01-12 Half-Rate Service.pdf

12 Half-Rate Service

About This Chapter

12.1 OverviewThe half-rate service is optional.

12.2 AvailabilityAvailability of the half-rate service consists of the related NEs, software version information,and license in the number of TRXs supporting the half-rate service.

12.3 Technical DescriptionThe technical description of the half-rate service consists of the channel assignment strategiesrelated to the half-rate service, the rate adjustment algorithms, and the resource reservationfunction involved in the rate adjustment. The rate adjustment consists of the adjustment from ahalf-rate channel to a full-rate channel and from a full-rate channel to a half-rate channel.

12.4 CapabilitiesBSC6000V900R001C01 supports up to 2048 TRXs used in the half-rate service.

12.5 ImplementationThe implementation on the half-rate service consists of configuring half-rate service, verifyinghalf-rate service, activating the function of reserving priority resources, adjusting half-rateservice, and deactivating half-rate service.

12.6 Maintenance InformationMaintenance information on half-rate service consists of the performance counters related to thehalf-rate service.

12.7 ReferencesNone.

HUAWEI BSC6000 Base Station SubsystemBSS Feature Description 12 Half-Rate Service

Issue 01 (2007-09-05) Huawei Technologies Proprietary 12-1

12.1 OverviewThe half-rate service is optional.

Definition

The half-rate service is a service where the speech coding rate is reduced to half the full-ratespeech coding rate through a new speech coding algorithm. If the half-rate service is enabled,the physical channel carrying the service of only one calling MS can be able to bear the servicesof two calling MSs.

Purposes

If the half-rate service is enabled, the number of system-enabled MSs holding speech servicesis doubled without the addition of TRXs. Thus the frequency reuse rate is enhanced. Therefore,the telecom operators can fully utilize the network resources and minimize the operation cost.

Terms

Term Definition

Couple A timeslot is composed of two half-ratesubtimeslots. If both half-rate subtimeslotsare idle, the channel where the twosubtimeslots are located is called a Couple.

Single A timeslot is composed of two half-ratesubtimeslots. If one subtimeslot is occupiedand the other subtimeslot is idle, the channelwhere the idle subtimeslot is located is calleda Single.

TCHF Full-rate speech channel

TCHH Half-rate speech channel

Rate adjustment The conversion from a full-rate channel to ahalf-rate channel or from a half-rate channelto a full-rate channel

Half-rate version 1 HR data (with the rate of 5.6 kbit/s)

Half-rate version 2 Reserved for protocols

Half-rate version 3 HAMR data (with the rate ranging from 4.75to 7.4 kbit/s)

Full-rate version 1 FR data (with the rate of 13 kbit/s)

Full-rate version 2 EFR data (with the rate of 12.2 kbit/s)

Full-rate version 3 FAMR data (with the rate ranging from 4.75to 12.2 kbit/s)

12 Half-Rate ServiceHUAWEI BSC6000 Base Station Subsystem

BSS Feature Description

12-2 Huawei Technologies Proprietary Issue 01 (2007-09-05)

Abbreviations

Abbreviation Full Spelling

AMR Adaptive Muti-Rate

EFR Enhanced Full Rate

FR Full Rate

HR Half Rate

12.2 AvailabilityAvailability of the half-rate service consists of the related NEs, software version information,and license in the number of TRXs supporting the half-rate service.

Network Elements Involved

Table 12-1 describes the NEs involved in the half-rate service.

Table 12-1 NEs Involved in the Half-Rate Service

MS BTS BSC MSC MGW SGSN GGSN HLR

√ √ √ √ – – – –

NOTE

l -: not involved

l √: involved

Software Releases

Table 12-2 describes the software releases that support the half-rate service.

Table 12-2 GBSS products and related versions

Product Version

BSC BSC6000 V900R001C01 andlater releases

BTS BTS3X G3BTS32.30000.01.1130 and later releases

BTS3002C G3BTS36.30000.02.0820 and later releases

BTS3001C G3BTS34.30000.07.0301

Double-transceiver BTSs All releases



MiscellaneousOnly when the license is obtained, the half-rate service can be enabled.

The license in the number of TRXs supporting the half-rate service needs to be requested for.The number of TRXs supporting the half-rate service must be within the range allowed by thelicense so that the TRXs can work normally.

