I'm currently working on a WiFi upgrade project. We have an apartment building that needs to have reliable WiFi throughout the entire building. This probably doesn't matter, but the hallways are in the shape of a Y. They currently have two access points on each hallway for a total of six access points on each floor. The three POE access points that are closest to the center of the floor are all hard wired and the three that are at the ends of each hallway feed wirelessly off of the ones in the center. One of the problems is the wireless connection between the access points is causing both devices to drop their signal. This combined with the residents are not able to get on WiFi from within their bedrooms. The walls are concrete. Can anyone suggest any possible solutions and also, they are looking at getting EnGenius EAP600, EWS210AP, or EWS310AP access points. Will any of these AP's be able to penetrate concrete and allow for wireless coverage in the resident bedrooms? Any help would be greatly appreciated.