Uplink-and-Downlink Balance Measurement per TRX

Description

In an optimum system, power should be well estimated in design to enable the balance between the coverage of uplink signals and the coverage of downlink signlas. If the coverage of uplink signals is wider than the coverage of downlink signals, the downlink signals at the cell edge are weak and easy to be overwhelmed by strong signals in other cells. If the coverage of downlink signals is wider than the coverage of uplink signals, the MS has to camp on the cell with strong signals; however, the uplink signals are weak and the speech quality is poor. The balance does not refer to the absolute balance. The MR on the Abis interface can be used to check whether the coverage of uplink signals and the coverage of downlink signals are in balance.

The MR received by the BSC contains the uplink receive level and the downlink receive level. Subtract the value of the uplink receive level from the value of the downlink receive level and add the value of the parameter X. The results in dB are graded from levels 1 to 11, and the number of MRs of each level is calculated. Table 1 lists the mapping between the balance level and the receive level.

The parameter X is calculated as follows:

X = Actual transmit power of the MS – Initial power of the TRX + Static power level x2 – Fine-tuned power + Combination loss + Downlink dynamic power control level x2 – Dynamic PBT gain

Initial power of the TRX: indicates the value (in dBm) of the Power Type parameter set on the Device Attributes tab page in the Configure TRX Attributes dialog box on the BSC6000 LMT.
Actual transmit power: indicates the value that is obtained according to the mapping relation between the maximum transmit power of the MS and the power level of the MS.
Dynamic PBT gain: If the dynamic PBT function is enabled for the call, the value of the dynamic PBT gain is 3 dB. Otherwise, the value of the dynamic PBT gain is 0.
Static power level: indicates the value of the Power Level parameter set on the Device Attributes tab page in the Configure TRX Attributes dialog box on the BSC6000 LMT.
Fine-tuned power: indicates the value of the Power Finetune parameter set on the Device Attributes tab page in the Configure TRX Attributes dialog box on the BSC6000 LMT. If the Power Finetune parameter is set to Default, the value is 0 dB.
Combination loss: indicates the value of Combiner Loss(0.1 dB) set in the Set Power Control Parameter dialog box on the BSC6000 LMT.
Downlink dynamic power control level: indicates the downlink power control level of the measurement reports.

**Table 1** Mapping between the uplink-downlink balance level and the receive level
Level of the Balance Between the Uplink and the Downlink	Downlink Receive Level - Uplink Receive Level + Parameter X
1	≤-15dB
2	-14dB,-13dB,-12dB,-11dB
3	-10dB,-9dB,-8dB
4	-7dB,-6dB,-5dB
5	-4dB,-3dB,-2dB
6	-1dB,0dB,1dB
7	2dB,3dB,4dB
8	5dB,6dB,7dB
9	8dB,9dB,10dB
10	11dB,12dB,13dB,14dB
11	≥15dB

If the balance between the uplink and the downlink is mainly at level 1, you can infer that the downlink loss is too great or the downlink transmit power is too small. If the balance between the uplink and the downlink is mainly at level 11, you can infer that the uplink loss is too great or the uplink transmit power is too small. The balance level helps to locate the faults in the TX/RX channel, such as the TRX and the antenna.

Measurement Object

TRXs.

Measurement Counter

The following table lists the measurement counters related to Uplink-and-Downlink Balance Measurement per TRX.

Counter	Refer to Section...
S462A:TRX_BALANCE_LEV_1	Number of MRs (Uplink-and-Downlink Balance Level = 1)
S462B:TRX_BALANCE_LEV_2	Number of MRs (Uplink-and-Downlink Balance Level = 2)
S462C:TRX_BALANCE_LEV_3	Number of MRs (Uplink-and-Downlink Balance Level = 3)
S462D:TRX_BALANCE_LEV_4	Number of MRs (Uplink-and-Downlink Balance Level = 4)
S462E:TRX_BALANCE_LEV_5	Number of MRs (Uplink-and-Downlink Balance Level = 5)
S462F:TRX_BALANCE_LEV_6	Number of MRs (Uplink-and-Downlink Balance Level = 6)
S462G:TRX_BALANCE_LEV_7	Number of MRs (Uplink-and-Downlink Balance Level = 7)
S462H:TRX_BALANCE_LEV_8	Number of MRs (Uplink-and-Downlink Balance Level = 8)
S462I:TRX_BALANCE_LEV_9	Number of MRs (Uplink-and-Downlink Balance Level = 9)
S462J:TRX_BALANCE_LEV_10	Number of MRs (Uplink-and-Downlink Balance Level = 10)
S462K:TRX_BALANCE_LEV_11	Number of MRs (Uplink-and-Downlink Balance Level = 11)