12.3 Technical DescriptionThe technical description of the half-rate service consists of the channel assignment strategiesrelated to the half-rate service, the rate adjustment algorithms, and the resource reservationfunction involved in the rate adjustment. The rate adjustment consists of the adjustment from ahalf-rate channel to a full-rate channel and from a full-rate channel to a half-rate channel.

The dynamic rate adjustment is triggered in the channel assignment procedure. Thus, the ratecan be adjusted in real time.

Based on the channel request type, the full-rate or half-rate selection procedure is triggered onlywhen the type of the request channel is half rate TCH only, half rate TCH preferable, full rateTCH only, or full rate TCH preferable.

After the

TCH Rate Adjust Allow is enabled, for the channels that are not requested for in the immediateassignment procedure or the handover channel requests caused by the dynamic adjustment ofother channels, the dynamic adjustment from a full-rate channel to a half-rate channel is triggeredif a half-rate channel is requested for. If a full-rate channel is requested for, the dynamicadjustment from a half-rate channel to a full-rate channel is triggered and a handover may betriggered.

12.3.1 Channel Assignment StrategiesIf the half-rate service is enabled, the BSC selects different channel assignment algorithms basedon the channel assignment strategies in the data configuration after the BSC receives anAssignment Request message from the MSC.

12.3.2 Rate Adjustment AlgorithmsRate adjustment algorithms consist of different request types of rate adjustment algorithms andthe full-rate and half-rate adjustment procedures.

12.3.3 Function of Reserving Priority ResourcesIf the applied channel is a TCH, an appropriate TCH needs to be found in the current resources.If the configured channel is a full-rate speech channel, you need consider the function ofreserving the priority resources.

12.3.4 Estimation of the Number of the Full-Rate and the Half-Rate Channels in a CellIn some situations, users need estimate the number of the full-rate and half-rate channels in acell.

12.3.1 Channel Assignment StrategiesIf the half-rate service is enabled, the BSC selects different channel assignment algorithms basedon the channel assignment strategies in the data configuration after the BSC receives anAssignment Request message from the MSC.

There are two channel assignment strategies:




l Channel rate assignment strategy controlled by the MSC

l Channel rate assignment strategy controlled by the BSC

By default, the channel rate assignment strategy controlled by the BSC is used.

In channel assignment algorithms, the system determines whether to assign half-rate channelsor full-rate channels based on the traffic volume of the network. If the channel seizure ratioexceeds the TCH Traffic Busy Threshold, you can infer that the current network is busy. Ifthe network is busy, half-rate channels are assigned preferably. If the network is not busy, full-rate channels are assigned preferably.

NOTE

Channel seizure ratio = (Number of busy full-rate channels + Number of busy half-rate channels/2)/(Number of available full-rate channels + Number of available half-rate channels/2) x 100%

12.3.2 Rate Adjustment AlgorithmsRate adjustment algorithms consist of different request types of rate adjustment algorithms andthe full-rate and half-rate adjustment procedures.

12.3.2.1 Different Request Types of Rate Adjustment AlgorithmsRate adjustment algorithms vary with the types of rates for requested channels.

12.3.2.2 Full-Rate/Half-Rate Adjustment ProcedureFull-rate/half-rate adjustment consists of the adjustment from a full-rate channel to a half-ratechannel and the adjustment from a half-rate channel to a full-rate channel.

Different Request Types of Rate Adjustment Algorithms

Rate adjustment algorithms vary with the types of rates for requested channels.

There are three types of channel rates in a channel assignment request:

l full rate TCH only

l half rate TCH only/half rate TCH preferable

l full rate TCH preferable

If the type of the rate in a channel assignment request is full rate TCH only, the channel requestis accepted when the following requirements are met. If the type of the rate in a channelassignment request is not full rate TCH only or if the following requirements are not met, thechannel request is rejected.

l If there are idle full-rate channels, they are assigned directly.

l If there is no idle full-rate channel but there is an idle Couple, the BSC converts the Coupleinto a full-rate channel, and then assign the full-rate channel.

l If there is no idle full-rate channel and there is no idle Couple, but there is an idle Single,the BSC determines whether the number of adjustable idle half-rate channels in a cellexceeds 1. If the number of adjustable idle half-rate channels in a cell exceeds 1, an intra-cell handover is initiated. The BSC coverts the Couples after the handover into full-ratechannels, and then assigns the full-rate channels. If the number of adjustable idle half-ratechannels in a cell does not exceed 1, the channel assignment request is rejected.



