Achieving high availability in wireless networks by inter-frequency multi-connectivity

Multi-connectivity is a promising concept for addressing challenging requirements in next generation wireless networks. We put forward a modeling framework for analyzing signal-to-interference-and-noise ratio (SINR) distributions in inter-frequency multi-connectivity scenarios. The most important features are a best server association based on random shadowing, multiple path loss models, and intra-/inter-frequency shadowing cross-correlation. Furthermore, we consider diverse antenna types, such as sectorized antennas and antenna arrays with beamforming, to accurately model the distinct properties of conventional as well as upcoming millimeter wave carrier frequencies. In the analysis, we focus on the lower tail of the SINR distributions in order to explore the availability performance. The modeling results, which are corroborated by simulations, show that certain combinations of carrier frequencies can significantly improve the availability as well as the throughput performance compared to single-frequency usage.