMOS multiplexes calls onto channels instead of compressing source signals to increase Um-interface capacity and spectrum efficiency. With an increase in voice capacity, VAMOS has the following impacts on the base station subsystem (BSS):

Transmission resources over the Abis, Ater, and A interfaces may need to be adjusted. In non-IP transmission mode, transmission resources over the Ater and A must be added.

Interface resources do not need to be added.

DPUC boards need to be added to provide sufficient speech paths for processing the increased traffic volume.

Planning of Power Control Parameters

To minimize interference between multiplexed calls after VAMOS is enabled, you must set PWRCTRLOPTIMIZEDEN to YES(Yes). If PWRCTRLOPTIMIZEDEN has been set to YES(Yes) on the live network and the HQI is normal, power control does not need to be optimized. If Huawei II power control is used on the live network, a license is required to support Huawei III power control. After Huawei II power control is upgraded to Huawei III power control, you need to replan power control parameters. If Huawei III power control is used on the live network, you also need to replan power control parameters.

1. Adjustment of BSC-level power control parameters

Table 9-11 lists the planning of basic power control parameters when Huawei III power control is used.

Table 9-11 Basic power control parameters

Parameter Name Parameter ID Basic Value

Power Control Switch PWRCTRLSW PWR3(Power control III)

III Power Control Optimized Enable PWRCTRLOPTIMIZEDEN YES(Yes)

DLRexLevAdjustFactor DLREXLEVADJFCTR 3

DLRexQualAdjustFactor DLREXQUALADJFCTR 6

DLRexLevHighThred DLREXLEVHIGHTHRED 28

DLRexLevLowthred DLREXLEVLOWTHRED 28

DLFSRexQualHighThred DLFSREXQUALHIGHTHRED 18

DLFSRexQualLowThred DLFSREXQUALLOWTHRED 18

DLHSRexQualHighThred DLHSREXQUALHIGHTHRED 18

DLHSRexQualLowThred DLHSREXQUALLOWTHRED 18

DLAFSRexQualHighThred DLAFSREXQUALHIGHTHRED 14

DLAFSRexQualLowThred DLAFSREXQUALLOWTHRED 14

DLAHSRexQualHighThred DLAHSREXQUALHIGHTHRED 16

DLAHSRexQualLowThred DLAHSREXQUALLOWTHRED 16

DLMAXDownStep DLMAXDOWNSTEP 30

DLMAXUpStep DLMAXUPSTEP 30

ULRexLevAdjustFactor ULREXLEVADJFCTR 3

ULRexQualAdjustFactor ULREXQUALADJFCTR 6

ULRexLevHighThred ULREXLEVHIGHTHRED 20

Parameter Name Parameter ID Basic Value

ULRexLevLowThred ULREXLEVLOWTHRED 20

ULFSRexQualHighThred ULFSREXQUALHIGHTHRED 18

ULFSRexQualLowThred ULFSREXQUALLOWTHRED 18

ULHSRexQualHighThred ULHSREXQUALHIGHTHRED 18

ULHSRexQualLowThred ULHSREXQUALLOWTHRED 18

ULAFSRexQualHighThred ULAFSREXQUALHIGHTHRED 14

ULAFSRexQualLowThred ULAFSREXQUALLOWTHRED 14

ULAHSRexQualHighThred ULAHSREXQUALHIGHTHRED 16

ULAHSRexQualLowThred ULAHSREXQUALLOWTHRED 16

ULMAXDownStep ULMAXDOWNSTEP 30

ULMAXUpStep ULMAXUPSTEP 30

III UL RexLev Protect Factor ULRXLEVPROTECTFACTOR 20

III UL RexQual Protect Factor ULRXQUALPROTECTFACTOR 40

III DL RexLev Protect Factor DLRXLEVPROTECTFACTOR 20

III DL RexQual Protect Factor DLRXQUALPROTECTFACTOR 40

2. Adjustment of cell-level power control parameters

After basic parameter values are used on the live network, collect busy-hour data of at least one day and compare the data with that before parameter adjustment. If the uplink or downlink HQI deteriorates, perform the following operations:

Adjust parameters on the entire network according to the procedure shown in Figure 9-3.

After adjustment, if the uplink or downlink HQI of top N cells remains bad, perform fine-tuning on these cells according to the procedure shown in Figure 9-4. Top N cells generally refer to 20% to 30% of the total number of cells on a network.

Figure 9-3 Adjusting parameters on the entire network

Figure 9-4 Fine-tuning for top N cells


None


None

9.4 Deploying VAMOSFor details about how to activate, verify, and deactivate this feature, see Configuring VAMOS.

9.5 Deploying Mute SAIC MS IdentificationFor details about how to activate, verify, and deactivate this feature, see Configuring Mute SAIC MS Identification.

9.6 Deploying VAMOS Call Drop SolutionFor details about how to activate, verify, and deactivate this feature, see Configuring VAMOS Call Drop Solution.

9.7 Performance Optimization

9.7.1 VAMOS

Monitoring

Traffic volume and VAMOS capacity gain

After VAMOS is enabled, the values of the following traffic-related counters increase in theory:

− CELL.KPI.TCH.TRAF.ERL.TRAF

− CELL.KPI.TCHH.TRAF.ERL

− CELL.CHAN.BUSY.NUM.VAMOS.TCHH.TRAF.AVE

− CELL.KPI.SD.TRAF.ERL

The increase in the values of these counters reflects the increase in the network capacity.