Figure 12-1 Full Rate TCH Only Channel Adjustment Procedure

Yes

No

No

Yes

No

Yes

Start

Whether thereare appropriate full-rate

channels?

TCHF only requests

Whether there areappropriate

Couple channels?

Whether there aremore than one half-rate

channels?

Convert all the Couple channels into the full-rate channels

Initiate an intra-cell handover,and then convert all the Couple

channels formed after thehandover into the full-rate channels

Assign full-rate channelsReject requests

End

If the type of the rate in a channel assignment request is half rate TCH only or half rate TCHpreferable, the channel request is accepted when the following requirements are met. If the typeof the rate in a channel assignment request is not half rate TCH only or half rate TCH preferable,or if the following requirements are not met, the channel request is rejected.

l If there is an idle Single, you can assign the Single directly.

l If there is no idle Single but there is an idle Couple, the BSC assigns the idle half-ratechannel on the Couple.

l If there is no idle Single and there is no Couple, but there is an idle full-rate channel, anadjustment is triggered. The BSC converts the full-rate channel into a Couple, and thenassign the idle half-rate channel on the Couple.

NOTE

If the BSC assigns the channels on Singles preferably, the half-rate channels can be seized collectivelyand fragments can be minimized.




l Figure 12-2 Half Rate TCH Only/Half Rate TCH Preferable Channel AdjustmentProcedure

Yes

No

No

Yes

No

Yes

Start


single channels?

Half-rate request


couple channels?


full-rate channels?

Convert thefull-rate channels into the

Couple trannels

Assign thefull-rate channelsChannels fail to be assigned

End

If the type of the rate in a channel assignment request is full rate TCH preferable, the channelrequest is accepted when the following requirements are met. If the type of the rate in a channelassignment request is not full rate TCH preferable or the following requirements are not met,the channel request is rejected.

l If there are idle full-rate channels, they are assigned directly.

l If there is no idle full-rate channel but there is an idle Couple, the BSC converts the Coupleinto a full-rate channel, and then assign the full-rate channel.

l If there is no idle full-rate channel and there is no idle Couple, but there is an idle Single,the BSC determines whether the number of adjustable idle half-rate channels in a cellexceeds 1. If the number of adjustable idle half-rate channels in a cell exceeds 1, anadjustment is triggered and an intra-cell handover is initiated. The BSC coverts the Couplesafter the handover into full-rate channels, and then assigns the full-rate channels. If thenumber of adjustable idle half-rate channels in a cell does not exceed 1, the BSC assignsthe idle Single.

NOTE

Only when the Enhanced TCH Adjust Allowed is enabled, the calls on a Single can be handed over andthen an adjustment is triggered when a half-rate channel is converted into a full-rate channel.



Full-Rate/Half-Rate Adjustment Procedure

Full-rate/half-rate adjustment consists of the adjustment from a full-rate channel to a half-ratechannel and the adjustment from a half-rate channel to a full-rate channel.

Adjustment from a Full-Rate Channel to a Half-Rate Channel

1. If the related resources are not assigned for the channel application, the channel applicationenters the queue. The queuing duration is set through the "Timer of Waiting Channel Adjust(ms)." By default, the duration is three seconds.

l Queuing fails

– For the application for full-rate only or half-rate only type, the queuing fails.

– For the application for full-rate preferred or half-rate preferred, channels that areselected secondarily, such as, Couples or full-rate channels are assigned. For detaileddecision procedure, refer to Figure 12-3. The procedure is complete.

Figure 12-3 Half Rate TCH Only/Half Rate TCH Preferable Channel AdjustmentProcedure

Yes

No

No

Yes

No

Yes

Start


single channels?

Half-rate request


couple channels?


full-rate channels?

Convert thefull-rate channels into the

Couple trannels

Assign thefull-rate channelsChannels fail to be assigned

End

l Queuing succeeds

The BSC adjusts a full-rate channel to two Couples, sets the necessary values of channelattributes, initiates the command of adjusting the BSC timeslots, initiates the "Timer of




Waiting BMRC Response(ms)", and takes statistics of related performancemeasurement.

2. The BSC sends the command of adjusting and setting the channel attributes to the BTSbefore adjusting the BSC timeslots. If the time of processing the commands of adjustingthe BSC timeslots and adjusting the channel types that are sent to the BTS expires, as longas the system is normal, the adjustment command is reinitiated.

