Reference Manual

Channel Measurements

The measurements of signal strength are referred to the RX reference

point. An R.M.S. value is formed for each timeslot. The logarithm of

this value, expressed in dBm, is coded as deﬁned for RXLEV in /GSM

05.08:8.1.4/. The average value is calculated from the RXLEV value,

After Initiation, a ﬁrst average value is calculated after two completed

measurement periods. The second value is calculated when the ﬁrst

averaging period is completed.

After this, a new average value is calculated after each new

measurement, that is a sliding window principle is used where the

oldest value within the averaging period is replaced by the new one.

The average value is classiﬁed into one of ﬁve Interference Level Bands.

Results from idle channel measurements are reported via the Abis

message RF_RESOURCE_INDICATION /GSM 08.58:8.6.1/. This is

done when the ﬁrst value has been calculated and thereafter when the

calculated average value is classiﬁed into a new Interference Level

Band.

29.4 Operational Conditions

The measurements of R.M.S. signal level fulﬁl the requirements in /

GSM:05.08:8.1.2/. When applicable, exceptions are stated within the

context of Radio Reception.

The measurements of RXQUAL fulﬁl the requirements in /GSM

05.08:8.2/, that is for BER from < 0.2 % to > 12.8 %.

The MEASUREMENT_RESULT message and the

RF_RESOURCE_INDICATION message are sent during the following

reporting period.

EN/LZT 720 0008 P2A

2001-11-28

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Preliminary