The following formulas are provided for your reference to calculate the VAMOS capacity gain:

− Based on the hardware capacity gain

Hardware Capacity Gain = VAMOS traffic/Total Traffic x 100%

− Based on the equivalent capacity gain

Equivalent Traffic Gain = 0.5 x VAMOS traffic/(Total Traffic – 0.5 x VAMOS) x 100%

VAMOS Traffic = 2 x CELL.CHAN.BUSY.NUM.VAMOS.TCHH.TRAF.AVE

Total Traffic = CELL.KPI.TCH.TRAF.ERL.TRAF

Call drop rate and VAMOS call drop rate

As mentioned in chapter 8 "Impact on Network Performance", VAMOS may increase the call drop rate. After VAMOS is enabled, check the following counters related to the call drop rate:

− CELL.RATE.TCH.CALL.DROP.INCLUDE.HO

− CELL.SD.CALL.DROP

− CELL.TCH.RD.DROP

If the values of these counters increase, check the VAMOS call drop rate to determine whether the increase in the call drop rate is caused by VAMOS. The VAMOS call drop rate is calculated with the following formula:

VAMOS call drop rate = (CELL.VAMOS.CALL.DROP.TIMES.HO.UNDO + CELL.VAMOS.CALL.DROP.TIMES.HO.OTHER + CELL.VAMOS.CALL.DROP.TIMES)/((CELL.VAMOS.INTRACELL.HO.TRY + CELL.VAMOS.INTRACELL.HO.FAIL) x 2)

HQI

Check the HQI before and after VAMOS is enabled. If the HQI increases after VAMOS is enabled, the network quality deteriorates. Then, check the VAMOS-related HQI to determine whether the increase in the HQI is caused by VAMOS.

The HQI is user-defined. The following formula takes the HR downlink HQI as an example.

HR downlink HQI = (TRX.HR.DOWN.RX.QLTY.0.NEW + TRX.HR.DOWN.RX.QLTY.1.NEW + TRX.HR.DOWN.RX.QLTY.2.NEW + TRX.HR.DOWN.RX.QLTY.3.NEW + TRX.HR.DOWN.RX.QLTY.4.NEW + TRX.HR.DOWN.RX.QLTY.5.NEW)/(TRX.HR.DOWN.RX.QLTY.0.NEW + TRX.HR.DOWN.RX.QLTY.1.NEW + TRX.HR.DOWN.RX.QLTY.2.NEW + TRX.HR.DOWN.RX.QLTY.3.NEW + TRX.HR.DOWN.RX.QLTY.4.NEW + TRX.HR.DOWN.RX.QLTY.5.NEW + TRX.HR.DOWN.RX.QLTY.6.NEW + TRX.HR.DOWN.RX.QLTY.7.NEW)

Before VAMOS is enabled, the HQI is calculated based on raw counters. After VAMOS is enabled, the VAMOS-related HQI is calculated based on the quality indication contained in the measurement reports transmitted on VAMOS channels. The formulas for calculating the HQI before and after VAMOS is enabled are the same.

MOS

Use a MOS measurement tool to measure the voice quality before and after VAMOS is enabled. If the MOS decreases, the network quality deteriorates.

Parameter Optimization

After VAMOS is enabled, if the capacity gain falls short of expectations, adjust parameter settings as follows to increase the VAMOS multiplexing times and duration:

− Decreases the values for VamosMultLoadThd and VamosLoadReuseLoadThd or increases the values for VamosQualReuseDownLinkQualThd andVamosQualReuseUpLinkQualThd.

− Decreases the value for VamosIntraHoSaicAtcbThd or increases the values for VamosIntraHoUlQualThd and VamosIntraHoDlQualThd to increase candidate VAMOS calls.

− Sets UnkownSaicMultSwitch to ON(On) to increase candidate VAMOS calls.

After VAMOS is enabled, if the call drop rate, HQI, and MOS deteriorate, adjust parameters as follows to improve these KPIs:

− Decreases the values for VamosQualReuseDownLinkQualThd and VamosQualReuseUpLinkQualThd to reduce the probability of an increase in the call drop rate caused by poor VAMOS call quality, improving the HQI and MOS.

− Decreases the values for VamosIntraHoUlQualThd and VamosIntraHoDlQualThd or VamosIntraHoSaicAtcbThd to improve the conditions for candidate VAMOS calls, improving the HQI.

− Sets UnkownSaicMultSwitch to OFF(Off) to prevent the increase in the call drop rate due to MS problems, reducing the call drop rate.

− Records MSs on which call drops occur. If a type of MS frequently experiences call drops, add the TAC of this type of MS to the blacklist in the SAIC MS capability database and forbid the use of VAMOS for this type of MS. This reduces the call drop rate and improves the HQI.

9.7.2 Mute SAIC MS Identification and VAMOS Call Drop Solution

Monitoring

After Mute SAIC MS Identification and VAMOS Call Drop Solution are enabled, check the call drop rate, VAMOS call drop rate, and HQI. For details, see section 9.7.1 VAMOS.

Parameter Optimization

After Mute SAIC MS Identification and VAMOS Call Drop Solution are enabled, if the call drop rate and HQI deteriorate, adjust parameters as follows to improve these KPIs:

Decreases the value for SpeMsIdeMaxCalls to reduce the number of identifications.

Decreases the value for SpeMsIdeLoad so that MS identification is performed when there is a low load and slight interference.

Decreases the values for SpeMsIdeUlRxQualThd and SpeMsIdeDlRxQualThd to raise the criteria for an MS to be identified.

