OEO300010 LTE Network Tuning

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LTE Network Tuning

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LTE Network Tuning


Single site verification:

Single site verification step ensures every single site can work normally.

Network tuning:

The main target of network tuning is to ensure the coverage, control interference

and clear basic handover problems. Normally network tuning is based drive test.

Network parameters optimization:

In network parameter optimization step, the main target is to ensure the KPI

performance by field test and KPI statistics analysis.

LTE Network Tuning


LTE Network Tuning


Weak coverage:

If the RSRP of pilot signal is very low, it is possible that UE can not camp in the cell

or UE can not trigger registration.

Weak coverage can also decrease the QoS of service, cause call drop sometimes.

Cross coverage:

Cross coverage can generate the phenomenon of an "island". Therefore, when a

call is connected to the island-shaped area far away from the eNodeB but still

served by the eNodeB, and the cells adjacent to this "island" are not set to the

neighboring cells of this cell during setting of cell handover parameters, call drop

may occur immediately once the UE leaves this "island". Moreover, even though a

neighboring cell is configured, call drop tends to occur as a result of untimely

handover as the "island" has a too small area.

Lack of dominant cell:

As a result of lack of dominant cell, handover occurs frequently, thus reducing

system efficiency and increasing possibility of call drop.

LTE Network Tuning


LTE Network Tuning


The figure in the slide shows the RSRP distribution of the best cell.

LTE Network Tuning


The figure in the slide shows the distribution of PCI for the best cell.

LTE Network Tuning


The distribution of UE transmission power reflects the distribution of uplink interference

and uplink path loss.

LTE Network Tuning


It can be seen from the figure in the slide that the UE transmission power is lower than 10

dBm in normal situations, and will rise dramatically over 10 dBm only when there is an

uplink interference or coverage area edge. In comparison, a macro cell is more likely to

subject to uplink coverage restriction than a micro cell.

LTE Network Tuning


As shown in Figure, Over coverage is caused by the cell whose PCI is 288.

Over Coverage will interfere with other cells and increase the call drop probability.

LTE Network Tuning


LTE Network Tuning


Uplink and downlink are not completely separated, poor downlink channel quality not only

affects the downlink signaling demodulation. For example, incorrect PDCCH demodulation

affects the scheduling of uplink signaling, resulting in uplink signaling lost. Therefore, we

cannot think easily that the lost of uplink signaling is the result of poor downlink channel

quality.

LTE Network Tuning


All the parameters can shown in GENEX Probe which is HUAWEI drive test software.

IBLER is initial BLER.

LTE Network Tuning


LTE Network Tuning


In the signaling trace result, UE sent several measurement reports to eNodeB by didnt

receive the handover command from eNodeB. Then call drop happened.

LTE Network Tuning


LTE Network Tuning


To confirm the problem, we can also check the neighboring cell configuration in eNodeB.

LTE Network Tuning


LTE Network Tuning


In eNodeB side we can see that eNodeB received several MEASUREMENT REPORT and

sent RRC CONNECTION RECONFIGURATION(handover command). Whats more,

eNodeB sent HANDOVER REQUEST to the target eNodeB.

LTE Network Tuning


In UE side we can see that UE sent several MEASUREMENT REPORT to eNodeB, but it

didnt receive RRC CONNECTION RECONFIGURATION(handover command) from

eNodeB.

LTE Network Tuning


LTE Network Tuning


We can see that the time duration is 2 seconds in which the RSRP in target cell is 1dB

higher than RSRP in serving cell. But after the 2 seconds RSRP in serving cell decrease very

fast. So UE can not receive handover command due to bad downlink channel quality.

LTE Network Tuning


LTE Network Tuning


Mn is the measurement result of the neighboring cell.

Ofn is the frequency-specific offset for the frequency of the neighboring cell.

Ocn is the cell-specific offset (that is, CIO) for the neighboring cell.

Ofs is the frequency-specific offset for the serving frequency.

Ocs is the cell-specific offset for the serving cell.

Hys is the hysteresis for event A3.

Off is the offset for event A3.

LTE Network Tuning


LTE Network Tuning


Documents

OEO300010 LTE Network Tuning