SON for Heterogeneous Networks (HetNet)
As introduced in Chapter 2, mobile operators acknowledge that the Heterogeneous Network (‘HetNet’) is an attractive solution, able to cope with the enormous data traffic increase.
In fact migration from HSPA to LTE brings additional improvements in the terms of higher spectral efficiency, but those alone are expected to be insufficient when compared to the traffic growth predictions from the industry. This essentially means that other performance boosters such as macro-site densification, improved receivers, higher order sectorisation and addition of small cells are likely to be needed. As the spectral efficiency per link for LTE is approaching the theoretical Shannon limit, it is postulated that the addition of small cells is amongst the most promising solutions for building improved spectral efficiency per area. Thus, the migration from macro-only networks to multi-layer topology networks, often referred to as Heterogeneous Networks or simply HetNet (see also Figure 10.1), is expected to further accelerate in the future. This chapter mainly focuses on LTE multi-layer networks and outlines some of the supportive mechanisms that help enable easy rollout and operation of such multi-layer deployments. In particular, we consider cases where the different LTE cell types as summarised in Table 10.1 are deployed. Notice that the main ...