The WiMAX mesh networks based on IEEE 802.16 standard is being implemented with the goal of establishing open, easily extensible and manageable networks for a variety of people-centric applications. As an extension of point-to-multipoint (PMP) configuration, the IEEE 802.16 mesh mode provides a quicker and more flexible approach for network deployment and administration. Multimedia networking requires Quality-of-Service (QoS) support, which demands promising and potential mechanisms in addition to the four service types defined in the specification. In this paper, the authors design a general algorithm for Subscriber Stations (SSs) to achieve concurrent transmission in both uplink and downlink streams. Mechanisms for constructing and making adjustment of routing trees are also given in this paper.