Distributed spectral efficiency optimization at hotspots through self organisation of BS tilts

Pop up traffic hotspots i.e. geographically concentrated user pockets are a time persistent reason behind poor user experience in wireless cellular system. Spatio temporal unpredictability of such pop up hotspots renders them difficult to be designed out in the planning phase of the cellular system hence dynamic and adaptive solutions are required to cope with them in an impromptu manner. In this paper we present a novel solution that addresses this problem by dynamically enhancing spectral efficiency in hotspot regions through optimisation of system wide BS antenna tilts in distributed fashion. Unlike most of the existing works that provide solutions for hotspot relief, our solution does not rely on load transferring to neighbour cells; rather it dynamically enhances the overall spectral efficiency and thus capacity of the system by jointly optimising antenna tilts of multiple adjacent cells with respect to hotspot locations in those cells. Furthermore, being designed on the principles of self organization in biological system, our solution is self organising and can improve the user spectral efficiency in a system by upto 1b/s/Hz in presence of hotspots with no significant overheads.