In this paper, we introduce a novel multiple access control (MAC) protocol for integrated wire-less voice and data services on the uplink channel in a cellular wireless network. The proposed protocol is TDMA based and the uplink frame is divided into two subframes: a request subframe and an information subframe. Our scheme, called CHARISMA (Channel Adaptive Reservation-based Isochronous Multiple Access), works by first gathering users' request via the mini-slots in the request subframe and then decides on the allocation of the information slots in the information subframe based on the channel states ranking of the mobile users. Our extensive simulation results indicate that significant improvements in terms of throughput, delay, and packet loss probability are achieved using the CHARISMA protocol.