ct the packet core against attacks from femto cells. - Similar architecture as in 3G. All 3G femto deployments have femto gateway. The same network element can be utilized also with LTE femtos. Femto cell architecture without femto gateway: - No single point of failure. If femto gateway fails, a large number of femto cells will stop working. Therefore, femto gateway needs to have high reliability. Less network elements without femto gateway. It is easier to upgrade new features to femto cells when femto gateway support is not required. - Lower latency. Femto gateway adds some delay. The additional delay can be SO low, 1-2 ms, that it has only marginal impact to end-to-end latency. Femto cells can utilize a concept called Local breakout where the data is routed directly from the femto cell to the local network. The concept is shown in Figure 5.11. The local break out has the benefit that the user can access local content and devices, for example, in-home multimedia, data backups or enterprise intranet. Therefore, femto cells can also create new services over LTE radio, which are not possible with the traditional network architecture. The Local break out Femto Femto gateway = Traffic to local network = Traffic to operator's network Figure 5.11 Local break out concept with femto cells LTE Small Cell Optimization Table 5.4 Cost-efficient indoor offload recommendation in traffic hotspot areas Offload technology Recommendations Wi-Fi Deployment for capacity enhancements, especially in high public indoor traffic areas Femto Residential deployment of femto cells provides excellent coverage and capacity for voice and data Indoor pico Deployment providing coverage but focused on capacity in indoor public and private hot zones. High number of cells deployed with easy, low impact and fast scalability. Suitable to provide cost-efficient coverage in large buildings and is operator neutral. Less cost-efficient for capacity-driven scenarios and small buildings than Wi-Fi. latency can also be minimized improving the performance f