Wireless communication technology has been evolving over the years. From the 2.5G era where the general packet radio service (GPRS) offered very low data rates of 171.2 Kbps to the 3.5G era where the high-speed downlink packet access (HSDPA) offered data rates of 10.8 Mbps, the increased data rates can support the delivery of richer mobile multimedia contents to end-users. With the growing demand in data throughput, the IEEE 802.16e promises to deliver high data rates over large areas to a large number of users in the near future. This exciting technology can rapidly provide broadband access to locations in the world's rural areas where broadband is currently unavailable, as well as competing for urban market share. In this paper, we will investigate the research issues in devising rate adaptation algorithms at the WiMAX PHY and MAC layers. We will propose a framework in which the PHY layer metrics can be passed into the MAC layer under practical simulation environment