10 ParametersTable 10-1 Parameter description

Parameter ID NE MML CommandFeature ID

Feature Name

Description

AlphaQpskCtrlSwitch BSC6900

SET GCELLVAMOSPWR

GBFD-115830

VAMOS Meaning: Whether to enable the alpha-QPSK power control algorithm in VAMOS. The value ON indicates that the alpha-QPSK power control algorithm is enabled; the value OFF indicates that the alpha-QPSK power control algorithm is disabled.

GUI Value Range: OFF(Off), ON(On)

Actual Value Range: OFF, ON

Default Value: ON(On)

Unit: None

DLAFSREXQUALHIGHTHRED

BSC6900

SET GCELLPWR3

GBFD-117601

HUAWEI III Power Control Algorithm

Meaning: If the downlink receive quality level of an AMR full rate call is greater than this parameter, the call needs to undergo Huawei power control generation III.

GUI Value Range: 1~30

Actual Value Range: 1~30

Default Value: 16

Unit: dB

DLAFSREXQUALLOWTHRED

BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: If the downlink receive quality level of an AMR full rate call is smaller than this parameter, the call needs to undergo Huawei power control generation III.



Default Value: 16

Unit: dB

DLAHSREXQUALHIGHTHRED

BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: If the downlink receive quality level of an AMR half rate call is greater than this parameter, the call needs to undergo Huawei power control generation III.



Default Value: 18

Unit: dB

DLAHSREXQUALLOWTHRED

BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: If the downlink receive quality level of an AMR half rate call is smaller than this parameter, the call needs to undergo Huawei power control generation III.



Default Value: 18

Unit: dB

DLFSREXQUALHIGHTHRED

BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Upper quality threshold for Huawei power control generation III on a full rate call. If the downlink receive quality level of a full rate call is greater than this threshold, the call needs to undergo Huawei power control generation III.



Default Value: 18

Unit: dB

DLFSREXQUALLOWTHRED BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Lower quality threshold for Huawei power control generation III on a full rate call. If the downlink receive quality level of a full rate call is smaller than this threshold, the call needs to undergo Huawei power control generation III.



Default Value: 18

Unit: dB

DLHSREXQUALHIGHTHRED

BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Upper quality threshold for Huawei power control generation III on a half rate call. If the downlink receive quality level of a half rate call is greater than this threshold, the call needs to undergo Huawei power control generation III.



Default Value: 18

Unit: dB

DLHSREXQUALLOWTHRED BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Lower quality threshold for Huawei power control generation III on a half rate call. If the downlink receive quality level of a half rate call is smaller than this threshold, the call needs to undergo Huawei power control generation III.



Default Value: 18

Unit: dB

DLMAXDOWNSTEP BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Maximum step by which to decrease downlink power according to signal strength.



Default Value: 30

Unit: dB

DLMAXUPSTEP BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Maximum step by which to increase downlink power according to signal strength.



Default Value: 30

Unit: dB

DLREXLEVADJFCTR BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: This parameter specifies the downlink signal strength factor multiplied by 10 during the calculation of the downlink power control step.

The downlink signal strength factor is a coefficient indicating how much the signal strength is considered during the calculation of the downlink power control step.



Default Value: 3

Unit: None

DLREXLEVHIGHTHRED BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Upper receive level threshold for downlink power control. If the downlink receive level is greater than this threshold, the power of the downlink signal needs to be decreased.



Default Value: 24

Unit: dB

DLREXLEVLOWTHRED BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Lower receive level threshold for downlink power control. If the downlink receive level is smaller than this threshold, the power of the uplink signal needs to be increased.



Default Value: 24

Unit: dB

DLREXQUALADJFCTR BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: This parameter specifies the downlink quality level factor multiplied by 10 during the calculation of the downlink power control step.

The downlink quality level factor is a coefficient indicating how much the quality level is considered during the calculation of the downlink power control step.



Default Value: 4

Unit: None

DLRXLEVPROTECTFACTOR

BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: A power control step cannot exceed the step computed according to "III DL RexLev Protect Factor" and "III DL RexQual Protect Factor".



Default Value: 20

Unit: None

DLRXQUALPROTECTFACTOR

BSC6900

SET GCELLPWR3

GBFD-

HUAWEI III Power

Meaning: A power control step cannot exceed the step

117601

Control Algorithm

computed according to "III DL RexLev Protect Factor" and "III DL RexQual Protect Factor".



Default Value: 60

Unit: None

MuteSaicIdeSwitch BSC6900

SET GCELLVAMOS

GBFD-115831


Meaning: Whether to enable automatic identification of mute SAIC-capable MSs in a cell. A mute SAIC-capable MS is a SAIC-capable MS that is reported as SAIC-incapable. The value ON indicates that automatic identification of such MSs is enabled; the value OFF indicates that automatic identification of such MSs is disabled.



Default Value: OFF(Off)

Unit: None

MuteSaicSwitch BSC6900

SET GCELLVAMOS

GBFD-115831


Meaning: Whether to enable the function for processing mute SAIC-capable MSs in a cell. A mute SAIC-capable MS is a SAIC-capable MS that is reported as SAIC-incapable. The value ON indicates that the function for processing such MSs is enabled; the value OFF indicates that the function for processing such MSs is disabled. Processing mute SAIC-capable MSs consists of identification of such MSs based on database records and automatic identification of such MSs.




Unit: None

PWRCTRLOPTIMIZEDEN BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Whether to enable the power control optimization algorithm III.

