Other works have looked more broadly at using WiFi in conjunction with cellular rather than as a replacement. Alternatively, there have been several studies exploring publicly and privately gathered available WiFi / cellular performance tests. Notably, such analytic efforts tend to focus on mobile network performance rather than actual device consumption of the users. Finally, the emergence of the 802.11 hew working group has noted the need for refinement of WiFi in ultra-dense environments, particularly those of sporting events for improved performance.