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- Units: number of connected UEs;
- Initial capacity: Number of connected UEs before any external interference is considered;
- Interfered capacity: Results after External interference is applied;
- Excess outage, users: How many UEs were dropped due to external interference;
- Outage percentage: Percentage of UEs dropped due to external interference.
When the CDMA system is the interfering link, the total received power at the receiver in the victim link, due to the transmit power of all the active mobile stations in the three cells of the center cell site of the CDMA cluster, adjusted for spectral masks, etc., is counted as the interfering power in the victim link. Therefore, it is not necessary to keep track of any capacity loss in this case, unless the victim link is also a CDMA system.
Figure 261: Example of the CDMA results display panel Anchor F261 F261
Figure 262: Example of the CDMA results display panel Anchor F262 F262
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System capacity loss = 100 - (interfered_capacity/ non-interfered_capacity)*100 (Eq. 70)
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2) Loss of UEs for the reference cell based on the before and after number of UE
Ref cell capacity loss = 100 - (interfered_capacity/ non-interfered_capacity)*100 (Eq. 71)
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3) Loss of UEs for the whole network based on the total number of dropped UE
System capacity loss = total_dropped_UE_system/total_simulated_UE*100 (Eq. 72)
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It is quite important to understand that there is not a 1-to-1 map between non-interfered active/interfered users and the dropped users. Dropped user can occurs at many level of the algorithm, it can be due to:
- “Unable to connect during first initialisation of UE” during the initialization (long before the step 2 balancing) but still it will be registered;
- During the balancing. For CDMA UL (no cell selection activated), when the noise rise is balanced, i.e. the number of UE is acceptable is reached after introduction of external interferers, then the BS estimates the signal-to-interference ratio (C/I), measured in bit energy-to-noise density ratio Eb/N0, and compares it to a target value (Eb/N0_target). If the difference between the estimated C/I and the Eb/N0_target, is higher than a call drop threshold, then the UE is dropped;
- “Eb/No requirement does not meet while scaling the channel power” during the scaling power.