Interference Control Mechanism for 5G Indoor Micro Operators Utilizing Dynamic TDD
Future 5G networks will increasingly target local small cell deployments complementing the coverage of the existing outdoor networks. To make the high-quality in-building deployments more cost-efficient, and to promote innovation and competition in the market, new local business and spectrum authorization models are needed. Recently proposed micro operator concept allows the establishment of building-specific 5G networks by different stakeholders through the availability of local spectrum micro licensing. However, in order to make the concept of local high-quality 5G networks feasible, impact of the inter-operator interference on the performance of the victim micro operator needs to be understood. This paper presents system simulation results demonstrating how the required minimum separation distance between two uncoordinated micro operators utilizing dynamic TDD in the 3.6 GHz band can be decreased by controlling the base station transmission power of the interfering network based on the measurements performed by the victim network. Without any interference control mechanism the required minimum separation distance can become as large as 400 meters, but with the proposed mechanism the required separation distance can be more than halved, or even made equal to zero. It is also shown that the interference threshold resulting in the smallest minimum separation distance is highly scenario-dependent: it will depend both on the network layout and load of both the victim and the interfering micro operator.