GUI Value Range: NO(No),

YES(Yes)

Actual Value Range: NO, YES

Default Value: YES(Yes)

Unit: None

PWRCTRLSW BSC6900

SET GCELLPWRBASIC

GBFD-110703

Enhanced Power Control Algorithm

Meaning: Whether to enable power control algorithm II or power control algorithm III

GUI Value Range: PWR2(Power control II), PWR3(Power control III)

Actual Value Range: PWR2, PWR3

Default Value: PWR3(Power control III)

Unit: None

SaicProMsIdeSwitch BSC6900

SET GCELLVAMOS

GBFD-115832


Meaning: Whether to enable automatic identification of SAIC-capable MSs with AFC defects in a cell. The value ON indicates that automatic identification of such MSs is enabled; the value OFF indicates that automatic identification of such MSs is disabled.




Unit: None

SaicProMsSwitch BSC6900

SET GCELLVAMOS

GBFD-115832


Meaning: Whether to enable the function for processing SAIC-capable MSs with AFC defects in a cell. The value ON indicates that the function for processing such MSs is enabled; the value OFF indicates that the function for processing such MSs is disabled. Processing SAIC-capable MSs with AFC defects consists of identification of such MSs based on database records and automatic identification of such MSs.




Unit: None

SicDiffHighThd BSC6900

SET GCELLVAMOSPWR

GBFD-115830

VAMOS Meaning: Upper threshold of the SIC offset in the SIC power control algorithm. The parameter setting affects the speed of adjusting the MS power.



Default Value: 15

Unit: dB

SicPwrCtrlSwitch BSC6900

SET GCELLVAMOSPWR

GBFD-115830

VAMOS Meaning: Whether to enable uplink Successive Interference Cancellation (SIC) power control algorithm in VAMOS. The value ON indicates that the uplink SIC power control algorithm in VAMOS is enabled; the value OFF indicates that the uplink SIC power control algorithm in VAMOS is disabled.




Unit: None

SpeMsIdeDlRxQualThd BSC6900

SET GCELLVAMOS

GBFD-115831

GBFD-115832



Meaning: Threshold of the downlink receive quality of a call for triggering automatic MS identification. When the downlink receive quality of a call is lower than or equal to the value of this parameter, automatic identification of mute SAIC-capable MSs and SAIC-capable MSs with AFC defects is performed.



Default Value: 10

Unit: None

SpeMsIdeLoad BSC6900

SET GCELLVAMOS

GBFD-115831

GBFD-11583



Meaning: Load threshold for performing automatic identification of mute SAIC-capable MSs and SAIC-capable MSs with AFC defects in a cell. MS identification request is triggered only when cell load is lower than or equal

2 to the value of this parameter.



Default Value: 25

Unit: %

SpeMsIdeMaxCalls BSC6900

SET GCELLVAMOS

GBFD-115831

GBFD-115832



Meaning: Maximum number of calls in a cell, on which identification of mute SAIC-capable MSs and identification of SAIC-capable MSs with AFC defects can be performed simultaneously.



Default Value: 5

Unit: None

SpeMsIdeUlRxQualThd BSC6900

SET GCELLVAMOS

GBFD-115831

GBFD-115832



Meaning: Threshold of the uplink receive quality of a call for triggering automatic identification of mute SAIC-capable MSs and SAIC-capable MSs with AFC defects. When the uplink receive quality of a call is lower than or equal to the value of this parameter, automatic identification of such MSs is performed.



Default Value: 10

Unit: None

ULAFSREXQUALHIGHTHRED

BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Current call is an AMR full-rate call, and when the uplink receive quality is greater than the threshold, Huawei III power control is performed.



Default Value: 16

Unit: dB

ULAFSREXQUALLOWTHRED

BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Current call is an AMR full-rate call, and when the uplink receive quality is lower than the threshold, Huawei III power control is performed.



Default Value: 16

Unit: dB

ULAHSREXQUALHIGHTHRED

BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Current call is an AMR half-rate call, and when the uplink receive quality is greater than the threshold, Huawei III power control is performed.



Default Value: 18

Unit: dB

ULAHSREXQUALLOWTHRED

BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Current call is an AMR half-rate call, and when the uplink receive quality is lower than the threshold, Huawei III power control is performed.



Default Value: 18

Unit: dB

ULFSREXQUALHIGHTHRED

BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Current call is a full-rate call, and when the uplink receive quality is greater than the threshold, Huawei III power control is performed.



Default Value: 18

Unit: dB

ULFSREXQUALLOWTHRED BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Current call is a full-rate call, and when the uplink receive quality is lower than the threshold, Huawei III power control is performed.



Default Value: 18

Unit: dB

ULHSREXQUALHIGHTHRED

BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Current call is a half-rate call, and when the uplink receive quality is greater than the threshold, Huawei III power

control is performed.



Default Value: 18

Unit: dB

ULHSREXQUALLOWTHRED BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Current call is a half-rate call, and when the uplink receive quality is lower than the threshold, Huawei III power control is performed.



Default Value: 18

Unit: dB

ULMAXDOWNSTEP BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Maximum adjustment step when the BSC decreases uplink transmit power.



Default Value: 30

Unit: dB

ULMAXUPSTEP BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Maximum adjustment step when the BSC increases uplink transmit power.



Default Value: 30

Unit: dB

ULREXLEVADJFCTR BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: This parameter specifies the uplink signal strength factor multiplied by 10 during the calculation of the uplink power control step.

The uplink signal strength factor is a coefficient indicating how much the signal strength is considered during the calculation of the uplink power control step.



Default Value: 3

Unit: None

ULREXLEVHIGHTHRED BSC69 SET GBFD HUAWEI Meaning: When the uplink

00 GCELLPWR3 -117601

III Power Control Algorithm

receive level reaches the threshold, Huawei III power control is performed.



Default Value: 20

Unit: dB

ULREXLEVLOWTHRED BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: When the uplink receive level is lower than the threshold, Huawei III power control is performed.



