User's Manual

Doc. No.
Rev.
Date
1.00
2011-12-08
Damm Cellular Systems A/S, Denmark
TETRAFLEX
®
V7.5 MANUAL - Network Management
TetraFlex® 7.5 Manual 3-25
below this level, it leaves the node again without any deregister signaling, and it
goes into scanning and checks for a node with better signal.
o Access - Radio access parameter -53dBm to -23dBm. This, to reduce the MS
output power depending on how close it is to the radio node. The ETSI defines it like
this: P = MIN ( MS_TXPWR_MAX_CELL, ACCESS_PARAMETER - RSSI )
o This means that a) the MS never chooses an output power above
MS_TXPWR_MAX and b) the output power depends on the downlink signal strength
RSSI in combination with ACCESS_PARAMETER. The idea is simple: If the MS is
close to the BS, it can reduce its output power. ACCESS_PARAMETER defines how
much it can reduce it.
Example: MS_TX PWR = 30dBm, ACCESS = -30dBm
MS is far away from the radio cell, RSSI=-105dBm.
P=MIN(30dBm, -30Bm-(-105dBm) = MIN(30dBm, 75dBm) = 30dBm MS transmits
full power.
MS is very close to BS, RSSI=-55dBm.
P=MIN(30dBm, -30Bm-(-55dBm) = MIN(30dBm, 25dBm) = 25dBm MS transmits
with reduced power.
The value of -53dBm maximizes the effect of power reduction:
P=MIN(30dBm, -53Bm-(-55dBm) = MIN(30dBm, 2dBm) = 2dBm MS transmits with
very reduced power.
The value of -23dBm minimizes the effect of power reduction:
P=MIN(30dBm, -23Bm-(-55dBm) = MIN(30dBm, 32dBm) = 30dBm No power
reduction yet.
o RDT - Radio Downlink Timeout: This it is a measurement of the downlink quality.
The higher the RDT value is, the longer the MS stays on a channel with bad quality.
Factory setting middle value (1152TS).
o SRT - Slow Reselect Threshold above fast (Factory setting 10dB)
o FRT - Fast Reselect Threshold (Factory setting 12dB)
o SRH - Slow Reselect Hysteresis (Factory setting 10dB)
o FRH - Fast Reselect Hysteresis (Factory setting 10dB)
The parameters SRT,FRT,SRH and FRH are for network planning and are defining the
behavior of MS cell reselection in a multi node system. The parameters are explained in
details in the ETSI EN 300 392-2 is chapt. 18.3.4.4 ”Ranking of neighbour cells” And
18.3.4.5.x “Criteria used during cell reselection”:
Unless there is trouble with MS cell reselection the factory settings should not be changed.
o Sub. Class - Subscriber Class (Class 1-16 , default all class present).These
parameters can be programmed in the MS to match the bit pattern of a radio cell to
obtain a preferred radio cell to connect to.