The Sofiare Communications Architecture (SCA) is middleware for providing component interfaces and dynamic reconfigurability to sofiare define radio (SDR) modems and it is widely adopted by the SDR forum. Although its main application domains include real-time signal processing, SCA lacks QoS support. We thus propose a QoS-enabled extension of SCA called Q-SCA. Our extended architecture incorporates a new waveform model, extended domain profiles that describe QoS requirements, and a modiJied application instantiation process that supports both admission control and resource allocation. We show the viability of Q-SCA through full implementation and experiments.