Default Value: 20

Unit: dB

ULREXQUALADJFCTR BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: This parameter specifies the uplink quality level factor multiplied by 10 during the calculation of the uplink power control step.

The uplink quality level factor is a coefficient indicating how much the quality level is considered during the calculation of the uplink power control step.



Default Value: 4

Unit: None

ULRXLEVPROTECTFACTOR

BSC6900

SET GCELLPWR3

GBFD-117601


Meaning: Signal strength factor for the protective limitation on calculating the uplink power control adjustment step. The calculated step value cannot exceed the step value that is obtained on the basis of the signal strength protection factor and the signal quality protection factor.



Default Value: 30

Unit: None

ULRXQUALPROTECTFACTOR

BSC6900

SET GCELLPWR3

GBFD-11760

HUAWEI III Power Control

Meaning: Signal strength factor for the protective limitation on calculating the

1 Algorithm uplink power control adjustment step. The calculated step value cannot exceed the step value that is obtained on the basis of the signal strength protection factor and the signal quality protection factor.



Default Value: 75

Unit: None

UnkownSaicMultSwitch BSC6900

SET GCELLVAMOS

GBFD-115831


Meaning: Whether to allow VAMOS multiplexing for an identified SAIC-capable MS with possible AFC defects.

When this parameter is set to ON, VAMOS multiplexing is allowed for such an MS and Alpha hopping modulation is required.

When this parameter is set to OFF, VAMOS multiplexing is not allowed for such an MS.




Unit: None

VAMOSDEPOLRXQUALOFT BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Receive signal quality threshold offset between a VAMOS call in the overlaid subcell and a VAMOS call in the underlaid subcell during channel demultiplexing due to bad quality. VAMOS channel demultiplexing due to bad quality is triggered if the P/N criterion is met and either of the following conditions is met:

The uplink receive signal quality of the VAMOS call in the overlaid subcell is higher than or equal to "VamosQualReuseUpLinkQualThd" minus "VAMOSDEPOLRXQUALOFT". The downlink receive signal quality of the VAMOS call in the overlaid subcell is higher than or equal to

"VamosQualReuseDownLinkQualThd" minus "VAMOSDEPOLRXQUALOFT".

The actual value for this parameter is the GUI value for this parameter minus 70.


Actual Value Range: -70~70

Default Value: 70

Unit: None

VAMOSOLRXLEVOFT BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Receive signal level threshold offset between a call in the overlaid subcell and a call in the underlaid subcell when a call is selected as the candidate VAMOS call during channel multiplexing in the overlaid subcell. A new call in the overlaid subcell is selected as the candidate VAMOS call if both of the following conditions are met:

The downlink receive signal level of the new call is higher than or equal to the sum of "VamosIntraHoDlRxlevThd", "VamosAssDlRxlevThdOffset", and "VAMOSOLRXLEVOFT".

The uplink and downlink receive signal quality, AdapTive Cell Border (ATCB), and P/N criterion meets specified conditions. An established call in the overlaid subcell is selected as the candidate VAMOS call if both of the following conditions are met:

The downlink receive signal level of the established call is higher than or equal to the sum of "VamosIntraHoDlRxlevThd" and "VAMOSOLRXLEVOFT".

The uplink and downlink receive signal quality, ATCB, and P/N criterion meets specified conditions.

The actual value for this parameter is the GUI value for this parameter minus 128.



Default Value: 128

Unit: None

VAMOSOLRXQUALOFT BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Receive signal quality offset between a call in the overlaid subcell and a call in the underlaid subcell when decisions on candidate VAMOS calls are made during VAMOS channel multiplexing in the overlaid subcell. A new call in the overlaid subcell can be used as the candidate VAMOS call if the following conditions are met:Uplink receive signal quality of the new call is smaller than or equal to "VamosIntraHoUlQualThd" minus "VamosAssUlQualThdOffset" and "VAMOSOLRXQUALOFT".Downlink receive signal quality of the new call is smaller than or equal to "VamosIntraHoDlQualThd" minus "VamosAssUlQualThdOffset" and "VAMOSOLRXQUALOFT".The downlink receive signal level of the new call, ATCB, and P/N criterion meet specified conditions.A established call in the overlaid subcell can be used as the candidate VAMOS call if the following conditions are met:Uplink receive signal quality of the established call is smaller than or equal to "VamosIntraHoUlQualThd" minus "VAMOSOLRXQUALOFT".Downlink receive signal quality of the established call is smaller than or equal to "VamosIntraHoDlQualThd" minus "VAMOSOLRXQUALOFT".The downlink receive signal level of the established call, ATCB, and P/N criterion meet specified conditions. The

actual value of this parameter equals the GUI value minus 70.



Default Value: 70

Unit: None

VamosAssDlRxlevThdOffset BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Offset of the downlink receive level of a new call from the level threshold of established calls if the new call is to be selected as a VAMOS candidate call during assignment. A new call can be selected as a VAMOS candidate call only when the following conditions are met: The downlink receive level of the new call is greater than or equal to the sum of DL Rx Lev. Thres. of VAMOS Calls and this parameter. The uplink and downlink receive quality as well as the ATCB meet relevant requirements.



Default Value: 128

Unit: dB

VamosAssSwitch BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Whether to enable VAMOS channel multiplexing during assignment in the network. The value ON indicates that VAMOS channel multiplexing during assignment is enabled in a cell; the value OFF indicates that VAMOS channel multiplexing during assignment is disabled in a cell.




