Performance of Neighboring Indoor 5G Micro Operators with Dynamic TDD

Local small cell deployments complementing the coverage of the existing outdoor networks are vital for the future 5G networks. To make the ultra-dense indoor network deployments more cost-efficient and to promote innovation and competition in the market, new local business and spectrum authorization models are needed. One such model is the recently proposed micro operator concept with spectrum micro licensing that allows the establishment of building-specific 5G networks. While evaluating the applicability of this new concept, the impact of the inter-operator interference on the performance of the victim micro operator needs to be understood. The system simulation results shown in this paper demonstrate how the cochannel interference between two uncoordinated micro operators utilizing dynamic TDD in the 3.5 GHz band and located inside neighboring buildings can result in large throughput losses if the buildings are within a few hundred meters from each other. The main cause for these losses is the interference from the other operator's base stations. Finally, it is shown that the performance losses are highly scenario-specific: a denser victim network deployment, or a victim network with a higher load suffers less from any external interference. Therefore, the traditional approach of defining a single separation distance for the worst case scenario does not properly model the specifics of 5G networks and can lead to overly protective requirements.