3. After receiving the command, the BTS starts converting channels. After channels areconverted, the BTS sends the "Status Change Report" to the BSC.

4. After receiving the "Status Change Report", the BSC set the converted Couples to idle andavailable. The BSC completes the adjustment and takes statistics of related performancemeasurement.

Adjustment from a Half-Rate Channel to a Full-Rate Channel1. If the current channel is a Couple, the corresponding channel application enters the queue.

The queuing duration is set through the "Timer of Waiting Channel Adjust (ms)." Bydefault, the duration is three seconds.l Queuing fails

– For the application for full-rate only or half-rate only type, the queuing fails.– For the application for full-rate preferred or half-rate preferred, channels that are

selected secondarily, such as, Couples or Singles are assigned. For detailed decisionprocedure, refer to Figure 12-4 and Figure 12-5. The procedure is complete.

Figure 12-4 Full Rate TCH Only Channel Adjustment Procedure

Yes

No

No

Yes

No

Yes

Start

Whether thereare appropriate full-rate

channels?

TCHF only requests


Couple channels?


channels?

Convert all the Couple channels into the full-rate channels

Initiate an intra-cell handover,and then convert all the Couple

channels formed after thehandover into the full-rate channels

Assign full-rate channelsReject requests

End



Figure 12-5 Full Rate TCH Preferable Channel Adjustment Procedure

Yes

No

No

Yes

No

Yes

Start


full-rate channels?

TCHF preferred request

Whether there areappropriate Couple

channels?


channels?

Convert all the Couplechannels into the full-rate channels

Initiate an intra-cell handoverand convert the Couple

channels formed after thehandover into the full-ratechannels

Assign the full-rate channelsAssign the half-rate channels

End

l Queuing succeedsThe BSC adjusts two Couples to a full-rate channel. For the subsequent procedure, referto Adjustment from a Full-Rate Channel To a Half-Rate Channel. The BSC setsthe necessary values of channel attributes, initiates the command of adjusting the BSCtimeslots, informs the BTS of completing the channel conversion, and takes statisticsof related performance measurement.

2. If the current channel is a Single, the corresponding channel application enters the queue.The queuing duration is set to 5.5 seconds. Because the defragmentation requires a longtime.l Queuing fails

– For the application for full-rate only or half-rate only type, the queuing fails.– For the application for full-rate preferred or half-rate preferred, the Single is

assigned. For detailed decision procedure, refer to Figure 12-4. The procedure iscomplete.

l Queuing succeedsThe system initiates an mandatory intra-cell handover on another occupied half-ratechannel that is corresponding to the Single. The handover is not controlled by the relatedconfiguration of handover. The system initiates the "Timer of Waiting CRDLC HOResponses(s)" and reserves sufficient time for the intra-cell handover.




Different processings are performed based on whether a forced handover response isreceived.– If a forced handover response is received, the "Timer of Waiting CRDLC HO

Responses(s)" is stopped. The BSC judges whether the forced handover successes.If the forced handover fails, an appropriate call needs to be found in the queue toassign the Single. The other occupied half-rate channel is not released. If the forcedhandover succeeds, the channel status is set to waiting for releasing the channel,when the channel status is set as the service is idle, refer to the Couple adjustmentprocedure to perform the dynamic adjustment.

– If a forced handover response is not received, but the "Timer of Waiting CRDLCHO Responses(s)" expires, the handover fails. A handover failure procedure isperformed.

12.3.3 Function of Reserving Priority ResourcesIf the applied channel is a TCH, an appropriate TCH needs to be found in the current resources.If the configured channel is a full-rate speech channel, you need consider the function ofreserving the priority resources.

This function can be performed to reserve some full-rate speech channels for the high-priorityusers so that the quality of services for the high-priority users can be improved.

12.3.4 Estimation of the Number of the Full-Rate and the Half-RateChannels in a Cell

In some situations, users need estimate the number of the full-rate and half-rate channels in acell.

Available Information

The traffic volume in a cell is 1 Erl and the call loss rate that is permitted by an operator is B%.Therefore, the number of the required channels in the cell is n. If the number of TRXs in the cellis m, the number of the service timeslots that can be supplied by the cell is a. Therefore, thenumber of service channels that can be supplied by the cell ranges from a to 2a.