Unit: None

VamosAssUlQualThdOffset BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Offset of the uplink or downlink receive quality of a new call against the quality threshold of existing calls. If a new call is to be selected as a

candidate call for VAMOS channel multiplexing during channel assignment, its uplink receive quality must be smaller than or equal to "UL Rx Qual. Thres. of Established Calls" minus "Channel Multiplex Rx Qual. Thres. Offset in Asgmt." and its downlink receive quality must be smaller than or equal to "DL Rx Qual. Thres. of Established Calls" minus "Channel Multiplex Rx Qual. Thres. Offset in Asgmt.".



Default Value: 4

Unit: None

VamosIntraHoDlQualThd BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Threshold of the downlink receive quality of an established call to be selected as a VAMOS candidate call. The decision on this call can be triggered successfully only when the following conditions are met: The ATCB of this call is greater than or equal to the ATCB threshold. The downlink receive quality is lower than or equal to the value of this parameter. The uplink receive quality is lower than or equal to "UL Rx Qual. Thres. of Established Calls". If the decision conditions are met for "Duration of Satisfying Candidate VAMOS Call" within "Watch Time of Candidate Calls", this call can be selected as a VAMOS candidate call.



Default Value: 10

Unit: None

VamosIntraHoDlRxlevThd BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Threshold of the downlink receive level of an established call to be selected as a VAMOS candidate call. VAMOS is short for Voice services over Adaptive Multi-user Orthogonal Subchannels. The decision on an established call can be triggered

successfully only when the following conditions are met:

The downlink receive level of an established call is greater than or equal to this threshold.

The uplink and downlink receive quality as well as the Adaptive to Cell Boarder (ATCB) meet relevant requirements. If the decision conditions are met for Duration of Satisfying Candidate VAMOS Call within Watch Time of Candidate Calls, this call can be selected as a VAMOS candidate call.



Default Value: 0

Unit: dB

VamosIntraHoSaicAtcbThd BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: ATCB threshold of an established SAIC call to be selected as a candidate call for VAMOS channel multiplexing. The decision on an established SAIC call can be triggered successfully only when the following conditions are met: The ATCB of the call is greater than or equal to the value of this parameter. The uplink receive quality is lower than or equal to "UL Rx Qual. Thres. of Established Calls". The downlink receive quality is lower than or equal to "DL Rx Qual. Thres. of Established Calls". If the decision conditions are met for "Duration of Satisfying Candidate VAMOS Call" within "Watch Time of Candidate Calls", this call can be selected as a VAMOS candidate call.



Default Value: 76

Unit: dB

VamosIntraHoSwitch BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Whether to enable VAMOS channel multiplexing through intra-cell handover in the network. The value ON

indicates that VAMOS channel multiplexing through intra-cell handover is enabled in a cell; the value OFF indicates that VAMOS channel multiplexing through intra-cell handover is disabled in a cell.




Unit: None

VamosIntraHoUlQualThd BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Threshold of the uplink receive quality of an established call to be selected as a VAMOS candidate call. The decision on this call can be triggered successfully only when the following conditions are met: The ATCB of this call is greater than or equal to the ATCB threshold. The uplink receive quality is lower than or equal to the value of this parameter. The downlink receive quality is lower than or equal to "DL Rx Qual. Thres. of Established Calls". If the decision conditions are met for "Duration of Satisfying Candidate VAMOS Call" within "Watch Time of Candidate Calls", this call can be selected as a VAMOS candidate call.



Default Value: 10

Unit: None

VamosLoadReuseLoadThd BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Load threshold for triggering VAMOS channel demultiplexing in a cell. If the cell load is lower than or equal to this threshold, channel demultiplexing is triggered.



Default Value: 25

Unit: %

VamosLoadReuseSwitch BSC6900

SET GCELLVAMOS

GBFD-

VAMOS Meaning: Whether to enable VAMOS channel

115830

demultiplexing when the load in a cell is low. The value ON indicates that VAMOS channel demultiplexing due to low cell load is enabled; the value OFF indicates that VAMOS channel demultiplexing due to low cell load is disabled.




Unit: None

VamosMultLoadThd BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Load threshold for triggering VAMOS channel multiplexing in a cell. When the load of a cell is higher than or equal to this threshold, the decision on channel multiplexing is triggered.



Default Value: 75

Unit: %

VamosOldCallLastTimes BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Duration within which a call satisfies the decision conditions for selecting a VAMOS candidate call. If the decision conditions are met for "Duration of Satisfying Candidate VAMOS Call" within "Watch Time of Candidate Calls", this call can be selected as a VAMOS candidate call.



Default Value: 2

Unit: s

VamosOldCallStatTimes BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Duration within which the ATCB and receive quality of a call are observed to determine whether this call can be selected as a VAMOS candidate call. If the decision is triggered for "Duration of Satisfying Candidate VAMOS Call" within the period of time specified by this parameter, this call can be selected as a

VAMOS candidate call.



Default Value: 3

Unit: s

VamosQualReuseDownLinkQualThd

BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Downlink receive quality threshold of a VAMOS call in channel demultiplexing due to poor speech quality in a cell. When the downlink receive quality is higher than or equal to this threshold or the uplink receive quality is higher than or equal to "UL RX Poor Qual. Demultiplex Thres.", the decision of channel demultiplexing due to poor speech quality is triggered. If the decision conditions are met for "Poor Qual. Duration for Demultiplex" within "Watch Time of Poor Qual. for Demultiplex", a call can be demultiplexed through handover.



Default Value: 55

Unit: None

VamosQualReuseSwitch BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Whether to enable VAMOS channel demultiplexing when the speech quality of a call is poor. The value ON indicates that VAMOS channel demultiplexing due to poor speech quality is enabled; the value OFF indicates that VAMOS channel demultiplexing due to poor speech quality is disabled.




