6 handover parameters

Major HO Parameters ConfigurationMajor HO Parameters Configuration

[Handover Control Table] -1Parameter

name Meaning Value range Recommen

ded value Co-BSC/MSC Adj.

It means whether the 12th and 13th bits acts in the 16bit order. “Yes” means handover in the same BSC/MSC is preferred. “No” means that the 12th and 13th bits are shielded and set to “0”.

Yes, No Yes

Penalty allowed

It determines whether to punish the target cell of handover failure, or the original served cell of handover upon too big TA or bad quality. The penalty measures can apply to cells in or out of the same BSC.

Yes, No No

Load HO allowed

It determines whether to perform the handover to share traffic load. Load sharing can lower the channel assignment failure ratio caused by cell congestion, so as to make evener allocation of the service in respective cells, and lower the cell congestion rate, and improve network performance. It only applies in the same BSC or cells at the same level.

Yes, No No

MS Fast moving HO allowed

It determines whether to handle the fast moving MS with the algorithm. It is only recommended in special areas (such as a highway), to lower CPU load. This algorithm should only be used in suitable conditions, and usually it is not applied.

Yes, No No


[Handover Control Table] -2

Parameter name Meaning Value range Recommended value

RX_Level_Drop HO allowed

It means whether RX_Level_Drop emergency handover algorithm is allowed, handover the MS which receiving signal level is dropping quickly in advance to avoid potential call drop. This algorithm should be applied in suitable conditions, and usually it is not used. To apply the handover algorithm, BSC must have original measurement report.

Yes, No No

PBGT HO allowed

It means whether PBGT handover algorithm is allowed. PBGT handover algorithm currently is processed on LAPD board. To avoid Ping-pang handover, PBGT handover is only performed between cells at the same layer and with the same priority, and meanwhile it is only triggered on TCH.

Yes, No Yes

MS power prediction after HO

It means after a handover whether MS is to use proper predicted transmitting power to access the new channel. This can reduce system interference and improve service quality (this parameter acts when intra BSC handover occurs).

Yes, No Yes


Parameter name

Meaning Value range Recommended value

MR. Preprocessing

“Yes” means perform measurement report preprocessing on BTS; “No” means preprocessing on BSC, then the two parameters of “Send original measurement report” and “Send BS/MS power level” do not act. “Yes” means decreasing of Abis interface signaling and BSC load, and improving of network response time performance. The switch determines where to perform power control. When it is set to “Yes”, power control is performed at BTS side. When it is set to “No”, power control is performed at BSC side. When setting this parameter, first be clear whether BTS supports the power control algorithm to set or not.

Yes, No Yes

[Handover control table] -3


[Cell Description Table] -1


[Cell Description Table] -2


[Adjacent Cell Relation Table] -1


[Adjacent Cell Relation Table] -2


[Penalty Table] -1


[Penalty Table] -2


[Emergency Handover Table] -1

Parameter name


TA Thrsh. When TA≥this value, emergency handover is triggered

0~63 bit period

63

DL QUAL. Thrsh

The downlink receiving quality threshold for BQ emergency handover. When frequency hopping or DTX is enabled, RQ becomes worse (normal phenomenon), this value should be set to 70. The adjustment should also base on the current network quality and handover statistics. When triggering emergency handover, the first to select is the inter-cell handover, the intra-cell handover is only triggered when there is no candidate cell and the intra-cell handover is allowed in the serving cell.

0~70, corresponding to BQ levels of 0~7

60

UL QUAL. Thrsh.

The uplink receiving quality threshold for BQ emergency HO.

corresponding to BQ levels of 0~7

60


[Load Handover Table] -1


[Normal Handover Table] -1Parameter

nameMeaning Value range Recommended value

Edge HO UL RX_LEV Thrsh.

During the statistics time, if the time in which the uplinkreceiving level is lower than the value is longer thancertain time called continuous time, edge handoverwill be performed. If PBGT handover is enabled,Corresponding edge handover threshold will be setlower.

