following settings for desired values and
weighting factors:
• SSDES = –94 dBm
• QDESUL = 10
• Uplink signal strength compensation factor
(LCOMPUL)2 = 50
• Uplink signal quality compensation factor
(QCOMPUL)2 = 30
These initial values correspond to an aggressive
power-down regulation aiming to minimize
uplink interference. However, it was observed
from analyzing drive test files and cell traffic
recording (CTR) files that the settings could lead
to performance deterioration. For instance, a
connection with received signal strength
(RXLEV)2 = –80 dBm and received signal quality
(RXQUAL)2 = 5, given the previous settings,
would be further down-regulated in steps of
2 dB, despite the obvious quality problem.
After studying the case, a more reasonable value
of SSDES = –88 dBm was introduced, while
QDESUL was set to zero. Also, compensation
factor LCOMPUL, which introduces a slope in the
September 2004 • Volume 2, Number 2 19
1/12 1/22 2/1 2/11 2/21 3/3 3/13 3/23 4/2 4/12
Date (MM/DD)
Figure 1. Network DCR After Implementation of Random Hopping Sequence
2.3
2.0
1.7
1.4
1.1
0.8
0.5
DCR (%)
Cyclic FH Random FH
Considerable
network
performance
gains can be
made by fully
utilizing the
available
functionality
and fine-tuning
the network
parameters
using statistics
to evaluate
the results.
_________________________________
2 An Ericsson DPC parameter
power reduction, was set to 100. This setting
corresponds to maximum uplink regulation (no
slope) because the algorithm was expected to
work rapidly on “good” signals. Quality
compensation parameter QCOMPUL was set to
60 to enhance up-regulation in case of interference
and to give the connection a chance to
overcome the bad quality by increasing the
output power.
THANK YOU SIR Michael Pipikakis