We define a utility-based framework for joint channel assignment and topology control in multi-rate multi-radio wireless mesh networks, and present a greedy algorithm for solving the corresponding optimization problem. The proposed approach can support different target objectives, which are expressed as utility functions of the end-to-end throughput from the gateways to the mesh nodes. The latter accounts for the 802.11 MAC sharing model and rate diversity. The model can be extended to the case of multipath routing, where there are multiple paths from the same or different gateways to the mesh nodes, and for performing joint channel assignment, topology control, and routing.