With the rapid growth of the Internet and other Internet protocol-related applications, wireless systems have shifted toward supporting a wider variety of data services. This has placed an enormous strain on the already tight capacity of wireless systems. Many improvements have been made at the link layer in second- and third-generation wireless systems. However, further improvements in packet data admission, scheduling, and policing are necessary to maximize capacity and user satisfaction. Of the three, efficient scheduling has the greatest impact on increased system capacity. In addition, proper scheduling can greatly improve user satisfaction. We introduce an adaptive cross-layer packet scheduler, which outperforms popular packet schedulers with respect to both packet delay and user throughput.