Rules

Based on the traffic volume (1 Erl) and the allowed call loss rate described in ERLANG B, thenumber of the channels required in the cell is n.

l If n <= a, all the service channels in the cell can be configured as the TCHFs.

l If 2a > n > a, the number of the TCHFs (f) configured in the cell must meet the condition,that is, f + 2 (a-f) > n (f = [2a-n]). Other timeslots are configured as the TCHHs.

l If n >= 2a, small number of the service channels (one or two channels) are configured asthe TCHFs in the cell. Other channels in the cell are configured as the TCHHs. At the sametime, Huawei recommends an expansion for the cell. The configured TCHFs are mainlyreserved for the MSs that can use only TCHFs. The call loss rate is greater than B%.

Examples

If a cell holds two TRXs, the cell is configured with one BCCH and two SDCCHs.



Based on ERLANG B, if the traffic volume is X, the number of configured channels is 10. Thenumber of channels that can be used as TCHs in the cell is 13 (2 x 8 - 3). Because 13 > 10, allthe channels in the cell can be configured as TCHFs.

Based on ERLANG B, if the traffic volume in the cell is Y, the number of configured channelsis 17 and the number of channels that can be used as TCHs in the cell is 13. Because 13 x 2 >17 > 13, Nine (2 x 13 - 17) channels in the cell should be configured as TCHFs. Other channelsin the cell are configured as TCHHs.

Based on ERLANG B, if the traffic volume in the cell is Z, the number of configured channelsis 28 and the number of channels that can be used as TCHs in the cell is 13. Because 28 > 13 x2, all the channels in the cell should be configured as TCHHs. At the same time, Huaweirecommends that a user should perform an expansion.

NOTE

The method of configuring the full-rate and half-rate channels described previously is only a simplecalculation method. The support capability of MSs for the full-rate and half-rate channels and the channelassignment strategies are not considered. In fact, the call loss rate in a cell is related to these factors.Therefore, Huawei recommends that the method described previously should be used as a rough estimationmethod used when the half-rate service is enabled in a cell. After the half-rate service is enabled, you needperform further optimization based on an actual situation in the network.

12.4 CapabilitiesBSC6000V900R001C01 supports up to 2048 TRXs used in the half-rate service.

12.5 ImplementationThe implementation on the half-rate service consists of configuring half-rate service, verifyinghalf-rate service, activating the function of reserving priority resources, adjusting half-rateservice, and deactivating half-rate service.

12.5.1 Configuring Half-Rate ParametersConfigure the half-rate parameters through the BSC6000 Local Maintenance Terminal.

12.5.2 Verifying Half-Rate ServiceBased on different channels configured on TRXs, the verification methods are different.

12.5.3 Enabling the Function of Reserving Priority ResourcesEnable the function of reserving priority resources through the BSC6000 Local MaintenanceTerminal.

12.5.4 Reconfiguring Half-Rate ParametersReconfigure the half-rate parameters through the BSC6000 Local Maintenance Terminal.

12.5.5 Disabling Half-Rate ServiceDisable the half-rate service through the BSC6000 Local Maintenance Terminal.

12.5.1 Configuring Half-Rate ParametersConfigure the half-rate parameters through the BSC6000 Local Maintenance Terminal.




Procedure

Step 1 Apply for and activate the license

1. To apply for the license for the half-rate service, in the BSC6000V900R001 ExceptionalCommercial License Application Template, you should fill in the number of the TRXs thatsupport half-rate service in a specified range in the corresponding row of Number of theTRX supporting half-rate in the Resource control items column.

2. Enable the license on the BSC6000 Local Maintenance Terminal. For details, refer toActivating License.

After the license is activated, the BSC supports the half-rate service. However, you still need toset the attributes of related objects and parameters through the BSC6000 Local MaintenanceTerminal.

Step 2 Configure the half-rate speech version

NOTE

The half-rate speech versions that the BSC supports consist of Half-rate Version 1, Half-rate Version 2,and Half-rate Version 3. Half-rate Version 2 in speech versions configured through the

BSC6000 Local Maintenance Terminal is reserved for protocols. Currently, no services are available.

1. On the BSC6000 Local Maintenance Terminal, right-click a cell on the ManagementTree tab page, and choose Configure Cell Attributes from the shortcut menu. A dialogbox is displayed, as shown in Figure 12-6.

