Configuring SDCCH Dynamic Adjustment

This section describes how to activate, verify, and deactivate the basic feature GBFD-113001 SDCCH Dynamic Adjustment.

Prerequisites

Dependencies on Hardware

This feature does not have any special requirements for hardware.

Dependencies on Other Features

This feature does not depend on other features.

License

This feature is not under license control.

Others

This feature does not need to be configured when PCU is inner.

This feature needs to be configured when PCU is outer.

Context

When the number of users in a cell increases substantially, some users may not be able to access the network because they cannot obtain SDCCHs. In this case, some TCHs need to be converted to SDCCHs. When TCHs are not sufficient enough to meet requirements of channel conversion, dynamic PDCHs are converted to SDCCHs to ensure that all the users can access the network.

When the traffic load decreases, the TCHs and dynamic PDCHs used as SDCCHs are converted back to TCHs to increase system capacity.

When SDCCHs are insufficient, channels are converted to SDCCHs in the following sequence: TCHs on the BCCH frequency band, TCHs not on the BCCH frequency band, and dynamic PDCHs.

Procedure

Activation Procedure

1. Run the BSC6900 MML command SET GCELLBASICPARA. In this step, set both SDCCH Dynamic Allocation Allowed and Dynamic PDCH Conversion toSDCCH Allowed to YES(Yes).

2. Run the BSC6900 MML command SET GCELLCHMGBASIC. In this step, set Idle SDCCH Threshold N1, Cell SDCCH Channel Maximum, TCH Minimum Recovery Time, and Num of TSs Convertible to SDCCHs per TRX to appropriate values.

 NOTE:

When TCHs on the BCCH frequency band are insufficient, set Dynamically Adjust Inter-Freq Band SDCCH to YES(Yes) as required.

3. Run the BSC6900 MML command SET GCELLPSCHM. In this step, set Maximum Rate Threshold of PDCHs in a Cell and Reservation Threshold of Dynamic Channel Conversion to appropriate values.

Verification Procedure

 NOTE:

Monitor Channel Status by referring to Monitoring Channel Status.

As all the channels are occlusive except BCCH.

1. The value of Idle SDCCH Threshold N1 is not smaller than the number of configured SDCCH channel, and make a CS call in the cell. Expected result: A TCH is converted to an SDCCH.

2. Run the BSC6900 MML command SET GCELLPSCHM. In this step, set Maximum Rate Threshold of PDCHs in a Cell to 100 and Reservation Threshold of Dynamic Channel Conversion to 0.

3. Perform PS services in the cell. Expected result: All TCHFs are converted to PDCHs.

4. Make another CS call in the cell. Expected result: A dynamic PDCH is converted to an SDCCH.

5. Enable the cell to remain in the idle state for two minutes. The minimum time of SDCCHs convert back to TCHs is 120 seconds. Expected result: The two channels used as SDCCHs are converted back to TCHs.

Deactivation Procedure

1. Run the BSC6900 MML command SET GCELLBASICPARA. In this step, set both SDCCH Dynamic Allocation Allowed and Dynamic PDCH Conversion toSDCCH Allowed to NO(No).

Example

//Activating SDCCH Dynamic AdjustmentSET GCELLBASICPARA: IDTYPE=BYID, CELLID=1, SDDYN=YES, PDCH2SDEN=YES;SET GCELLCHMGBASIC: IDTYPE=BYID, CELLID=1, IDLESDTHRES=8, CELLMAXSD=100, MINRESTIMETCH=60;SET GCELLPSCHM: MAXPDCHRATE=30, DYNCHTRANRESLEV=2;//Deactivating SDCCH Dynamic AdjustmentSET GCELLBASICPARA: IDTYPE=BYID, CELLID=1, SDDYN=NO, PDCH2SDEN=NO;