Indoor planning and optimization of LTE-U radio access over WiFi

The pursuit of more bandwidth and more efficient spectrum usage has led to consider the use of Long Term Evolution (LTE) technology in unlicensed frequency bands, a concept known as LTE-Unlicensed (LTE-U). This feature would be especially useful in hot-spots and indoors, where short-range pico-base stations could be used. However, indoor WiFi on unlicensed bands calls for coexistence mechanisms between LTE and WiFi. Accordingly, methods including listen-before-talk, advanced channel selection, duty-cycle, and variations of them, have been proposed. While these protocols are of great importance, we are approaching the coexistence issue from the radio access planning/optimization point of view by presenting a statistical system model for LTE-U indoor planning. The proposed optimization framework allows to obtain network topologies that maximize the benefits from the LTE-U deployment and fulfill coverage criteria. The performance of the statistically-optimized network topologies has also been validated by means of system level simulations.