Figure 12-6 Configuring Cells Attributes dialog box (1)

2. Double-click a corresponding cell in the Cell view area, and then add it to the list of theSelected cells.

3. Click Next. A dialog box is displayed, as shown in Figure 12-7.




4. In the Cells to be set area, select a corresponding cell. Then, click Set Cell Properties. Adialog box is displayed, as shown in Figure 12-8.




Figure 12-8 Set Cell Attributes dialog box

5. Click Call Control. A dialog box is displayed, as shown in Figure 12-9.



Figure 12-9 Setting call control parameters

6. Click Advanced. A dialog box is displayed, as shown in Figure 12-10.




Figure 12-10 Set Call Control Parameter[Cell: BTS22C] dialog box

7. Click Access Control tab. On the tab page, set the value of Speech Version to SupportHalf-rate Version 1, as shown in Figure 12-11.

Figure 12-11 Setting speech versions

8. Click OK to return to the dialog box shown in Figure 12-8.9. Click OK to save the configuration of cell parameters. A previous dialog box is displayed,

as shown in Figure 12-7.10. Click Finish to end the configuration.

Step 3 Adjust the type of the TRX channel as "TCH Half Rate"



NOTE

The standard of selecting the type of a channel is as follows:

l If the half-rate channels are configured fixedly, the type of the channel is adjusted as "TCH Half Rate."

l If the full-rate channels are configured fixedly, or the channels whose rate can be dynamically adjusted,the type of the channels is adjusted as "TCH Full Rate."

If a TRX is not configured with the half-rate channels, and if the TRX supports the half-rate service, theTCH Rate Adjust Allow must be enabled.

A TRX channel is configured as "TCH Half Rate" to support the half-rate service. The detailedprocedures are as follows:

1. As shown in Figure 12-8, select a TRX to be adjusted in the Assigned TRXs area. ClickTRX Config. A dialog box is displayed, as shown in Figure 12-12.

Figure 12-12 Configure TRX Attributes dialog box

2. Select Channel Attributes tab. On the tab page, select the channel number to be adjustedin the Channel No.[0] area. In the Channel Type drop-down list box, select the channeltype to be set, as shown in Figure 12-13.




Figure 12-13 Configure TRX Attributes-TRX0 dialog box

3. Click OK. The configuration of the TRX parameters is complete.

Step 4 If a TRX does not have "TCH Half Rate" channels and only has "TCH Full Rate" channels, theTCH Rate Adjust Allow needs to be enabled to enable the TRX to support the half-rate service.

NOTE

For a TRX whose TCH Rate Adjust Allow is not enabled, channels on the TRX are assigned preferably.Therefore, the channels on the TRXs that support the rate adjustment can be reserved for further use. Theresources can be used maximally.

1. As shown in Figure 12-8, in the Assigned TRXs area, select a TRX to be adjusted. ClickTRX Config. A dialog box is displayed, as shown in Figure 12-12.

2. On the Device Attributes tab page, set the value of the TCH Rate Adjust Allow to Yes,as shown in Figure 12-14.



Figure 12-14 Device attributes

3. Click OK. The configuration of the TRX parameters is complete.

----End

12.5.2 Verifying Half-Rate ServiceBased on different channels configured on TRXs, the verification methods are different.

Procedure

Step 1 The TRX is configured with a "TCH Half Rate" channel.

1. On the BSC6000 Local Maintenance Terminal, right-click a TRX on the ManagementTree tab page. Choose Monitor Channel Status from the shortcut menu. A dialog box isdisplayed, as shown in Figure 12-15.




Figure 12-15 Monitor Channel Status(1) dialog box

2. Click Start. If a channel shown in Figure 12-16 is found, the TRX supports the half-rateservice.

Figure 12-16 Half-rate channel status

Step 2 The TRX is configured with only "TCH Half Rate" channels.

1. Use an MS that supports the half-rate service to lock the frequencies in a cell where a TRXis located.

2. On the BSC6000 Local Maintenance Terminal, right-click a TRX on the ManagementTree tab page. Choose Monitor Channel Status from the shortcut menu. A dialog box isdisplayed, as shown in Figure 12-15.

3. Click Start and view the channel status.4. On the BSC6000 Local Maintenance Terminal, right-click a cell where the TRX is

located on the Management Tree tab page. Then choose Modify Administrative Statefrom the shortcut menu. A dialog box is displayed, as shown in Figure 12-17.