Unit: None

VamosQualReuseUpLinkQualThd

BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Uplink receive quality threshold of a VAMOS call in channel demultiplexing due to poor speech quality in a

cell. When the uplink receive quality is higher than or equal to this threshold or the downlink receive quality is higher than or equal to "DL RX Poor Qual. Demultiplex Thres.", the decision of channel demultiplexing due to poor speech quality is triggered. If the decision conditions are met for "Poor Qual. Duration for Demultiplex" within "Watch Time of Poor Qual. for Demultiplex", a call can be demultiplexed through handover.



Default Value: 55

Unit: None

VamosSwitch BSC6900

SET GCELLVAMOS

GBFD-115830

VAMOS Meaning: Whether to enable the VAMOS function. If this parameter is set to ON(On), the VAMOS function is enabled. If this parameter is set to OFF(Off), the VAMOS function is disabled.




Unit: None

11 CountersTable 11-1 Counter description

Counter ID Counter Name Counter Description

Feature ID

Feature Name

1282431236

CELL.VAMOS.ASS.ADJUD A3100J:Number of Successful VAMOS Candidate Call Decisions (Assignment)

GBFD-115830

VAMOS

1282431237

CELL.VAMOS.ASS.TRY A3100L:Number of VAMOS Channel Multiplexing Attempts (Assignment)

GBFD-115830

VAMOS

1282431238

CELL.VAMOS.ASS.CMD A3100M:Number of VAMOS Channel Multiplexing Commands (Assignment)

GBFD-115830

VAMOS

1282431239

CELL.VAMOS.ASS.FAIL A3100N:Number of Failed VAMOS Channel Multiplexing Attempts (Assignment)

GBFD-115830

VAMOS

1282431240

CELL.VAMOS.INTRACELL.HO.ADJUD H3050:Number of Successful VAMOS Candidate Call Decisions (Intra-Cell Handover)

GBFD-115830

VAMOS

1282431241

CELL.VAMOS.INTRACELL.HO.TRY H3051:Number of VAMOS Channel Multiplexing Attempts (Intra-Cell Handover)

GBFD-115830

VAMOS

1282431242

CELL.VAMOS.INTRACELL.HO.CMD H3052:Number of VAMOS Channel Multiplexing Commands (Intra-Cell

GBFD-115830

VAMOS

Handover)

1282431243

CELL.VAMOS.INTRACELL.HO.FAIL H3053:Number of Failed VAMOS Channel Multiplexing Attempts (Intra-Cell Handover)

GBFD-115830

VAMOS

1282431244

CELL.VAMOS.INTRACELL.HO.TRY.UNDO H3054:Number of VAMOS Call Handover Attempts (Demultiplexing)

GBFD-115830

VAMOS

1282431245

CELL.VAMOS.INTRACELL.HO.CMD.UNDO H3056:Number of VAMOS Call Handover Commands (Demultiplexing)

GBFD-115830

VAMOS

1282431246

CELL.VAMOS.INTRACELL.HO.FAIL.UNDO H3057:Number of Failed VAMOS Call Handover Attempts (Demultiplexing)

GBFD-115830

VAMOS

1282431247

CELL.VAMOS.INTRACELL.HO.TRY.OTHER H3058:Number of VAMOS Call Handover Attempts (Others)

GBFD-115830

VAMOS

1282431248

CELL.VAMOS.INTRACELL.HO.CMD.OTHER H3059:Number of VAMOS Call Handover Commands (Others)

GBFD-115830

VAMOS

1282431249

CELL.VAMOS.INTRACELL.HO.FAIL.OTHER H3060:Number of Failed VAMOS Call Handover Attempts (Others)

GBFD-115830

VAMOS

1282431250

CELL.VAMOS.CALL.DROP.TIMES.HO.UNDO H3061:Number of VAMOS Call Drops (Demultiplexing Handover)

GBFD-115830

VAMOS

1282431251

CELL.VAMOS.CALL.DROP.TIMES.HO.OTHER H3062:Number of VAMOS Call

GBFD-115830

VAMOS

Drops (Other Handover)

1282431252

CELL.VAMOS.CALL.DROP.TIMES H3063:Number of VAMOS Call Drops (Stable State)

GBFD-115830

VAMOS

1282431253

CELL.VAMOS.MR.NUM.WHEN.MAX.UP.PWR S4464:Number of MRs with Maximum Uplink Power of VAMOS Call

GBFD-115830

VAMOS

1282431254

CELL.VAMOS.UP.MR.NUM S4465:Number of Uplink MRs of VAMOS Call

GBFD-115830

VAMOS

1282431255

CELL.VAMOS.UL.SIG.STRENGTH S4466:Uplink Signal Strength of VAMOS Call

GBFD-115830

VAMOS

1282431256

CELL.VAMOS.UL.SIG.STRENGTH.AVR S4467:Mean Uplink Signal Strength of VAMOS Call

GBFD-115830

VAMOS

1282431257

CELL.CH.BUSY.MAX.NUM.VAMOS.TCHH R3563:Maximum Number of Busy Channels (VAMOS TCHH)

GBFD-115830

VAMOS

1282431259

CELL.TOTAL.CALL.NUM A03640:Number of Calls

GBFD-115830

VAMOS

1282431260

CELL.SPT.VAMOS1.CALL.NUM A03641:Number of VAMOS-1 Calls

GBFD-115830

VAMOS

1282431261

CELL.SPT.VAMOS2.CALL.NUM A03642:Number of VAMOS-2 Calls

GBFD-115830

VAMOS

1282431262

CELL.VAMOS.MR.NUM.WHEN.MAX.DOWN.PWR S4468:Number of MRs with Maximum Downlink Power of VAMOS Call

