DT Test Analyzing Application in Optimization,coverage analyzing and How to evaluate network coverage performance

DT test application in coverage analyzing
According DT test, the following data can be got and they can be used as coverage performance parameters:
· The strongest pilot strength (Ec/Io dB):

- MS Rx power (dBm): the total power received by MS inside 1.23MHz bandwidth including interference.
· MS Tx power (dBm): MS transmitting power in calling or access statate.
· MS Tx-Adj (dB): MS adjustment parameter in transmitting power. For 800MHz system, TxPwr= -73 – RxPwr +Tx-Adj; For 1.9GHz system, TxPwr= -76 – RxPwr + Tx-Adj
· F- FER (%): Forward frame error rate

How to evaluate network coverage performance with DT test data
Single index analyzing
1. MS received power (RxPwrdBm)
MS received power is one index to measure forward link coverage deepness.
MS received sensitivity is -105dBm, consider 5dB edge coverage margin, for different environment DT test data should satisfy the following requirement:
Rx Power > -100dBm is the range for outdoor coverage;
Rx Power > -85dBm is the range for indoor coverage;
Rx Power > -80dBm is the range for dense indoor coverage;

2. MS transmitting power (TxPwrdBm)
MS transmitting power is one index to measure reverse link coverage deepness.
MS maximum Tx power is 23dBm, consider 5dB edge coverage margin, for different environment DT test data should satisfy the following requirement:
Tx Power < 18dBm is the range for outdoor coverage;
Tx Power < 3dBm is the range for indoor coverage;
Tx Power < -2dBm is the range for dense indoor coverage;

3. The strongest pilot (Ec/IodB)
Pilot Ec/Io is one important index to measure forward link coverage performance. Usually the cell threshold is >-15dB. In order to guarantee reliable demodulation, the maximum pilot threshold need >-13dB. Pilot power ratio usually can not be changed.

4. MS (Tx-AdjdB)
Tx_Adj reflects closed-loop power control adjustment. Usually, Tx_Adj range should be 0~-10dBm. Too high or too low Tx_Adj value are all abnormal phenomena and indicate forward and reverse link are not balanceable. Too low Tx_Adj indicates reverse link is better than forward link, or reverse link initial power is too high; too high Tx_Adj indicates forward link is better than reverse link, or there is reverse interference.

5. Forward frame error rate (Fwd FER %)
Forward FER reflects forward link coverage integrated quality. In CDMA system, the ideal objective FER is about 1% for 8K voice service. For data service the FER can be a little high. The actual objective should be adjusted by operators’ requirement. For voice service, FER increase will lead to bad voice quality. In coverage edge area, because of bad signal, FER may be high.

Integrated analyzing
Use Tx, Rx and Ec/Io to evaluate coverage ratio:
Urban DT test: calculate the average result for test data in 0.1km*0.1km Bin and get the average Tx, Rx and strongest Ec/Io. Record the total Bin ratio that can satisfy Tx<=3dBm, Rx>=-85dBm and Ec/Io>-12dB simultaneously, that is the integrated coverage ratio.
Main roads DT test: directly use test data to calculate the ratio: Tx<=3dBm, Rx>=85dBm and Ec/Io>-12dB, then combine them to get the integrated coverage ratio.