Figure 12-17 Modifying management status

5. Block all the other TCHs in the cell where the TRX is located so that a new speech serviceinitiated by an MS in the cell can only use TCHs that is on the TRX.

6. As shown in Figure 12-18, click Channel Management. A dialog box is displayed, asshown in Figure 12-19.







Figure 12-19 Setting channel management parameters

7. Click Advanced. A dialog box is displayed, as shown in Figure 12-20.




Figure 12-20 Set Channel Parameter[Cell:3002E] dialog box

8. Select the HWII Channel Assignment and Radio Channel Control tab. On the tab page,set the value of the TCH Traffic Busy Threshold(%) to 0.

9. Click OK. The configuration of parameters is complete.10. Initiate a new speech service in the cell.11. View Figure 12-15 to check whether the latest occupied channel on the TRX is a half-rate

channel. If the channel is a half-rate channel, the TRX supports the half-rate service.

----End

12.5.3 Enabling the Function of Reserving Priority ResourcesEnable the function of reserving priority resources through the BSC6000 Local MaintenanceTerminal.

Procedure

Step 1 Apply for and activate the license

1. To apply for the license for the half-rate service, in the BSC6000V900R001 ExceptionalCommercial License Application Template, you should fill in the number of the TRXs thatsupport half-rate service in a specified range in the corresponding row of Number of theTRX supporting half-rate in the Resource control items column.

2. Enable the license on the BSC6000 Local Maintenance Terminal. For details, refer toActivating License.

After the license is activated, the BSC supports the function of reserving priority resources.However, the attributes of related objects and parameters need to be set through the BSC6000Local Maintenance Terminal.

Step 2 On the BSC6000 Local Maintenance Terminal, right-click a cell on the Management Treetab page, and choose Configure Cell Attributes from the shortcut menu. A dialog box isdisplayed, as shown in Figure 12-21.




Step 3 Double-click a corresponding cell in the Cell view area, and then add it to the list of the Selectedcells.

Step 4 Click Next. A dialog box is displayed, as shown in Figure 12-22.





Step 5 In the Cells to be set column, select a corresponding cell. Then click Set Cell Properties. Adialog box is displayed, as shown in Figure 12-23.


Step 6 In the Advanced Attributes area, click Channel Management. A dialog box is displayed, asshown in Figure 12-24.



Figure 12-24 Set Channel Parameter[Cell: 3002E] dialog box

Step 7 Set the value of Grade Access Allow to Yes. Set the value of Highest Priority to 1. Set thevalue of Reserved Channel Number to 3. Click OK.

NOTEThe value of

Reserved Channel Type can be only TCH FULL RATE. This parameter does not need to be adjusted.

Step 8 Click OK. The Configuring Cells Attributes dialog box is displayed.

Step 9 Click Finish to complete enabling the function of reserving priority resources.

----End

12.5.4 Reconfiguring Half-Rate ParametersReconfigure the half-rate parameters through the BSC6000 Local Maintenance Terminal.

Context

The reconfiguration of the half-rate parameters mainly refers to the modification of the channelmanagement parameters in a cell.




Procedure

Step 1 As shown in Figure 12-25, a parameter reconfiguration is complete. Click OK.

Figure 12-25 Set Channel Parameter[Cell:3002E] dialog box

NOTEAs shown in

Figure 12-25, the channel management parameters related to the half-rate service can be configured. Basicparameters consist of Grade Access Allow, Highest Priority, Reserved Channel Number, andEnhanced TCH Adjust Allowed. Advanced parameters consist of TCH Traffic Busy Threshold(%).

Step 2 Click OK. A dialog box is displayed, as shown in Figure 12-26.




Step 3 Click OK to save the configuration of cell parameters. A previous dialog box is displayed, asshown in Figure 12-27.





Step 4 Click Finish to end the configuration.

----End

12.5.5 Disabling Half-Rate ServiceDisable the half-rate service through the BSC6000 Local Maintenance Terminal.

ContextIf a site does not supply the half-rate service, a license that is applicable to the site and that doesnot support the half-rate service can be reapplied. For the disabling of the license, refer toMaintaining BSC License.

If you need only disable the half-rate service for a TRX, you need modify only the TRX attributes.For detailed procedures, refer to the following:

Procedure

Step 1 On the BSC6000 Local Maintenance Terminal, right-click a TRX on the ManagementTree tab page. Choose Configure TRX Attributes from the shortcut menu. A dialog box isdisplayed, as shown in Figure 12-28.



