You can add another wireless router and have it configured with the same SSID or a different SSID. I would set them to different wireless channels so as you move around the building, you connect different routers.
We have 4 routers in our church. Two for wired connections for the office staff and two for wireless for the visitors and members. I just spent 4 hours this week reconfiguring all four routers, upgrading the firmware on all four, then making sure they all work.