Selasa, 28 Desember 2010

Steps for Drive Test -4

MOC and MTC
Given are parameter need to be checked while performing MOC and MTC
RX Level (-47 dbm to -110dbm)
RX Quality (0 to 7)
SQI (20 to 30)
DTX
HSN (Hopping Sequence Number) (0 to 63)
MAIO
Hopping Frequency
C/ I Ratio (>15 dbm)
C/ A Ratio (>12 dbm)


Definition of Radio Parameters:
RxLev : Receiving level in terms of dBm that mobile is receiving from the site. Range of -30 dBm to -110dBm.
RxQual : Quality of voice which is measured on basis of BER. Range of RxQual 0 -7.
FER : Frame Erasure Rate it represents the percentage of frames being dropped due to high number of non-corrected bit errors in the frame. It is indication of voice quality in network.
BER Actual : Ratio of the number of bit errors to the total number of bits transmitted in a given time interval. BER is a measure for the voice quality in network.. Depending on BER RxQual is measured. E,g, BER 0 to 0.2 % corresponds to RxQual 0. Max. BER countable and useful is up to 12.8 % which corresponds to RxQual of max. 7.
SQI : SQI is a more sophisticated measure which is dedicated to reflecting the quality of the speech (as opposed to radio environment conditions). This means that when optimizing the speech quality in your network, SQI is the best criterion to use. SQI is updated at 0.5 s intervals. It is computed on basis of BER and FER. For EFR 30, FR – 21 & HR – 17 are respectively ideal values.
C/I : The carrier-over-interference ratio is the ratio between the signal strength of the current serving cell and the signal strength of undesired (interfering) signal components. It should be atleast > 9 .
MS Power Control Level : Displays range of power control from 0 to 8 depending upon network design. E.g. 0 means no power control and 1 means level that is defined by operator viz. 2 dBm less acc. To airtel.

DTX : Discontinuous transmission (DTX) is a mechanism allowing the radio transmitter to be switched off during speech pauses. This feature reduces the power consumption of the transmitter, which is important for MSs, and decreases the overall interference level on the radio channels affecting the capacity of the network..
TA : Value that the base station calculates from access bursts and sends to the mobile station (MS) enabling the MS to advance the timing of its transmissions to the BS so as to compensate for propagation delay. Value of 0 means MS in radius of 550mt. From BS.
RL Timeout Counter (Cur) : This parameter define the maximum value of the radio link counter expressed in SACCH blocks. Range of 4 – 64 in step size of 4. it shows current value of RLT. Decrease by 1 but increase by 2. When it reaches zero it results in normal DROP Call.
RL Timeout Counter (MAX) : This parameter define the maximum value of the radio link counter expressed in SACCH blocks. Range of 4 – 64 in step size of 4. it shows current value of RLT. Normally 16, 20, 24.
MS Behavior Modified : This window shows current settings for the mobile station, for instance whether handover is disabled or multiband reporting enabled.

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