Figure 12-28 Configure TRX Attributes dialog box

Step 2 In the TRX view area, select a TRX whose attributes to be modified. Then, click Set TRXAttributes. A dialog box is displayed, as shown in Figure 12-29.

Figure 12-29 Configuring TRX attributes




Step 3 Click Channel Attributes tab. On the tab page, select a channel number that can enable theChannel Type to be TCH Half Rate from the Channel No.[0]. In the Channel Type drop-down list box, choose TCH Full Rate, as shown in Figure 12-30.

Figure 12-30 Configure TRX Attributes-TRX0 dialog box

Step 4 On the Device Attributes tab page, set the value of the TCH Rate Adjust Allow to Yes orNo.

Step 5 Click OK. A dialog box is displayed, as shown in Figure 12-28.

Step 6 Click Finish to complete the modification of TRX attributes.

----End

12.6 Maintenance InformationMaintenance information on half-rate service consists of the performance counters related to thehalf-rate service.

Alarms

None.

Counters

Table 12-3 describes the performance measurement counters involved in the half-rate service.



Table 12-3 Counters related to the half-rate service

Counter Description

H3023A: Failed Internal Intra-Cell Handovers(Dynamic Conversion, TCHF-TCHH)

In an intra-cell handover procedure, whenan MS accesses to the target cell correctly,and when the BSC receives any reasonthat causes a failed handover before thehandover complete timer expires,statistics are performed for relatedcounters based on different channel types.The channels can be TCHs. Channels canbe handed over from TCHFs to TCHHs(TCHF-TCHH) or from TCHHs toTCHFs (TCHH-TCHF).

H3023B: Failed Internal Intra-Cell Handovers(Dynamic Conversion, TCHH-TCHF)

H3003A: Internal Intra-Cell Handover Requests(Dynamic Conversion, TCHF-TCHH)

This counter indicates the times of theintra-cell handover requests from TCHFsto TCHHs.

H3003B: Internal Intra-Cell Handover Requests(Dynamic Conversion, TCHH-TCHF)

This counter indicates the times of theintra-cell handover requests from TCHHsto TCHFs.

H3013A: Internal Intra-Cell HandoverCommands (Dynamic Conversion, TCHF-TCHH)

This counter indicates the statistics ofrelated counters based on handover typesand channel types when the BSC sends anHO CMD message to an MS through thesource cell.H3013B: Internal Intra-Cell Handover

Commands (Dynamic Conversion, TCHH-TCHF)

TH3003A: Success Rate of Internal Intra-CellHandover (Dynamic Conversion, TCHF-TCHH)

Success Rate of Internal Intra-CellHandover (Dynamic Conversion, TCHF-TCHH) = [Successful Internal Intra-CellHandovers (Dynamic Conversion, TCHF-TCHH)] + {100}/[Internal Intra-CellHandover Requests (DynamicConversion, TCHF-TCHH)]

TH3003B: Success Rate of Internal Intra-CellHandover (Dynamic Conversion, TCHH-TCHF)

Success Rate of Internal Intra-CellHandover (Dynamic Conversion, TCHH-TCHF) = [Successful Internal Intra-CellHandovers (Dynamic Conversion,TCHH-TCHF)] + {100}/[Internal Intra-Cell Handover Requests (DynamicConversion, TCHH-TCHF)]

CH3033A: Successful Internal Intra-CellHandovers (Dynamic Conversion, TCHF-TCHH)

Successful Internal Intra-Cell Handovers(Dynamic Conversion, TCHF-TCHH) =[Internal Intra-Cell Handover Requests(Dynamic Conversion, TCHF-TCHH)] -[Failed Internal Intra-Cell Handovers(Dynamic Conversion, TCHF-TCHH)]




Counter Description

CH3033B: Successful Internal Intra-CellHandovers (Dynamic Conversion, TCHH-TCHF)

Successful Internal Intra-Cell Handovers(Dynamic Conversion, TCHH-TCHF) =[Internal Intra-Cell Handover Requests(Dynamic Conversion, TCHH-TCHF)] -[ Failed Internal Intra-Cell Handovers(Dynamic Conversion, TCHH-TCHF)]

12.7 ReferencesNone.



Documents

01-12 Half-Rate Service.pdf