5.4.3 Coverage and capacity optimization

28.6273GPPRelease 17RequirementsSelf-Organizing Networks (SON) Policy Network Resource Model (NRM) Integration Reference Point (IRP)Telecommunication managementTS

Although, it is of primary interest to provide coverage to users during a roll-out, it is equally important to enhance the capacity of the network during operation. As such, both coverage and capacity are considered in the use case and supported by the SON function. The CCO SON function should be configured through appropriate objectives and targets in order to meet the operator’s requirement on coverage and capacity, and the prioritization between them.

1. E-UTRAN Coverage holes with 2G/3G coverage

In this scenario, legacy systems, e.g. 2G/3G provide radio coverage together with E-UTRAN. However, in the first deployment stage of E-UTRAN, unsuitable planning or error parameters settings will lead to coverage holes in some area. In this scenario, there may be too many IRAT HOs. The SON use case coverage and capacity optimization should enable to detect this kind of problems on network coverage automatically. Another case similar with this is that coverage problems exist between different frequencies in E-UTRAN, i.e. inter-frequency case. For simple reasons, this case is also described here.

Specific Freq

Coverage of LTE

Coverage holes

Figure 5.4.3-1: Coverage holes with 2G/3G coverage

2. E-UTRAN Coverage holes without any other radio coverage

In this scenario, there is no 2G/3G coverage except E-UTRAN. In the first deployment stage of E-UTRAN, unsuitable planning or error parameters settings will lead to un-continuous coverage in some area. That will lead to many drop calls because of bad coverage. The SON use case coverage and capacity optimization should enable to detect this kind of problems on network coverage automatically.

Radio Coverage of E-UTRAN

Coverage holes

Figure 5.4.3-2: Coverage holes without any other radio coverage

3. E-UTRAN Coverage holes with isolated island cell coverage

In this scenario, the actual coverage area of an isolated island cell is smaller than the planned isolated island cell area. The uncovered planned cell area is the coverage holes that need to be detected and optimized by the coverage and capacity optimization.

Actual Isolated Island Cell

of E-UTRAN

Coverage holes

Planned Isolated Island Cell of E-UTRAN

Coverage holes

Figure 5.4.3-3: Coverage holes with isolated island cell coverage

4. E-UTRAN cells with too large coverage

In this scenario, the operator does a gradual network evolution using LTE cells in location where higher capacity is needed. Here the actual LTE coverage is greater than the planned LTE coverage. The overflow area is shown in figure 5.4.3.4. The problem with a too large coverage is that the planned capacity may not be reached. As such, it is important to keep the coverage within the planned area.

Actual LTE coverage

Overflow area

Overflow area

Planned LTE coverage

Figure 5.4.3-4: Difference between actual and planned LTE coverage