Guideline
Neighbor Optimization and Pilot Pollution
Cleaning
Version 1.1
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Presentation / Author / Date
Objective
• To have the optimum number of ADJS/ ADJI/ ADJG of 3G
network both in F1 and F2.
• To optimize the 3G coverage in both layers. This can help to
– Clean up Pilot Pollution,
– Reduce Overshooting
– Increase Cell Capacity
– Reduce the possibility of SC conflict.
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Scope
• Optimisation will be done for 2nd carrier cluster only. This may
have to include sites outside the cluster that affect the
performance of sites in the cluster.
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Network Design Scenario
Connected Mode Strategy (Macro)
• Inter frequency handover adjacency is defined oneway F2 -> F1 to
ensure mobility (except for colocated site, IFHO F1 -> F2 must be
defined only for HSDPA to make sure HSPA Capability Handover)
• ADJG from F2 on 3G-2G border to ensure mobility. One-Way
From F2  2G Only
F2 Border
F2:
HSDPA+R99
HS+R99
F1: R99
2G
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Network Design Scenario
Connected Mode Strategy (Site-Level) Zoom In
Below ADJI Strategic is ideally used for Capability Based Handover.
Figure shows How to define ADJI in one site.
F2:
HSDPA+R99
F1: R99
S1
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S2
S3
Methodology
• Neighbour Optimisation
– Deletion
– Addition
• Coverage Optimisaton (Tilting)
Data and Tools
• OSS Data
– Autodef (RSRAN044/ RSRAN045/ RSRAN046)
– PRACH Delay Class 0-20 (M1006C128 – C148)
– SHO Overhead (RSRAN028) (optional)
• PE Dump ( To get actual ADJx)
• Site Location Info ( To get Latitude/ Longitude)
• MapInfo ( To have visualize for neighbor planning)
• Planning Tool to calculate Antenna Tilting
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Propagation Distance Mapping Table
Our Parameter Setting for Propagation Cell Range is:
PRACHDelayRange = 3 (20 km)
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Propagation Distance Distribution
Value can be
changed
depend on
cluster
environment
205 Cells in UPD3 is having propagation distance farer than 7 km.
Need to carefully visualize on Mapinfo for downtilt decisions.
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Propagation Distance list
This is an example PRACH Delay Class from OSS.
(7 days data)
Microsoft Excel
Worksheet
This could be used as an indicator for cells with having
improper coverage footprint (Overshoot).
We may plot the MAX PRACH Delay Class on Mapinfo for better
visualization of coverage footprint of cells in our cluster. (See
Next Slide)
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Propagation Delay Plot on MapInfo
Missing ADJS
detected by Autodef
Overshooting
detected by
Autodef+ PRACH
Delay
From Propagation Delay on Mapinfo, we can get an
insight of How coverage propagation look like.
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Neighbour Deletion Diagram
Distance can be
changed according
to environment
Value can be
changed depend on
traffic density in
each cluster.
Adjs/Adji/Adjg
respectively
Use Autodef Data for last 7 days, Aggregate “Whole Period”
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Neighbour Addition Diagram
Value can be
changed depend on
traffic density in
each cluster.
Adjs/Adji/Adjg
respectively
Use Autodef Data for last 7 days, Aggregate “Whole Period”
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Optimisation Sequence
1. Start with ADJx Deletion. F1 and F2 (Autodef 7-days Data)
2. Delete ADJI F1 F2 for Non-Collocated Site, if any
3. Create ADJI F1<--> F2 for Collocated Site (like Page 5)
1/2/3 can be
executed at the
same night.
4. ADJS Addition in each Layer.(Autodef 7-days Data)
F1 <-> F1
F2 <-> F2
ADJS addition MUST be done before ADJI and ADJG addition. Good ADJS planning can
significantly reduce interference, as a result number of required ADJG and AGJI will also decrease.
5. ADJI Addition. (Autodef 3-5 days Data)
F1 <-> F2
F2 <-> F1
Again, well planned for ADJI will reduce Number of ADJG neighbors
6. ADJG Addition (Autodef 3-5 days Data)
F2  2G
F1  2G
At the end, we also expect to see number of ADJG from:
F2  GSM
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< F1  GSM
**F2  GSM (for F2 Border)
SIB11 Planning
•
•
IF ADJS+ADJG+ADJI <= 47, Set ADJx = SIB11(1) for all ADJx
IF ADJS+ADJG+ADJI > 47,
– For F1
Set ADJx = SIB11(1) for (all ADJS + main ADJI + main ADJG) <= 47
Set ADJx = SIBbis(2) for the “Remaining” ADJI and ADJG.
– For F2
Set ADJx = SIB11(1) for (main ADJS + all ADJI + main ADJG) <= 47
Set ADJx = SIBbis(2) for the “Remaining” ADJG and ADJS.
• IF Overshooting case,
Set ADJx = Not Broadcast (0).
[This is not to allow UE camping on cells that very far away and later the
ADJx will be deleted anyway, when downtilt done]
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End Results
• In general case, Final combined Neighbour (Adjs+Adjg+Adji)
<= 36 Neighbours
• Try NOT to use SIB11bis, or use it as less as possible.
• No Cell blocking Alarm due to Too many neighbors (Alarm
ID_7771)
• Provide Antenna Downtilting List to Customer.
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Thank You
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