GBFD-115830

VAMOS

1282431263

CELL.VAMOS.DOWN.MR.NUM S4469:Number of Downlink MRs of VAMOS Call

GBFD-115830

VAMOS

1282431264

CELL.VAMOS.DL.SIG.STRENGTH S4470:Downlink Signal Strength of VAMOS Call

GBFD-115830

VAMOS

1282432165

CELL.VAMOS.ASS.ADJUD.OLCELL A3100O:Number of Successful VAMOS Candidate Call Decisions in Overlaid Subcell (Assignment)

GBFD-115830

VAMOS

1282432166

CELL.VAMOS.ASS.TRY.OLCELL H3064:Number of VAMOS Channel Multiplexing Attempts in Overlaid Subcell (Assignment)

GBFD-115830

VAMOS

1282432167

CELL.VAMOS.ASS.CMD.OLCELL H3065:Number of VAMOS Channel Multiplexing Commands in Overlaid Subcell (Assignment)

GBFD-115830

VAMOS

1282432168

CELL.VAMOS.ASS.FAIL.OLCELL H3066:Number of Failed VAMOS Channel Multiplexing Attempts in Overlaid Subcell (Assignment)

GBFD-115830

VAMOS

1282432169

CELL.VAMOS.INTRACELL.HO.ADJUD.OLCELL H3067:Number of Successful VAMOS Candidate Call Decisions in Overlaid Subcell (Intra-Cell Handover)

GBFD-115830

VAMOS

1282432170

CELL.VAMOS.INTRACELL.HO.TRY.OLCELL H3068:Number of Successful VAMOS Channel Multiplexing Attempts in Overlaid Subcell (Intra-Cell Handover)

GBFD-115830

VAMOS

1282432171

CELL.VAMOS.INTRACELL.HO.CMD.OLCELL H3069:Number of VAMOS

GBFD-115830

VAMOS

Channel Multiplexing Commands in Overlaid Subcell (Intra-Cell Handover)

1282432172

CELL.VAMOS.INTRACELL.HO.FAIL.OLCELL H3070:Number of Failed VAMOS Channel Multiplexing Attempts in Overlaid Subcell (Intra-Cell Handover)

GBFD-115830

VAMOS

1282432173

CELL.VAMOS.INTRACELL.HO.TRY.UNDO.OLCELL H3071:Number of VAMOS Call Handover Attempts in Overlaid Subcell (Demultiplexing)

GBFD-115830

VAMOS

1282432174

CELL.VAMOS.INTRACELL.HO.CMD.UNDO.OLCELL H3072:Number of VAMOS Call Handover Commands in Overlaid Subcell (Demultiplexing)

GBFD-115830

VAMOS

1282432175

CELL.VAMOS.INTRACELL.HO.FAIL.UNDO.OLCELL H3073:Number of Failed VAMOS Call Handover Attempts in Overlaid Subcell (Demultiplexing)

GBFD-115830

VAMOS

1282432176

CELL.VAMOS.INTRACELL.HO.TRY.OTHER.OLCELL H3074:Number of VAMOS Call Handover Attempts in Overlaid Subcell (Others)

GBFD-115830

VAMOS

1282432177

CELL.VAMOS.INTRACELL.HO.CMD.OTHER.OLCELL H3075:Number of VAMOS Call Handover Commands in Overlaid

GBFD-115830

VAMOS

Subcell (Others)

1282432178

CELL.VAMOS.INTRACELL.HO.FAIL.OTHER.OLCELL H3076:Number of Failed VAMOS Call Handover Attempts in Overlaid Subcell (Others)

GBFD-115830

VAMOS

1282432179

CELL.VAMOS.CALL.DROP.TIMES.HO.UNDO.OLCELL H3077:Number of VAMOS Call Drops in Overlaid Subcell (Demultiplexing Handover)

GBFD-115830

VAMOS

1282432180

CELL.VAMOS.CALL.DROP.TIMES.HO.OTHER.OLCELL H3078:Number of VAMOS Call Drops in Overlaid Subcell (Other Handover)

GBFD-115830

VAMOS

1282432181

CELL.VAMOS.CALL.DROP.TIMES.OLCELL H3079:Number of VAMOS Call Drops in Overlaid Subcell (Stable State)

GBFD-115830

VAMOS

1282432183

CELL.CH.BUSY.MAX.NUM.VAMOS.TCHH.OLCELL R3564:Maximum Number of Busy Channels in Overlaid Subcell (VAMOS TCHH)

GBFD-115830

VAMOS

1282449198

CELL.CHAN.BUSY.NUM.VAMOS.TCHH.TRAF.AVE R3501:Mean Number of Busy Channels (VAMOS TCHH)

GBFD-115830

VAMOS

1282449199

CELL.VAMOS.DL.SIG.STRENGTH.AVR S4471:Mean Downlink Signal Strength of VAMOS Call

GBFD-115830

VAMOS

1282449349

CELL.CHAN.BUSY.NUM.VAMOS.TCHH.TRAF.AVE.OLCELL

A313A5:Mean Number of Busy Channels in Overlaid Subcell (VAMOS

GBFD-115830

VAMOS

12 GlossaryFor the acronyms, abbreviations, terms, and definitions, see the Glossary.

13 Reference Documents[1] Half-Rate Service Feature Parameter Description

[2] Channel Management Feature Parameter Description

[3] Handover Feature Parameter Description

[4] Power Control Feature Parameter Description

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