The figure shows the floorplan for the sixth floor of Soda Hall. IR cells are deployed in individual offices and classrooms. The figure show one RF cell covering the lower righthand corner of the floor, with three additional cells covering the rest of the floor. Note that there are only a few feasible paths between the RF cells. If the network "knows" that the mobile is currently located in Room 637, the next RF cell can be reached by one of the arrowed paths: the north corridor to Cell D, the east corridor to Cell B, and the center corridor to Cell D. Cell C is not immediately reachable. Multicast techniques can be exploited to send packets to the likely adjacent cells.