The call admission problem for a wireless packet-switched network supporting homogeneous applications -such as a cellular voice network -i s an old one and has been extensively investigated in the past. The focus of the present article is to investigate the call admission region for a TDMA (wireless) system supporting heterogeneous real-time VBR applications with distinct QoS re uirements and traffic and dropping probability; packets may be dropped due to delay violations or channel-induced errors. The call acceptance region is investigated in this article under the assumption that each user's per-frame resource (slot) requests are communicated to the scheduler (resource allocation authority). The call acceptance region is shaped by the QoS that can be delivered by the uplink scheduling policy. In the beginning of this article, some mechanisms employed to inform the scheduler of the users' requests along with some schedulin policies are discussed. While these reveal the entire region. In this article, an approach is outlined on how to precisely determine the call admission region (largest set of QoS points delivered under any scheduling policy) for a TDMA system. This approach is shown to lead to the precise description of the reduced call admission region in the presence of channel errors. In order to demonstrate the performance improvement provided by an error control scheme, a simple QoS-sensitive forward error control protocol operating over an erroneous channel is employed, leading to an enlargement of the calculated call admission region. Finally, it is shown that feasible scheduling policies exist which do deliver at least the minimum QoS requirement of the applications whose associated QoS vector falls within the determined call admission region.characteristics. The QoS is defined in terms of a maximum to 7 erable packet delay scheduling policies identify QoS points in t a e call admission region, they cannot n a wireless network many users communicate over a shared unreliable channel. Several network architectures have been designed to facilitate this communication, but typically only cater to one traffic type. These architectures include a medium access control (MAC) protocol to coordinate the sharing of the channel and possibly an error control scheme to combat the unreliability of the wireless link. Two popular time sharing approaches are carrier sense multiple access (CSMA) and time-division multiple access (TDMA). In CSMA, the user senses the channel and, if it is idle, transmits a packet (information unit) without any coordination with the other users. Collisions are possible, in which case retransmissions are scheduled after a random