The various macro network enhancements available today offer a cost-efficient and smart approach to increase the capacity in mobile networks. In the previous 3 parts of this series, we discussed the two hardware-related capacity-enhancing features carrier aggregation and 4×4 MIMO, and we covered antenna tilt optimization. The final part of this series looks at yet another antenna approach to optimize mobile network capacity: higher-order sectorization of base stations, commonly referred to as 6-sector sites.
As with all the aforementioned macro network enhancements, higher-order sectorization also aims to keep inevitable investments for mobile network operators to a minimum.
The sectorization antenna technique is used to increase the capacity in wireless cellular networks by reusing air interface resources (time, frequency, and space). Typically, a 3-sector site can be split into 6 horizontal sectors, requiring antennas with higher directivity; or each of the 3 horizontal sectors is divided into 2 vertical sectors. In the latter concept, different antenna downtilts are used to cover the inner and outer circle of the cell.
The strategy is always the same: increase the number of cells per area and more effectively reuse the available air interface resources, resulting in a so-called cell-splitting gain (increased number of channels). In theory, doubling the number of sectors of a standard 3-sector macro cell site would translate into twice the capacity. In reality, however, the available capacity is diminished because the larger overlapping areas between the cells are prone to higher interference.
6-sector sites are beneficial and often deployed in rural or suburban areas, where cells are still big and overlapping areas can be planned more accurately than in urban environments with multipath transmissions due to reflections. The challenge for operators is to ensure that these overlapping areas are large enough to ensure handovers, but as small as possible to limit interference to the neighboring cell.
Prior to increasing network capacity: verify and optimize
This is where Rohde & Schwarz mobile network testing solutions come into play, helping mobile operators verify planned and optimize upgraded base station sites. To verify the objectives with a high degree of accuracy, coverage should be measured – before and after changes to the network.
Measuring signal strength, signal quality, and interference per RF channel and on multiple technologies simultaneously, is best done with a dedicated scanner. Rohde & Schwarz mobile network testing offers a broad range of scanners that, together with our ROMES4 software platform, present the optimal solution for RF optimization, coverage verification, troubleshooting, and interference detection.