We present a new approach to find a collision-free transmission schedule for mobile ad hoc networks (MANETs) in a TDM environment. A hexagonal cellular structure is overlaid on the MANET and then the actual demand for the number of slots in each cell is found out. We assume a 2-cell buffering in which the interference among different mobile nodes do not extend beyond cells more than distance 2 apart. Based on the instantaneous cell demands, we propose optimal slot assignment schemes for both homogeneous (all cells have the same demand) and non-homogeneous cell demands by a clever reuse of the time slots, without causing any interference. The proposed algorithms exploit the hexagonal symmetry of the cells requiring
) time, where
is the number of mobile nodes in the ad hoc network,
being the number of cells and diameter of the cellular graph.