OFDMA-based IEEE802.16 implements among other features Adaptive Modulation and Coding (AMC) which results in a different bit rate for each user depending on its position in the cell as well as the radio condition it experiences; users away from the base station experience lower throughput. In case of (intra-cell) mobility, the download time for the data user will thus depend on the different locations she or he visits. This in turn impacts the overall (Erlang) capacity of the system defined as the maximum number of users that can be handled simultaneously by the system for a given target blocking probability. This is the focus of the present work where we model the cross-layer capacity of the system under a general user mobility pattern