Channel Measurements
The RBS measures BER (Bit Error Rate) and the signal strength over
each active channel per reporting period. All SACCH frames are
included in the measurements.
The reporting periods are different for different TNs, and for different
channels, and are the same as for the MS, defined in /GSM 05.08:8.4/.
The measurements of signal strength are referred to the RX reference
point. An R.M.S. (Root Mean Square) value is created for each burst.
Then, the logarithm of this value, expressed in dBm, is averaged over
the reporting period. The mapping of this average and RXLEV is as
defined in /GSM 05.08:8.1.4/.
The signal quality measurements are sampled per reporting period.
The mapping between BER and RXQUAL is as defined in /GSM
05.08:8.2.4/.
RBS calculates RXLEV_FULL, RXLEV_SUB, RXQUAL_FULL and
RXQUAL_SUB as an average of the frames as defined in the following
table:
Table 151
Frame calculation
Channel
Combination
RXQUAL_FULL,
RXLEV_FULL
RXQUAL_SUB, RXLEV_SUB
(i), (viii), (ix)
All TCH and SACCH frames
(96 TCH, 4 SACCH)
8 SID + 4 SACCH
(x)
Channel measurements are unspecified.
TCH/S: 8 SID + 4 SACCH
(ii)
All TCH and SACCH frames
(48 TCH, 4 SACCH)
TCH/Data: 10 SID + 4 SACCH
(iii)
TCH/S: 8 SID + 4 SACCH
All TCH and SACCH frames
(96 TCH, 4 SACCH)
TCH/Data: 10 SID + 4 SACCH
(v), (vii)
All SDCCH and SACCH
frames (8 SDCCH, 4 SACCH)
Same frames as for RXLEV_FULL
and RXQUAL_FULL
The SID frames for the TCH channels are defined in /GSM 05.08:8.3/.
The Speech Quality Index, SQI, is an index which shall be a
measurement of the subjective speech quality of the uplink speech. The
algorithm to obtain the index uses BER and FER measurements over a
defined period of frames, excluding DTX, as input.
Results from channel measurements are reported by A-bis message
MEASUREMENT_RESULT /GSM 08.58:8.4.8/.
29.3.2
Idle Channel Measurements
The RBS can perform signal strength measurements of disturbances on
all idle uplink dedicated channels.
The function is set to on or off on full rate or half rate basis when the
TS is configured by the BSC.
Measurements of signal strength are made over an averaging period.
The averaging period specifies the number of measurement periods
from which an average value is to be calculated. The averaging period
is specified for each TS by the BSC.
282 (485)
EN/LZT 720 0008
P2A
2001-11-28
© Ericsson Radio Systems AB
— All Rights Reserved —
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Summary of Contents for RBS 2106
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