Reference Manual

Frequency Allocation Support
34.3.3 Stop measurement
FAS measurement will be stopped either by directed O&M message, or
by receiving a new configuration.
34.3.4 FAS measurement
The FAS measurements are performed according to the following:
4. A FAS measurement is done every 15:th second. During that FAS
measurement interval the signal strength of each frequency in the
frequency list is measured once.
5. During the first 10 seconds of the FAS measurement interval, only
idle channels will be measured on, then all available resources are
used.
6. If the configuration includes frequencies, for which the TRXC
lacks capability to measure on, they are neglected.
7. The measurements are done on idle traffic channels, TCH/F and
TCH/H , and on the idle positions in active TCH/F.
8. Frequency hopping is supported, but limited to a maximum of 63
frequencies. Measurements on frequencies belonging to the own
TRXC only take place when reception is scheduled for these
frequencies (On idle bursts).
9. Measurements are started on a, from one FAS measurement
interval to another, sliding position in the FAS frequency list (To
avoid that some frequencies may be underrepresented if there isn’t
always time to measure on them all).
10. The measurements are as equally distributed as possible over all
available time slots
11. The measurements are as equally distributed as possible in the
multiframe structure, except for active channels where the
positions are fixed.
12. The signal strength of each frequency is measured during one
burst, in the same way and with the same resolution as in active
channel measurement. Not more than four bursts are used for
FAS measurements on one time slot during one SACCH
measurement period.
13. The result of the measurements are stored in a histogram
consisting of 64 counters for each frequency, one counter for each
signal level. The number of times a specific signal level has been
measured is accumulated in the corresponding counter.
34.3.5 Measurement reporting
Measurements are reported on request by O&M messages.
The TRXC will, for each frequency measured upon, calculate the
median value, the percentile value according to the percentile parameter
and the number of measurements done on the frequency.
The result of the calculations sent on Abis O&M link in ”FM Reports”.
If a frequency has not been measured upon, i.e. if a number of
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EN/LZT 720 0008 R1A
2001-06-26
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