In a time division multiplex access asynchronous transfer mode wireless network wherein network interface units (NIUs) are connected to a base transceiver station (BTS) by way of a radio frequency (RF) wireless link comprising time slots which are grouped into frames, there is presently no method or apparatus to allow dynamic bandwidth allocation while maintaining a minimum bandwidth allocation to NIUs. Using a combined Guaranteed Bandwidth Allocation (GBA) scheme with a Dynamic Bandwidth Allocation (DBA) scheme, a configurable number of time slots can be permanently assigned to an NIU using GBA while the NIU can request additional timeslots using DBA. Using a queue occupancy threshold and a queuing delay threshold, the DBA scheme takes into account the GBA time slots which have been allocated, so that time slots are not unnecessarily requested by an NIU. At the BTS level, a time slot manager utilizes a frame look ahead procedure to allocate time slots based on the queue occupancy forwarded from the NIU. Additionally, a configurable parameter is defined which reflects the level of traffic in an NIU, to allow pro rated allocation of time slots.