0~63 25 (without PBGThandover, downtown),15 (single station onoutskirts), 15 (withPBGT handover,downtown)

Edge HO DLRX_LEV Thrsh.

Downlink consideration for edge HO. 63 30 (without PBGThandover, downtown),20 (single station onoutskirts), 20 (withPBGT handover,downtown)



name Meaning Value range Recommended

value Edge HO watch time

It means that within the time statistics, if the time in which the signal level is lower than threshold is higher than the continuous time, then margin HO is to be triggered.

1~16 seconds 5

Edge valid time

See the above. 1~16 seconds 4


[Normal Handover Table] -3

Parameter name


PBGT watch time

Statistics time for PBGT HO signal level judgment. 1~16 seconds 5

PBGT valid time

Continuous time for PBGT HO signal level judgment. 1~16 seconds 4



name Meaning Value range Recommended

value Layer HO watch time

Statistics time for Layer HO judgment 1~16 seconds 5

Layer HO valid time

Continuous time for Layer HO judgment. 1~16 seconds 4


[Fast-Moving Handover Table]


[Concentric Cell Handover Table] -1

Parameter name


UO signal intensity difference

BTS transmitting Power difference between underlaid and overlaid may cause MS receiving signal intensity difference in underlaid and overlaid . The parameter uaually indicates the antenna EIRP difference in dB between underlaid cell and overlaid cell. According to field measurement, multi-point measurement is necessary if the underlaid and overlaid use different antenna.

0~63db Set according to actual conditions



Parameter name


RX_LEV Thrsh

Rx level hysteresis, TA threshold and TA hysteresis jointly define underlaid area and overlaid area. It must be bigger than edge handover threshold, and the recommended value is: edge handover threshold + signal intensity difference between underlaid and overlaid .

0~63 25

RX_LEV hysteresis

Works with Rx threshold. 0~63 5

TA Thrsh. It must be bigger than TA emergency handover threshold.

0~63 bit period, with 1 bit period corresponding to 0.55km

TA hysteresis

Works with TA threshold. 0~63 bit period


[Concentric Cell Handover Table] -3Parameter name Meaning Value

range Recommended

value UO HO watch time P/N judgment statistics time for U/O HO judgment. 0~16

seconds 5

UO HO valid time P/N judgment continuous time for U/O HO judgment. 0~16 seconds

4



Parameter name


Assign optimum layer

In Overlaid/Underlaid, the following selection are available for TCH assignment: (1) The system judges according to the measurement report on SDCCH and assign to the best sub-cell. (2) Select the overlaid first for TCH assignment. (3) Select the underlaid first for TCH assignment. (4) Do not give extra priority.

System optimization, overlaid , underlaid , no preferential

System optimization

Assign-optimum level Thrsh.

If system optimization is selected, estimate (interpolate, filter) current SDCCH level value through uplink measurement value in the former SDCCH measurement report, and compare with “ Assign-optimum Level threshold”, so as to assign overlaid or underlaid channel.If SDCCH is in the overlaid : edge handover threshold + signal intensity difference between underlaid and overlaid + uplink and downlink balance allowance + SDCCH and TCH difference allowance. If SDCCH is in the underlaid : edge handover threshold + uplink and downlink balance allowance + SDCCH and TCH difference allowance.

0~63



Parameter name

Meaning Value range

Recommended value

Pref. subcell in HO of intra-BSC

When the cell is configured into a Overlaid/Underlaid, there are two processing methods for incoming handover request in BSC: (1) No special processing for channel assignment. (2) Add BCCH signal level value of the target cell in inter-cell handover request message to BSC to make BSC allocate optimum channel for MS from underlaid or overlaid .

Yes, No Yes

Incoming-to-BSC HO optimum layer

If there is a incoming BSC HO, and the target cell is a Overlaid/Underlaid, then, this parameter will show which layer is preferred to provide service for the MS.

overlaid , underlaid , none

None

6 handover parameters

Documents

current network quality

cell description table

normal handover table

emergency handover table

handover control table

original serving cell

densely populated downtown

fast moving ms