An advantage of CDMA-based protocols is that packets can be transmitted immediately without prior channel access or resource reservation. In this paper, however, we propose to incorporate a reservation mechanism into CDMA-based protocols for next-generation wireless networks with data, voice, and multimedia applications. The resultant paradigm is called code division multiple access with adaptable reservation (CDMA/AR). The motivations for this change include that QoS guarantees can continue to be provisioned in CDMA/AR-based systems even when many handoff mobile stations enter an already heavily utilized cell. Our simulation results and mathematical analysis show that the adaptable reservation and differentiated admission control mechanisms of CDMA/AR can considerably reduce the handoff-rejection and call-blocking rates for higher-priority traffic to very small values, while achieving throughput close to 100% at the same time.