 Options assumed that the different network evolution scenarios perform in the same way and satisfy the same traffic requirements. A number of different deployment options are considered for the network evolution. 5.7.1 Macro Network Extension Tilt optimization is a very cost-efficient method for signal-to-interference and noise ratio (SINR) optimization and thereby increases network capacity. Tilt optimization should always be pursued before any further optimizations. If spectrum is available, adding more carriers to already existing macro sites provides easy and low-cost capacity enhancements. The main cost is in CAPEX (Capital Expenditure) and IMPEX (Implementation Expenditure) - OPEX (Operating Expenditure) for the base station increases only slightly. The OPEX comes mainly from electricity, Operations and Maintenance (O&M), backhaul and software fees. However, dedicating spectrum to micro cells can provide an even bigger increase in capacity. Therefore, traffic growth and traffic hotspots play an important role in any site evolution strategy. Further- more, reframing of spectrum is a cost-efficient way to increase both coverage and capacity. The most cost-efficient approach is to deploy the lower spectrum initially for coverage and deploy the higher spectrum later for macro or micro cells, depending on the traffic density and spectrum availability. Sectorization in the vertical or horizontal plane provides a simple yet cost-efficient way to increase capacity in the macro network. The main portion of the cost is CAPEX and IMPEX (equipment, antennas and deployment) but OPEX is also raised owing to higher electricity costs, backhaul and additional site rent for new antennas. Six-sectorization is most efficient for uniform traffic distribution and may not be the best option in localized areas of high traffic or in very dense urban deployments where adaptive beamforming could be more attractive. 5.7.2 Outdoor Small Cells Micro and pico cell deployment is a cost-efficient way of increasing network capacity and cov