The IEEE 802.16 standard was designed for Wireless Metropolitan Area Network (WMAN). The coverage of this new technology is expanded up to 50 km. IEEE 802.16 also has inherent QoS mechanism while the transmission rate can be up to 70Mbps. However, the main part of 802.16 – packet scheduling, was not defined and left as an open issue. In this paper, we present an uplink packet scheduling with call admission control (CAC) mechanism that is token bucket based. Also, a mathematical model of characterizing traffic flows is proposed. Simulations are carried out to validate our CAC algorithms and models. These results show that the delay requirements of rtPS flows are promised and the delay and loss can be predicted pr e c i sely by usi ng our mathematical models .